The Cal-look Lounge

Cal-look/High Performance => Cal-look => Topic started by: Martin S. on September 13, 2013, 01:16:41 am



Title: Project Berg 1679 rebuild and update with squish!
Post by: Martin S. on September 13, 2013, 01:16:41 am
My wife's 65 Bug was repainted last year and now the engine needs attention. I built it in 1999 with all Berg parts and the 88 thick wall PCs and running the stock carb. 75,000 MILES later it was ok still but a lot has changed in motor building since then and I wanted to give it new life with more CR and squish to get better fuel economy and power. It had semi hemi heads with 6.8:1 CR. Upon tear down one head was warped and the pistons were worn enough to see a different gap to the cylinder depending where you looked. The bottom of the pistons inside showed the overheating that the leaking head was causing. I ordered AA 90.5 69 stroke PCs which are the normal style piston, not the slipper skirt style of the stroker ones. They are nice and light with graphite coating and drilled oil holes. I had a pair of bare 041 heads there were ok used so we are working with them. I ordered new made in Italy SS valves (40x32).
Since the engine had thick wall 88 cylinders, the new 90.5s won't fit. The answer was to turn down the base of the cylinder 1.5mm to a tight register of 10 thou clearance to the case. As the trimming was being done to the outside of the cylinders, Steve also decked the cylinders to the case to get an exact height installed without shims. The slight radius where the deck edge meets the lower part of the cylinder was retained, just like factory machining. He likes squish so we decided to go with a super tight 30 thou deck (see pic). Then the heads are being milled down to get the desired 9.5:1 CR to get the squish happening. As the milling is done, the squish pads get larger which is good. This is going to be a low speed mini torque monster. With this awesome Nairex cutter he gave the sealing surface inside the head a slight texture to help seal as it crushes into place, and up the side of the hole he gave a different finish as it's enlarged for the 90.5s.
Note in the pic where you can see both chambers how much more squish pad area is there after the milling.
(http://img.photobucket.com/albums/v415/mschilling/IMG_0400.jpg) (http://smg.photobucket.com/user/mschilling/media/IMG_0400.jpg.html)
(http://img.photobucket.com/albums/v415/mschilling/IMG_0401.jpg) (http://smg.photobucket.com/user/mschilling/media/IMG_0401.jpg.html)
(http://img.photobucket.com/albums/v415/mschilling/IMG_0403.jpg) (http://smg.photobucket.com/user/mschilling/media/IMG_0403.jpg.html)
(http://img.photobucket.com/albums/v415/mschilling/IMG_0404.jpg) (http://smg.photobucket.com/user/mschilling/media/IMG_0404.jpg.html)


Title: Re: Project Berg 1679 rebuild and update with squish!
Post by: markvo on September 13, 2013, 02:55:53 am
I would not go less than .043 deck height, as the piston at speed, will hit the head!  Compression ratio with your 47cc head with .043 deck, would still be 9.21 to 1
What cam and carbs and octane fuel are you running? What is the elevation above sea level?


Title: Re: Project Berg 1679 rebuild and update with squish!
Post by: modnrod on September 13, 2013, 06:30:43 am
Engine pics, cool!  ;D

Would you have some pics of the cylinder base machine work you had done please?

I like little motors, they just sound "busy" and "urgent", especially with the old 041s, hard to describe though. The higher comp should make it crackle a bit!


Title: Re: Project Berg 1679 rebuild and update with squish!
Post by: Martin S. on September 13, 2013, 14:28:39 pm
I meant to get pics of the cylinders on the lathe. I'll try for some today. The chuck had to hold on to the outside of the part at the top that extends above the fins, just enough there to grip and make 3 or 4 passes to slim down the base without the cylinder coming loose in the chuck. He said the cast iron wore out his tool quicker than expected, especially with new cast which is not work hardened yet. He's only done that operation once before on some birals as normally the case is opened but this time there is no need to split the case.
The idea of the tight deck is squish. Only have enough to not have the piston hit the head, and because of the low speed intended for this motor 30 thou will suffice. When he was drag racing VWs he has run deck so low that the piston has hit the head and even then there was no damage. The squish idea worked so well on my turbo motor that I want it on my other engines. Cool heads are the result. Everything that goes in gets burned, so efficient, like a damn miracle! ;D

The engine is for my wife putting around town mostly, she doesn't need/want a screamer so it's running a stock carb and cam with regular fuel (87 octane) at just about 250' above sea level.

The other reason for a textured surface cut into the head chamber is to collect and retain carbon. The carbon acts as a heat barrier similar to thermal coatings. Don't clean the piston tops!


Title: Re: Project Berg 1679 rebuild and update with squish!
Post by: markvo on September 13, 2013, 21:26:43 pm
The AA pistons have about .002 more piston to wall clearance than a Cima/Mahale! The pistons will rock and carbon will add about .010 it may unseat the rings. I did a test on a stock VW motor going from 7 to 9 to one on the same day. The detonation on the 9 to 1 was so bad with 9 to 1, I couldn't even make another pull on the dyno,even retarding the timing and upping the jet on the stock carb! That was on 91 octane about 50 feet above sea level.


Title: Re: Project Berg 1679 rebuild and update with squish!
Post by: Martin S. on September 13, 2013, 23:48:27 pm
Berg was a proponent of the 7:1 engine and I built three of them 15 years ago. They worked fine, but always got poor fuel economy and didn't make the power I hoped. This new build is an experiment to see if squish can overcome those problems. A high squish chamber minimized pinging by design, not by lowering CR.

I dropped by the shop today and snapped a couple more shots of the progress. The SS valves arrived and machining is done. These old CB 041 heads measured only 3 thou difference between the two heads when put on the mill !! .040" or about 1mm was removed from the heads revealing more squish area. Final compression ratio is 9.6:1. Deck is .030".
Note the tool used for the flame port has 3 cutting edges.

(http://img.photobucket.com/albums/v415/mschilling/IMG_0406.jpg) (http://smg.photobucket.com/user/mschilling/media/IMG_0406.jpg.html)
(http://img.photobucket.com/albums/v415/mschilling/IMG_0407.jpg) (http://smg.photobucket.com/user/mschilling/media/IMG_0407.jpg.html)
(http://img.photobucket.com/albums/v415/mschilling/IMG_0408.jpg) (http://smg.photobucket.com/user/mschilling/media/IMG_0408.jpg.html)
(http://img.photobucket.com/albums/v415/mschilling/IMG_0409.jpg) (http://smg.photobucket.com/user/mschilling/media/IMG_0409.jpg.html)
(http://img.photobucket.com/albums/v415/mschilling/IMG_0410.jpg) (http://smg.photobucket.com/user/mschilling/media/IMG_0410.jpg.html)
(http://img.photobucket.com/albums/v415/mschilling/IMG_0411.jpg) (http://smg.photobucket.com/user/mschilling/media/IMG_0411.jpg.html)
(http://img.photobucket.com/albums/v415/mschilling/IMG_0412.jpg) (http://smg.photobucket.com/user/mschilling/media/IMG_0412.jpg.html)
(http://img.photobucket.com/albums/v415/mschilling/IMG_0414.jpg) (http://smg.photobucket.com/user/mschilling/media/IMG_0414.jpg.html)


Title: Re: Project Berg 1679 rebuild and update with squish!
Post by: modnrod on September 14, 2013, 01:47:12 am
I know your build is all about utilising and maximising the engine using the parts you have, but I'm sitting here wondering whether welding the chambers up opposite the plug to get a deep but narrow "heart" shaped chamber for ultimate squish ratio percentage, is even worth the bother compared with just milling it down to get a wider but shallower chamber with the same cc's?
It does seem like a lot of extra work to g the welding route, when your way of optimising squish is vastly quicker and easier.
 ???


Title: Re: Project Berg 1679 rebuild and update with squish!
Post by: markvo on September 14, 2013, 01:54:41 am
Good luck, make sure you clean up the exhaust ports, If you run the wider 11.3 by 912mm alt. belt and add about 8-12shims between top alt. pulley, the fan will turn faster, for more low speed cooling!


Title: Re: Project Berg 1679 rebuild and update with squish!
Post by: Zach Gomulka on September 14, 2013, 07:14:00 am
Still running the small stock exhaust valves?
Which cam?
Why didn't you go with 94's? Same amount of cost and work...


Title: Re: Project Berg 1679 rebuild and update with squish!
Post by: hotrodsurplus on September 14, 2013, 08:38:27 am
Berg was a proponent of the 7:1 engine and I built three of them 15 years ago. They worked fine, but always got poor fuel economy and didn't make the power I hoped. This new build is an experiment to see if squish can overcome those problems. A high squish chamber minimized pinging by design, not by lowering CR.

I have encouraging words for you: the tight deck and increased effective CR will indeed reduce if not eliminate your fuel economy and power issues. I fell for Berg's theories in the '80s and in 1993 I had my heads hemi cut when I rebuilt the engine they were on. That turned a wonderful running stock 1600 into a lazy, hot-running, gas-happy pig with major flat-spot issues. I had to use third to buck a headwind. I couldn't sustain 65mph for long periods without the engine running alarmingly hot--like down-on-power hot. I burned a set of rings in like 15,000 miles and the valve guides were loose. I followed all the dogma, including advancing the timing.

Three years ago I bought a pair of new heads. I had the step flycut. My deck is .050" as the result of faced case openings from the rebuild. I can't remember exactly but I think the chambers measure 48cc. Whatever they are, the static CR comes out to 8.1:1. I run Kadrons and a Mallory set to 10 initial and 30 total (it hated 32 total and is lazy at 28 total). With a stock cam at sea level I usually run 89-octane fuel. I heard some light rattles here and there but that was with a leaner tune. Now that I've fattened it back up a bit I need to try 87-octane fuel again.

Now the engine charges up any hill and can push a really nasty headwind with relative ease (in a lifted Thing with a surrey top--probably the worst aerodynamic combo). I almost have to work to make the engine run hot and I go 70 to 75 on the freeway whenever legally possible (I have photos of the GPS at 81mph--did I mention it's a Thing?). I frequently drive over one of the gnarliest mountain passes on the west coast and I need to hit third in only two spots. And they're relatively short spots at that. Bear in mind that the only air-cooled cars that weigh more than Things are transporters and Type IVs.   

Even with the super-tight deck I still suspect you may have some detonation issues at sea level with a stock cam. The stock cam reduces the static CR by .5:1 to create the effective CR. As a rule of thumb 92-octane fuel will sustain an 8.5:1 effective CR at sea level. There are exceptions to the rule--like a more efficient chamber design will resist detonation to a greater degree. Note that I'm not trying to discourage you. If anything I really want this to work. Me an' Javabug have been talking about building such an engine but finances prevent it from happening anytime soon. You're our guinea pig.  ;D

Hey, if all else fails you can bleed off a little of that effective CR with a slightly more aggressive cam. And as a bonus output would increase across the board provided you matched the induction to the engine's needs. But I really hope that 92 will sustain your target CR. I mean if a carbureted V-8 with only a little more cam than we use can handle 11.5:1 then why can't we run 9:1?


Title: Re: Project Berg 1679 rebuild and update with squish!
Post by: benlawrence on September 14, 2013, 13:51:20 pm
a freind of mine just put together a "Bitser" engine out of old stuff laying around, this comprised of a set of 92s, old c/w crank, engle 120 and a bunch of other used stuff that measured out ok.  He had a set of 1300 heads that were good no cracks and the valve seats were still in good shape, he cutback the exhaust guide and cleaned up the exhaust ports but that was it, new stock valves no valve/seat job, left the inlet ports as stock, flycut the heads for 9.6-1 and threw on a set of chinese empi 40's and a cheap used 4 into 1 exhaust.
It really is about as basic as it gets, on fire up i put an initial tune on it and was surprised how snappy the motor sounded, we installed it in an old race car and took it round the block, it lights the tyres in 1st and 2nd (lightweight car)

we then stuck it on the dyno just to see and i was very surprised, it made 122flb tq, and 101bhp, on a dyno dynamics chassis dyno, a ton of fun on the cheap, im sure with minor work on the heads we could squeeze a bit more easily but as a throw together engine that measured out ok everywhere its hard to beat it for fun.


Title: Re: Project Berg 1679 rebuild and update with squish!
Post by: Martin S. on September 14, 2013, 19:49:12 pm
Good question about using 94s. I'm paying for this rebuild with wife's cash so there is no budget for welded heads, new cam, etc. She likes the car because it's a stylish economy ride. I'm going with Steve's recommendations and he says it will run fine on regular 87 gas. I'm ok with using premium if it gets better economy, but he says it won't ping. I believe him because he's got the experience from years of breaking parts racing. In the 90s when Berg was racing on the west coast, Steve was a young teenager building motors every weekend on the east coast and doing very well. Here's a pic of one of the race motors that turned well over 10,000 rpm until...
(http://img.photobucket.com/albums/v415/mschilling/IMG_0099.jpg) (http://smg.photobucket.com/user/mschilling/media/IMG_0099.jpg.html)


Title: Re: Project Berg 1679 rebuild and update with squish!
Post by: markvo on September 15, 2013, 15:12:54 pm
You can run 1.4 rockers on a stock cam ! I have, it made 10% more power though the whole rpm band. Just make sure you have enough clearance from retainer to guide boss in the head and no spring coil bind! You can always add rockers later you may want chromemoly shorter pushrods too with a heavy duty single spring at least.


Title: Re: Project Berg 1679 rebuild and update with squish!
Post by: Martin S. on September 17, 2013, 02:19:32 am
I asked about using 94's vs 90.5's and he said that 94's would have too high a CR with the deck height we want (.030). The heart shaped chamber with more squish area is a good idea he said too! Also moving the plug in and adding more squish area on the opposite side would be desirable as well. The heads are together and the cylinder lengths all set to the thousands of an inch (by matching individual cylinders to their respective places with respect to the absolute seating area height). Number 3 seating area on the case is slightly pounded out due to that cylinder running hot and the head lifting and wearing the case so that cylinder will be slightly longer to keep the deck height consistent among the four cylinders. DECK HEIGHT is key here. The heads are assembled now and the engine is ready to assemble. Here's a pic of a finished head. Chambers measure 48cc, deck is .030 (3.22 cc) CR is 9.6:1.
(http://img.photobucket.com/albums/v415/mschilling/IMG_0440.jpg) (http://smg.photobucket.com/user/mschilling/media/IMG_0440.jpg.html)


Title: Re: Project Berg 1679 rebuild and update with squish!
Post by: Martin S. on September 18, 2013, 02:34:55 am
Long block is together, next step is setting up the rocker geometry and assembling the tin. Does everybody agree on the 18 ft lbs. of torque for the 8mm stock head studs?
(http://img.photobucket.com/albums/v415/mschilling/IMG_0441.jpg) (http://smg.photobucket.com/user/mschilling/media/IMG_0441.jpg.html)
(http://img.photobucket.com/albums/v415/mschilling/IMG_0442.jpg) (http://smg.photobucket.com/user/mschilling/media/IMG_0442.jpg.html)
(http://img.photobucket.com/albums/v415/mschilling/IMG_0443.jpg) (http://smg.photobucket.com/user/mschilling/media/IMG_0443.jpg.html)


Title: Re: Project Berg 1679 rebuild and update with squish!
Post by: hotrodsurplus on September 18, 2013, 02:41:56 am
Long block is together, next step is setting up the rocker geometry and assembling the tin. Does everybody agree on the 18 ft lbs. of torque for the 8mm stock head studs?

18 lbs-ft dry. Don't know how you assembled yours but I see a lot of people use oil, antiseize, and thread locker on critical-torque fasteners. That will skew the torque load and damage studs and/or cases. "Lubricated" torque specs are considerably looser due to the friction reduction.

Not that it's a huge deal but setting rocker geometry without the pushrod tubes installed makes life a bit easier.




Title: Re: Project Berg 1679 rebuild and update with squish!
Post by: richie on September 18, 2013, 07:24:54 am
Long block is together, next step is setting up the rocker geometry and assembling the tin. Does everybody agree on the 18 ft lbs. of torque for the 8mm stock head studs?

18 lbs-ft dry. Don't know how you assembled yours but I see a lot of people use oil, antiseize, and thread locker on critical-torque fasteners. That will skew the torque load and damage studs and/or cases. "Lubricated" torque specs are considerably looser due to the friction reduction.

Not that it's a huge deal but setting rocker geometry without the pushrod tubes installed makes life a bit easier.




Chris

if you do them dry how do you know you get a consistent reading? the friction from different nuts to stud and or washer seems to vary greatly to me so I do them with stud/bolt lube on the threads and on the washers


cheers Richie


Title: Re: Project Berg 1679 rebuild and update with squish!
Post by: hotrodsurplus on September 18, 2013, 15:14:32 pm
Chris

if you do them dry how do you know you get a consistent reading? the friction from different nuts to stud and or washer seems to vary greatly to me so I do them with stud/bolt lube on the threads and on the washers

cheers Richie

It's easy to get a consistent reading: do them dry. I know that sounds smartassed but it's valid and it was a point driven home with great emphasis when I worked with ARP on a fastener tech piece.

I have a mayonnaise jar with an inch or so of acetone in the bottom. I drop all of my head nuts and washers in it for an hour or so, blow them off with compressed air, and store them in a clean place. Before I drop the head on I cover the cylinders and spray the threaded ends of the studs with brake cleaner and wipe them with a terrycloth towel. Maybe it's superstition but I feel as if the fibers better displace into the threads to clean them out. They always look dry when I'm done. I avoid spraying the studs with compressed air. I don't want to blow grime into a fresh cylinder for obvious reasons.
 
Now this assumes that the threads are clean. Rust will definitely interfere with torque values. So for that reason and to make fasteners go on by finger force I chase every thread with a tap or die. In critical applications like aeorspace the class fit (1A, 2A, 3A, and so on--aerospace often uses 3A and 3B) is critical and a garden-variety tap will destroy the tolerance. It's best to use a dedicated thread-cleaning tap in those applications. But tolerances aren't all that tight in automotive (usually 2A and 2B). Good quality taps and dies are just fine. In fact if you do this to every fastener in your car you will find it so much more enjoyable to work on it. Fighting bollocky nuts and bolts is for the birds.

Of course it's not the end of the world to do it with dirty and/or lubricated head nuts. A lot of us do it on a consistent basis and I did it that way for years. But it's considered poor practice and may cause issues in specific applications. To do it by the book eliminates that variable.


Title: Re: Project Berg 1679 rebuild and update with squish!
Post by: Pedalpusher on September 19, 2013, 06:19:50 am
I have a mayonnaise jar with an inch or so of acetone in the bottom. I drop all of my head nuts and washers in it for an hour or so, blow them off with compressed air, and store them in a clean place. Before I drop the head on I cover the cylinders and spray the threaded ends of the studs with brake cleaner and wipe them with a terrycloth towel.

I did that way too, and chased the threads of the headstuds to remove any bits also. Nuts move really easy on the studs then.

Do you use any grease or something under the washers on the heads when you torque the thing in place? To prevent any oil from the heads to go on the other side.

-Mikko-


Title: Re: Project Berg 1679 rebuild and update with squish!
Post by: hotrodsurplus on September 19, 2013, 07:17:34 am
I did that way too, and chased the threads of the headstuds to remove any bits also. Nuts move really easy on the studs then.

It's an old-man luxury. When I was young I just suffered with sticky fasteners. I do not have that much patience anymore. I am grumpy.

Do you use any grease or something under the washers on the heads when you torque the thing in place? To prevent any oil from the heads to go on the other side.

No. I install the washers dry too. I never had a problem with oil leaking from the stud holes in the heads. The oil would rather drain down the wall than flow sideways out of those holes. 


Title: Re: Project Berg 1679 rebuild and update with squish!
Post by: Dalland on September 19, 2013, 07:52:11 am
..... Flame port.....
.....singh groove....

Looks cool for people that don't understand combustion engines....


Title: Re: Project Berg 1679 rebuild and update with squish!
Post by: Martin S. on September 19, 2013, 14:28:32 pm
Heh yes doesn't it! ;D Another snag in assembly. The old Berg crmo pushrods are too long now with this new build and the close deck height. I'm going to find some stock aluminum pushrods and use those instead. The engine should run quieter with the al pushrods anyway. Interesting that the 15 year old 75,000 mile Berg single springs still have life left in them and are tight. Hopefully not too tight for stock pushrods. Steve loves VW valve springs and has replaced both Porsche and BMW race engine springs with VW springs (NOT Chevy ones). Long block went together with a quick lap of the valves and he found some leak down. Being the perfectionist that he is, it's coming apart to do more lapping. I'll let him explain that to the wife!  :o


Title: Re: Project Berg 1679 rebuild and update with squish!
Post by: Martin S. on September 21, 2013, 15:45:29 pm
Turns out that the seats were out a fair amount. The lapping ended up taking forever and he said he's never seen seats do that, especially not on a racing engine. It's done now and seals good and is back together still with the too long pushrods and a number of rocker stand shims to get them to work to check the leak down. Meanwhile check out these interesting pieces that arrived at the shop. Anyone guess what these are for? ???
(http://img.photobucket.com/albums/v415/mschilling/IMG_0451.jpg) (http://smg.photobucket.com/user/mschilling/media/IMG_0451.jpg.html)
(http://img.photobucket.com/albums/v415/mschilling/IMG_0450.jpg) (http://smg.photobucket.com/user/mschilling/media/IMG_0450.jpg.html)


Title: Re: Project Berg 1679 rebuild and update with squish!
Post by: modnrod on September 22, 2013, 14:46:25 pm
Anyone guess what these are for? ???
(http://img.photobucket.com/albums/v415/mschilling/IMG_0451.jpg) (http://smg.photobucket.com/user/mschilling/media/IMG_0451.jpg.html)

Cool! I like guessing games!
No good at them, but I like them.......

They look to me like cast iron barrels or transfer tubes out of an old boiler or for a steamy motor (ships?).
I rekn they would be just the thing to make up into custom barrels. ;)


Title: Re: Project Berg 1679 rebuild and update with squish!
Post by: Martin S. on September 23, 2013, 14:32:52 pm
Good! Those are centrifugally cast iron blanks for making cylinders. They're from the same guys in the US that produce cylinders for bikes. If any of you are following Revmaster on their FB page you may recognize the same pieces in this picture... https://www.facebook.com/photo.php?fbid=553729827974780&set=a.316978494983249.95435.316970098317422&type=1&theater


Title: Re: Project Berg 1679 rebuild and update with squish!
Post by: Martin S. on September 24, 2013, 15:40:59 pm
The engine is back in the car now. Steve's super happy with it saying it starts instantly and burns whatever mixture is thrown at it. He's driven it around a little, and even though it needs to be broken in, he's tried a third gear roll-on from 1000 rpm and it's super responsive and NO PING! I asked about what happens if the piston ever touches the head with a tight or zero deck motor. Apparently nothing happens but you can hear it. The go kart racers run theirs up until the piston touches and you can hear a ring when it does. That's when they know their engine is set up correctly. I'm looking forward to driving the car again and I'll report my impressions and fuel economy.  ;D


Title: Re: Project Berg 1679 rebuild and update with squish!
Post by: hotrodsurplus on September 24, 2013, 16:15:29 pm
even though it needs to be broken in

Huh? That doesn't make much sense. The cam breaks in well before you start driving the car and if I have it right you're reusing an existing camshaft anyway. What else is there to break in? Certainly not the bearings--they don't even touch anything. At least they shouldn't.

Now he has to seat the rings and the last thing you want to do at that stage is baby an engine. Do you think all of those sprint and drag engines get tenderly broken in? How about all of those engines that go on the dyno first for tuning? They go like hell for leather the moment the cam gets broken in.

What base and total timing is he running with that CR/deck? I'm really encouraged that it does so well on pump with a stock cam.


Title: Re: Project Berg 1679 rebuild and update with squish!
Post by: Martin S. on September 24, 2013, 16:21:45 pm
It's still got the regular 87 gas from a month or so ago :)
As for break in, he's a firm believer in the procedure. He says that many times new engines have been damaged on the dyno or drag strip because they haven't been broken in. Besides the ring sealing which is kinda obvious, he says that a coat of carbon on the new parts needs to be there to insulate against heat transfer into the piston especially. If the engine is run too hard right away, you run the risk of heating the rings and losing the heat treat and seal. Plenty of people make this mistake, but I've always been careful to break my engines in properly.
He says the distributor I have on the engine has too much total advance. Right now it's at zero at idle. He needs a timing light to check actual numbers so I'll dig mine out and find out the timing.


Title: Re: Project Berg 1679 rebuild and update with squish!
Post by: hotrodsurplus on September 24, 2013, 16:50:22 pm
Quote
He says that many times new engines have been damaged on the dyno or drag strip because they haven't been broken in.

I'll agree that lots of engines have gotten damaged on the dyno or drag strip but unless it's cam related it has little-to-nothing to do with break-in procedure. Damage that early in an engine's life is from improper machining or assembly.

Quote
Besides the ring sealing which is kinda obvious

Your chances of establishing a good ring seal decrease if you baby an engine during the seating stage. The ring needs to encounter a pretty significant load in both directions if it's to conform to the cylinder wall. That means vigorous acceleration and frequent hard deceleration. It holds especially true when trying to break in very hard chrome-faced rings. You have to run those extra hard otherwise they won't seat for a damn.

Quote
he says that a coat of carbon on the new parts needs to be there to insulate against heat transfer into the piston especially.


With that tight of a deck the piston crown will remain largely bare. There won't be much of a buildup in the combustion area if the tune is right.

Quote
If the engine is run too hard right away, you run the risk of heating the rings and losing the heat treat and seal. Plenty of people make this mistake, but I've always been careful to break my engines in properly.

The only way you can overheat the rings to the point of losing ring seal is to overheat the engine and that's irrespective of whether the engine is fresh or aged.

The 'run it easy' school of thought is a holdover from grandpa's day and actually threatens to do more harm than good. I'm lucky to work with some very prominent manufacturers and engine builders and if they've reached consensus on anything it's that the slow-and-easy process required for flat-tappet cam break-in is a burden that threatens the integrity of the ring seal.

Don't take any single person's word for it--certainly don't take my word for it. Call some reputable dyno operators. They're often engine builders and they know their stuff.

Quote
He needs a timing light to check actual numbers so I'll dig mine out and find out the timing.

He builds engines and doesn't have a timing light?


Title: Re: Project Berg 1679 rebuild and update with squish!
Post by: modnrod on September 25, 2013, 02:17:45 am

He builds engines and doesn't have a timing light?

Good engine builders and tuners can time it by ear anyway, and so are not overly worried if their timing light is lost under a bench somewhere.

Not to get involved with an argument, coz we all know an argumentative website or a dogmatic website is a soon-to-be-quiet website (like others in the near past..........), but there are still many different trains of thought and ideas on engine building, assembly, useful features or otherwise, and also running-in procedures.

I'm interested in the end results too, it sounds like a great success! I rekn it must crackle and fart on over-run........ ;D


Title: Re: Project Berg 1679 rebuild and update with squish!
Post by: hotrodsurplus on September 25, 2013, 05:08:25 am
Good engine builders and tuners can time it by ear anyway, and so are not overly worried if their timing light is lost under a bench somewhere.

Oh now you're just being silly.

I want to clarify one thing: I'm not trying to impose my will. I'm not the expert. The argument I make is advocacy.

I'm so incredibly lucky to work with some incredibly knowledgeable experts in the automotive field, some of which are engineers trained in their area of expertise. I get to see a lot of the folksy myths shattered and trust me there are a TON of them. And yes, theories vary among builders and tuners but the information is pretty consistent among builders like Kaase, Robatnick, Dove, Beck, and others. The engines they build aren't test mules and they're quite frequently for customers who pay huge bucks for street engines. They don't take risks on $40,000 engines.

I don't want anyone to take what I say or any single other person says as gospel either. Do the research. You'll be surprised to learn what's out there.

And Martin, don't take this as me disparaging what you're doing. I really do want to see this work. And I think your engine builder is on point with things like deck height, CR, and such. I really appreciate that you're updating us. But I also want you to take the opportunity to expand your knowledge. It's a bittersweet feeling to know more than the experts you hire to work for you and I guarantee you that if you keep your mind open you'll learn more than most experts. 


Title: Re: Project Berg 1679 rebuild and update with squish!
Post by: Martin S. on September 25, 2013, 15:35:07 pm
According to Steve, grandpa was right! Take it easy on your new engine if you want it to last a long time.
When tuning on the dyno some tuners will go straight for the high end to start their tuning. Steve does the opposite and starts tuning by getting the motor to idle. Then works his way up the rpm range tuning the low, the mid, and then extrapolates the tune for the upper ranges using math. This way the engine doesn't get damaged on the dyno.
I picked up the car last night and it sounds unlike any stock mufflered bug I've ever heard. I have a crappy EMPI stock 30PICT1 carb on the engine which is total garbage. On the previous build it couldn't accelerate feeling like the accelerator pump wasn't working. The same carb runs fine on this new engine just because it will burn any mixture thrown at it. I do plan to switch back to a German carb, and it should get a 34PICT3 if anything. Haha, funny about the timing light. He tunes by ear for the most part, and using the laptop for fuel injected engines where a timing light is an anachronism. My wife left for work in the car this am, so I got a short vid of her starting the engine. Amazing how it will fire in a quarter turn and instantly idle (choke on) cold or hot, doesn't matter. Awesome! ;D ;D ;D
The engine sounds more urgent, less lazy, with smooth power, no hiccups or glitches. Here's the youtube. http://youtu.be/sSXDBX6cXRQ


Title: Re: Project Berg 1679 rebuild and update with squish!
Post by: modnrod on September 25, 2013, 15:41:32 pm
Awesome! ;D ;D ;D

Bloody lovely!  ;)


Title: Re: Project Berg 1679 rebuild and update with squish!
Post by: Zach Gomulka on September 25, 2013, 16:08:28 pm
Peashooters? :o


Title: Re: Project Berg 1679 rebuild and update with squish!
Post by: Martin S. on September 25, 2013, 16:28:49 pm
As in 'old lady' stock. Amazing my marriage is lasting longer than that last engine build in 99.


Title: Re: Project Berg 1679 rebuild and update with squish!
Post by: hotrodsurplus on September 25, 2013, 17:42:22 pm
Quote
I picked up the car last night and it sounds unlike any stock mufflered bug I've ever heard. I have a crappy EMPI stock 30PICT1 carb on the engine which is total garbage. On the previous build it couldn't accelerate feeling like the accelerator pump wasn't working. The same carb runs fine on this new engine just because it will burn any mixture thrown at it.


Amazing what a little bit of compression will do ain't it? Increasing the efficiency decreases the BSFC which makes the engine more tolerant of iffy mixtures (to a point anyway). Back when I ran semi-hemi heads on my 1600 every carburetor felt 'broken' and I had to run like a 135 main in a 34. Flat spots abounded.

Quote
I do plan to switch back to a German carb, and it should get a 34PICT3 if anything.

Torben Alstrup runs them quite frequently on big engines that need to pass TUV and other certification standards. He might have some tips.

Quote
Haha, funny about the timing light. He tunes by ear for the most part, and using the laptop for fuel injected engines where a timing light is an anachronism.


You can't achieve consistency if you can't establish a baseline and recreate those parameters. How else can one determine an advance curve or total timing without a distributor machine? Certainly not by ear. Timing lights aren't anachronistic for injection tuning either. A timing light offers about the most convenient way to measure offset angle, the baseline for aftermarket injection tuning. A timing light is another measurement tool and to say you don't need one is to claim you don't need feeler gauges. You could build a house without a tape measure but it would take leagues more trial and error.

I'm stoked to hear it work out well. Are you getting any sort of rattle at WOT?


Title: Re: Project Berg 1679 rebuild and update with squish!
Post by: Martin S. on October 09, 2013, 15:41:31 pm
This engine makes the car a joy to drive. It keeps up with modern cars in traffic without a problem, no drama, just grabs and goes in any gear. I did get slight pinging when going up a big long hill in 3rd and gave it some gas but mostly I'm babying it until it carbons up some and breaks in the rings so no WOT on this motor yet plus you barely need to touch the gas with the torque. Steve said these squish motors need very little advance, and I should retard the timing 5 degrees from where it is now. I've got a vacuum dist with the small can right now. I'm going to check the total advance of this dist with the timing light soon. Then try a 009 because they don't have much for total advance. He said it won't help to have idle with a retarded timing and should have advance even at idle.  As for economy the first tank of gas got about 24.5 US MPG (29.5 UK) which is about 5 higher than before and I hope to get it better with some tuning and the 34PICT3 carb I'm going to try. ;D


Title: Re: Project Berg 1679 rebuild and update with squish!
Post by: hotrodsurplus on October 09, 2013, 16:26:18 pm
Then try a 009 because they don't have much for total advance.

You'll find that an 009 has a ton of advance--in stock form way too much for an engine with lots of compression. The German ones usually have 22 to 25 degrees advance. I'm betting that the engine won't tolerate more than about 26 to 28 degrees total (mine at 8.1:1 and a .055" deck runs decent with 28 total, best with 30 total, and won't tolerate even 32). Assuming a 28-degree total timing and a 25-degree advance curve that means the base timing will come in around three degrees. You'll leave a ton of performance and drive quality on the table with three degrees of base timing. Insufficient base timing will make the engine feel real piggy despite the extra CR even with a stock cam.

I'm also going to say that the 009 is going to really disappoint you if you're going for any sort of fuel economy or part-throttle drive quality. The vacuum-advance mechanism will deliver lots more performance. I don't know what you have for a distributor now but I'm assuming that it's a small-body single-port distributor with a vacuum-only mechanism. For this application you might prefer a distributor with a mechanical and vacuum advance (like an early autostick or a dual-port distributor). If you run the dual-port distributor just don't run a line to the retard port (leave it open to atmosphere).

He said it won't help to have idle with a retarded timing and should have advance even at idle.

It shouldn't advance at idle but it should have sufficient timing at idle. Advance is a function of the mechanism altering the position of the points lobe in relation to the shaft and you want the advance to come in a bit later than idle if you want to avoid ping.

As for economy the first tank of gas got about 24.5 US MPG (29.5 UK) which is about 5 higher than before and I hope to get it better with some tuning and the 34PICT3 carb I'm going to try. ;D

You should be getting way better than 25mpg even with this mild tune. Stock fuel economy is in the 30 range. My heavy lifted Thing with the big tires, surrey top, and less CR than yours gets 25mpg and its jetting is far from ideal. Good luck with that 34pict and an 009. You'll have lots of fun with that combo.


Title: Re: Project Berg 1679 rebuild and update with squish!
Post by: Zach Gomulka on October 09, 2013, 17:20:31 pm
Yeah, mileage should be better... My old 1679 was getting 27-28 right off the bat, 40PII's, stock cam w/1.4's, ported stock heads, 8.6:1. And I never babied it.


Title: Re: Project Berg 1679 rebuild and update with squish!
Post by: Martin S. on October 09, 2013, 17:44:21 pm
Hah, yeah, everybody gets better mileage than me. :o
The dist I'm using is a late model one with vacuum and cent advance and has the small vacuum can. The point of trying out a 009 is that it won't have too much total advance while still having enough advance at idle. With my current dist, to get the low total advance I want, the idle advance would be zero or less which is not ideal.
I'll try the different combos and run a tank thru it to check economy. Remember this motor runs a stock exhaust and cam.


Title: Re: Project Berg 1679 rebuild and update with squish!
Post by: hotrodsurplus on October 09, 2013, 17:58:27 pm
The dist I'm using is a late model one with vacuum and cent advance and has the small vacuum can.

That sounds like an autostick distributor. It's a good piece--about the best for your application. You're going to have to bend the stops to limit your total mechanical advance but that's not difficult. If you want to spend money then get a fully adjustable unit like a Mallory with a vacuum advance mechanism. Then you can fiddle with the amount of advance and the rate. The stock distributors don't offer that much versatility.

The point of trying out a 009 is that it won't have too much total advance while still having enough advance at idle. With my current dist, to get the low total advance I want, the idle advance would be zero or less which is not ideal.

You're going to be really disappointed with the 009. They have about the same mechanical advance as the stock distributor--maybe one or two degrees less than your existing distributor. That's not enough to warrant a change. In fact from a functional standpoint you'd be giving up more than you're gaining simply by eliminating the vacuum advance mechanism.

Remember this motor runs a stock exhaust and cam.

Which means you should get even better fuel economy. Longer-duration cams induce some reversion due to the late intake-valve closing event and increase overlap. Both of those hurt fuel economy. And the stock exhaust is tuned to give the maximum velocity within the speed range and engine size (well, within reason) that you run. A few years back I built a 1600 for a friend's convertible. We flycut the step from the chambers and got the deck to like .050". But otherwise it was a stone-stock dual-port engine with the stock muffler and everything (I shortened the curve a bit). It's his wife's car and she got 32 to 34mpg by just driving normal.



Title: Re: Project Berg 1679 rebuild and update with squish!
Post by: Martin S. on October 09, 2013, 18:42:17 pm
I haven't got great mileage with any bug (especially dual ports) except a 36hp that came in a 65 I bought once. I'm jealous of everyone who gets great mileage with these cars! Although I'm real happy with the 25 US mpg I'm getting with the turbo :D


Title: Re: Project Berg 1679 rebuild and update with squish!
Post by: hotrodsurplus on October 09, 2013, 18:55:02 pm
I haven't got great mileage with any bug (especially dual ports) except a 36hp that came in a 65 I bought once. I'm jealous of everyone who gets great mileage with these cars! Although I'm real happy with the 25 US mpg I'm getting with the turbo :D

Seat your rings properly and your chances will improve greatly. Of course then you'll suffer the premature failures that the rest of us do. I can't seem to get more than 20 years out of an engine. ;)

My old coworker Ron Silva got better than 30mpg from his 2276 in his notch going from Costa Mesa to Bakersfield. We went 70mph once we got north of LA and that mileage included the Grapevine. Then he clicked off a 14-flat pass on pumped-up tires. 


Title: Re: Project Berg 1679 rebuild and update with squish!
Post by: Ron Greiner on October 10, 2013, 22:16:04 pm
What is the notch or groove cut into the top of the head for ?
I have not seen this before


Title: Re: Project Berg 1679 rebuild and update with squish!
Post by: Martin S. on October 11, 2013, 15:59:46 pm
It's a flame port, or singh groove. http://somender-singh.com/content/view/7/31/


Title: Re: Project Berg 1679 rebuild and update with squish!
Post by: Martin S. on October 12, 2013, 15:31:23 pm
We were talking about the next mileage motor build. Steve pointed out that the best economy engines (Honda, e.g.) were small bore long stroke. Thinking of building a stock length rod, stroker 85.5 motor. I wonder how it would work out piston pin-height-wise. And cylinder length. There aren't the piston choices in the kits sold in that size and I want to build it 'cheaply'.


Title: Re: Project Berg 1679 rebuild and update with squish!
Post by: modnrod on October 13, 2013, 21:54:50 pm
From Aircooled.net.........

This may be confusing to you, so here is a recap to clarify it.

If you use 88mm “A” Pistons use 5.325″ H-beam Rods and a 74mm Crankshaft, VW Rod Journals. Alternative P&Cs are 90.5mm A Piston and Cylinders, 92mm A Piston and Cylinders, and 94mm A Piston and Cylinders with the 74mm Crankshaft, VW Rod Journals, using the 5.325″ H-beam Rods.  Bigger bore engines are NOT going to be as MPG Friendly as the 85.5mm or 88mm bore engines will. But adding a big bore because the engine is apart, and “Why not?” are both valid reasons to do it!

If you use 85.5mm Stroker pistons, use the 76mm crankshaft, VW Rod Journals and 5.5″ rods. 90.5mm B Pistons and Cylinders, 92mm B Piston and Cylinders, and 94mm B Piston and Cylinders are also optional. Know that using the 76mm crankshaft, VW Rod Journals will require some light case machining, nothing major. If you are really uneasy about this, just go the 74mm Crankshaft, VW Rod Journals and either stock 85.5mm Mahle P&Cs, or the 88mm Slip Ins. We even have a nice Mexican 85.5mm P&C set if your purse strings are tight!

http://www.aircooled.net/vw-type-1-mileage-engine-mpg/


Stock pistons, 74mm crank, Porsche rod length.
Stroker ("B") pistons, 76mm crank, 5.5" rods.

The stroker pistons could also come out of a To#¤ta 3S-GTE or a 1JZ-GTE, both are 35mm pin height (same as "B" pistons), but are 86mm so you can hone out the stock 85.5mm barrels to suit, and the also use 22mm piston pin same as Type 1. I happen to have a 1JZ-GTE or 3 out the back, and the stock pistons will take 100HP per bore easily, my last 1JZ-GTE pumped out 250rwkW all day, and had 300K km on it. With a 76mm crank out of a wasserboxer (also use the flywheel, no dowels to break off) and 5.5" rods from John at Aircooled.net, you'd be good to rev to the moon for bugger all money. Do you have a wrecking yard nearby with a rusty old '90s Celica by chance?

You said it was to be a cheap racer, just thought I'd mention it in passing..........  ;)


Title: Re: Project Berg 1679 rebuild and update with squish!
Post by: Martin S. on October 14, 2013, 15:43:32 pm
Great article, thanks! The other idea Steve had is to use EFI. He has a way to adapt a GM factory system and make it adjustable like a standalone yet cost a lot less.


Title: Re: Project Berg 1679 rebuild and update with squish!
Post by: modnrod on October 14, 2013, 20:10:08 pm
There used to be a system years ago called Kalmaker that did that, made the Delco ECU programmable. Locally we used to use the ECU off our Camira (GMs 4cyl fwd '90s platform), full OEM finesse with adjustability, excellent results.

EFI gives driveability and ease of tune certainly.


Title: Re: Project Berg 1679 rebuild and update with squish!
Post by: Martin S. on October 16, 2013, 15:30:05 pm
Talking more about the next thing to try on this engine with tuning. Since there was some ping going up a big hill, he said that the vacuum advance could be cutting in and causing too much advance. The late model dist is giving over 26 degrees total timing. I retarded the timing 2 degrees. This type of engine doesn't need the amount of advance of a lower CR engine. He's thinking that mechanical advance only would be good enough. Total advance to just before it pings is what we want, he said, which will make maximum power too. We are going to install colder plugs (there are stock Bosch ones in it) because it runs on after shutting off the ignition. That will be helped by putting a 34PICT3 carb on with the solenoid cuts off the fuel/air mixture.


Title: Re: Project Berg 1679 rebuild and update with squish!
Post by: Zach Gomulka on October 16, 2013, 16:23:12 pm
How about dual 36's and an exhaust? Too easy? ::)


Title: Re: Project Berg 1679 rebuild and update with squish!
Post by: Martin S. on October 16, 2013, 16:42:07 pm
I'd like to keep it quiet for her so the new stock muffler and heater boxes will stay, but I like the idea of dual 36s. I've found that with our shit weather the duals tend to ice up less being closer to the heads. Duals are probably the best option, I'll try to find a set.


Title: Re: Project Berg 1679 rebuild and update with squish!
Post by: hotrodsurplus on October 16, 2013, 17:39:44 pm
Since there was some ping going up a big hill, he said that the vacuum advance could be cutting in and causing too much advance.

Opening the throttle enough to climb a hill increases the manifold pressure close to if not atmospheric level. Without low manifold pressure the vacuum-advance mechanism won't work. If you suspect that the vacuum mechanism is causing problems you can limit its operating range.

This type of engine doesn't need the amount of advance of a lower CR engine. He's thinking that mechanical advance only would be good enough.

The engine doesn't need as much mechanical advance as a low-compression engine does. But that doesn't mean that it won't benefit from the additional advance that a vacuum mechanism offers. Remember, vacuum advance is load conditional: it exists only during low-load applications like when you're barely tipped in to the throttle to maintain cruise speed. All engines benefit from earlier spark events in low-load applications because the cylinder pressure drops through the floor when the throttle butterflies are near closed. The combustion efficiency suffers in those situations and that results in incomplete combustion. The advanced spark incident lights the flame early enough to achieve adequate combustion.

Yeah, a mechanical-only distributor would work but that defeats the purpose of building an ultra-efficient engine.

We are going to install colder plugs (there are stock Bosch ones in it) because it runs on after shutting off the ignition.


The engine may well need colder plugs; however, the glow-plugging condition that you described isn't by itself justification to change temperature. In fact it's akin to loosening your belt as a consequence of gaining weight. It may make things feel better but it doesn't address the root problem.

Heat range plays the most vital part of WOT combustion and not the engine's general operating range. You choose a plug temperature based on the heat pattern on the ground strap. This explains it well. If these readings indicate that you need a colder plug then it's probably wise to do it. But to change plugs just because you raised the CR or are trying to address an underlying issue is a fool's errand.

http://members.uia.net/pkelley2/sparkplugreading.html (http://members.uia.net/pkelley2/sparkplugreading.html) 

That will be helped by putting a 34PICT3 carb on with the solenoid cuts off the fuel/air mixture.


An engine shouldn't glow-plug without a cut-off valve. Otherwise engines with Webers, Dellortos, Zeniths, Solex PII, Holleys, Carters, and Demons would suffer run-on problems.

You're running an application where you need a distributor that lends itself to tuning. As you've learned, conventional total timing figures will cause the engine to detonate. But retarding the entire spark curve leads to insufficient timing at idle and low-speed applications. Insufficient timing in those applications WILL INCREASE CHAMBER TEMPERATURES. The results you're getting suggest that the chambers are exceedingly hot (glow-plugging, preignition, detonation under load).

Your engine will benefit from a distributor that offers sufficient timing at slow AND fast engine speeds as well as an advance curve that matches the engine's needs. You're not going to get that with a production distributor like a Bosch. Your engine would benefit greatly from a distributor where you can manipulate those settings. Mallory for one makes such a distributor that also has the vacuum-advance mechanism. Sure, you COULD tune a Bosch distributor to do what you want but because those don't have any inherent adjustment properties you have to invent ways to do it and that's a real bitch without a distributor machine. The time and effort it would take to do that would far outpace the cost of a distributor that was designed for adjustment.

Look, I know you don't like me because I wrote some things that offended you or went against the teachings of your guru. But you would be foolish to dismiss everything that I say just because you think I'm an ass. The information that I've presented is very conventional and well proven by decades of tuning. This is how the rest of the world does it. You need to research the causes and intelligent solutions because band-aid solutions will only compound the problems.


Title: Re: Project Berg 1679 rebuild and update with squish!
Post by: Zach Gomulka on October 16, 2013, 18:30:26 pm
I'd like to keep it quiet for her so the new stock muffler and heater boxes will stay, but I like the idea of dual 36s. I've found that with our shit weather the duals tend to ice up less being closer to the heads. Duals are probably the best option, I'll try to find a set.

My point is that one venturi per cylinder is more efficient, and the stock exhaust isn't just holding back power but heat as well, could be part of your problem.


Title: Re: Project Berg 1679 rebuild and update with squish!
Post by: Martin S. on October 16, 2013, 19:01:09 pm
Just to clarify, there really isn't much of a problem. Even the fuel economy is excellent for me. In Toronto the traffic is spazmodic so it is hard to compare to someone else's driving conditions. I'm loving the car again now that it's being so good. Tweaking it is fun and I'm keeping track of mileage. Of course the easiest solution is for her to get a Honda, but that wouldn't be as fun.  :D


Title: Re: Project Berg 1679 rebuild and update with squish!
Post by: hotrodsurplus on October 16, 2013, 19:20:41 pm
My point is that one venturi per cylinder is more efficient

Totally agreed. It helps atomization big time and eliminates fuel-distribution problems inherent with the firing order and cylinder layout (cylinders 2 and 4 disrupt the AFR for cylinders 1 and 3). That said I think you can make the system work fine with a single carburetor and a short-duration cam. I mean every other single-carburetor engine seems to pull it off.

and the stock exhaust isn't just holding back power but heat as well, could be part of your problem.

I don't think the stock exhaust hurts in this application. This engine is less than 200cc larger than stock and it doesn't spin any faster than stock. Look at it in terms of gross volume. A 1776 is only 12 percent larger than a 1585. So a 1776 at 3,200rpm flows about the same as a 1585 at 3,600rpm.

Sure, that exhaust on a 2-liter engine at 5K rpm might generate enough resistance to increase EGTs and CHTs. But that exhaust on a 1776 bumbling along at 3,200 shouldn't cause problems.


Title: Re: Project Berg 1679 rebuild and update with squish!
Post by: Martin S. on October 17, 2013, 16:03:14 pm
 ;D This 1776 does more than bumble along. It's got over 500 miles on it now and I haven't stepped on the gas much yet, as there is no need to in order to keep up with traffic and I'm babying it until it's broken in fully.


Title: Re: Project Berg 1679 rebuild and update with squish!
Post by: Martin S. on October 17, 2013, 18:26:27 pm
Speaking of heat, Steve said that the exhaust temps go up using EFI compared to carbs. They found that by richening up the mixture enough to lower the exhaust temps back to what they were with carbs, the engine was now running too rich. EFI is that much more efficient than carbs. ;)