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Cal-look/High Performance => Technical stuff => Topic started by: Mike Cott on December 23, 2016, 21:49:11 pm



Title: 76mm CB crank and 5.4 rods FK8 cam
Post by: Mike Cott on December 23, 2016, 21:49:11 pm
Hi, this is my first post on the forum, been reading through all the posts for months and found loads of great reading material.
I'm building an engine to go in my camper I have a 76mm CB forged crank with 5.5 CB unitech rods, will this combo work well and which B&Ps would suit ie 69mm or stroker? I'm having my case machined at the mo so trying get my head round what I need to order to get going. Any help is much appreciated and I know that people's views are all different and mostly valid but all from experience id imagine.
Cheers
Mike


Title: Re: 76mm CB crank and 5.5 rods,
Post by: Zach Gomulka on December 23, 2016, 23:16:17 pm
100% stroker.


Title: Re: 76mm CB crank and 5.5 rods,
Post by: Mike Cott on December 24, 2016, 01:46:24 am
Just been reading up, stroker pistons should be close zero deck height too 😎
Are forged a must or would cast be ok?


Title: Re: 76mm CB crank and 5.5 rods,
Post by: Zach Gomulka on December 24, 2016, 02:26:33 am
 I believe with large bore stroker pistons you'll only have a choice between hypereutectic and forged, for a low rpm camper engine the hyper's will be fine.


Title: Re: 76mm CB crank and 5.5 rods,
Post by: nicolas on December 24, 2016, 08:19:46 am
both can work. personally i would use strokers. what i also would do is have the case machined where the barrels seat. that way you have a fresh flat surface to work with and it is easier if a shim would be needed to lower the CR.
as for the size of the pistons, i am still tempted to believe 90.5's will outlast 94's, but it can be used both, budget wise it is the same work and money.


Title: Re: 76mm CB crank and 5.5 rods,
Post by: Mike Cott on December 24, 2016, 09:54:08 am
Hypers it is as I only travel around 800-1000 miles a year in her each year, the guy that is machining my case has suggested That he bores out to 90.5 and have 94mm barrels machined to fit this way the case doesn't need to be decked. I trust his judgment as he is a well known guy in the uk and has been building engines for customers for good while.
Cam choice is my next question, thinking an Engle w120 for this as they are readily available at a decent £ and have a good review on what this would be a 2109cc

Thanks for your input guys 👍🏻


Title: Re: 76mm CB crank and 5.5 rods,
Post by: andy198712 on December 24, 2016, 20:02:29 pm
Hypers it is as I only travel around 800-1000 miles a year in her each year, the guy that is machining my case has suggested That he bores out to 90.5 and have 94mm barrels machined to fit this way the case doesn't need to be decked. I trust his judgment as he is a well known guy in the uk and has been building engines for customers for good while.
Cam choice is my next question, thinking an Engle w120 for this as they are readily available at a decent £ and have a good review on what this would be a 2109cc

Thanks for your input guys 👍🏻

i have a 2110 so 82x90.5 and have the 86B, i got it from stateside tuning in the uk, and find it great, loads of bottom end pull, idles fine, although i'm cheating with EFI. and can be had at about the same cost as the 120. although it really wants 1.4 rockers, so if you already have 1.1 rockers.... :(


Title: Re: 76mm CB crank and 5.5 rods,
Post by: Zach Gomulka on December 25, 2016, 04:42:45 am
My knee/jerk reaction is that's more cam than you want for a camper engine. What heads/carbs/exhaust?


Title: Re: 76mm CB crank and 5.5 rods,
Post by: brian e on December 25, 2016, 06:15:10 am
I did a 76x92TW with B pistons and 5.5" rods. Ended up with I think a .010" spacer to make a perfect .045" deck.  I built it for an early bus with a straight axle conversion.  I used a set of Tims S1 heads and a fk7 cam, and 40mm IDF's.   It worked awesome, and was a near perfect daily driver engine.  Minimal case clearance work. 

A web 218 or a fk41 would also be good choices.  The new CB Panchito heads are awesome also. I did a 2234cc with a 218 and Panchito's. It also had great low end power.

Brian


Title: Re: 76mm CB crank and 5.5 rods,
Post by: Zach Gomulka on December 25, 2016, 06:19:06 am
I did a 76x92TW with B pistons and 5.5" rods. Ended up with I think a .010" spacer to make a perfect .045" deck.  I built it for an early bus with a straight axle conversion.  I used a set of Tims S1 heads and a fk7 cam, and 40mm IDF's.   It worked awesome, and was a near perfect daily driver engine.  Minimal case clearance work. 

A web 218 or a fk41 would also be good choices.  The new CB Panchito heads are awesome also. I did a 2234cc with a 218 and Panchito's. It also had great low end power.

Brian

Yeah, that's what I'm thinking. 218 and Panchito's. Make the power where you'll use it.


Title: Re: 76mm CB crank and 5.5 rods,
Post by: Mike Cott on December 25, 2016, 14:38:20 pm
I've not purchased anything else just yet so not limited by certain parts ie carbs or heads. I'd struggle to find anyone who supplies webcam cams in the uk, although they look a good cam for low end torque so the fk7 is a great call and I could get my hands on one of those easy enough, which ratio rockers tho?   Panchitos look the business also, good flowing heads with 44s?


Title: Re: 76mm CB crank and 5.5 rods,
Post by: andy198712 on December 25, 2016, 15:12:16 pm
http://www.rjvolksperformance.com/engine-parts.html

scroll down there, he has most cams, FK's and web ect


Title: Re: 76mm CB crank and 5.5 rods,
Post by: Mike Cott on December 25, 2016, 17:16:23 pm
That's a great website, thanks sells quite a lot of top quality great. Do you know of anymore sites like this besides the usual heritage etc


Title: Re: 76mm CB crank and 5.5 rods,
Post by: Mike Cott on December 25, 2016, 17:42:51 pm
Just took a look at the rods I have and the box has 5.4 on it not 5.5 as I thought 🙄 How check this ?
So I could use the 69mm B&Ps now?


Title: Re: 76mm CB crank and 5.5 rods,
Post by: brian e on December 25, 2016, 18:36:30 pm
Just took a look at the rods I have and the box has 5.4 on it not 5.5 as I thought 🙄 How check this ?
So I could use the 69mm B&Ps now?

With the taller A pistons, you will end up with tall spacers and a wide engine.  If it is close between using an A or a B, I always go with the B style.  They usually have the shorter skirt, shorter pin height, and lighter weight.  All good things to have in a piston.  If you use the 5.4 rods, you will need to get the case decked or the barrels trimmed to get the deck down.  This is nice because you can dial the deck to exactly what you want, and the engine will be narrower then stock, but it adds extra cost, and you might need to trim the piston skirts to keep them from hitting the crank cheeks.     

I did like both the 218 and the FK7, and both Tims and Panchito's heads.  If your bus is light and you prefer a little more zippy of an engine, I would probably pick the FK7.  For a heavy bus with more low end, the 218.  The Tims heads are about $150-200 cheaper once the Panchito's have the options you need.  Both will work good.  The 218 can use stock rockers, and the FK7 will need ratio rockers.  I would shoot for about .500"-.520" lift with the FK7.

I think you could use 40mm IDF's w/ 32mm vent's, and a 1 1/2" header. 

Brian


Title: Re: 76mm CB crank and 5.5 rods,
Post by: DWL_Puavo on December 25, 2016, 23:40:30 pm
I've got 76x90,5 B stroker pistons, mildly ported 1600 heads with 37mm inlet valves. I made the engine with W100 and now 1,25 rockers, dual 36 dells (30 venturies) and 8.6:1 static compression, deck height is 1,1mm. Stock 1600 rods. Now it's driven for a few thousand km's without any problems, but would definitely up the cam a bit, maybe to W110 or equivalent. It's very civilised dynoed 100hp / 5200rpm engine that's easy to drive and pulls my -72 doppelkabiner just fine.

With stock rods I had to deck the engine case a bit to get the deck height I wanted. Then had to file head bolts a bit so that they didn't touch the rockers. And I had to shorten the stock alu pushrods for about 1cm to get ideal rocker geometry. Empi/bugpack/general exhaust header fits without excess force. Air deflector plates on the top of heads also fitted just about as tight as they can be, and same can be said for the stock pushrod tubes. So altogether quite a lot of small modifications but all quite simple and easy to do yourself. Also about all of them of the sort you really can't measure beforehands :)


Title: Re: 76mm CB crank and 5.5 rods,
Post by: Zach Gomulka on December 26, 2016, 00:04:01 am
I'd swap the crank for an 82mm.


Title: Re: 76mm CB crank and 5.5 rods,
Post by: Torben Alstrup on December 26, 2016, 20:21:30 pm
I'd swap the crank for an 82mm.
I would not! 76-78,4 stroke is great for campers.

T


Title: Re: 76mm CB crank and 5.5 rods,
Post by: Zach Gomulka on December 26, 2016, 20:48:17 pm
I'd swap the crank for an 82mm.
I would not! 76-78,4 stroke is great for campers.

T

Yeah but the 5.4's with a 76 is just a bit of a pain.


Title: Re: 76mm CB crank and 5.5 rods,
Post by: Mike Cott on December 27, 2016, 00:17:25 am
In what way Zach? Setting up the spacing on the cylinders for the deck height


Title: Re: 76mm CB crank and 5.5 rods,
Post by: Zach Gomulka on December 27, 2016, 00:43:37 am
In what way Zach? Setting up the spacing on the cylinders for the deck height

Stroker pistons also have shorter skirts to clear the crank/opposing rod cap at BDC, expect to have to do clearancing there. You'll need roughly .140" of spacers, which makes tins fit terrible. It can be done but it's more work. I'm just not a fan of wide engines. Or overly narrow engines, either. There are many combos that are easy to build and end up very near stock width, why make it more difficult?


Title: Re: 76mm CB crank and 5.5 rods,
Post by: modnrod on December 27, 2016, 00:46:43 am
To the OP.......
I have some Isuzu pistons (why? Uhhmmm, yeah, well.....never mind  :D) to go with my 76mm crank and stock 5.394" rods. They have a 36.6mm pin height, and so when all mocked up I have a 0.040" deck height. Perfect for most.
If I had the stock VW pin height (39.6mm), then they would stick out the tops of the cylinders by 2mm, so I need to add 3mm somewhere to make it all fit.
If I had the "B" VW pin height (35mm) then they will sit 2.6mm down the cylinders, so I either need to machine the cases or each cylinder by 1.6mm to make it all work.
This is why Zach is saying they are a pain.

The easiest way to get it all going, since you are still collecting parts, and without spending a heap of money (because large VW parts like crankshafts outside of the US cost at least twice as much), is to front up for some new rods, and yes, "I" beams will do the job perfectly well, no need for "race rods" here. If you already have the stock height "A" pistons, then get some 5.325" length rods, throw some thin shims under the cylinders and you're done.
The other option if you have "B" pistons, is to front up for some 5.500" rods and bolt it all up.

My personal pick would be a 76 x 92 thick wall, with some of CBs new Panchitos or plain 049s with good seat cuts, whatever cam you like around 280/240, and whatever exhaust sounds the best to you..........but that's just my preference, yours will be different of course.
It will be a nice cruiser when done, you'll be happy.  8)

PS: I just read Zachs post, but put it up anyway.


Title: Re: 76mm CB crank and 5.5 rods,
Post by: Zach Gomulka on December 27, 2016, 01:04:47 am
If you already have the stock height "A" pistons, then get some 5.325" length rods, throw some thin shims under the cylinders and you're done.

The other option if you have "B" pistons, is to front up for some 5.500" rods and bolt it all up.

The first option gives a lower (better) rod ratio, but the short rods will give you even more piston skirt clearance issues. The short rods are lighter but the A pistons are heavy. You'll still need .060"-070" spacers (mathematically speaking), which is acceptable.

The second choice has a higher, less than ideal rod ratio, uses lighter B pistons but longer, heavier rods. It will come out very, very close to stock width and be an easier engine to build. It is the better choice, IMO.


Title: Re: 76mm CB crank and 5.5 rods,
Post by: Mike Cott on December 27, 2016, 01:59:16 am
The options I have are

1; use the 5.4s I have now and shim the barrels for the A pistons
2; swap out the 5.4 and get a longer set then machine the  B  barrels to suit

Just to keep things simple in my head of what to do for the best ie; engine width and machining costs. Options 1&2 have implications on what barrels and pistons I use.

Remember I have the 5.4s not 5.5s I first thought when I started the thread and I DONT have any barrel and pistons yet

As you can tell I'm a novice at this 😃


Title: Re: 76mm CB crank and 5.5 rods,
Post by: brian e on December 28, 2016, 17:41:28 pm
Build this.  It will work awesome.

76 crank
5.5 I beam rods
AA 92mm TW " B" p&c's.
CB Panchito heads with CNC chambers, bored for 94's, single springs.
Web 218 w/ stock rockers on solid shafts, elephant foot adjusters
HD Aluminum push rods
8.5--9cr, w/.040" deck
40mm IDF's w/32mm vents, CB offset linkage and manifolds.  Make sure the manifolds are ported!!
1 1/2" sidewinder header
case machined for full flow.  26mm aluminum pump, steel FF pump cover. 
HD 200mm pressure plate, Daiken super disk

There will be minimal case clearance work, and the deck should set up with minimal shims.  You could use Tims Stage 1 heads also.  I have had both on the flow bench, and they are really close.  The CB's are slightly smaller ports, with a couple CFM more.  Both run awesome. 

You should be able to sell your 5.4 rods pretty easy. 

Brian


Title: Re: 76mm CB crank and 5.5 rods,
Post by: Mike Cott on February 04, 2017, 11:31:02 am
Ok so since last post I may have purchased something that potentially will be a little bit of fun so the engine may take a different route



Title: Re: 76mm CB crank and 5.4 rods FK8 cam
Post by: Mike Cott on February 04, 2017, 11:41:25 am
Update on parts I have so far

76mm  CB CRANK
Case is machined 94mm full flow
CB 5.4 uni rods
FK8 cam
30mm shadek pump

So I need lifters, heads, B&P's and carbs ignition etc
I'm looking to go drag racing with the rail once I've got the parts together and built up, thinking
48 Ida's
Steve tims stage 2 heads
Not sure on the ignition side of things, but that will be a while till that comes into play


Title: Re: 76mm CB crank and 5.4 rods FK8 cam
Post by: Zach Gomulka on February 04, 2017, 15:31:16 pm
Sell those 5.4's and pick up some 5.5's with stroker B pistons. It will make your life easier. FK8 and stage 2's will work great. You'll need 1.4:1 rockers as well.


Title: Re: 76mm CB crank and 5.4 rods FK8 cam
Post by: Mike Cott on February 04, 2017, 16:10:49 pm
Zach, do you mean with regards to setting up the deck height??
The case is having to be spot faced as they're worn a little round the barrel seat, would my machine man be able to set the deck height if he knows what is going in it ie crank and rods etc?
Yep 1:4 rockers are a given, as for the heads Steve Tims are great value for a quality head I just need them sending across which Is playing with the what if they have an issue the after sales would be an issue being across the pond


Title: Re: 76mm CB crank and 5.4 rods FK8 cam
Post by: Zach Gomulka on February 04, 2017, 17:03:04 pm
Zach, do you mean with regards to setting up the deck height??
The case is having to be spot faced as they're worn a little round the barrel seat, would my machine man be able to set the deck height if he knows what is going in it ie crank and rods etc?

You're really fighting this switch to longer rods, aren't you?  ;)

No. Why would you remove material/strength that you don't have to? You could machine the decks deeper to correct for deck height but you would have to mock the engine up first and take actual measurements, don't just use maths. IMO that will also effectively ruin the case for the next time it gets built/upgraded.

I could keep going on and on about this but it looks like you're going to do it your way. I'm not saying it can't be done but you're certainly making it harder on yourself.


Title: Re: 76mm CB crank and 5.4 rods FK8 cam
Post by: Mike Cott on February 04, 2017, 17:24:29 pm
 ;DHaha yep, I have the case in a very reputable builders hands and I'm only going on his vast experience and advice regards parts, I don't see how •1 different rods would make that much difference. im not that sure what is involved in spot facing etc but as I said I'm sure he knows what he's doing with it. IF I build another I think this case would not be on the menu as it's old and probably be past another messing with so new would be the way to go.


Title: Re: 76mm CB crank and 5.4 rods FK8 cam
Post by: brian e on February 10, 2017, 04:53:40 am
76 crank, 5.5 rods, and B pistons works out almost perfect with a light skim cut to clean up the decks.  With the 5.4 rods, you will either need to deck the case an extra .100", or cut the barrels down the same amount.  The B pistons are also lighter, slipper skirt style, and the pin is higher. All good things to have in a piston.

Brian


Title: Re: 76mm CB crank and 5.4 rods FK8 cam
Post by: uk ida on March 22, 2017, 12:09:00 pm
Hi, this thread makes for some interesting reading, I hear all different tails, about stroker engines in a bus, I'll depends what you what from the finished product,  I have run a  17.76cc in my bus for about 3, years, was OK, but whent 22.76cc about 6years ago best thing ever! pull a house down in any rpm range. Think about final drive and tyre size also of motorway Cruiseing. Keep the good info coming on the thread.  B-) thanks


Title: Re: 76mm CB crank and 5.4 rods FK8 cam
Post by: Mike Cott on March 22, 2017, 13:03:10 pm
Will do Uk Ida, Zach and Brian- I will be purchasing the 5.5s and stroker Pistons as you say it should be close to the correct deck height 👍


Title: Re: 76mm CB crank and 5.4 rods FK8 cam
Post by: Mike Cott on January 14, 2018, 22:01:31 pm
Santa dropped these off for me, 5.5 scat H-beams, stroker B&P’s ordered too
 (https://uploads.tapatalk-cdn.com/20180114/f0c71924cf447b5af8e1eb60f588765b.jpg)


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Title: Re: 76mm CB crank and 5.4 rods FK8 cam
Post by: Mike Cott on January 14, 2018, 22:02:00 pm
94mm


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Title: Re: 76mm CB crank and 5.4 rods FK8 cam
Post by: Martin S. on January 15, 2018, 18:46:01 pm
Decking the case like what you are describing is well worth the time/money. Not for setting the deck height to the head, but for a blueprinted engine.
I had this done on my engine and when the heads were dropped into place, there was a nice thunk, as the barrels were square to the crank centerline and to each other.
This will help your engine to not leak at the cylinder head surface, and as well let it rev easily.  ;)


Title: Re: 76mm CB crank and 5.4 rods FK8 cam
Post by: Mike Cott on January 15, 2018, 21:40:44 pm
Decking the case like what you are describing is well worth the time/money. Not for setting the deck height to the head, but for a blueprinted engine.
I had this done on my engine and when the heads were dropped into place, there was a nice thunk, as the barrels were square to the crank centerline and to each other.
This will help your engine to not leak at the cylinder head surface, and as well let it rev easily.  ;)

That’s good to hear Martin, got B&ps coming then I can take a look at the deck height, been looking heads 🙃 a mind field but I’d say budget will probably play a factor


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Title: Re: 76mm CB crank and 5.4 rods FK8 cam
Post by: Mike Cott on April 25, 2020, 21:32:17 pm
well its been a while since I last posted, life gets in the way with kids and work, hope everyone is staying safe with this Corona virus!!!!

Update on the parts I've collected so far, still not managed to get this built but nearly there now.

AS21 case full flowed, hoover mods etc
CB 76mm forged crank
5.5 Scat H-beam rods
FK8 cam
straight cut gears
Scat lightweight lifters
94mm stroker Mahle forged pistons
Weber 44 IDF's
CB Big beef manifold coming that I need to match port
CB Ultra mag heads polished/ported  42 x 37.5
CB Aluminium pushrods
Equalizer pulley

need 1:4 ratio rockers and some  covers, think that's not far off!!!  staying with stock fuel pump, ignition and oil cooling unless there is any gain in swopping out to upgrade

Hopefully get the bottom end built next week whilst we are still in lock down.


Title: Re: 76mm CB crank and 5.4 rods FK8 cam
Post by: Karlos99 on April 29, 2020, 11:42:44 am
The 2110 in my baywindow originally was 9:1cr had an FK8, 40x35.5 heads and twin 44’s with a 1” 5/8 header. Drove fantastic with plenty of bottom grunt, happily pull to 6500 and was generally a nice drive. Thoroughly recommend the FK8 in a bus.


Title: Re: 76mm CB crank and 5.4 rods FK8 cam
Post by: leec on April 29, 2020, 19:09:44 pm
Yep, I got scared silly in an early bay with a 76x94 FK8 motor. Proper honked on :)


Title: Re: 76mm CB crank and 5.4 rods FK8 cam
Post by: Mike Cott on April 29, 2020, 20:02:28 pm
Happy days, good to get some feed back on real on road experience. This will probably go in my rail at some point also for a little bazz up the 1/4 mile  ;D

what product should I be using to break the cam in?