The Cal-look Lounge

I'm in the planning stages of a pretty basic 1500/1600 engine and want to run a single Weber 40/44 Carb.

I'm thinking some very minor/basic headwork and possibly ratio rockers matched to a nicer cam?

That's it basically. I'm not any kind of engine builder/tuner as you can plainly see, but I'd very much like some opinions and experiences of anything similar to what I'm proposing.. 

All and any advice will be gratefully received.. ;D

The reason for the single carb is purely aesthetic..  ::)

Thanks Paul

How about a WEBER 40dcn - I ran this set up for 4years 100% trouble free  :)

I'd certainly consider that if all the additional items were available in good condition?

A new Weber/Empi HPMX Kit isn't too much cash, but I'm not sure a very good DCN Kit could be assembled for less?  ???

Well I only mentioned it as I ran a DCN for a long time inc NORWAY and back - 100% fault free, Perfect idle, etc etc etc
(check this picture/thread for my set up)

-  http://cal-look.no/lounge/index.php/topic,6900.0.html

I resently brought a NOS/BOXED Weber 40dcn for my next manx but realisticlly I am not going to building this motor for a while and I could let it go - I also have a MASSIVE collection of spare/jets/parts etc etc

Trust me it will be a MILLION times better than that "empi" crap - I have messed around with one of those on a customers car and they are RUBBISH!  :)

Drop me a PM dude  ;)

PM sent.  ;D

I used to run a single weber 44 centrally mounted on my old 1914 back in 94, that was on a fairly mild motor, my fond memory of it was it was a bitch to start from cold, wether it was because the fuel had a long way to get to the cylinders i cant be sure,  but i know with duals it was always easy to start, when it was warmed up on the single it started up and drove and pulled just fine.

Mine was fine - Hot & Cold, From cold I just used to give 3 full pumps on the gas pedal and it would fire up and idle straight away

Also here is the picture of the linkage  ;)

I loved this set-up  ;D

both very cool  :)

Zenith 32ndix.

Recently sold 1835 running isolated manifold with 40 DRLA, stock ported heads, cb2234 cam, 009 dizzy. Ran real nice and smooth.

(http://i105.photobucket.com/albums/m208/benito26/IMG_2201.jpg) (http://s105.photobucket.com/user/benito26/media/IMG_2201.jpg.html)

Back in the mid 80's when I ran a single 2bbl 36DRLA was manifold icing, which on cold nights, renderned the car literally undriveable. Make sure you have a way to get warmed air to air intake for cold part of the season. The preheat circuit off of exhaust header wasn't enough to keep mine from icing, in SF Bay Area.

From what several people are saying the single carb set up is prone to manifold icing (in a big way)..

This is good info and exactly the kind of experiences that I wanted to find out about.

It's not what I was hoping for as the single carb was my preference, but invaluable in making the right choice?

As I'm not planning a larger displacement motor (1600-1641) I had no visions of a dual carb set up. I'm not considering 34ICT's or similar as this would not be the look I'm after at all?

Some helpful folk have mentioned a single 40DCN's on a single manifold, but I not sure if such old carbs would prove reliable over time. Also the complete DCN set up leaves me close to a dual carb (IDF) price?

Am I best to forget the single carb idea and go dual instead?  ???   

For stock displacement to 1641cc, with mild cam timing, my favorite setup has been Kadrons. With wilder cam timing, twin Weber IDF or Dellorto DRLA.When I was young and really green, not understanding how valve timing and intake design worked and clashed, I ran a long duration (256' @ .050/288' adv) with center 2bbl and it idled roughly and would die under 1300rpm. Once I had the money for the dual 2bbl, I went to dual 36DRLAs and the engine became silky smooth from 900rpm idle up. Read the Berg catalog in the cam section- similar experience.
when you say "nice" cam, it doesn't really communicate what you want/are looking for. There's a lot to consider if you're starting from scratch.
Good luck

Why not just use a stock 34 mm PICT3 carb and be done with the hazzle. Then spend some of the "carb money" on a good cam for the combo. With a little attention to the heads and CR you will soon pull the same power and torque as with a centermount DCN or IDF and a stock cam. If not more.

T

Why not just use a stock 34 mm PICT3 carb... With a little attention to the heads and CR you will soon pull the same power and torque as with a centermount DCN or IDF and a stock cam. If not more.

Planned engine will be stock (crank) with possibly a slightly better cam..

 The look I'm after is with either the single Weber (40/44IDF) or going down the Dual Carb route (last resort)

Joel Mohr has adapted a single Kadron to the 1600 engine.  I saw it at Sacramento one year when his dad drove a Ghia with it.  If we could get him to chime in it might be worthwhile.  From what his dad said it worked great.  I have no idea what mods he made to make it work. 

Thanks Jim.. Not enough info on my part really ::)

By Nice Cam I was thinking about an Engle 110 which historically should suit a 1600-1641 well?

I'm thinking of 1.4:1 Ratio Rockers to go with the cam?

I'm not sure about Kadrons really.. certainly not what I'm looking for aesthetically in truth.

110 cam doesn't work with 1.4's

Another plan foiled there then..... Am I best to just use 1.25: 1 on the standard cam  ???

This isn't a 'all out power' engine obviously, but I'm trying (with my clearly limited knowledge) to keep things simple, reliable and hopefully within reasonable cost?

Once again over to you Guys....   :-\

A stock cam will work with 1.25's or 1.4's, but a mild cam grind with stock rockers will be much cheaper and more beneficial than high lift rockers with a stock cam. You don't need to spend extra money and have a mild cam with high lift rockers for your application.

If I was in your shoes, I would build a 1600 with an Engle 100, around 8:1, cleaned up stock valve heads, standard header, 010, and a single Zenith. The Zenith runs phenomenally well.

Having built and run a number of single carb combinations the CB2234 with stock or even 1.25 rockers on stock heads with Dellorto has been the smoothest with loads of torque 2k-5k pull 8:1 comp. I would easily run this again in 1600 or better still 1776 if you wish to go bigger bore. Balance the rotating assembly and with the addition of more head and exhaust this engine will surprise you, however if you leave in cold morning climate you will need to heat the manifold, it's not so much icing up than de-atomising the fuel and dropping from suspended turbulence.

If I was in your shoes, I would build a 1600 with an Engle 100, around 8:1, cleaned up stock valve heads, standard header, 010, and a single Zenith. The Zenith runs phenomenally well.
[/quote]

Sounds Good.. ;)

I like the sound of the Zenith, it certainly has  the 'look' that I hoping to achieve and there seem to be quite a few out there at the kind of prices I can afford  ;D

I was planning to run a single Zenith NDIX carb on my single port until I located and purchased manifolds for the Kadrons. Art @ACE, Mr. Raby, and Jeff Denham all recommended the Zenith immediately when I mentioned that I wanted to run a single carb. It was the first carb of choice for each of them in regards to being smooth running and trouble free. I did much research on manifold heat and it seems that a very common fix for preheat is to move the left preheat tube on the header down to the collector so the manifold heat works like VW intended it to work (you must fab up some tubing and weld the flange to fit your intake). Another idea that Jake gave me was to run heat to the base of the air cleaner from each nipple on the later style heater boxes. I have always liked the idea of using a single carb due to ease of engine removal and install. Lets face it, adding dual carbs does complicate things more and I hate removing manifolds and carbs, then dealing with linkage, multiple fuel lines, etc....Especially when I'm trying to get the car back on the road quickly so I can drive it!   

Andy

More good advice/information.  ;)

The more I hear from people on hear about the Zenith, it really does seem that my best bet is to go that way?

As I said previously there seem to be a good number out there to choose from and the Zenith seems to meet all my requirements pretty much.

So that's the Carb sorted, now I just need to match the rest of build to what the Zenith can do.

I'm thinking just 1.25:1 Rockers, standard cam and some mild Head Work? I'm planning a custom exhaust set up which will be pretty much straight through?

any thoughts folks.......  ???

 

After reading this thread and posting, I just went and searched for a Zenith carb and was able to buy one from Joel Mohr. I would like to make my own manifold if I could get the materials I'm missing  (I have some of the materials needed).  I have a 1700cc single port that is nearly stock with Kadrons, but I want to run those on my performance 1915cc single port. One thing to consider is that the Zenith NIDX will need a modified manifold and/or a custom throttle tube inside the fan shroud in order for the throttle cable to line up and work correctly. Otherwise you need to remove the oil cooler from the shroud and run it remotely.

For what it's worth, I spent over an hour talking to Jake Raby about building my high performance 1915cc single port, and he recommended the NDIX even with all the other mods I am going to run. The heads are Jeff Denham 37x35.5 ported heads, DPR CW crank, Webcam 218/119, 1-1/2" merged header, etc. He never said it would have a smooth or low idle, but he mentioned that the carb would be smooth and perform well otherwise. I am going to run my Kadrons instead on that one since the idle of a single carb would be too high and erratic, but I think you could make it work with a modified engine. My 1700 has the stock cam, slightly ported heads, 1.25 rockers, and a 1-3/8" header, so a Zenith should work out just fine.

One thing to consider is that the Zenith NIDX will need a modified manifold and/or a custom throttle tube inside the fan shroud in order for the throttle cable to line up and work correctly. Otherwise you need to remove the oil cooler from the shroud and run it remotely.

He mentioned that the carb would be smooth and perform well..
[/quote]

I'm sold on the Zenith now and am on the hunt already. I've seen a nice looking set up on the Samba, which might suit.

Some more info on the Acc Cable would be of great help. I have no plans to change the oil system so will need some guidance please..  :)

I used the stock throttle cable, etc on my Zenith and it worked fine. It wasn't absolutely perfect in regards to angle but it did the job, got full throttle, didn't hang up, and so on.

A mild cam costs less and will make more power than a stock cam with ratio rockers.

Thanks for that Zach. ;)

I'm glad to hear that the Acc Cable isn't a major issue and I'll enjoy fiddling with that to get it as I require..

What do you think Engle 110/120?? Matched to some simple Head Port/Polishing?

Yes, simple port and valve job will go a long way. Engle 100 will be plenty, although I'm sure you'll find people who disagree. I prefer not to over cam small engines, especially when using a single carb.

i ran a single carb and fitted one of those heater blanket things, it was fine even in winter

Agreed, I'd rather have a really useable set up, that can be used everyday? Do you have any thoughts on a Lightened Flywheel added into the mix?

Am I right in thinking the Flywheel will lose me some top end performance but help with take off  ???

This is type of Manifold I'm looking for.
  http://www.thesamba.com/vw/classifieds/detail.php?id=1409760

Counterweighted crank and a light flywheel. Standard lightened flywheel is 12.5 pounds. Super light flywheels can sometimes make it tricky to get going smoothly from a stop.
The carburetor you want is a PO10 (sometimes just marked PO), that is for a single carb application. There are also PO3(R&L) and PO19(R&L). The R&L is right and left, for Porsche dual application. The jetting is different as well as the throttle plate and of course the linkage arm.
With the PO10 carb you want an individual runner manifold, NOT a plenum style. The one you pictured is the correct style, but I don't have any experience with that style manifold specifically- the one I used retained the factory VW end castings, which I prefer.

Good info again Zach Thanks...

I'll make sure I get the right PO10 type carb.  8)

You can see in the link below what I'm talking about with the manifold being setup for better throttle cable alignment. If you look at the carb and manifold base, it appears as if someone grabbed the base and "twisted" it clockwise (like tightening a lid on a jar) before it was welded together. From what I can tell, some of the more popular bugspray manifolds come with that "twist" in the flange already, but I don't know if the they have the same bolt pattern as a Zenith or not.   

http://www.thesamba.com/vw/forum/viewtopic.php?t=466289&highlight=bugspray++zenith

http://www.thesamba.com/vw/forum/viewtopic.php?t=423070&highlight=bugspray++zenith

I've heard both arguments about the Zenith single needing a plenum manifold or an isolated manifold with the PO10 model carb, but I also notice that a lot of PO10 carbs don't have the slot in the throttle plate base. That leads me to believe someone has swapped bases in order to get one that didn't have loose throttle shaft bushings. I will probably experiment with my manifold setup and see what works best. It's my understanding that if the throttle plate base has the slot connecting both bbls., you can run the isolated manifold. If not, you must run the plenum style manifold.

Zach is right about using a small aftermarket cam (like the Engle 100) over the stock cam with 1.25 rockers, but with my case (pun intended) I didn't want to split the bottom end open just to replace the cam. The engine only had 45,000 miles on it so I just did the top end and added a few upgrades like the 1.25 rockers, headwork, and Kadrons (for now). More head work, larger valves, and more displacement will all allow you to run a slightly "bigger" camshaft with little or no ill effects other than high idle speed when using a single carb. Don't go overboard though!

As for the lightened flywheel, I can't say one way or the other with a single carb application since I am treating my engine as if it were stock (with a little more power). On all of my performance engines with dual carbs, I have always run with a 12lb flywheel and a CW crank, which does rev a little faster (although the Counterweights offset the lightened flywheel). With a bigger camshaft, a stock heavy flywheel can help smooth out the rough idle a little bit though. 

Andy

Thanks for the links Andy.

Lots of very helpful information and especially regarding the Zenith Base Plate issue.

I'm undecided about the Lightened Flywheel and need to be sure of the positives & negatives at the top and bottom end of performance.

I'm not planning any upgrades such as twin carbs or anything. I want a particular look and twin carbs don't meet my requirements. 

The slot issue is the same for the Holley Bugspray set up regarding manifold choice.

The only negative about a lightened flywheel is that if it is lightened too much it may be difficult to keep the revs up from a dead stop. This effect is compounded if you have an engine that makes very little low rpm torque, the combo I suggested will be very torquey off the line and pull well to about 5k rpm. You won't have that issue with a 12.5lb flywheel (I believe a stock flywheel is about 17-18lbs?). A counter weighted crank ads about 3 pounds. A lightened flywheel will get to the power much quicker and be much more entertaining to drive. I wouldn't personally build any engine without a c/w crank and a lightened flywheel, even if the rest of it is 100% stock.

I wasn't planning on the c/w crank and will have to think seriously about this. It's a few £100's more but perhaps well spent.

My initial aim was to buy an off-the-shelf 1600 engine and go from there... Perhaps I'm going to have to spend the extra to have all the internals just right...

If smoothness and longevity is a concern, it's the way to go. I wouldn't lighten the flywheel with a stock crank.

I'll have to re think the engine budget a liitle and make sure that it's going to last.

NOTHING beat a nice counterweighted crank and fully balanced bottom end - Such a noticeable difference  :)

At present all my engine plans are up in the air, but I have an outline and have gained a massive amount of good information from this thread.

Thanks All..  8)

I had a 1776 with stock balanced crank, lightened flywheel, stock ported heads, AP3 cam, stock lifters, stock pushrods, twin 36 IDF webers
pulled 74 hp atw, same combo with 6.5 psi 94 hp atw.

I've had a few single carb streeters.
1641, stock cam and 1.4 rockers (didn't split the cases), ported 355A TP heads, Solex 34 and custom centrebranch into stock end-pieces, cheap crappy 4-1 and hotdog........mid-15s with 1300 gearbox pushing 850kg. I reckon that's a good result for a daily driver. An upgrade to an Engle 100 and 1.25 rockers gained less than 2 tenths, so unless your cases are already split, for a mild combo like this I wouldn't bother camming it up. Engle 110 MIGHT give you an extra 5HP, but you WILL lose grunt under 2500-3000.
Single carb streeters work well, but yes, when it gets below 5*C they get a bit ugly without heat. You can use hot exhaust air into air filter like stock, heated manifold like stock, I've even seen copper tubing holding engine oil wrapped around a single SU carb manifold in an older Type 3 which worked fine for pre-heat. It won't adversely affect performance more than a few HP, even in 45*C, but you will gain a good 10-15% fuel economy everywhere, and really nice driveability. If your temps are always over 20*C you can easily live without the pre-heat though.

That's what I've found anyway over the years.

I'm still hoping that I can put together the single carb set up with either a Zenith or Weber DCN.

 It does look though as if the engine is going to make this a longer project than I had first thought.... ::)

i still got that NOS dcn  ;)