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Tue Aug 27, 2013 8:11 am

Hi Guys

Finished the 1600 single port for my 56 van just in time for hessisch so had little time to pay too much attention to jetting. I wondered if there was any advice before I start spending cash with a tuner as I fear it may be quite far out and would like to have jets to hand

The engines fairly stock but well built with everything checked. Based on a new ali case with a later doghouse cooler and an external oil filter. mahle 1600 b and p with stock rebuilt 1500 heads (new valves and guides) and a stock cam. Balanced crank etc. Its using an older 009 till I rebuild my 010. Carbs sit on home made manifolds and a homemade linkage that works well. Carbs are tuned for idle by ear and balanced with a snail guage.

When I rebuilt the 2 solex 34 pci carbs I fitted the jets as suggested on this website with one or two tweeks depending on the parts I could get.

http://www.majnet.de/Technik/Motor/motor.html

So thats

venturi 27mm
Main jet 145
Main air flow 175
Idle air 1.1
Idle 50g
mixing tube 10

The whole system is running really well but I fear they are way too rich as I'm getting a little over 20mpg. Any advice welcome. I realise I need to get it on a rolling road or at least on a wideband O2 monitor but want to spend as little time on these as possable as they are never cheap!!

Seb

Wed Aug 28, 2013 4:17 am

I had a antique German TDI kit for the 1500. The kit was original and used 135 mains with the 28mm vents. The kit also used a balance tube between the carbs.

Wed Aug 28, 2013 4:41 am

Hi

Cheers, I did pop this in the vintage speed section as its an old school setup.

Do you know what the other jets are?

I can't find any 28mm vents, happy to swap if I can find them but parts for these are hard to get.

There is a big balance tube, about 16mm if I remember rightly.

Seb

Thu Aug 29, 2013 3:08 am

Sorry, I never looked at the other jets in the carbs. They worked well on both the 1500 and the 1600 I had in that car without changing jets. I doubt 1mm in vent size is going to make a differance.
You should use a pressure regulater with these carbs. The fuel can push past the needle and seat leading to excess fuel use. (Running rich while driving and bad gas mileage.) I only needed 2 psi at the carbs.

Thu Feb 12, 2015 3:48 am

beetleseb wrote: Hi

Cheers, I did pop this in the vintage speed section as its an old school setup.

Do you know what the other jets are?

I can't find any 28mm vents, happy to swap if I can find them but parts for these are hard to get.

There is a big balance tube, about 16mm if I remember rightly.

Seb

Hi Seb,

Where you able to run the 34 PCI on the 1600 well? Did you change the jets?
Was it necessary to mount a pressure regulator (bugguy076's suggestion)?
I have the same carb setup on a 1641 engine, but it runs to rich...

Thanks!!
Peter

Thu Feb 12, 2015 7:28 pm

I have no experience with Solex 34PCIs. However, I did purchase and run a new set of Dell'Orto 34FRDs on a 1600 single-port over 25 years ago. That set came with 27mm venturies, and 128 main jets. It was my first set of dual carbs, and after the basic linkage adjustment and carb mixture/synching, the engine ran very well. Good throttle response, no black exhaust smoke; leading me to believe that the jetting was reasonably close to favorable. I removed those carbs when I came across a set of used Kadrons for $100.

So- even though I might be way off with assumptions and oversimplification, in my opinion if the FRD's venturie size is the same as your PCIs, then your main jet should be close to the 128 as well. And even that size might be slightly big... The 140 mains in the Riechert link carb set "seem" way too big; though it's possible they chose that size to accomodate minutes of full-throttle top speed running on the German Autobahns. Both Riechert and TDE were acknowledged experts on tuned VW engines.

Fri Feb 13, 2015 1:33 am

Hi Peter

I am still running these carbs and they work well.

I have reduced the jet sizes (although I need to open one up see what I used) and I run a simple fuel pressure regulator I set with a friends pressure gauge

I've rebuilding a vj4 br8 distributor to better suit the engine and then I intended to buy some jets and pop her on a rolling road to get it spot on

If you want the current sizes I can open a carb up next week or will share the rolling road data in a couple of months

Seb

Fri Feb 13, 2015 9:58 am

Thanks lads!

Today we were able to make the Riechert Solex 34 PCI's (NSU based) run great on the 1641, big thanks to my buddy Cedric!!

Setup:

Bosh 010
Riechert Solex 34 PCI with Knecht mushrooms
Venturi: 27
Main jet: 112,5
Air jet: 200 (used to be 170)
Idle jet: 50
No fuel pressure regulator

Peter

Fri Feb 13, 2015 5:10 pm

beetleseb wrote: Hi Peter

I am still running these carbs and they work well.

I have reduced the jet sizes (although I need to open one up see what I used) and I run a simple fuel pressure regulator I set with a friends pressure gauge

I've rebuilding a vj4 br8 distributor to better suit the engine and then I intended to buy some jets and pop her on a rolling road to get it spot on

If you want the current sizes I can open a carb up next week or will share the rolling road data in a couple of months

Seb

Seb,

In fact I'm a bit curious about your jet sizes, so if it isn't too much trouble... ;-)
Please share us your rolling data, as soon as you have one!

Much appreciated,
Peter

Fri Feb 13, 2015 10:29 pm

I think there are higher on see level then we are...so other jetting...

Sat Feb 14, 2015 1:13 am

Hi

I'm 62m above sea level, you're 13 according to google. She ran very well on my trip to ninove last year. Still a bit rich.

The 27mm ventures make a huge difference, there is a downloadable book that solex wrote back in the 50's for working out jets.

Give me a week or two and I will whip a carb out.

Sat Feb 14, 2015 11:33 am

He drives with muschroom airfilters and they are lean on air intake
So i did main 112,5,idle 50,27 venturi,200 air...
Run strong now and good torq
If you have normal airfilters i think you can drive 170air
Just my 2 cents..
Are you comming to ninove?
Maybe meet up?i will be @ the entrance
Greets cedric

Sat Feb 14, 2015 9:25 pm

cedricv wrote: He drives with muschroom airfilters and they are lean on air intake
So i did main 112,5,idle 50,27 venturi,200 air...
Run strong now and good torq
If you have normal airfilters i think you can drive 170air
Just my 2 cents..
Are you comming to ninove?
Maybe meet up?i will be @ the entrance
Greets cedric

The mushrooms may be lean, they're damn sexy though! :lol:

Sun Feb 15, 2015 12:41 am

Deff up for saying hello and talking vintage speed, we'll swap details via pm.

Not sure what we are going in yet

Mushroom filters are sexy. I might make some for the bug when I build the twin 28pci set up

Wed Mar 18, 2015 4:53 am

Just wondering what you guys are getting mpg wise?

On our trip to ninove I averaged 20.6mpg that's 13.7L/100km! I know the jets are a bit big but this seems very high.

Still not been to the rolling road as sorting the dizzy still.

Wed Mar 18, 2015 9:47 am

beetleseb wrote:
On our trip to ninove I averaged 20.6mpg that's 13.7L/100km! I know the jets are a bit big but this seems very high.

Not that high, I suppose.

The result of the test from an independent car magazine performed in 1963 (when the gasoline was better than today) with the 1200cc 36hp Kombi was 13.3L/100km unloaded and 14.8L/100km loaded, in a rush traffic. About 30% better mileage at constant cruising speed.

Add 400 cc of displacement and another carburetor then expect less.

Fast forward to 2006 -- the test result from the same magazine for the multi point injected (from factory) 1600 cc Kombi was 13.3 / 12 city / road.

Wed Mar 18, 2015 9:56 am

Interesting, but really I only care about cars with the 34 pci set up in this instance.

A stock 67 bus averages 29mpg according to vw. Twins should get more. My bus is basically on stock 67 running gear

I mainly worry about running over rich washing oil off the barrels.