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Carb options 1600 single port

Posted: Thu May 04, 2017 6:45 am
by Olirindis
Greeting enthusiasts,

What is the best carb for a standard single port 1600 engine?

Thanks in anticipation..

Re: Carb options 1600 single port

Posted: Fri May 05, 2017 7:54 am
by acpaterson
Hi,
Welcome to the Forum. Perhaps pop an "intro" thread, and tell us about yourself and your car? Also Pics, we do love Pics..

If you're asking for the Speedy replica, then try find a good Spanish set of Weber' 34 ICT's, They will certainly liven up the Speedy plenty as it's so light. If you don't want to spend the coins, then a stock 34 PICT will work well.

good luck.

Alan

Re: Carb options 1600 single port

Posted: Fri May 05, 2017 9:07 am
by Olirindis
I've got a Speedster 356 Replica with a single port 1600 VW motor. It's got a PICT 34 carb which is mounted on top of an extension of sorts, not sure why. This carb has never run well, spluttering and stumbling on acceleration. Can't find the problem,and the carb is new.

Re: Carb options 1600 single port

Posted: Fri May 05, 2017 9:24 am
by fig
Olirindis wrote: Fri May 05, 2017 9:07 am I've got a Speedster 356 Replica with a single port 1600 VW motor. It's got a PICT 34 carb which is mounted on top of an extension of sorts, not sure why. This carb has never run well, spluttering and stumbling on acceleration. Can't find the problem,and the carb is new.
The "extension" is an adaptor to allow the 34mm carb to fit on the 30mm single port manifold.

Correct carb for SP is a 30PICT or the new 31PICT. A 34PICT will work if jetted and set up correctly. Don't give up on it just yet. If you really can't get the carb to work, it may possibly be one of the Brazilian carbs specifically set up to run on methanol. Get a workshop manual and use the procedure to establish basic settings on a 34PICT and take it from there.

If you are running a "009" distributor (centrifugal advance only), then you'll struggle to get the 34PICT to work. That combination is notorious for bad flat spots off idle. Either change to a stock SVDA distributor or change to the correct 30PICT carb.

I have a number of used Beetle workshop manuals for sale, PM me.

Re: Carb options 1600 single port

Posted: Fri May 05, 2017 12:23 pm
by Dawie
If it still has that original, "non-centrifugal/vacuum only" distributor... (the one with large vacuum can and big cap), that came with singleport beetle and kombi engines of the 60s...

Remember that is a highly unusual design that works only together with 28/30 pict carbs. (And some later replacement "universal" 31Pict's, but not original German 31Pict's). These carbs were designed specifically for non-centrifugal distr's and have dedicated vacuum takeoff passages which mainly draw from underneath the venturi, instead of only below throttle valve. This works in conjunction with a special large high-sensitivity vacuum can, mounted on a wide distr body where it has more leverage.

Trying to use these distributors with the wrong carb will cause overheating, laziness and extreme fuel consumption.

Re: Carb options 1600 single port

Posted: Fri May 05, 2017 10:24 pm
by Olirindis
Thanks for the replies gents,

I'm using a 009 centrifugal advance distributor. So I either have to correctly jet the present 34 carb or source a 30........................ what re-jetting is required on the 34PICT?

Re: Carb options 1600 single port

Posted: Fri May 05, 2017 11:25 pm
by Dawie
As Fig mentioned earlier:
"If you are running a "009" distributor (centrifugal advance only), then you'll struggle to get the 34PICT to work. That combination is notorious for bad flat spots off idle. Either change to a stock SVDA distributor or change to the correct 30PICT carb."

Best would be to dump that vacuumless 009. (It basically behaves like a late beetle distributor with faulty vacuum can). Timing with 009 is 10 degrees too late under part-load conditions because of missing vacuum advance. Causing higher fuel consumption and flat spots.

Get the centrifugal/vacuum combination distributor from a 70's dual port beetle.

If you somehow really have to live with the 009, try plugging the hole in the throttle plate with a rivet or something.

Also make sure the pre-heater tubes in the inlet manifold is open, not blocked with carbon inside, and connected to the exhaust.

Re: Carb options 1600 single port

Posted: Sat May 06, 2017 5:16 am
by fig
This once again makes the point that one should always first eliminate all ignition faults before messing with the carb.