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Carburetor difference

Posted: Sun Jan 11, 2015 8:25 am
by monkslayer
Hi guys.I have searched through the forums and can't find an adequate answer to my question.My engine is a 1600 single port.I am looking for an economical and reliable carb for my daily car.
I am replacing my 30-pict 3 carburetor and would like to know which is the better option between the two carb links for my setup? what is the difference between the two carbs in the first place?

1: This it the 30 Pict-http://www2.cip1.com/ProductDetails.asp ... -98-1288-B

2. This is the 30/31 Pict-http://www2.cip1.com/ProductDetails.asp ... -129-029-A

Thank you in advance

Re: Carburetor difference

Posted: Sun Jan 11, 2015 9:13 am
by sideshow
The square bowl is the more correct, the round bowls were phased out in the 1300cc era

Re: Carburetor difference

Posted: Sun Jan 11, 2015 11:49 am
by monkslayer
Huh..sorry but I didn't get you:-(

Re: Carburetor difference

Posted: Sun Jan 11, 2015 2:12 pm
by helowrench
30/31 was a later model replacement carb for the 30 series.

They are fairly good. should bolt in place of the 30-3 that you have on there right now .
I prefer the 30/31 over the 30-3 but you know what they say about opinions.......

Re: Carburetor difference

Posted: Sun Jan 11, 2015 10:41 pm
by monkslayer
Thank you for your response.In regard to quality,I see on the website they denote the 30-pict as a top quality reproduction piece.Any one have any experience with this carb?

Re: Carburetor difference

Posted: Mon Jan 12, 2015 2:01 am
by aussiebug
The 30PICT/1 carburettor (round bowl) was designed for the first 1300 engines. It has a 24mm throat. The first versions did NOT have a power jet. That means they work Ok with the 1200 and 1300 engines but not so good with the 1500 and 1600 sizes, where the engine will start to run lean at higher speeds. The later Solex 30PICT/1s, and the /2s and /3s all have the power jet, so work OK with 1500 and 1600 engines. So you need to check with CIP1 if the advertised version has the power jet.

The H30/31 is a modern replacement carb for all the 30 and 31 series carbs. It has a slightly larger throat at 25.5mm so has better airflow for the 1600s. BUT - the H30/31 has a lower than normal vacuum signal, so it can struggle to pull in all the vacuum advance on an SVDA distributor. That usually means running it more like a 009, using a 009, or having the points plate spring lightened so it will react bette to the lower vacuum signal. The H30/31 usually comes with very lean jetting too (an emissions thing), making the car hard to tune and to keep in tune, and you might find that it runs better with more "stock" jetting. It usually comes with a super lean 117.5 main jet, an oversized idel jet so it wont stall at low revs (65), a 125 air correction jet and a smallish 47.5 power jet. You can try a 55 idle, 125 or 127.5 main jet, leave the 125 air correction jet and use a 65 power jet (swap the 65 idle to the power jet location).

Both carbs have the same manifold fitting, so will fit on the SP manifold.

The tuning of these carbs is different.
http://www.vw-resource.com/30pict2.html for all carbs having a single adjusting screw in the left side - 28PICT, 30PICT/1, /2
http://www.vw-resource.com/34pict3.html for all carbs having two adjusting screws in the left side - 30PICT/3, 31PICT/3, 34PICT/3, and H30/31

Re: Carburetor difference

Posted: Mon Jan 12, 2015 6:33 am
by helowrench
aussiebug, that is one of the reasons I prefer the 30/31.
I am so used to the 34-3 and it tunes the same way.

Thank you for a nice explanation of the rest of it. Well done.

Re: Carburetor difference

Posted: Tue Jan 13, 2015 12:30 am
by monkslayer
Thanks guys for the responses.Helped me decide.I decided to go for 30 pict since from overall reviews from users who have used the two,i see most people telling reporting that they get better overall driveability with the 30 pict as compared to the H30.

Cheers.