TheSamba.com :: View topic

Fri Jun 20, 2025 3:03 pm

Hey guys,

Possibly beating a dead horse with this topic so I apologize but im wondering if anyone can shed some light;

I have a 1300 that has had 85.5mm P&Cs installed with the 1300 heads.
I have got some dual port heads for it and I'm wondering if I can run the 31 pict 3 carb that was on there with the single port heads. As far as I'm aware the 31 has a 25.5mm venturi and the 34 has a 26mm one.
So, could I run the 31 or do I need to upgrade the carb? My other option I have as I have one already is a weber 32/36.

Any insight would be appreciated.

Sat Jun 21, 2025 6:33 am

I like the old 30PICT1 we got here in '66 and '67. That's what we used to run in limited desert classes.

Lacking a 30 I'd use your 31. Save the progressive for a Ford Pinto if you happen to see one.

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Sat Jun 21, 2025 7:06 am

I am running a Solex 30 PICT-2 and matching distributor on my 1641 SP with excellent drivability. It's my view that a 34 PICT and the Weber progressive would have no advantage because of your valve sizes. In fact they may run worse.

Sat Jun 21, 2025 7:50 am

You will need the cooling tin and the intake for the DP , also a adaptor for the carb. Yes it will work try it first. the 30 and 31 were a good option for the 34.

Sat Jun 21, 2025 7:53 am

It has been done about a million times, - each.
The 31 carb on a 1302(3) manifold on an otherwise stock 1600 will pull better lower rpm power, but stifle the power above 4000 rpm. The aux idle jet likely needs to be increased to 55-57. and the idle from 46 to 50. Main jet 0,25 up. (Provided that you have the distributor matched to the carb.)

The progressive on an otherwise stock 1600 is not worth the trouble. The carb is too big. More compression, better ignition, better exhaust and the progressive begins to pay off. Better cam (not too much) better head work etc and it can come to live. Remember, the 32/36 carb can support up to about 130 hp in a decent set up.

The 34 Solex PICT is simply a very misunderstood carburettor. That said, on a bone stock 1600 it can be a challenge to get to run perfect. BUT, increase cr to just 8-1 and do a simple 3 angle valve job along with a coil with some proper reserve capacity and the whole package comes to life.

Sat Jun 21, 2025 2:13 pm

halfassleatherworks wrote: You will need the cooling tin and the intake for the DP , also a adaptor for the carb. Yes it will work try it first. the 30 and 31 were a good option for the 34.

Yep working on getting the cooling parts together at the moment, will need an intake as well.

There is alot of info out there saying you should do this or not run that so good to know some have some real world experience on the matter.