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Carb Choice for 1905cc
hulbyw - January 24th, 2019 at 03:39 PM

I am building a 1905 motor with mild cam, 1.25 ratio rockers, mildly ported reconditioned DP heads with standard valves, Vintage Speed sports exhaust and probably a 123 ignition
I have a choice to make between:-
a single Weber 40DCN which has been on a VW (but don't know the capacity) which has working heat risers and I also have an electric heater coil to go round the top of the manifold (copy of Joel's setup)

and a pair of Weber 36IDF's which I will have to mod to suit the VW (also have CSP centre pull linkage).
Constructive comments are sought from folks who have played with Webers as to the power and driveability of either setup.
Cheers.............Wayne


vw54 - January 24th, 2019 at 04:07 PM

i have just fitted a 42 DCNF to my 1916 runs nice with 1.4 c65 cam big valve heads

I think the twins are harder to keep synchronized


Bizarre - January 24th, 2019 at 08:14 PM

What happened to the injection Dave?

I have never really seen a single perform better than a good set of duals.

Single needs a decent manifold - which you say you have.
Never been a big believer in the amount of heat the electric coil can produce.

I have run single carbs on my 1916, but never run a single DCN. Only progressive and PICT's
Didnt think the DCN was a particularly good carb? Happy to be wrong.

The CSP bell crank is a beautiful set up and easy to get the twins working smoothly
When I ran IDF 36's on my 1600, 1776 & 1916, I found you needed 45 idles - and they are a bitch as they block easily.

At least the idle is on the top like a DRRLA - and not on the side like other IDF's

I also ran 32 vents and found that they were a very sweet set up

You will get more power from the set up the IDF 36's but I will be interested in what jetting you have


vw54 - January 25th, 2019 at 06:10 AM

Injection set up is up for sale

The DCNF is running nice still doing some jetting adjustments


vassy66T1 - February 5th, 2019 at 08:46 AM

Personally I would go for the twin 36IDF carbs everyday of the week.
Very good driveability and performance.
I have had this setup on both beetles and kombis. I currently run twin dellortos on 4 cars one of which is a daily driver.
Synchronising is not hard at all.
Just practice makes perfect.