Race Engine Forum UK

Hi Guy,

Have been looking at carbs for my car and was wondering do Webers have any advantages over Dellortos or vice versa?

Thanks,

Ben

Functionally there is no difference at all.

Me, I prefer Weber because they make a superb linkage, no other reason!
Also there are many more people with Weber jets on hand than Dellorto, this has always been so (unfortunately).

GC

Hi Guy,

Thanks for this.

I'm also a little unsure which size to go for, 40's or 45's?

My engine target power seems to put me right on the threshold between the two. I'm expecting to get 150bhp at approximately 6500 from my 8v SOHC Peugeot 1900cc engine. Cam is the standard item, 11.3mm lift and 265 deg duration at 0.1mm lift.

I was thinking 40's with 33mm chokes.

Based on the flow measurements you have taken of the head, can you make a better recommendation?

Thanks,

Ben

Ben, hi

here is a overlay of your 1.9 SOHC Peugeot head on a 2 liter Lancia TC I did a while back. The Lancia was 9.5/1CR and gave 145bhp on downdraft 40DCNF with std ex cam and Columbo 10.3mm lift inlet cam.

Your cam lift is higher, and although the lower to mif lift flow is not as good as the TC your head has better flow over say, 9.5mm and the cam is higher lift. Plus DCOE sidedrafts are certainly more powerful than DCNF downdrafts. I'd go for 34mm chokes not 33m and yes, you could expect something around 145, maybe more. I think 45s on 36mm chokes would be more powerful still.

GC

I think 45s on 36mm chokes would be more powerful still.

Without any loss of torque lower down the rev range?

Ben

More powerful - top end.

A bit of a trade off under 3000, 45s vs 40s - but that's quite a big engine and it depends how fast you want to go.

GC