carburator and 3.2

[hugo]

on my 911 73 . 2.4 e i put an 3.2 engine with CIS , but what is the bes carburator to change?. who has made this modification? thanks

[Formerly Steve Wilkinson]

I have PMOs on my '83 SC engine, which is a 3.0 that has been taken out to nearly 3.4 liters. It was originally a CIS engine, of course. The PMOs are expensive (around $2,500) but superb. They are new-manufacture carburetors that are essentially Weber copies but with a number of improvements over the no-longer-manufactured Webers. You'll find them advertised in a number of U. S. Porsche magazines. If you don't have such magazines available in France, let me know and I'll get you the address.

Stephan

[jabb]

Here is the link for PMO

Next choice would be a set of used Webers

[hugo]

weber are less expensive and easyer to find in my country, but i m suprised that nobody in US make this upgrade... and what is the best ignition , exhaust , fuel pomp etc for carbs (46 ids i think) and 3.2 liter ?..

[jabb]

For exhaust you can use the stock exhaust, if you do not need heat you can use headers with the stock muffler. Or SSI exhaust with the stock muffler or an other muffler you would like.

Fuel pumps you need either a Facet or a Bosch Rotary type pump.
With low pressure. I would also install a preesure regulator... the carbs only like about 3.5 pounds of pressure.... more than that and you will have problems.

[silverc4s]

Hugo,
All 3.2 engines in the US (1984 to 1989) were motronic FI, not CIS as on the previous years of 911 SC which were all 3.0 liter here.
Is there a euro 3.2 engine that came from the factory with CIS, or do you have a 3.0 with larger pistons?? Just curious, as we always want to know more.
By the way, I have a motronic 3.2 in my 73 targa, and I love the FI for the street. Pretty responsive, no fuel leaks, and good mileage!! On the track, Webers are the way to go, no doubt there.. ;~)>

[kellzey]

According to Bruce Anderson the 3.2 motors are on the borderline between a 40 IDA and 46 IDA Weber. What will make the difference is the cam. If you have a cam that produces peak power somewhere over 6300 RPM, then the 46 IDAs are the way to go.

PMO makes a better 46 mm carb than the original Webers, but they are expensive.


As far as fuel pumps, an early 911 Bosch carbureator pump or a rotary pump would be fine. A fuel regulator is actually optional. If the pump is designed to output pressure at 3.5 PSI, then why regulate it? If it pumps out 5 or 6 PSI, then you would want to regulate it down to 3.5 to 4.0 psi.

Also, your cam (CIS) may not work the best with the carbs. You may consider switching to a differnt (more carb friendly) cam. Then you also have to make sure your pistons match the cams okay. You dont want your valves slapping into your pistons!

I have heard people with much success with a Webcam 2021 cam and 40IDA3C carbs and stock CIS pistons that runs great on an otherwise stock 3.0 or 3.2 engine.

I am building a 3.2 short stroke (3.0L core motor, with 98mm pistons), a modifed S cam, 46 IDA carbs, and Electromotive HPX distributorless ignition. This car has the early SC heads with the larger intakes. Should produce 250-260 HP. (BTW, im stuffing this in a 914, so watch out!)



Good luck

[hugo]

today : i have an european (of course)) 3.2 liter , whith cis from 83 and ssi inox from 2.4 and ansa exhaust whith petronix ignition and jacob coil, it works fine but i have project to put carb ...