3.2 vs 3.0 Heads.............

fred cook · fred cook's Garage

How much additional horsepower would 3.2 twin plug heads add over late 3.0 (SC) twin plug heads? I'm trying to finish putting my shopping/wish list together.Thanks,

Flat6pac · 09-02-2010, 05:05 PM

They will definitely breath better and thats where the power is. With the Carrera heads you will need the carrera insulator spacer from on top of the intake side, all Carrera have them. You need them to give you the correct height as the heads are shorter on the intake.
Bruce

Jim Dorociak · 09-18-2010, 10:36 PM

The 3.0 in 78/79 had intake port sizes of intake 39 , exhaust 35. the 1980-83 had I 34, E 35. The 3.2 engine had I 40 E 38. The Carrera heads probably will not need any porting as most guys was E36 at least. Jim

aws · 09-19-2010, 08:02 AM

The 3.2 heads in stock configuration will flow 260/265 cfm. This can be increased to 270/280 cfm with very little clean up work. This number is very close to the factory 935 heads. I do not have numbers for the early large port 3.0 heads, the later small port 3.0 heads flow 230/240 cfm in stock form.
aws

carslutt · carslutt's Garage

id like to see some flow #'s for stock 78-79 3.0 heads from an SC motor.

KNIGHTRACE · KNIGHTRACE's Garage

send me a stock head with 5 angle cut and I can out flow them by 15% I will help any Pelican person for free. I challenge anyone to out engineer me on heads. 307cfr at 1 atm. William Knight knightrace@mac.com

KNIGHTRACE · KNIGHTRACE's Garage

heads in stock

nardo911 · nardo911's Garage

Hello
I have one 3.2 stock with spag OBX and I would like to put an injection CIE above I would like to have information above how much we obtain from Hp

Manasie · 10-08-2010, 08:08 PM

Anybody knows William Knight's number? I bought a 911 years back with a really wicked suspension set up and had a local Porsche shop here in Chicago set up my other 911 and it's not even close to my old one.Wish I never had sold it.Anyway, has anyone dealt with him recently to tell me if he still does this type of work and if anybody has dealt with him,what has their experience been? I'm about to throw about $15k in my SC and kind of need some help with suspension mod's and engine work. Well I hope he still does because my last 911 I had bought from him was a SC with a 3.6 mod with some custom headers, on the street it whipped ass and auto crossing.
Any help would be appreciated. Thx

KNIGHTRACE · KNIGHTRACE's Garage

Hi Manasie, I am in business still, just email me at william@knightrace.com Be happy to help you.

fred cook · fred cook's Garage

Bought a set of 3.2 heads that have been ported slightly, twin plugged and are equipped with racing springs and titanium retainers. I also have acquired a set of Mahle 100mm 10.3:1 pistons. Assuming the use of the SC cams, the CIS injection and XRi direct fire ignition, what would be the optimum compression ratio that I should run? I can make some adjustment to the C/R by shimming the cylinders, but would like to run slightly over 10:1 if possible.

Thanks,

Walt Fricke · 10-10-2010, 06:21 AM

Fred

That is an unusual design you are pursuing. Twin plug, high RPM, large flow heads, high compression pistons, larger bore, and a crankfire ignition, but CIS and CIS cams?

Is that to give you a lot of grunt down low?

Walt

fred cook · fred cook's Garage

Walt,Exactly. I believe that with the additional displacement, increased compression and improved ignition, this should be a great street engine with lots of low and mid range torque. The CIS on my (almost) stock 3.0 SC engine works very well and pulls quite strongly up to 7,000 rpm. I don't know what cams or other internals are in this engine, but since it works well as is, I can't help but believe that it will be that much better as a 3.3 liter. Also, it it doesn't work out as anticipated, it will be little trouble to replace the cams and induction with higher performance alternatives.