Recurving Bosch Distributor to suit a 2.7S conversion
 

Hi,
I'm in the process of converting a 2.4T stock engine to a 2.7S.
Starting originally from a 2.4T engine, my components are:
90mm mahle NOS cylinders
90mm J&E 10.5:1 pistons (running on high octane U.K. fuel).
2.4T crank
S cams
2.4T cylinder heads ported to 36mm so far
Original Bosch 2.4T distributor
Zenith carbs with 34mm venturis, 145 main jets, 60 idle, 185 air correction jets.

Please can anyone give me advice on the spec for recurving the distributor to suit the 2.7S engine.
Cheers,
Rob.

You don’t need to recurve that distributor at all. If you look at the original factory workshop manuals you’ll find that the 72-73 T,E,and S distributors were all the same. Just time it to give you 30-35 degrees total advance with vacuum disconnected at 6000 RPM.

The RS curve is almost identical.

I believe the timing for the S and Carrera is 30 degrees. Especially with 10.5 to 1 CR I would not go 35 degrees.

advance
 

I would have it recurved with a spring change and keep the total advance at 28 degrees or less for the compression.When the early 911S ran with high compression the octane was around 100.Fred

Thanks Guys.
That gives me plenty to go on.