Bistributor info needed for 911 2.7RS spec motor

blau911 · 05-09-2008, 11:53 PM

Installed a 2.7RS spec motor in my 73T. Mechanic advised that it was set up for Petronix pointless ignition. My mechanic advises that I am better off going back to points. He said that I can use a T distributor for the motor since the advance curve is very similar. However, I will be losing some of the power of the motor by doing so. Can anyone advise whether I am better off buying another distirbutor and having it recurved so that I can maximize performance or is the difference negligible?
Mechanic also said that I will be disappointed with the solex cams as they are significantly milder than the original S cams. I have heard otherwise. Any running a 2.7RS spec motor with Solex grind cams?

BURN-BROS · 05-10-2008, 04:14 AM

The 2.7RS has less mechanical advance and more initial making for a peppier motor in the lower rpms. Total adavance is close to the same for both dizzys. I have recurved quite a few to RS spec for customers doing the same thing as you.

blau911 · 05-10-2008, 05:52 AM

Quote:

Originally Posted by BURN-BROS

The 2.7RS has less mechanical advance and more initial making for a peppier motor in the lower rpms. Total adavance is close to the same for both dizzys. I have recurved quite a few to RS spec for customers doing the same thing as you.

So the question is since the curves are so similar, am I better off having my 911T dizzy recurved or just leave it the way it is?

BURN-BROS · 05-10-2008, 06:42 AM

Quote:

Originally Posted by blau911

So the question is since the curves are so similar, am I better off having my 911T dizzy recurved or just leave it the way it is?

Yes, recurving the distributor is the better of the two choices.

blau911 · 05-10-2008, 07:03 AM

Am I losing less power having a T distributor curve since I have a slightly milder cam grind (solex versus S)?

BURN-BROS · 05-10-2008, 07:26 AM

RS spec motors have little in the compresion dept. The Solex cams may help to increase dynamic compression but you will still lose power not having more initilal timing.

911pcars · 05-10-2008, 10:14 AM

Quote:

Originally Posted by blau911

So the question is since the curves are so similar, am I better off having my 911T dizzy recurved or just leave it the way it is?

They're similar in that they curve, but they're different. As Aaron says, the S curve, along with more static ignition timing (5ºBTDC instead of 5ºATDC) provides more advance at lower rpm for increased engine torque. In addition, the max. advance curve on an S-spec distributor is shorter due to more advance at initial timing. The overall advance is shorter by about 4-5º.

It'll work with the T distributor, but you'll be leaving some power on the plate.

Sherwood