Compression and Leak Down numbers are in

[Dan Morton]

After noticing more blue smoke from my 1970 911T, I had my mechanic do a compression and leak down test. Unfortunately it didn't do so well. Here are the results:

#1 55 - 17%
#2 70 - 15%
#3 70 - 22%
#4 100 - 15%
#5 105 - 2%
#6 100 - 19%

All leakeage was past the rings. The car has 95k miles and probably has never been rebuilt and still has the 2.2.

Here is where I stand:
1) Get a second opinion - I know and trust my mechanic but I should probably have this done nonetheless.
2) Buy a complete rebuilt engine.
3) Spend the $$ to have it rebuilt - Estimate is anywhere from $4-8k depending on condition of pistons and cylinders.
4) Rebuild it myself. I am somewhat handy with a wrench but do not have the time or energy to do so myself. Although maybe with Wayne's soon-to-be released book, I will change my mind once I see how easy it is

Ideally I would like to swap this out for a rebuilt engine. Any recommendations on shops to purchase from? ( I've been reading all the recent threads about a certain company in CA so I will form my own opinion with regards to that shop).

I'm not looking to break the bank on this project. The car still starts and runs well but I just want to drive it without the smoke screen.

Thanks for any help!
--Dan

[pwd72s]

Dan...ouch! But you're wise...you seem to realize that a rebuilt engine is only as good as who rebuilt it. I'd suggest you get a copy of Bruce Anderson's 911 handbook...read it all. There are several ways to go with your 2.2. Do you plan on keeping your 901 gearbox? If so, you don't want to go too high up the torque/horsepower range. Going to street the car mostly? If so, I'd opt for a mild displacement increase, go with E cams for a better torque curve. But tons of options open to you. The early 911 is a natural for hot rodding...with it's ease of parts interchangeability. Get Anderson's book, have a ball reading it!

[nhromyak]

Find a good used 3.2 or 3.6 if you have the $.

Then swap the motors yourself.

Rebuild the OEM when you have $ and time.

That's (3.6) what I want to do. When my trusty 3.2 (130k) needs it.

[pwd72s]

See Dan? Like I said, TONS of options open to you! THe choices are almost as vast as the million and one ways to build a small block Chevrolet V-8!

[john walker's workshop]

something's odd here. a cylinder that only pumps 55# should have a LOT higher leakage than 17%. more like 50-60%. did he check for tight valves after finding such low readings? was the test done with open throttles? with closed throttles on a carbed, or EFI engine, you basically create a vacuum when the piston tries to suck in air, and then the vacuum is compressed as the piston comes up, resulting in a low reading.

[Early_S_Man]

Dan,

I vote for doing a rebuild yourself ... with a significant power increase by boring out your cylinders to 85 mm and getting JE forged pistons with 9.5:1 compression and valve-relief pockets, an then installing early-S or GE-60 cams. Webers would be preferable, but 32 mm venturis and the appropriate jets can sometimes be found for Zeniths, too.

The late '60s factory 'rally' engines used 'S' cams and pistons with stock 'T' heads and ports for a significant bottom-end torque increase, and they only lost 10 hp off the top end. The above 'package' should be good for 160 hp and a much more 'fun to use' engine ... your valve sizes are already the same sizes as used thru the 2.7 engine, including the RS 2.7!

Get Bruce Anderson's Porsche 911 Performance Handbook ... and look up the 901/30 engine! Add 10-12 hp for the 256 cc displacement increase ... and you find yourself at 2.4 'E' power level! Talk to EBS about boring your cylinders and the JE pistons , and throw your head work into the discussion for a final price. I think you can do this rebuild and enhanced engine for less than an exchange rebuilt engine!