1990-964

Well today I got the inevitable news that a rebuild is in my near future. Leakdown @ 18% enough so that it is starting to affect how the engine runs. Not sure if I should run it till it dies or get to it now. I will go 3.8 since I am going to need Ps & Cs anyway. I've got a good local builder that has his own dyno and has done many of these and can easily get 310-320 hp @ the wheels without getting at all radical. With that much it should be able to run with the late model cars. It is an appealing scenario but the cost of a new engine is a big pill to swallow. Let the opinions begin.

race911

Nice to hear he can get that amount of power to the rear wheels when the engine Steve Weiner built for Kim in the yellow car has pretty much everything known to man, and is about 315 at the crank.

Unless you've got a specific motorsports purpose, you're not going to notice it all that much. My best estimate is 1-1.5 sec/lap at Thunderhill.

Colin 90 C2

Why do you think you need new p&c's? Could be rings or valves. Did you identify where the air was going?

BlueHeeler

I am no sure about 'everything known to man'. Geoffrey’s motor is 322wtq and 412whp.

https://rennlist.com/forums/964-foru...ngine-2-a.html

1990-964

have not taken the diagnostic time far enough to determine the exact location of the leak. But at 160,000 miles I am not going to tear into the engine and not at this point do an overhaul. The pistons have already been re-rung once and with the original valve guides in there I don't want to take half steps that will cost more later.

wellcraft290

on a leak down you should be able to tell what happened to the motor.
Air coming thru oil fill means rings
air coming thru exhaust exhaust valves
air coming thru intake intake valves

This i sthe whole purpose of a leak down test

stevepaa

at 160K miles, I redid mine. Tore it down to the crank. Did not need new P and C set. Just a good valve job and decking the cylinders.

1990-964

The actual need for the Ps & Cs will be determined after breaking it all down but I will let the opinion of the mechanic I am trusting with the overhayul be my guide. Besides if I am going to sink that much money into this car then I want to be sure that it will be very solid for many years to come. Also if I do end up needing to replace them then I feel like it would be nice to bump the displacement and get more power and torque out of it if the cost is relatively similar.

1990-964

That is interesting. I would think that there is quite a lot more power to be had if everything known to man had been done. There have been many articles written about early smaller displacement engines that have bee tuned to higher horsepower than this and are still streetable. Is the 3.6 lesser in the power potential department? Hard for me to think so. With the right approach I want to think that the power goals can be reached, but we'll see.

Vifa

What is the mileage of your car?

race911

To be more clear, with a streetable smog legal in California engine. I just throw this build out there as a datapoint from a known builder we all admire and respect.

N51

And may I add to your clarity? Three hundred twenty to the rear wheels and non-radical is...interesting. So many have tried.

1990-964,
Care to give us a quote and specifics on the build?
Care to name your builder?

This could be fun.

BlueHeeler

I am sure your data shows a great build. As far as 'everything known to man', that is not true. That was my single point.

FWIW I have Steve's parts are in my engine. That is real admire and respect.