3.2 engine rebuild and mod advice

[911st]

100,000 miles and only burning a quart every 500 miles is still a good motor and that level of oil burning is very much acceptable.

I would not toutch anything unless you have a bunch of leaks and need to do a reseal. Spend you money on exhaust and suspension.

Our P&C's are almost indestructible and I am not an exert but with that mileage I would not disturb the pistons unless you are going to become a track king and or run a high rpm chip. Then the reason to touch them becomes the want for stronger rod bolts. To me the risk of braking a fin or not getting a good seal on the new rings is not worth it.

There is really nothing wrong with the stock rod bolts if you keep close to the stock rev limits.

Again, a quart every 500 miles is considered in spec. Especially you use the car for short runs around town. In a motor like ours we will always get a little oil burn on first start up.

You could get someone that really knows 911's and has and educated touch to check the valve guides by side loading the valve stem and check the play and have a leak down done.

I would not distrub a 100k motor without cause.

[jschauer]

good point that it's not enough oil burn to really disturb anything. There are zero leaks. And at new, the factory said 750-800 miles per quart was within spec. I'll be waiting till it burns like a quart every 3-400.

[scarceller]

Here is my 3.2L setup:

Euro PCs
WebCams 20/21 grind
ExtrudeHoned intake manifolds (flowed intake)
SSIs with 2in2out M&K pipe

Stock Motronic with stock AFM
Car pulled about 223HP at the wheels on the dyno

This setup required a custom tuned chip to get the most out of the mods but the car is a screem with incredible throttle response via Steve Wong chip.

[porschenut]

Originally Posted by scarceller

Here is my 3.2L setup:

Euro PCs
WebCams 20/21 grind
ExtrudeHoned intake manifolds (flowed intake)
SSIs with 2in2out M&K pipe

Stock Motronic with stock AFM
Car pulled about 223HP at the wheels on the dyno

This setup required a custom tuned chip to get the most out of the mods but the car is a screem with incredible throttle response via Steve Wong chip.

What kind of gas are you running in it? I was under the impression that Euro pistons yielded too high a compression ratio to use with pump gas, unless you twin plug it and retard the timing.

[scarceller]

Originally Posted by porschenut

What kind of gas are you running in it? I was under the impression that Euro pistons yielded too high a compression ratio to use with pump gas, unless you twin plug it and retard the timing.

I run 93 octane all the time and the car runs just fine. I also have driven the car at WOT from 1500RPMs to 6800RPMs (about 25 runs) while tuning the WOT Fuel Map and have never had any issues.

If you are still concerned, ask around to folks like Steve Wong and others who have more experience with this type of setup.

Good luck.

[rickdm]

IMO other than a performance chip and exhaust I would not do any performance mods to the engine that will bump you out of class. On the track the small gain in power is not worth it. I would focus on durability upgrades. Losing weight will give you a more significant performance upgrade. Even under track conditions these engines really don't wear out, they mostly get damaged by missed shifts, so anything you can do to give yourself a higher rev limit before damage will pay of. This would mean new rod bolts, performance valve springs, and titanium spring retainers. With this you could safely hit 8,000 rpm without hitting the valves (I have already tested mine ;-). FWIW my 911 is an '87 and I had Nickasil cylinders.

[scarceller]

Originally Posted by rickdm

IMO other than a performance chip and exhaust I would not do any performance mods to the engine that will bump you out of class. On the track the small gain in power is not worth it. I would focus on durability upgrades. Losing weight will give you a more significant performance upgrade. Even under track conditions these engines really don't wear out, they mostly get damaged by missed shifts, so anything you can do to give yourself a higher rev limit before damage will pay of. This would mean new rod bolts, performance valve springs, and titanium spring retainers. With this you could safely hit 8,000 rpm without hitting the valves (I have already tested mine ;-). FWIW my 911 is an '87 and I had Nickasil cylinders.

Rick, I can see your point here. Not really sure what diffrent cams would do in terms of HP? By my bet is your not going to gain all that much. The best improvement is the exhaust but the SSIs are not the best choice for the 3.2L, the are to small and you are better off with some bigger headers. My car came with the SSIs and I'm looking around for a better Header solution (bigger) that still supports heat.

Bottom line is that Headers, new pipe and chip should be a very good improvement. Then +1 on dropping pounds from the car.

[rickdm]

Sal, my car came with a Ruff Euro pre-muffler and a Ruff twin outlet muffler. I don't know about the power increase, but it sounds great. The previous owner paid $2400 for the parts in 1996. My SW chip is tuned for this exhaust. As long as I put the factory chip back in I can pass the smog inspection without the catalytic converter.

Good luck,

[911st]

Rick,

There is a dyno compairison running around that has your comb.

A stock Carrera dynoed at 217HP, the RUF muffer system at 229.2, and an SSI with sport muffler at 229.9. at 6000rpm.

Matched the SSI/Sport everyware except right at 3500rpm where stock/RUF/SSI-sport was 115.3/118.1 / 124.6.

[rickdm]

Wow, thank you, I had not seen that before.