race911

Should be easy enough to find out from the build sheet, or a casual inspection.

They're fine, for the most part. Until you're the unlucky sucker who gets a set that came from a batch that had a QC issue.............. Current ones should be bulletproof. Right, engine builders out there? Not that you'd get anything more than ____ off from the manufacturer themselves.

Geoffrey

Aase springs have been used for a long time in many engines. When I see broken aftermarket springs in a basically stock engine it is usually a result of an overrev where the spring has coil bound and broken. This obviously will not control the valves properly.

Looking at the leakdown, I would say that you need to investigate cylinder #1 because it has a significantly higher leakdown than the other cylinders. Do you know where the leakage was from? Piston rings, intake, or exhaust valves? That is the most valueable information from a leakdown test, not the raw number which can vary by engine temperature and method of using the leakdown tester.

race911

No doubt. However, when I notified Steve of this (he did the engine for the previous owner).........the first comment that came back was to the effect of "not again, they had some problems during that time and this is the second time around on this engine."

Make of that what you like.

rabjohns

Are you talking about my car/engine that this Steve did?

rabjohns

This leakdown number was from the PPI I did when I bought the car. At the time I was told 10% was acceptable.

After the recent leaskdown (post problem) he said the leak was "from the top" but was not more specific. I will let you know what I find out.

I also checked my traqmate logs for every session I have run since I have owned the car and found no overrevs. Could it have been over revved before I bought the car, survived 8+ track hours and then exibited this symptom?

Cheers

David

rabjohns

One more thing. We roughly calculated that we run about 45 miles per hour on track. Thus 5374 (miles since re-build) / 45 = 119 hours. How often should you re-build a stock, unchipped, 964 engine used to race? Seems like it might be due.

race911

No, the yellow faux RS Steve Weiner did for Kim Ouye. Phenomenal build quality; sometimes you get caught out by an aftermarket vendor.

race911

I absolutely tortured (along with others) the factory original engine in RSA #1 from 2000-3. 5K track miles, 42-7K on the odo; it was never street licensed. This thing was stock down to the catalytic converter, no second cooler, nothing. Crappy maintenance. Ran it into the ground from fire-up on cold days, routinely ran it past 250 degrees at Thunderhill/Willow/Buttonwilow when it hit 100 ambient. When I pulled it apart? Looked just fine. Never bothered with a leakdown since I figured it was only going to be a core engine. But whenever I put it back together, pretty much all it needs is guides if I want to do it on the cheap.

Geoffrey

In the competitive 964 Cups, we rebuild the engines about every 100-125 hours. I think you can go longer, however, at those hours, the heads need refreshening at a minum. This assumes you are not using factory rod bearings though. They don't last.

rabjohns

Very helpful info, thanks guys.

Indycam

Ok , top = top end .
The top end is leaking .
I guess your exhaust valve is not so good .

rabjohns

So if I do need an engine rebuild......how much (professional shop, racing spec)?

Feeling sick

rabjohns

The last rebuild used rod bearing set 930 103 147 15.

Indycam

You might just need to fix one valve in one head .

Geoffrey

We, along with a number of other shops had issues with those rod bearings about 4 years ago and no longer use them.