How do I check for broken head studs on 2.7?
 

I'm about to buy a 270,000 mile '76 911 with stock 2.7. Engine was rebuilt with all the best stuff-correcting all 2.7 issues-at 140,000. Owner has told me of an apparent exhaust leak that no one has been able to figure out, and I am worried that the sould might actually be a broken head stud. Strange thing is, engine is strong,160-175 psi on all 6, and oil reads 50-60 psi at 180 degrees. Am I just freaking out here, or do I have valid concern? What would you all advise me to look for, and how do I check it? Sadly, I can't take the thing to a spcialist for a pre-purchase inspection because I can buy it over the weekend, and no shops are open. Please advise.

Aron944,

When you say the engine was rebuilt "with all the best stuff-correcting all the 2.7 issues-at 140,000", what was actually done, what do you mean by the “best stuff”? Were either new or reconditioned, line-bored, time-serted cases used? Were raceware head studs used? It’s critical that you know all of this before going any further.

The reason I ask is that 130,000 miles is certainly enough time for something to happen after a ‘corner’s cut’ rebuild, and if the cases are the original cases, regardless if they have been line-bored and time-serted, those cases needed replacing at 140,000 miles due to metal fatigue, which is why the studs started pulling in the first place.

Be careful; I have lived this nightmare with my first 911 - a 76' CIS 2.7.


Matt Holcomb
www.holscope.com/74Carrera

Again I remind folks that I've only dealt with Porsches for about a year now and someone else will have to comment but: I think you can do a compression check with the engine COLD and tell a lot. At this time, cylinders, heads cases and studs will be small and most likely to pass air. Once heated up, those parts expand. Again, it makes sense that if you catch them COLD with a compression and leakdown test, it might be obvious. One Cylinder might hardly register at all. You might even hear the hiss.



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'83 SC