engine defects question for model years.
 

buddy of mine may buy a porsche (used), and i am wondering , what were the major problems with different models. if he 19XX year porsche, what in the engine will have to be fixed.

any help here would be apprciated.

78-86? 911
87-89 911
89-94? 964

78-86 watch for broken exhaust headstuds, and look for upgraded chain tensioners.

86-89 check for broken headstuds particularly exhaust studs again, and there is some premature valve guide wear.

964, I have no idea on earlier models I think there was a cylinder to head leak problem, but I could be wrong.

I would highly suggest getting both of Waynes books, 101 projects for your 911, and his 911 engine rebuild book. The other book that would be helpful in looking into problem issues with model years is Bruce Andersons book Porsche 911 Performance Handbook. Before buying a car make sure that you have a Pre-Purchase Inspection (ppi) done by a qualified Porsche Mechanic. The books and PPI will save you 10 times the cost of finding out after the purchase.

You can get both of Wayne Dempsey's books here:
http://www.101projects.com/Porsche-101/index.htm
and I am sure pelican carries Bruce Andersons book

Rich

all valve guides
all head studs older is more likely to have an issue
'78-89 disintegrating rubber clutch centers
'90 up dual mass flywheel
'89-92 head gaskets
'89 up cyl base seals
'78-83 exploding air boxes, earlier is more likely to have an issue
'78-83 chain tensioner issues
'78-80 oil pressure issues in track use

1982 930 - look out for stupid previous owner's crummy rebuild (ok, maybe this is just my experience).

aluminum cases and power
 

I keep reading that the early aluminum cases, 66', were a pretty good lot. Few case problems. Is there a way to re-build one of these early 2.0's, and increase the performance substantially without going bankrupt? I've been told that the opportunity costs are best served by getting a 3.0 or 3.2 for transplant. Is it most peoples experience that the cost of building-up one of these older engines is just not worth the effort and money? Any advise on re-building the 66' greatly appreciated. I know that there's no substitute for displacement. but with nostalgia in mind, and trying to keep the original pieces together. ?? Thank you in advance!

The 3.2's also have a problem with rod bolt stretching, then nut backing off then .................lots of noise, then empty wallet.

I thought mine was safe, made it to 95K ('85 Targa) drove it another 1500 miles or so and then noise "appeared" I drove the car sanely by the way.

My prior research suggested that if the engine was cared for and lasted 'till 95K I should be alright.....................Guess not