Any Ideas

[tomireland]

Hello Lad's & Lass's, I'm new to this forum so I'll quickly introduce myself, My name is Tom, I'm 21yrs old and have been living/working in Georgia USA for 2yrs now as a heavy vehicle mech, last year I bought a 1975 911s (which I think has a 2.7i engine although the engine serial # doesn't appear to be in the correct place so I'm not 100% certain), a car I have dreamed about having since I was a kid although never thought possible. The car needed a little work when I bought it, I have replaced the front suspension pan, both upper & lower panel, as rust had set in underneath the battery and various other odd's & end's! Anyway I'll get to the point I recently developed a new problem, I went for a blast at the weekend and had a slight shifting incident, I changed from flat out in 3rd to 2nd (as opposed to 4th) mid corner causing the car to go sideways and the engine revs to go off the clock for a second since then the car has been missing on one maybe two cylinders, I have a compression test kit to check to see if I have kissed a valve although I've not had the chance to check it out, just thought I'd ask to see if anyone has had similar fault in the past, any advice would be greatly appreciated!

Cheers

Tom

[dtw]

Bent valves. Stop driving the car so you don't drop a valve and really dork things up in there - check compression ASAP to confirm. If you have compression losses confirming bent valves, you'll be wanting to order Wayne's book and the Bruce Anderson 911 engine book. This forum will be your friend...

[Jandrews]

Yes, you are not the first one to violently introduce a valve to a piston. I shifted from "flat out" in 4th to "just plain flat" in 3rd (on a racetrack) at about 130 mph. I bent 8 valves in the process, and my car ran similar to what you are describing afterwards.

Time for that top-end rebuild, and complete bottom-end inspection.

Good luck. You are in a good place with this board to make this an enjoyable and effective repair.


JA

[ChrisBennet]

Whatever you do, don't tear the bottom end apart until you get Wayne's book.
The bottom end on 2.7's requires expensive machining if you unbolt the case halves.
Have fun!
-Chris

[kenikh]

Here's the link to the best books you'll ever buy:

http://www.101projects.com/911-Rebuild/index.htm

[tomireland]

I'll check the compression this wknd, already have the books so I'm good to go, I'm currently living with two other mechanics, all eager to drag the motor into the kitchen and tear it to bits, will keep you updated on the progress, I've no doubt there will be a few questions coming your way too!

Thanks for your replies

Tom