5.7L SBC Interference Engine?
Kevin,
Question:
First off, you have a great blog. Very informative and useful.
I own a 1982 Corvette with a 5.7L(350 cu) V8. Is this an interference
Engine?
My timing chain broke, and I’m wondering if there will be valve or cylinder
damage.
Thank you very much,
David
Answer:
From my knowledge the stock 350 is not an interference engine, so you should be ok. If you were at very high rpms or have an aftermarket cam shaft, then all bets are off. A higher lift cam could cause the valves to hit the pistons. Also if you have a set of high compression pistons in the car, same outcome.
The good news is that it’s fairly easy to change the timing chain on the SBC and you should be able to do it in a day and fire it up to see if there was any damage. This will save you the hassle of taking the intake and heads off to inspect for valve/piston damage.
Good Luck,
Kevin
Update…
Kevin,
Thanks for your answer to my last question. I have another question.
My car is a 1982 corvette with a 5.7L V8. My car started with a timing
problem. It would idle, but stall when I tried to drive it. I replaced
the fuel filters and retimed the distributor. Everything was fine for 2
days, but suddenly it refuesed to start. It won’t even turnover. It just
cranks.
I have replaced the ignition coil and module in the distributor. The car
is getting plenty of fuel. Also, the spark looks “weak.” It just has a
small orange spark. I have been told that a HEI should have a good strong
spark.
The only idea i have left is the timing chain, but to change that I am
supposed to remove the oil pain, steering linkage, water pump, etc.
Do you have any ideas what might be my problem?
David
———————————————-
Take the distributor cap off, and crank the engine… see if the rotor is spinning, if it’s not then the timing chain is the problem. More than likely the chain skipped a tooth, and when you readjusted the timing, it ran for a little bit until it skipped again.
If the rotor is turning, then I would recheck the timing. The engine won’t fire, but you can still spin it over with the started and get a reading. If it’s off again, I would still suspect the timing chain, it just has not fully snapped. If the timing is ok, then I would check spark again, check the power wire to the coil for loose connections. If nothing shows up with those checks, then it’s time to check vacuum leaks, fuel issues (fuel pump, float level, or sensors) I can’t remember if the 82 had a carb or had that goofy crossfire fuel injection !
Good Luck,
Kevin
———————————————-
Kevin,
I haven’t seen you post this on your blog, but I thought I’d let you know what I found out. The timing chain did slip.
And the 1982 corvette had the crossfire fuel injection. However, MY 1982 ‘vette has a holley 4 barrel and an edelbrock intake manifold. I bought the car as a project car, and I”m having a lot of fun.
You’re blog is awesome and you do great work. Keep it up!
David
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Posted: 20th August 2006 | Author: Kevin Schappell | Category: Engine
