vet69

Hello All,

I (or more correclty my neighbor) just solved a 3 week mystery. I got a new corvette about a month ago, had it for a few days drove it to the dmv to get registered, idled a little fast but not bad.

Then I changed valve covers to this set that looked great. they were supposed to be original for chevy small block.


after that the car would not run, it was only hitting on a few cylinders. the guy before me had put on a holley 770 double pumper and edelbrock air flow manifold. I had to make an makeshift air cleaner because of lack of clearance from these high performance pieces.

after a week of trouble shooting, I had the original stock Rodchester carb reworked, and put back the original manifold. still did not work, I had guys setting the timing all over the place, still did not work. I took off the valve cover to see what was going on it worked, put it back did not work.

apparently the cover was holding the valves open so no compression. Who would have thought that.

has anyone heard of this problem?

Vet69

Roco71

I had a set of aftermarket tall valve covers that the ends of the rockers were just barley hitting the side of the valve cover. It was just enough to create a ticking noise like a rocker that needed adjusting.

MrJlr

Wouldn't you have noticed a lot of pressure when you tried to bolt them on?????

tfi racing

Stock,stamped steel rockers?

vet69

yes but I thought it was the cover being a little warped just cinched it down with the nuts.

yes all stock, I think the cover pressed the rockers depressing the spring on the valves enough to keep them open

Dustup7T2

I took a look at your profile to see if there was any information on your wrench-twisting experiences but I didn't see any.

With only 4 posts so far, I won't jump to conclusions. For your car's sake, I hope that when you run into any interference when disassembling or assembling automotive parts and pieces, that there may be a reason for that. Putting the big arm on stuff isn't always the answer. That's a nice looking '69 you have.

I wish you well and please feel free to ask the CF about any future issue if something like this happens again. One of us may have already been there and done that.

Good luck.

LeMans Pete

Where did you get those valve covers? I have not heard of aftermarket L46 valve covers causing interference with the rockers, especially enough to compress valve springs.

What did you do for a PCV? Do you have a picture of your engine bay with it all assembled?

razman

PCV was my very first THOUGHT also....is your crankcase "breathing"???? Rick

MelWff

the covers may have drip rails which way did you install them the drip rail should be over the pushrod end not the valve end.

bondoboy

Do you have stock or aftermarket roller rockers? Sometimes they require taller valve covers to fit.

JimT

Same problem with my stock 350 ('72 with new valve covers). I was going to Fla in my car - an 8 hour drive - and I decided to tighten up everything under the hood. My valve covers must have been too close to the valve train and I noticed a noise. Determined that the valve covers were touching the rocker arms, so I purchased the thicker valve cover gaskets - almost 1/2" thick - installed them and resolved the issue. You should check you local hotrod shop for the gaskets.

super-bee_ski

Gee
Sorry to hear that.