Just did a 383 stroker and when I tried to start it the engine was very hard to turn over but after about 10 tries if finally started. If felt like the motor was very tight or it had way to much compression. I had to keep my foot on the gas to keep it running and as soon as I let my foot off the gas it shut off instantly. I don't have a check engine light on and when the engine was running it sounded ok but it had a slight popping from the exhaust like a miss but it wasn't consistent.

I am wondering if the valve adjustment is correct. When I got the motor back from the machine shop the valve covers where on it and they said they had done the valve adjustment. Before we put the intake on I tried to turn the pushrods in the valley with my hand and I couldn't even get a slight bit of movement from them - is that normal?

I am using the GMPP roller rockers and I think the machine shop set them by using the directions in the box which says find zero lash and then turn them another 1/2 to 1 full turn. If they turned them 1 full turn would that cause the problem I am having. Thanks

 

It kinda depends what kind of lifters u are useing. Im now using my stock lifters and i only went about 1/8th to 1/4 turn. If they went a full half turn or a full turn, that could be your problem. I would suggest getting someone to keep it running while you loosen each rocker untill they start clacking slightly. Let it clack for a few seconds then slowly tighten till the tick goes away, then an additional 1/8.
Also, my car did a something very similar when my Opti was bad. You could try that also.

 

One full turn on my set up will open up the valves..... Cause I am using thicker Studs with a different thread on them...

do yourself a favor and open up the valve covers and turn the engine on and adjust them to 1/8 to 1/4 turn. I had mine adjusted to 3/4 turn at one point but when I got stuck in traffic and the temp went up.... the valves began to open from metal expansion in the whole set up... I barely made it to the curb... it had gotten so bad till it cooled down a bit. Now with 1/4 turn they are quiet and smooth.


Marvin

 

Setting valves is what they do for a living, assume for now that the machine shop did their job right and look for other causes. You will sometimes get that popping on fresh cold start. Do you have a tune in there with more fuel?

 

Finally figured it out. It ended up being the opti-spark.