Thread: Valves?

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Hi i was just wondering if anybody can tell me the symptoms for having the valves in a chevy SB to tight?

Originally Posted by Dean C.

Hi i was just wondering if anybody can tell me the symptoms for having the valves in a chevy SB to tight?

Welcome,it will pop out the intake and exhaust and will have a rough idle and low vaccum.

I have a slighly rough idel, vacuum at 20" 14 degrees advanced, but very hard for the starter to turn over expecialy after it runs for 5-10 min.

Originally Posted by Dean C.

I have a slighly rough idel, vacuum at 20" 14 degrees advanced, but very hard for the starter to turn over expecialy after it runs for 5-10 min.

Your starter may just be getting heat soaked.
With 14 degree's it will be hard for a stock starter to turn it over.

I'm sorry i should have said i'm using a gear reduction starter, good to 11.1 com, and im only running 9.5-1

Originally Posted by Dean C.

I'm sorry i should have said i'm using a gear reduction starter, good to 11.1 com, and im only running 9.5-1

With that comp. ratio and a gear reduction starter you should have no problem
Check your wires,how much cold cranking power does your battery have.

750 cca on batt, due to the rough idel, and having to advance to 14 initial timing, i was just thinking the valves may be over tightened.

Tight valves in your question cause less cylinder pressure therefore making it easier on the starter. No cmpression from the standpoint of cranking pressure. Rethink the amperage and starter overheating type of scenarios.

I just redid the valves i did not touch nothing eles, the car started mutch better ran great , i ran it for about 5 minutes the idel creeped up to 1500 from 1000, i shut it down to recheck timing now the car will not start at all.. any suggestions? my fuel pressure gauge now drops strait to 0 when i stop cranking the motor, 5-5.5 while cranking.

vaccuum leaks? Also, if your fuel pump is mechanical, when you stop trying to crank, the fuel pressure should be zero since the pump stops running. check your battery as well and the output from the alternator.

shouldent the pressure hold, maybe drop very slowly overtime?

Ok i backed off on the valves 1/16 each cleaned the carbs there was dirt in one of the needles for the float. pressure is holding now, drops off very slowly when engine is off. but rpm's jumped up to 2000, can't seem to bring idel down with out it trying to stall, could the valves be to loose now?

Maybe check your plugs to see what they look like?