I just had a 383 built a couple of months ago and my engine builder told me use a high volume not high pressure oil pump.The clearences are main-.0026 rod-.0021 no oiling mods were done to the block also using a stock 89 firebird oil pan.I used a melling M55HV and used the spring for normal pressure (there was a high pressure 60-70psi spring installed and it came with a normal 45-60psi spring that I changed it to).Now some times when I punch it I get a weird noise a cross between clothes pins snapping and a sound like when your sucking the last bit of soda from the bottom of glass through a straw.It doesnt happen all the time only some times.Think I might be sucking air in to the pump?Would I even here any thing if was air getting in the pump?

 

There is no way you would hear the oil pump sucking air, what you describe sounds like detonation and you best deal with it as soon as possible. If you are running 10.4:1 compression as you mention in your sig then you best feed your beast high octane fuel! At least retard the timing a couple of degrees, that will help.

Detonation is an engine killer, a small amount can damage parts in time, a large amount will break something, lose a head gasket... Something bad and probably avoidable.

 

I dont think its detonation but the next time it happens Ill check to see how many knocks counts the ECM picks up.I allways put super in it and the timing is isnt all that agressive 32* at max.Its really a weird noise to describe. Any other ideas?

 

if the engines together and installed i wouldn't worry about it, keep the rpms below or around 6000 and you should be ok. i also believe what you hear is preignition or detonation

 

E-Man,

Ed's the man. Don't sweat it now. At least you went with the lighter pressure relief. The only time I've used an HV pump was with a 9-quart pan, gun-drilled crank, oiling nozzles up front, and full grooved bearing shells. Keep a close eye on pressure. In your case, you might want to use a slightly lower viscosity than you normally would, just to aid in drainback. Did you install screens in the valley, or seal/paint the inside of the block?

 

No nothing done to the block and Im not really that troubled by the drain back issue the crane blazer roller rockers Im using dont really let that much oil go to the top end.It was just after reading alot of posts where alot of people said not use a HV pump got me little worried about what im using. Also I took a quick scan earlier today and I was getting some knock counts so I guess Ill have to keep my foot of the gas till this weekend when I have time to do some tuning.