Whining

[Shane22696]

Hey guys, today I finally got my truck timed right after playing with it for a few days. Well anyway, now it runs better than before, but when I'm in 4th gear (sm465) and give it some gas, it makes a whining noise. It sounds like it's coming from the passenger side. I opened the hood and I sounds like my header may be leaking, but why would changing the timing make it noticeable? Before it was retarted to like 8 degrees after TDC and now it's set to 10 before. Any help is greatly appreciated!

[Shane22696]

Okay, I figured out it's spark knock. I don't understand why it's knocking, it has dished pistons, stock HO heads, and I run mid grade gas in it. It's newly rebuilt so I know it's not from carbon build up. I've tried everything from 8 degrees BTDC like the manual says, all the way to 8 after which I know isn't close to right. It's not near as bad at 8 degrees after, but it just makes absolutely no sense to me how a mostly stock motor would spark knock THAT BAD on mid grade. Were the HO motors required to run 93 octane from the factory? It has the 601 heads with the 53cc chambers so I know the compression ratio is decently high.

[Shane22696]

Am I right in thinking that adding EGR back on the motor would help with the detonation? I would have to swap intake manifolds for the 3rd time this month but if I can get the truck to run better it would be worth it. I have a GM aluminum intake with an EGR provision on it. Can someone please tell me how to go about hooking it up?

[Mrknowitall]

is the distributor clocked correctly? is the cam degreed correctly? going from 10btdc to 10atdc is CRAZY.

i have flat top foregided pistons with 327 heads running 9:5:1 @ 13 btdc i believe. idk i havent checked timing in a long time.

if shes knocking, READ THE PLUGS. post pics of results, a spark plug tells no lies. i reccomend u change NOTHING until u read the plugs.

whinning usually isnt associated with pinging, thats odd to me, does ur trans have a highway gear switch?? im not familiar with that transmission.....

[Shane22696]

Distributor is clocked right as is the cam, and the plugs look good. I just said whining because I wasn't sure how to describe the noise but my dad's a mechanic so he figured it out. I know the timing change was crazy, I was just doing it to see if it helped. I have it set back to 6 btdc now until I can figure out how to fix it. Thanks for the reply!