cooler plugs?

[Eggman]

I am currently using Autolite #65 plugs in my 360.I can't use 87 octane fuel due to detonation and I was wondering if using lower heat range plugs would help?

[ehostler]

I think that we would need to know more about your engine, before anyone can make a recomendation.

[Eggman]

O.K. here goes.360 bored .060,flat top hyperutectic pistons,2.02-1.60 valves heads shaved .050 chambers hogged out,.212-.216/ .447-.447 cam,eddy performer intake,670 street avenger carb.M.P. distributor,MSD blaster 2 coil and 8.5 mm wires,MP chrome ECU.

[racintracy]

With the KB's you might have close to 10 to 1 compression so that could very well be why you can't run 87 octane fuel. Why don't you just run 89 octane? That might do it. You could also retard the timing some but that will cost you performance and fuel mileage.

[ehostler]

What is your initial timing set at? What is your total timing at 2,000 RPM?

[Eggman]

Initial is 8 degrees,28 at 2000

[jelsr]

Not a SB person but 28 total sounds slow to me. If your plugs are not showing a tan color or darker they may be too hot.

[rumblefish360]

Originally Posted by Eggman

O.K. here goes.360 bored .060,flat top hyperutectic pistons,2.02-1.60 valves heads shaved .050 chambers hogged out,.212-.216/ .447-.447 cam,eddy performer intake,670 street avenger carb.M.P. distributor,MSD blaster 2 coil and 8.5 mm wires,MP chrome ECU.

This part of the combo, the pistons. How far down the hole are the pistons?
Zero deck?
What gasket is being used? (How thick?)
Whats the total amount of cc's in the heads chamber?
I'm looking for the total actual comp. ratio.
Also, whats the cam centerline?

[Eggman]

The engine is an 86.We used the stock rods and shaved the heads because the pistons were deep in the hole.The cam has a 112 degree centerline and was installed straight up.

[George G. Leverette]

The 60 over bore size probably causes a heating problem with the 1986 engine which contributes to the detonation. High compression ratio and timing all indicates that preminum gas should be used. Cooler weather will lessen the chance of pinging. A performance built engine is not noted for economy, other parimeters will have to be changed to meet th 87 octane goal.

[rumblefish360]

Well, George beat me to it. Also I'd like to add, the head milling probably pushed the octane requirement up just enuff for 89 octane.
The cams centerline is wide. This points to a cam ground for a low comp. engine. The wide centerline helps keep the comp. ratio (When running) up instead of bleeding off like on a 110 or numericaly smaller centerline.

What head gaskets are being used?
You can get thicker gaskets form Fel-Pro. There PT-8553 (I think it is) is .054 thick. Theres also Cometic for gaskets. A bit more in price, but an excellent gasket.
The slight drop in the ratio can/coulod help. Your going to have to know where the piston sits in the hole and how thick your current gaskets are now before you order one. Otherwise, you could be wasteing money and time on a gasket swap.

[Eggman]

I think I will try mid-grade fuel and if that doesn't work i'll quit trying to be cheap and run high test.This cam by the way was reccomended because of the weight of my truck-about 4000 pounds.