j par
Well-hung Member
I don't think I've had the RPMs up over 4000 and really probably only up to 3,000. It's built and balanced to do way more than that but it's just kind of a fun driver truck I have my duster for all the insanity...
Yes my intention was to have dish pistons and domed heads.. keep the compression low and use cheap pump gas and drive the hell out of it with the AC ah blowin......I just think you mis-used the 8553. Be thankful you close to home. 1008's will serve you better but will push the compression up just a tad more.
Did you have the heads resurfaced before assembly ? (not reading 52 pages for that info lol) Just sayin', if they were raised in the center even .005 that wouldn't help the 8553's out at all eitherYes my intention was to have dish pistons and domed heads.. keep the compression low and use cheap pump gas and drive the hell out of it with the AC ah blowin......
There were the heads that came off of my duster when I put the speedmaster aluminum heads on my duster. They had been previously machined...Did you have the heads resurfaced before assembly ? (not reading 52 pages for that info lol) Just sayin', if they were raised in the center even .005 that wouldn't help the 8553's out at all either
You are correct, they would help lower the compression a little. I've never lost a 8553 head gasket, but I like them on stuff under 180 psi cyl pressure. I have them on half my small blocks now, but most my stuff is nowhere near even 180 psiActually the 8553's I was thinking that they would be a little thicker and lower the compression...
It certainly wasn't thinking they would be a weak link...
A forged piston not likely...
Again there's no signs of detonation...
That’s a lot of cranking compression. What fuel are you using? What’s the timing CURVE look like? And how do the plugs look?
16 initial and 34 total is not the curve. Those are just numbers. How fast is the curve and what rpm is you total all in at?I was using 91 non ethanol but have been backing that off just to 87 as that's what I built it for at about 9.3:1 compression.…
As I recall I was at about 16 initial and 34 all in with no vacuum advance.
The plugs were looking great until this happened..
Again everything was working running and operating absolutely perfect until this happened..
The tops of the Pistons in the spark plugs weren't showing any signs of detonation....
I don't know the curve and all in at 34...16 initial and 34 total is not the curve. Those are just numbers. How fast is the curve and what rpm is you total all in at?
Sorry I'm not going to let the guru's get in my head... Seen it happen to many times.View attachment 1715982825
J par, THAT ^^^^ is about the biggest sign of detonation I’ve ever seen.
I've seen the signs of detonation on my duster when I took these heads off of it the first time to have the 202 valves put in them. There was kind of a blistering in the carbon on the tops of the Pistons. I have none of that here... And I swear not even my duster with flat top pistons have this much compression but then again I had a much more radical cam in the duster at that time...Usually with detonation, the spark plug insulator will generally have "metallic" looking specs on it. Detonation will cause the ring to overheat, and it can freeze up in the landing. Piston will show as well. Detonation is like most things, mild to wild. Just want to make sure you don't miss the mild symptom or it can go wild .... LOL
You're fine I just I'm not going to let it get to me that much I'm going to clean up the mess put it back how it was and see what happens...Concern is all it is Jpar, not trying to bust your balls. You built a bad *** truck and I’d rather see you enjoy it then have to rebuild it. Thanks for calling me a guru. That puts me in good company. I’ll watch quietly.
that's exactly what I did too; and away we went..... and that was 20plus years ago..Now I'm going to chalk it up as bad luck and again clean up the mess put back together and continue forward...
The odd part was some of them did some of them didn't so it's leading me to believe I have distributor problems as well..
I never use the vacuum on the distributor I had in there. I just purchased a new distributor this morning that has full adjustments for the curve the limitation and the vacuum advance which I probably won't use again...Just get a FBO limiter plate and recurve the existing one . Check the vacuum can specs as well