Engine Carnage

Another one bites the dust. I think i had too much timing and detonated causing a spark plug to explode and went into an overboost situation. The car still ran, surprisingly enough, so i was able to make it back home just fine...just a little smokey. haha.

As a side note, this engine was so powerful on only 7psi its crazy. I have a 650 rwhp 2006 GTO and Id say the Buick was faster by quite a bit. All in all, the damage isn't too bad. No metal in the oil, cam bearings are still good, and the cylinder walls dont have any scratches or gouges.

Dont know if im going to rebuild another 455 this time. I think im probably going to get a 572 or 632 BBC crate motor from Shafiroff or Blueprint and stay n/a for this next round. Boost is fun but after 8 years Im ready to go back to a rowdy big block with headers. I'd happily build a 455 but i dont think i could do one for 750ish hp reliably without spending some serious coin on an aluminum block and who know how long it would even take to get one.

Stayed tuned on the classified as i start posting up all my parts for sale.

 

Wow, you pushed all of them on that side well beyond their limits. Have it checked for true and put it back together with the headers and a nice rowdy cam.

 

How much timing were you running and how much boost did it take to do that??

And what fuel???

 

He said to much timing and was @ 7PSI of boost.

 

Look at those head gaskets! I installed a BP 750HP 572 in a buddy's Chevelle. It certainly made some power, but it was supposed to be 10:1 or so cr and somewhat street friendly. It is not street friendly.

 

I doubt there would be any block shift with the coolant passages filled and the girdle on there but who knows. I would love to reuse this block if i was just using the car for racing but keeping this thing cool on long drives is a challenge, even with a giant oil cooler out front. Plus, its a low compression piston set anyway so id need to change those out to up the compression. if i stay Buick, im goignt o have to build a whole new engone.

 

Timing was at 23* on 93 octane. I usually keep my MSD 6BTM at 2* per lb of boost but i was testing it at 1* and it was apparently too much. haha.

 

Shafiroff has some great deals, stand behind there engines, dynoed,start to delivery in 8 weeks

 

Do you know what boost it went too?

 

With hot air you need meth or corn...i would reseal it...let the gasket settle 24hrs retq..repeat..repeat..then put a ais meth kit on it

 

That head lifted imo...one retq on boost is no good....2 colds..one hot is best....8yrs is a good run..when did you check the heads last?

 

The gaskets pushing out was your “safety” blow off valve
Happens a lot on Turbo 3.8’s if you get crazy with boost (over 25 or so and too much timing)
Six head bolts per cylinder would help, which Buicks don’t have, BUT it’s better than driving over the crank.

 

Yeah, i actually had my meth inj disabled because i was trying to tune the fuel curve without. I dont know what boost level it went to unfortunately, i was paying attention to AFR. lol. I would try to bolt it all back up but the damage to the piston and combustion chamber require some attention so i dont have a bunch of sharp edges causing isolated heat spots. I still had proper compression on all cylinders except #4.

 

Ehhh...i would scotch brite wheel the piston and head to soften them up....check the head for flatness an roll again..not beat up enough to worry too much imo..certainly not enough to cause any catastrophic failure...just keep that meth hooked up

 

^^^^^ what he said

 

Those Fel-Pro gaskets are good gasket, however, in a boosted application I would use Cometic

 

I would stick with the felpro like with the GNs they can save your ass....if i was doin a proven combo with a good bottom end i may would go cometic...but even then probably not....if they can hold a 3.8 bore to 30psi on the reg they can hold 10 with ease...like i say i bet you lost your torque and it if it hit spring which surely isnt more than 12psi?? ...that would do it everytime

 

I concour. I would suggest a better head gasket. I've not read the entire thread.

As for boost. Doing something simular with a blower. It was recommended for me to fun a thicker head gasket to lower compression. BDS said let the blower/boost make the HP.
like changing blower pulley sizes to increase or decrease boost. You turbo guys can do it easier or faster from what I've seen.
Anyway. I'm sure a better head gasket will stop the problem. But take Huggers advise and make sure your heads and decks are flat.

 

Sometimes it's nice to weak link in a combo that isn't to bad to fix that goes b4 the big bang

 

I would prefer getting the tune right,properly torquing the head and use a metal layered gasket. Bad **** can happen when head gaskets go out.