Need to freshen up short block?

[ironhead498]

The short block in question has 90,000+ miles on it, and has two cylinders that the rings are shot in.

The combo is TFS h/i/c, 70mm turbo making 11 psi. It made 507hp and 497ftlb to the wheels with a Bob Kurgan tune at his shop.

I know I'm going to hear the whole "buy a good block" shpeal, but it's not realy in the funds.

I was just thinking of buying some new forged pistons (the ones in the block now are cast...lol) and punching the block out .030, new berings and call it good.

What do you think???????????

 

[stdyhand]

You can get away with using the stock block as long as you don't put it to the floor very often. Your making 500+ hp so your right at the limit already. You can only do what you can afford. The Forged pistons might be better against detonation but they aren't going to keep that block from coming apart.

I just wouldn't "drive it like you stole it" as some like to say. Have fun but keep it within its limits.

 

[Gearbanger 101]

If you insist on sticking with the stock block, then I'd be pulling a lot of ignition timing out of that engine to keep it alive. That, and/or some lower than stock compression pistons to help ward off detonation. You might give up 30-40hp, but it's better than picking up pieces of your engine all over the road one night you can't resist the urge to push it.

 

[2vNotch]

+1

 

[ironhead498]

Bob set the tune with 19* total advance if I remember corectly. When he put it on the dyno I told him that it was a high milage cast piston short block. He said that he wasn't worried about that and once he hit 500 he would call it good. Four pulls later and he was done. The car drives great and I've put about 2k miles on it since with no problems.
I know it's still on borrowed time, but I'm a firm believer in the "if it's no broke don't fix it".
I'm sure even if I just do a 306 rebuild that I'd need to turn the boost down a little to keep it alive.