Well, after 10 years of putting out 600+ RWHP I think my ARE 360 twin turbo may be in serious trouble. During some spirited highway driving, it developed a cyclical clacking/slapping noise and lost power. At the bottom of the ramp, there was a severe miss and grey smoke. I had it towed to a mechanic that listened to the noise and ran a compression check and leak down. Looks like no oil in coolant, but light puffing from oil cap. There is a good bit of leaking down on all cylinders, and 1 and 3 have no compression. Looks like a shot head gasket (at minium) with some valve train damage, or he said it could be dead pistons or rings on 1 and 3. With the amount of oil on/around the turbo's (original Incon twin turbo kit) they need rebuilt too.

I'm thinking next step is pull the head and see what's going on. Might get lucky and only have a dead head gasket, but the mechanic is saying if that went, I'd probably need to have that head trued before reinstalling, and that is going to be some $$. Then, how long do we have before the other one lets loose?

If rebuilt I'd still have the bad leakdown, turbo's needing to be rebuilt, etc.

Looking for folks to throw stuff on the wall...

Bandaide it and see how long it runs?

Re do both heads, freshen valve train, rebuild turbos?

Other options are start with a new LS series long block and add turbo's back or put in a 500+ CU big block thats reliable at 800HP and get off the boost.

Looks like I quickly go from under 1K for fixing one head to 3,000 for a freshening of the existing heads (if there is no piston / rod / block damage) to 10,000 to 15,000 for a new motor. I can't see putting 10K into a 1998 Z28....

Looking for thoughts...might be time to send this one to Camaro heaven....

 

No way to tell until the heads are off (at least). Stock pistons?

 

Personally I would do a 408 short block and transfer most of the stuff. TSP has pretty good prices on forges short blocks. Right now is the time to build it alittle bigger. Of course if the funds permit, here's me;
Get 408 short block
Transfer anything you can from old to new
Rebuild turbos
you could do this for under 5k if you play your cards right. Assuming your trans and rear end are already built for it.

 

Parks450,

The trans was rebuilt last year by Tick Performance (all goodies added) and guaranteed at the 750HP level for a year. Also added a McLeod twin disk clutch at the same time. Rear end is also rebuilt and in good shape.

I'll give TSP a call and chat about the situation and see what they'd recommend. Maybe even have the car sent down there for them to do the work.....

S10xGN,

The motor was a balanced, blueprinted 360 with forged pistons, rods, and crank.

 

Pull it apart and see whats up. Maybe tou get lucky, if not Id buy a new stroker shortblock from a vendor and transfer everything over, maybe a few upgrades along the way.

 

Think you're worrying to much guy. 3K is way overboard for head rebuilding and 10k is way more than enough for a long-block and definately a shortblock if thats all you need.

What are the bore and stroke specs on the engine you have now?

 

It's original bore and destroked via rods / piston to 8.5 compression @ 360"