Ouch...
07-29-2009, 12:55 PM
#1
Ouch... My ProCharger finally bit the dust. 
Took it off and was planning to just drive the TA NA, but then new badness appeared.
Started it up and the idle was HORRIBLE. Totally undriveable. Smoothed out after a few minutes. Started digging under the hood, and it turns out I've blown my intake gasket and a head gasket, and I've oil soaked the optispark. Start pulling things apart, and the timing chain is stretched.On the plus side, the cylinders look fine. A leakdown test prior to pulling the heads looked fine on the passenger side (with the non-blown head gasket) and the cylinders look fine (thank you Mobile 1!) so I think I am OK there. So... intake and heads, optispark, water pump, timing set, and misc small parts.
I don't think I am going to replace the ProCharger though. The car has 161K on it, and the engine (and blower) are over 100K. I kind of think putting a fresh blower on a high mileage engine is asking too much.
And I think the money would be better spent on the 'Vette project.
Anybody seen a blower failure cause this sort of damage?
Took it off and was planning to just drive the TA NA, but then new badness appeared. Started it up and the idle was HORRIBLE. Totally undriveable. Smoothed out after a few minutes. Started digging under the hood, and it turns out I've blown my intake gasket and a head gasket, and I've oil soaked the optispark. Start pulling things apart, and the timing chain is stretched.On the plus side, the cylinders look fine. A leakdown test prior to pulling the heads looked fine on the passenger side (with the non-blown head gasket) and the cylinders look fine (thank you Mobile 1!) so I think I am OK there. So... intake and heads, optispark, water pump, timing set, and misc small parts.
I don't think I am going to replace the ProCharger though. The car has 161K on it, and the engine (and blower) are over 100K. I kind of think putting a fresh blower on a high mileage engine is asking too much.
And I think the money would be better spent on the 'Vette project.
Anybody seen a blower failure cause this sort of damage?
07-29-2009, 01:17 PM
#3
The bottom end is already forged. I don't think it would have gone over 100K under boost (although I don't hammer it all that often...) otherwise. The heads are ported LT4s. I don't think I need to rebuild the bottom end. I just don't think I want to cough up the cash to rebuild or replace the blower on a high mileage engine. I'd rather spend the money on the Vette, I think. And yes, I am sure the timing chain is stretched.
Mostly I'm just asking if anybody can figure why the blower failure would blow both the head and intake gasket.
Mostly I'm just asking if anybody can figure why the blower failure would blow both the head and intake gasket.
07-29-2009, 03:10 PM
#6
I know it's a lot of miles. I've always been incredibly **** about maintenance, and I truely believe this is how it pays off. And I don't spend that much time under boost.
I know that boosted engines make more power if you go low CR and high boost. But while that build makes all the sense in the world for a race engine, I don't think it's the way to go for a street driven car.
This engine only made 9lbs of boost. It's got a 10.5:1 static CR. That's high for a boosted engine. The idea when this engine was built was:
1 - Build it to make good power without boost, since that is how it is mostly driven.
2 - Add the blower for the rare time when you need TONS of power.
3 - Build it with parts rated for considerably more power than is actually made, even under boost, to improve the lifespan of the engine.
The bottom end was supposed to be built to handle 1000HP. Obviously I never came near this, but I believe this overbuilding, combined with my **** retentiveness regarding maintenance, is why she's hung together this long.
The other bonus of this build idea is that she'll still make respectable power without the blower.
I'm still hoping somebody will have an idea why the other problems came up at the same time as the blower failure. I suppose the timing could be coincidental, but I distrust coincidence.
I know that boosted engines make more power if you go low CR and high boost. But while that build makes all the sense in the world for a race engine, I don't think it's the way to go for a street driven car.
This engine only made 9lbs of boost. It's got a 10.5:1 static CR. That's high for a boosted engine. The idea when this engine was built was:
1 - Build it to make good power without boost, since that is how it is mostly driven.
2 - Add the blower for the rare time when you need TONS of power.
3 - Build it with parts rated for considerably more power than is actually made, even under boost, to improve the lifespan of the engine.
The bottom end was supposed to be built to handle 1000HP. Obviously I never came near this, but I believe this overbuilding, combined with my **** retentiveness regarding maintenance, is why she's hung together this long.
The other bonus of this build idea is that she'll still make respectable power without the blower.
I'm still hoping somebody will have an idea why the other problems came up at the same time as the blower failure. I suppose the timing could be coincidental, but I distrust coincidence.
07-29-2009, 03:19 PM
#7
You have it backwards. In a race engine you would likely be running race fuel so it makes sense to run higher compression, and they do. Street engines typically run a lower CR to get away with running pump fuel without detonation. Maybe it was detonating and popped the head gasket?
