Stripped my damaged LS1
Discussion
This is the engine out of my HSV GTS VT2. It was advertised as needing big ends. I've been told that you could hear the piston whacking into the head and that it was possible that piston would have broken up, scrapping the engine.
Off comes the inlet with, what looks like a new C5 Corvette throttle body (the TB came with the engine now in the HSV):
Off came the rocker covers to reveal a nice surprise:
One of the bolts holding the rockers in was impossibly tight. I lost two sockets to it before it released:
With the heads off it was clear that the engine isn't toast (happy days).
One piston has been tapping the head though.
Seven pistons like this:
And one like this (the outline of the cylinder head chamber is imprinted in the coke and there are 'dents' in the surface):
This cylinder bore shows very light scoring:
Seven cylinder head chambers like this:
And one like this:
A prize goes to the person who guesses which cylinder went down.
So, I'm guessing as a minimum it needs a bit of cylinder work, new set of pistons and rings (will be forged), crank regrind and new bearings. Worse case would be a new crank and rods too. Given it'll need stripping, maybe a forged rotating assembly would be a better idea. A four inch stroke and a mild bore should run to 6.3-litres. Hmmm....
Off comes the inlet with, what looks like a new C5 Corvette throttle body (the TB came with the engine now in the HSV):
Off came the rocker covers to reveal a nice surprise:
One of the bolts holding the rockers in was impossibly tight. I lost two sockets to it before it released:
With the heads off it was clear that the engine isn't toast (happy days).
One piston has been tapping the head though.
Seven pistons like this:
And one like this (the outline of the cylinder head chamber is imprinted in the coke and there are 'dents' in the surface):
This cylinder bore shows very light scoring:
Seven cylinder head chambers like this:
And one like this:
A prize goes to the person who guesses which cylinder went down.
So, I'm guessing as a minimum it needs a bit of cylinder work, new set of pistons and rings (will be forged), crank regrind and new bearings. Worse case would be a new crank and rods too. Given it'll need stripping, maybe a forged rotating assembly would be a better idea. A four inch stroke and a mild bore should run to 6.3-litres. Hmmm....
There is a good chance the piston is still fine. As long as it hasnt bashed so hard the ring lands are compressed and rings sticking, it would be re-usable. Likewise the rings and boree which dont look that bad really.
If the bearing has spun in the rod, which sounds likely, then that rod is scrap.
Crank itself may be ok, or a re-grind would most certainly sort it.
Going to the extreme of a new crank...would be an extreme if not absolutely needed.
So it could be fixed very cheap, cheap, silly, or upgrade silly pricing.
If the bearing has spun in the rod, which sounds likely, then that rod is scrap.
Crank itself may be ok, or a re-grind would most certainly sort it.
Going to the extreme of a new crank...would be an extreme if not absolutely needed.
So it could be fixed very cheap, cheap, silly, or upgrade silly pricing.
stevieturbo said:
There is a good chance the piston is still fine. As long as it hasnt bashed so hard the ring lands are compressed and rings sticking, it would be re-usable. Likewise the rings and boree which dont look that bad really.
If the bearing has spun in the rod, which sounds likely, then that rod is scrap.
Crank itself may be ok, or a re-grind would most certainly sort it.
Going to the extreme of a new crank...would be an extreme if not absolutely needed.
So it could be fixed very cheap, cheap, silly, or upgrade silly pricing.
You're quite right. I think this could be fixed and freshened up quite cheaply. The other bores are spotless, so it would be a crime to bore them if a hone will suffice.If the bearing has spun in the rod, which sounds likely, then that rod is scrap.
Crank itself may be ok, or a re-grind would most certainly sort it.
Going to the extreme of a new crank...would be an extreme if not absolutely needed.
So it could be fixed very cheap, cheap, silly, or upgrade silly pricing.
If I was on a budget, I'd probably go that route an pray that the piston isn't cracked. Roger has seen a few cranks bent by similar failures, though the regrind may sort that. The rod has the be suspect too, now.
Given I like spending money on upgrades, £1300 plus delivery and duties is a cheap upgrade to 6.3-litres of forged LS1
Number 1. Bent cranks, that's a new one for me. I used to buy loads of the early GM warranty returns. This was before there were any spares on the aftermarket. Spun bearings were quite common as well as the occasional valve imprint on a piston. I came across scored cranks but never a bent one.
As Stevie says, should be a nice easy fix. I've got ls1 ring packs if you do decide to do a hone.
My best purchase was a c5 engine with 3k miles on it. A gorilla had broken off the starter motor lug which meant an engine out job and a replacement engine :-) It was like new inside.
As Stevie says, should be a nice easy fix. I've got ls1 ring packs if you do decide to do a hone.
My best purchase was a c5 engine with 3k miles on it. A gorilla had broken off the starter motor lug which meant an engine out job and a replacement engine :-) It was like new inside.
Edited by Boosted LS1 on Saturday 3rd January 20:32
Boosted LS1 said:
Number 1. Bent cranks, that's a new one for me. I used to buy loads of the early GM warranty returns. This was before there were any spares on the aftermarket. Spun bearings were quite common as well as the occasional valve imprint on a piston. I came across scored cranks but never a bent one.
As Stevie says, should be a nice easy fix. I've got ls1 ring packs if you do decide to do a hone.
My best purchase was a c5 engine with 3k miles on it. A gorilla had broken off the starter motor lug which meant an engine out job and a replacement engine :-) It was like new inside.
Good guess - but wrong...As Stevie says, should be a nice easy fix. I've got ls1 ring packs if you do decide to do a hone.
My best purchase was a c5 engine with 3k miles on it. A gorilla had broken off the starter motor lug which meant an engine out job and a replacement engine :-) It was like new inside.
Edited by Boosted LS1 on Saturday 3rd January 20:32
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