Dropped the vette off at Vette Doctors

[BADDASSC6]

My move to Connecticut is complete. It sucks here. The good news is that I dropped the vette off at Vette Doctors in NY two days ago and expect them to call me by the end of hte week with the verdict. I'm hoping that I don't need to buy a new motor, but if it's required I'm upgrading to a 402ci LS2.

[enkeivette]

Why not an LS7 with a bigger cam?

[Vettezuki]

Why not an LS7 with a bigger cam?

That's got to be considerably more scrilla.

[SeanPlunk]

That's got to be considerably more scrilla.

Definitely, and for what he does with the car a well built 402 should make more than enough power. I think the biggest advantage the LS7 would have for Carlos is the dry sump. It sounds like oil starvation may have played a part in blowing the motor from what I recall. Can you adapt an LS7 oil system to an LS2 and have it be cost effective?

[Vettezuki]

Definitely, and for what he does with the car a well built 402 should make more than enough power. I think the biggest advantage the LS7 would have for Carlos is the dry sump. It sounds like oil starvation may have played a part in blowing the motor from what I recall. Can you adapt an LS7 oil system to an LS2 and have it be cost effective?

I was wondering about that too. It did seem like it could have been a oil starved motor issue.

[BADDASSC6]

Well tyhe oil starvation issue was speculation. I did recieve a call from Vette doctors yesterday. The prognosis is that there is "a Big fucking hole in the side of the engine and a Big fucking hole in the oil pan". They are removing the heads and seeing how damaged they are and if they are repairable. So here are the possibilities:

1) Forged 402 with the old heads
Pros: save $2.5K on heads
Cons: will need bowl work and New clutch to handle the torque (~$3k)
2) Forged 418 (LS3 block) with New heads
Pros: Should make at least 530 whp and 500ftlbms
Cons: Heads are expensive and will require a new clutch also
3) Stock LS3 with my old cam
Pros: Cheap(er) (savings of at least $2K)
Cons: I will be down 30 whp from where I was at.

Right now I'm praying the heads are ok so I can go with option 1. Option 2 would be awesome, but that is a lot of money to shell out right now. If the heads are done the I will most likely go with option 3. The car gets paid off this year. My orders are in flux, but it's looking like I will (now) end up in Hawaii where there are no tracks. This would allow me to save money. The extra cash would open up a lot of options for when I return to SD.

[SeanPlunk]

Well tyhe oil starvation issue was speculation. I did recieve a call from Vette doctors yesterday. The prognosis is that there is "a Big fucking hole in the side of the engine and a Big fucking hole in the oil pan". They are removing the heads and seeing how damaged they are and if they are repairable. So here are the possibilities:

1) Forged 402 with the old heads
Pros: save $2.5K on heads
Cons: will need bowl work and New clutch to handle the torque (~$3k)
2) Forged 418 (LS3 block) with New heads
Pros: Should make at least 530 whp and 500ftlbms
Cons: Heads are expensive and will require a new clutch also
3) Stock LS3 with my old cam
Pros: Cheap(er) (savings of at least $2K)
Cons: I will be down 30 whp from where I was at.

Right now I'm praying the heads are ok so I can go with option 1. Option 2 would be awesome, but that is a lot of money to shell out right now. If the heads are done the I will most likely go with option 3. The car gets paid off this year. My orders are in flux, but it's looking like I will (now) end up in Hawaii where there are no tracks. This would allow me to save money. The extra cash would open up a lot of options for when I return to SD.

Good luck Carlos - I hope the heads are okay.

If they aren't though, and you go with option 3, aren't you going to have the same problem as with this motor? An LS3 isn't that much more robust than an LS2?

[jedhead]

If you are experiencing oil starvation, a cheaper alternative to a dry sump would be a Accusump. You can use the Accusump to preoil the engine at start up too.

Bob

[BADDASSC6]

Accusumps are nice I have never used one though. I would be interested to see if it discharged while I was racing. I dont think it was oil. I think it was a rod end bolt or wrist pin. Moroso also makes a Road race specific oil pan for the C6 that is supposed to be better than the factory pan. I will look at the accusump.

[SeanPlunk]

Accusumps are nice I have never used one though. I would be interested to see if it discharged while I was racing. I dont think it was oil. I think it was a rod end bolt or wrist pin. Moroso also makes a Road race specific oil pan for the C6 that is supposed to be better than the factory pan. I will look at the accusump.

Stupid question, but what would cause a rod end bolt or wrist pin to fail? Is it just wear and tear?

[Vettezuki]

If you are experiencing oil starvation, a cheaper alternative to a dry sump would be a Accusump. You can use the Accusump to preoil the engine at start up too.

Bob

Cool I didn't know anything about the Accusump.

[BADDASSC6]

Stupid question, but what would cause a rod end bolt or wrist pin to fail? Is it just wear and tear?

Every part in your motor has existing cracks. Dont care how is was manufactured if it's been heat treated polished what ever. You can stress the parts to the point where the cracks will grow, but the entire part will not fail. As the cracks grow over time the parts will weaken until the bottom end grenades. They call it the KIC curve and it shows what stress you need to stay under to prevent the crack from propegating. SAE states that it a part can survive 10^6 cycles at the maximum load then the part will last "forever".

This is why in drag racing they say a a LS2 is good for ~550 rwhp. I ws 90 rwhp down, but I had 3 seasons of racing.

Sean,
If I took option 3 I would be in the same spot, but I don't think I will be racing much in the next 3 years. Cruising Honalulu will not stress the motor the same.

[BRIAN]

Cruising Honalulu will not stress the motor the same.

Sounds like a good time though.:thumbs_up:

[BRUTAL64]

Every part in your motor has existing cracks. Dont care how is was manufactured if it's been heat treated polished what ever. You can stress the parts to the point where the cracks will grow, but the entire part will not fail. As the cracks grow over time the parts will weaken until the bottom end grenades. They call it the KIC curve and it shows what stress you need to stay under to prevent the crack from propegating. SAE states that it a part can survive 10^6 cycles at the maximum load then the part will last "forever".

This is why in drag racing they say a a LS2 is good for ~550 rwhp. I ws 90 rwhp down, but I had 3 seasons of racing.

Sean,
If I took option 3 I would be in the same spot, but I don't think I will be racing much in the next 3 years. Cruising Honalulu will not stress the motor the same.

Were the rod bolts intact?

[jedhead]

When I did some rebuilds in the past I had magnafluxed the block, heads, caps, crank and rods to check for those cracks to see if any of those items needs to be replaced. The machine shops that did the machining and balancing did the checks for me.

Bob

[Vettezuki]

When I did some rebuilds in the past I had magnafluxed the block, heads, caps, crank and rods to check for those cracks to see if any of those items needs to be replaced. The machine shops that did the machining and balancing did the checks for me.

Bob

Magnaflux no worky so well on aluminum. :) Also, I think Carlos is referring to micro-cracks.

[BADDASSC6]

Brutal: I don't know yet. The only info that I have recieved was about the holes. They are pulling the heads off and I'm expecting them to determine the mode of failure.

I was refering to micro cracks in all materials. Magnaflux is a great form of non-destructive testing. I've never really done any of it with my cars because there are never any usable parts left when I'm done with it:huh:. I have used similar stuff at work. Our machinist mates ( I was one in my enlisted days) are also our welders and a few of them had to maintain a high enough level of certification.

[jedhead]

Magnaflux no worky so well on aluminum. :) Also, I think Carlos is referring to micro-cracks.

Kinda gave away how long ago my last rebuild was.

Bob

[BRUTAL64]

Brutal: I don't know yet. The only info that I have recieved was about the holes. They are pulling the heads off and I'm expecting them to determine the mode of failure.



I have found 90% of rods causing massive damage was due to rod bolt stretch--bolt stretches nuts loosens then boom.:rolleyes::rolleyes: