Tahoe Motor Is Blown Up

[littleboy]

Very nice!! Which Cat turbo do you have ?

 

[turbonator]

Very nice!! Which Cat turbo do you have ?

looks like a s-300 variant... but waste gated... hey 6.2turbo, can you post up a couple more pics of the turbo?

 

[littleboy]

Hmmm..... reading back over this thread an i see that this 52 is a regular 52 ! The pro 52 has the same exhaust wheel as the 55 . This would free up the exhaust side up an create a little more airflo.... but it will also spool a little harder!

 

[buddy]

Nice work getting it going

psi is psi, doesnt make a difference which turbo it came from. The difference is what the turbos contribution to backpressure and heat transfer to the intake air. So a larger turbo wont flow more volume at 40psi than the smaller one, but it could flow more mass if it has reduced IATs. You can get a very slight increase in volume flow from reduced backpressure leaving less dense exhaust gases in the cylinder at the end of the exhaust stroke. That is because the valve closes before the cylinder can be completely emptied, and if there is less backpressure on it then there is less pressurized exhaust gas when the valve closes. (so when the cylinder expands again its not as much volume)

Get your boost down around 30-35psi, with as much fuel as you can throw at it and see what it can do.

 

[6.2 turbo]

Some pictures of the broken pieces.

 

[6.2 turbo]

The rods seem to be ok,after about 150 miles, lots of beating and 42 psi boost. No more high compression 6.5's for me.

 

[littleboy]

Nice work getting it going

psi is psi, doesnt make a difference which turbo it came from. The difference is what the turbos contribution to backpressure and heat transfer to the intake air. So a larger turbo wont flow more volume at 40psi than the smaller one, but it could flow more mass if it has reduced IATs. You can get a very slight increase in volume flow from reduced backpressure leaving less dense exhaust gases in the cylinder at the end of the exhaust stroke. That is because the valve closes before the cylinder can be completely emptied, and if there is less backpressure on it then there is less pressurized exhaust gas when the valve closes. (so when the cylinder expands again its not as much volume)

Get your boost down around 30-35psi, with as much fuel as you can throw at it and see what it can do.

If this is true , why do we have different size of turbos?

 

[buddy]

If this is true , why do we have different size of turbos?

I believe the answer to that question is in the text you quoted. Starting with the 2nd sentence. Bigger equals less backpressure with better exhaust flow, so can achieve higher horsepower and efficiency. Slower spinning larger diameter wheels move the same volume of air at lower speed. But too big is obsiously bad if it cannot build enough boost.

 

[6.2 turbo]

Pretty sure it just threw a rod again. This time it went at part throttle pulling away from a stop light. Looks like it might be a rerun of the last time. Apparently 18-1 was not low enough ?

 

[Mike K3500]

That sux... are you running forged rods like what comes in the GEP Optimizers.. ?? If not, I wonder if they would be beneficial to what you are doing with these engines.

 

[Landmine]

Damn i was excited to see you on the dyno

How much boost were you at when it went? Was it full throttle, or just moving along?

 

[NVW]

That sucks, how many miles since the last rebuild?

 

[6.2 turbo]

No they are stock 6.5,but still forged I believe ? From what I can find it looks like the p400 has different rods. Not sure if the GEP optimizer has better rods or not. Just looking at a stock rod,they look fairly strong. For some reason this seems to be a problem area for me. Apparently some serious cyl psi. It could be I had too much timing,but kinda doubt it. More like too much fuel and boost,just wish I could make it last.

 

[6.2 turbo]

It might be 500 mile or so. For sure it blew from beating it earlier,and then let go at part throttle/no boost. There was no knocking sounds beforehand,just one big bang,sounded like a drive shaft.

 

[oldblacksmoker]

This would be awesome.

One thought I had in the past was modding some Dmax pistons and rods to fit into a 6.5. Other than piston design, the measurements are similar as far as bore and center of bottom ring to piston top. The piston is a bowl though, lower compression because of it. Its been a long time since I looked into that, but it seemed possible with a little machining. I even have a used set of rods and pistons from a DMax in my garage, and dont think I'll ever use them.

 

[6.2 turbo]

Well I dropped the pan,#3 rod broke,and all the rest look bent. The cyl has a pretty big chunk missing,but should be ok. Probably has a bent cam, it has no charge psi,so the ip's not turning.

 

[oldblacksmoker]

I think it's awesome your main caps held.

 

[oldblacksmoker]

Did you use studs on the mains, or locktite?

 

[6.2 turbo]

It has all stock bolts,but the block is oringed,so the headgaskets are not the fuse. Now its the rods instead,I'm not even worried about the block.

 

[oldblacksmoker]

I meant the main caps. Does o-ringing help that too?