What do you think caused this hole in my head?

gmduramax

gmduramax

Shits broke
Jun 12, 2008
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IIRC Pat changed thermostats because the stock ones wouldn't open fast enough. If your thermostats stayed closed while you were pulling would your heads get hot?
 
LBZ

LBZ

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Jul 2, 2007
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In a dedicated drag or puller truck, I'd mod or pull the thermostat all together and put in some sort of a fixed orfice to control flow because I believe the heads could get really hot really fast if the thermostat can't open fast enough. Not sure what size of orfice one would need, but I did this in my sled to fix sticking or thermostat's the don't open fast enough. Worked for me.
 
JoshH

JoshH

Daggum farm truck
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Feb 14, 2007
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LBZ said:
In a dedicated drag or puller truck, I'd mod or pull the thermostat all together and put in some sort of a fixed orfice to control flow because I believe the heads could get really hot really fast if the thermostat can't open fast enough. Not sure what size of orfice one would need, but I did this in my sled to fix sticking or thermostat's the don't open fast enough. Worked for me.
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We put these in the shop race truck: http://www.summitracing.com/parts/MIL-16420/
 
JD Dave

JD Dave

In way over my head
May 19, 2008
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gmduramax said:
IIRC Pat changed thermostats because the stock ones wouldn't open fast enough. If your thermostats stayed closed while you were pulling would your heads get hot?
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I've ran Pats thermostats for 3 years and I've never pulled with out my truck being at operating temperature.
Leadfoot said:
I know Johnboy and others have opened up the valve guides a bit as soot tends to be an issue (especially on the exhaust valves) at the level and fueling of competition motors. It wouldn't take much for a valve to hang a SLIGHT amount and the fueling and heat to act as a torch and cause the issue you have. It could be compounded by a poor casting but at the level you are running, I think you had a good life (nothing in these motors will last "forever" when being pushed).

I would be willing to bet it was a combination of things that led to the ultimate failure, so it might take a combination of changes to "fix" it.

Good luck, you sure seem to have a very healthy running rig. :thumb:
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Thanks and thanks for that information. It's something I will look into.

Rhall said:
From the vids you've posted your truck runs lean. I'd hate to see your egts.
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I agree it looks lean but with 350 over injectors and the pulse width I'm running there is a lot of fuel there. My w2a intercooler needs to be a few times bigger and water injection would be great. We tried giving it more fuel and all it did was make more power and heat. We thought my truck wasn't holding rail with how lean it ran but when we looked at the logs it's holding perfect. I really do appreiciate people's opinions on things as I really am new to all this.
 
JD Dave

JD Dave

In way over my head
May 19, 2008
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The good news is the truck is up and running now. Just have ot button a few small things up and I should be good to pull tomorrow night.
 
Rhall

Rhall

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Aug 12, 2006
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JD Dave said:
I've ran Pats thermostats for 3 years and I've never pulled with out my truck being at operating temperature.
Thanks and thanks for that information. It's something I will look into.



I agree it looks lean but with 350 over injectors and the pulse width I'm running there is a lot of fuel there. My w2a intercooler needs to be a few times bigger and water injection would be great. We tried giving it more fuel and all it did was make more power and heat. We thought my truck wasn't holding rail with how lean it ran but when we looked at the logs it's holding perfect. I really do appreiciate people's opinions on things as I really am new to all this.
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Lmms are tricky, what's ur big charger? A gt47? It's a lot of air but you should still be able to fuel it hard with 200 overs much less 350s. If ur fueling hard with 350s I doubt 2 stroker cp3s would maintain rail.
 
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