This is something that doesn't happen often but I'm going to have to agree with just about everything Forced said here. 800F is a little high for highway cruising exhaust temps. Running at 1200F is OK, even for sustained periods under load. 1300F or 1400F is definite engine damage territory. The aluminum alloy that the pistons are made of starts to soften (melt) at just over 1250F. By the time the exhaust gasses get to the EGT thermocouple they have already cooled at least a little.

Mash, if you keep hitting 1300F to 1400F EGTs on your gauge you're going to slag a piston or two - maybe even all of them. You may have gotten away with it so far, and if you want to keep taking that risk, then more power to ya', but it WILL catch up with you sooner or later and you'll be doing a complete rebuild.

That just means you have no idea what you are actually doing.

No, its clear that extremely bad ideas must be called out to prevent other people from making the same mistakes.

rcounts's has it right. High EGTs are not a "blow your engine up" kind of damage, it causes cumulative damage. Just because you have 50k miles of extreme abuse on your engine right now does not mean it will make it to 100k miles. It definitely won't see the normal 300-400k mile lifespan.

My temps are fine. It will only go into the 1300+ range at full load above 110 mph. If I follow a big rig at 60 mph then it runs at 600-700 deg. If there is a long incline temps will go up e few hundred. If it's 100 deg summer weather with five people in the car with A/C then things will run hotter. With the wastegate disabled on the turbo the ALDA must be leaned to acceptable emissions/power. MY Garrett turbo puts out around 15 psi at 3000 rpm in first and 25 psi in fourth with very little smoke. The wastegate is inherently inefficient since it starts to crack open before full boost. I tried a Greddy Profec Type-S boost controller but in the end I didn't need it. Since getting rid of the wastegate the turbo spools up faster hence the change in noise. My turbo is not over-spinning and my EGT''s are in check. The turbo isn't producing high boost at low rpm's so the rods are safe. I have rebuilt a 617 and 603 motor with success. I mentor at a friend of the family's business(Mike's ******** in Hawaiian Gardens CA) where there are a lot of interesting projects like a 58 220 converted into a pickup with wooden bed, 616 motor and auto trans or a Mercury Cougar coupe with 616 and manual trans. His latest is a 617A in a 84 SL. I can post pics if anyone is interested. It would be nice if people could treat each other like friends on this site instead of competitors or foes. Take care

Thats why people make those $10 manual boost controllers.

http://www.geocities.com/chmwatson/F...stcomplete.jpg

Actually, it is. That noise you hear is the turbo hitting its 155,000rpm choke line.

The rods were never a concern.

That actually explains a lot of your problems. Now I know exactly who you are, the same guy that was trolling the Lovecrap forums some time ago trying to sell that Cougar at a ridiculously high price. :rolleyes:

MY turbo is fine. That was Mike's car but he has a guy who he contracts to sell his cars. Mike is a great guy and you don't know exactly who I am. Trolling is not a word you should be using an attitude check is in order.

Once airflow reaches the speed of sound, it can't move any faster to fill the void created by the turbo's compressor. Thats why you make no more than 25psi and your turbo screams, it can't flow or pressurize the air any higher, just spin faster.

No, trolling is what I call your kind of very bad advice, taking over threads with completely unrelated, unsolicited and useless information and ignoring the good advice of the many far more knowledgeable and experienced people here telling you what you are doing wrong.

I believe the limit is 128k but either way 25psi is choking, heating and overspinning his turbo. 1300*F is not cool.

lol :2thumbsup