pyrometer

[MRowe]

I have a pyrometer installed in my 89 5. 9 with the thermocouple placed in the exhaust manifold about 2 inches from the turbo flange. Does anyone know how hot i should let the exhaust get before backing off to kool it down? The motor is in a 93 gmc carrier and being in the mountains of vt it works hard.

 

[Paychk]

This should help:



https://www.turbodieselregister.com/forums/showthread.php?t=96798

 

["Mad Max"]

I think the general consensus is around 300*.

- S

 

[bmoeller]

Great info on this site-



http://www.dodgeram.org/tech/dsl/FAQ/turbo_faq.htm

 

[BushWakr - RIP]

1250*F is accepted max temp for sustained driving... there are a couple of factors to keep in mind here.

First, the engine you're running is using the larger injector bodies (9mm) compared to the later (91. 5-93) engines... as a result the head had a tendancy to crack between the valve seats due to heating /contraction. (less material in that area to accomodate the larger injector bodies)

That means extra care is needed to keep that problem from becoming a big issue for you... so, keep your temps lower than even 1250*F if you can.

Second, the max temp of 1250*F max is ok as long as you keep an eye on your coolant temps during sustained periods. Eventually it is possible to see your coolant temps climb because the engine/head etc becomes heat saturated and the radiator/cooling system can't keep up.

Watch those issues and you should be ok.



pb.