Exhaust...... How Hot?

[KillJoy]

How hot do MM Manifolds get under "normal" driving conditions.

How about under "race" conditions?

And then...the same Q's, but with Headers installed....

KillJoy

[Haggis]

How hot do MM Manifolds get under "normal" driving conditions.

How about under "race" conditions?

And then...the same Q's, but with Headers installed....

KillJoy
Hot enough that you don't want to touch them.

[TAF]

From experience....H-O-T!!!!!!

1500 - 1800 degrees F...is my understanding, but I've never seen specific 'science".....just been "burnt"

[KillJoy]

Dayum! That's hotter than I expected....

Thanks guys!

KillJoy

[Marauderjack]

Normal driving (whatever that is) you will get 600*-800* and under WOT at the track you will probably see 1100*++??:cool:

The combustion chamber will never see this much heat as it is cooled by the incoming intake charge and in our street cars the EGR.:beer:

The hottest points will be the turns in the exhaust manifolds just outside the exhaust ports.:eek:

Marauderjack:burnout:

[SergntMac]

I have the Reinhart Cobra manifolds on my #3 MM, and the Kook's mid-length headers on my #1x, and both have been ceramic (aka "Jet Hot") coated.

This process fires the coated part to 1200 degrees for "baking to seal" to the surface to be coated. I've tried this process on other engine components, and it's failed because the process melted the component in the baking. Our coil covers are an example of what cannot be ceramic coated.

Therefore, without any other scientific data to work with right now, I would estimate (IMHO) that the exhaust manifolds/headers do not exceed 1200 degrees. Otherwise, I would expect to see peeling, cracking and other signs of errosion in the ceramic coated surfaces, and I have not seen that. BTW, 20K on the DR Cobra manifolds, 5K on the Kook's, all season driving.

This doesn't help. I know it.

I'm just boosting my post count.

[snowbird]

Killjoy,

I have an EGT plugged at the collector on Kooks. I read 800-1000 F on very smooth sailing and 1200 to 1300 F on short supercharged stunts. A sustained third gear to the redline give 1500F. I guess the outside surface would be a couple hundreds degree less but depends on the amount of time the temperature load is applied. When you lift throttle, it take only a couple of seconds to go back to 1000F. Again, the outside surface probably lag a little more.

[SergntMac]

Killjoy,

I have an EGT plugged at the collector on Kooks. I read 800-1000 F on very smooth sailing and 1200 to 1300 F on short supercharged stunts. A sustained third gear to the redline give 1500F. I guess the outside surface would be a couple hundreds degree less but depends on the amount of time the temperature load is applied. When you lift throttle, it take only a couple of seconds to go back to 1000F. Again, the outside surface probably lag a little more. I suppose this is where (and why) ceramic coating makes sense. It's a heat barrier, and while exhaust gasses get as hot as you describe, telegraphing those temps through the header/manifold would not be a good thing.

[Bluerauder]

A sustained third gear to the redline give 1500F.
Marine engine manifold coatings typically provide protection to 1,500 degrees F. Boats tend to have longer sustained runs at or near WOT.

[DEFYANT]

If I am reading the data logger right, the highest exhaust temps I've seen are around 1800*.