#6 piston hotter than 1-5

[PKitzman]

Is the EGT out of #6 piston always about 100 degrees F hotter than the outher five pistons? I took a look at mine with an IR gun and at idle 1-5 were about 270 - 290 F and #6 (closest to the firewall was about 380 F. This all normal??



I saw another post about the melted #6 piston where someone mentioned #6 runs hotter due to the restricted exhaust gas path and less inlet air. If that's the case, you'd think a slight modification in the air distribution and exhaust gas manafold would make this engine a little more efficient (and less prone to melting #6)

 

[CumminsBu]

The two piece ATS exhaust manifold should help. But the biggest problem is the intake side which has the smallest air passage to the #6 cylinder as of now there is no fix because it is part of the heads design.

 

[WCounts]

When you shoot the manifold with a ir gun you are reading the temp of the outside of the manifold. The air flow cools the outside and the front will be cooler. The exhaust gasses will be hotter.

 

[Vaughn MacKenzie]

There was an article several years ago about putting the Banks Twin Ram on a 12-valve and comparing EGTs on the dyno for every cylinder before and after. The Twin Ram did balance out EGTs considerably, even though the 12-valve in the test didn't have a dramatic range between coolest & warmest. Seems like before it was 75F and after it was 25-30F.



I think the HPCR motor could benefit from a Twin Ram. The ATS exh. manifold is a big improvement, since it directly passes exhaust to the turbo inlet. I think anyone in competition should seriously consider one.



Another problem at #6 is the cooling system. Someone posted that the coolant tends to stall out there and not carry heat away as well. There is some sort of retrofit available on other B-series engines where the rear freeze plug is knocked out and a fitting & hose added to carry the coolant away more readily and balance the cooling at #6. Anyone remember where that thread was?



Vaughn

 

[RJOL]

Not an engineer but I read some of the same things listed above. That's why I mounted my EGT probe in the 5/6 web (see reader's gallery). The highest temp I've seen, while towing my 32' fifth wheel, was about 1250 degrees. This is a totally stock truck...

 

[PKitzman]

It just boggles my mind why anybody would design an engine with an obvious problem like this. Of course, it's not REALLY a problem for a totally stock truck, but why not design it so all 6 pistons get an equal amount of air, exhaust back pressure, and coolant?