Pyrometer Readings

[BethT46]

I have a new (to me) Itasca Horizon with a 300 hp turbo charged Cummins ISB 5.9L diesel pusher. The pyrometer readings are consistently at the high end of the "normal" range (about 1000 degrees), with fairly frequent rise into the "yellow" range between 1100 and 1200 when climbing and without towing.

Perhaps some of you Horizon owners can share your expertise with me regarding safe EGT range for this particular engine?

I know high EGT can be the result of restricted air flow.

I've been reading about the Banks Power Pack System and wonder if anyone recommends this modification, which is supposed to reduce EGT and increase fuel efficiency.

[wolfe10]

Welcome to the FMCA Forum.

Is the pyrometer in the exhaust manifold between head and turbo or downstream of the turbo? Readings will be very different based on location.

Brett

[BethT46]

Good question, and I don't know the answer to that just yet. From what I've read, I understand there can be a significant difference in the readings depending on the location. I'll try to get that info. Is there a way to tell with a visual inspection?

[desertdeals69]

Look for the thermocouple location.

I have a 275 ISB and I mounted mine 2 inches behind turbo exhaust flange. My temp is about 1150 at 24 pounds of boost.

[MikeCanter]

I had an EGT sensor on my last MH with a Cummins motor and a Banks Power Pack kit. When installing the Banks kit one adjusted the fuel so you had a max EGT of 1300* at wide open throttle under load going up a steep grade. This is the max power EGT. The EGTs on a diesel are very different to those on a gasoline motor. On a gas motor the leaner the mixture the higher the EGTs. Not so on a diesel, it is totally opposite, the more fuel the higher the EGT. It has nothing to do with boost but the higher the EGT the more the turbo will spin up so more boost and power. According to Banks the straight and level normal cruise will be in the 700 to 1000* range and wide open full more should not exceed 1300*. If it does then you need to either downshift or let up some on the throttle. I would say your motor is 100% normal. Does your pyrometer redline at 1300*? I would expect it is because mine was.

[BethT46]

Thanks for all the information. MH is at the dealer right now so I am guessing on the redline....I think the bottom end of the redline is in the 1200-1300 range. So perhaps mine is pretty much normal.

[MikeCanter]

Like I said I have had pyrometers on a diesel and I tune several professional racecars as a paying hobby. I use eight EGTs on each engine and use them to tell me what is going on with the motor. I do know pyrometers and EGTs reading very well. If those were the readings I was getting on my diesel I would be happy. Let me know if you have any questions about it. I will be more than glad to answer them.

You might find this to be interesting reading.

http://www.bankspower.com/techarticles/show/25-why-egt-is-important

[BethT46]

Like I said I have had pyrometers on a diesel and I tune several professional racecars as a paying hobby. I use eight EGTs on each engine and use them to tell me what is going on with the motor. I do know pyrometers and EGTs reading very well. If those were the readings I was getting on my diesel I would be happy. Let me know if you have any questions about it. I will be more than glad to answer them.

You might find this to be interesting reading.

http://www.bankspower.com/techarticles/show/25-why-egt-is-important

Thanks, Mike. Yes, I was on the bankspower website a couple of days ago and read that article (very informative), and I talked to someone at their facility in Azusa about installing a Banks system sometime later this year when I'm down that direction.