Help me out here... I need some learnin'.
Growing up, I raced gassers, and never heard the term EGT's. Why is this not a problem in gas motors? I've had headers glowing cherry red during a race, but never worried about it. From what I understand with diesels, EGT's are a sign of what your cylinder temp is, and too much heat will kill your turbo.
I guess that my two specific questions are:

1. Why is it not such a big deal in a gas burning motor?

2. Are there any other reasons other than the above listed for them to be important in diesels?

TIA!!

Madhat

 

Our pistons are aluminum, which begins to melt at (I think) 1300 degrees, so there's the main reason. Not sure about the gasser question, but getting a thin walled header to glow probably takes a lot less heat than getting that log of an exhaust manifold we've got to glow---that thing's gotta be well over 1/8'' thick.

 

The low compession of gas motors will vever build up enough heat to worry about melting pistons. The headers glow because they are thin 16ga steel stock gasser manifolds will never glow red.

 

the turbo is the cheapest, easiest to replace component that can nbe damaged due to excessive egt.

piston crowns, exhaust valves, rings, valve seats, the turbo all can be damaged by high temps.
the 3rd gen engines while being design to run higher temps due to emissions, have better materials able to withstand slightly higher egt's, will still be damaged by heat.

a turbo may cost $1200 and take 2 hours to change, what do pistons cost?

 

Wanna bet a gas engine can't melt pistons?? They Can max out a 1500 deg EGT gauge. i have heard of gas engines reaching 1700 deg!!

 

Thanks for the info, guys. I'm just trying to get smart about this stuff, can't play with it unless you know about it...

 

Marine pistons for a 12valve can be had for $300

 

maybe someone can give an explaination on how to control egt's while driving?

 

I understand that one (I think). EGT's go up with boost+fuel increase. Extra timing and fueling, towing, and high ambient air temps contrubite. Bigger turbo, water meth injection, twins (turbos) and better air flow (bigger intercooler) will help keep EGT's down. That, and a lighter right foot.

Someone check my know how... what am I missing? I'm still small beans here, so don't take this as gospel from me... let some of the older and wiser chime in...

 

I thought more timing helps reduce EGTs.

 

most gas motors that experience that high if EGT has Forged pistons.... IIRC we have cast pistons.... or atleast that's what i've read.... correct me if i am wrong....

 

pistons may be $300, most people can change a turbo, most cannot replace a piston. hopefully they have some good buddies that can help. but the cost of having some shop hone, sleeve, re ring, replace the head, etc. will quickly surpass the cost of a turbo.

 

so what if we had forged piston? would that allow us to run higher egt's?

 

I know. I was just givin ya a hard time. The amount of work required in replacing a turbo vs. a piston is no comparison.

 

Help me out here. If these EGT's are so important, why don't we have a gauge to keep track of them? I don't mean one I buy, I mean one from Dodge. Evidently they don't think they are anything to worry about. Just keep waiting for the idiot light.