Does anyone know what the "safe" head temperature range would be. I was thinking about running a head temp. gauge rather than an oil temp. Anyone have an opinion on this? It seem's to me that head temp. would be faster reacting to engine temp. change.
DaveCo11 replied the topic: Re: cylinder head temp.
I only run a oil light and a alt light, nothing more. I have found threw some of my racing friends that they have slowed down worring about what a gauge says when the motor would be fine regardless. Oil light will let you know when you have a problem, doing the same as a guage that may or may not be giving you the rite info. That is the way I look at it and dont have any engine problems. Besides what are you going to do in a race when the temp looks hi??
I agree with you about keeping it simple --- all I have now is oil and alt. light. the reason I was thinking about engine temp. was that I had a situation with a long uphill sand wash where I could run first gear @ 6000 rpm or second gear @ 4,500 rpm the speed was about the same but I thought it would be nice to know if the engine was running cooler in first or second? Thanks for your response Dave. any thoughts as to what gear would keep the engine cooler?
michaelbrenner replied the topic: Re:cylinder head temp.
Your calculations are all wrong with the rpms. 6000 in first would be about 3200 in second. I know the engine will run cooler at the higher rpm almost always. Our car runs hotter when you lug it around, downshift, get that fan pushing air over the heads. But, 3200 isn't lugging it too much, I would shift because my engine will start pulling at that speed. You're talking about 33 mph or so.....With big tires.
BTW. Cylinder head temp doesn't react quick enough to help you avoid engine damage. You're better off doing a pyrometer on cylinder number 3. That will help you with tuning the engine as well.
When you are running a long run under high load you'll see the EGT creep up slowly, you check up and the carb squirts extra gas and BAM, the EGT goes down like 200 degrees. That's why you check up ever minute or two.
You really don't need to worry about any of this stuff like Dave says. I wouldn't worry about it unless your engine builder recommends it. Some Majors guys run a pyro because they are running right at the edge of valve/piston melting (1350F EGT) You're not gonna hit that until you run too lean combined with more then 12:1 compression. Remember to to feed that thing pleanty of fuel and it won't run hot.
Our car runs 50 psi, 180-210F oil all race last time, it was 90F ambient. That's nothing. Some 12 car engines will heat the oil to 300F. That's cookin' it!
Thanks for all the info. I thought that the higher rpm would keep it running cooler but I'am not familiar with air cooled engines. I was told by my engine builder to always run on the rich side to keep it cool---never thought about checking up on the pedal every minute or so to feed it that extra fuel. As for pulling over to let the other 11's pass wasn't necessary they had already passed me! Thank's agin for all the help looking forward to racing with you all soon.