Late Chief cylinder temperature question

[cdf6333]

Another try. Has anyone measured the temperature of stock Chief cylinders during normal use? I figured we'd have at least one engineer that "had to know". I'm still looking to powder coat my cyls, as all the new HD's are powder coated. I know side valve engines run hotter, which explains lower engine efficiency, but how much hotter?
Thanks, Bob

[phillie]

Bob I think I am gonna have to do this this summer. However that doesn't help you now.

[kval]

Bob
I will be down in a few weeks, we can check it then

[tfburke3]

Hey Bob,I have had a IF temp gun for a long time and my 47 ususally reads in the 375 range,but I have seen as high as 425F.

Tom

[cdf6333]

Hey Tom/ Thanks a lot. It seems that the magic number for powder coat is 400. but this is from Figure Finishing, and sort of mentions occasional 450.
Where are you measuring this? Cyls or heads?

Q: How does powder coating hold up on finned (air-cooled) motorcycle cylinders and heads? Can it handle the heat? A: Powder holds up great on motors. Most powders are baked at 400*F, and most engines shut down at 250*F, Harley Davidsons included. Also, powder technology has been progressing aggressively, and most powders have an excellent overbake stability, easily exceeding 450*F operating temperatures without failure.

The only part of my Chief that bites is the cylinders. Everything else stays nicey-nicey, but I keep getting rust there.
What do you think of powder coating them? I'll probably give it a try, as I'm down from an accident and I'm stroking this bad boy.
Nice to hear from ya and thanks for the info.
Bob

[cdf6333]

Picked up a IF temp gun at Home DEpot for $40. Dennis lives a couple miles away from me here and when he does his 10 mile test lap, I'm going to check it. I'll measure at 3 or 4 places on the cylinder, near the ex valve, in valve, other side of cylinder and base. I'll post it next week, but I'm probably going to give the powder coat a try anyway.

[fabercycle]

Powdercoat will look nice for a really long time on your cylinders, but the plastic coating will trap heat in your engine, and not allow the fins to dissapate the heat in the air,(heat = friction = wear). The fact that you are stroking it will also add more friction from a faster reciprocating piston speed, more friction, more heat & wear. Expect to be rebuilding your motor a little more often.

[cdf6333]

Thanks Tom
I'm almost guessing heat will be a wash with the modern lubricants available. I am really loving the lead free gas too, less deposits.
Figure Finishing has a neat web site and they state that it won't raise the engine temp, that's where I got the quote above.
I'm 66, I got about 20 years and 30,000 miles on my last engine, the days of cleaning it after every ride are long gone.
Best to ya
Bob

[PRG]

Howdy Bob,

PC will look fantastic for a while and where it will begin to yield is the machined face surface at the exhaust ports where the headers insert. As PC is more viscous when momentarily liquified prior to baking than a high quality urethane it does not get the penetration into all the voids on rough cast iron so this allows moisture to creep in underneath the surface into these voids. It then flakes off like any paint would that has been applied to a poorly prepared surface. I went back to a standard glasurit 22line high solids polyurethane. Most PC shops want to give you "your money's worth", by applying very heavy coats, this would seem to exacerbate the problem.

[cdf6333]

Thanks Peter, but what type of this do you use? I didn't see a "high temp" listed. And how do you apply it? Big gun and cover or touch up gun? Interesting web description, but didn't see anything about engines or anything.

[PRG]

Howdy Bob,

I used Glasurit's then 22line single stage polyurethane from a large stash from which I did both my 348 and 441 cycle parts. It is not high temp rated but lasts far longer if you bake it following initial application. For a more authentic look one's advized to mix some deglosser in otherwise it has a very high sheen. I shot the 348 cylinders and both entire machines with a Sata MiniJet graviity feed gun.