Lets See Some Rear Cylinder Heads

[Greydog]

I haven't had a chance to snoop around other Triglides to see if they are exhibiting the same thing as my dads 09 and my former 10 did. Both or our Triglides where tuned on the dyno and running a richer than the lean 14.6 and sometimes higher AFR Harley Davidson delivers them at. I started noticing the powder coat lightening or burning off around the spark plug area including down some on the fins. I'm not sure if this is due to running 8-12 hour days on the freeway at speeds of 75 mph + during the the hot months of summer, or something else. I'm thinking its just plane not getting enough air flow across the rear cylinder while riding at those speeds.

Sure looks like a "hot spot" to me. Lack of air flow could be the problem as well as a leaking exhaust valve. What does the rear plug look like? I'm not sure but I think ignition timing can also cause that. I do know that if it's getting hot enough you can experience pre-ignition or detonation and eventually a cracked or warped cylinder head.

 

[KindaOldTriker]

Eighty80,
Are you the guy I talked with twice at CENTURY? with black trike? :>)

Dale

 

[msocko3]

Sure looks like a "hot spot" to me. Lack of air flow could be the problem as well as a leaking exhaust valve. What does the rear plug look like? I'm not sure but I think ignition timing can also cause that. I do know that if it's getting hot enough you can experience pre-ignition or detonation and eventually a cracked or warped cylinder head.

Rear plug looked fine, wasn't showing signs of being lean or pre-ignition. The trike never pinged a day it its life, I even verified it via data logs with the TTS. My timing was conservative, I tuned it with running poor quality fuel in mind. I could run 89 octane with 10% ethenol in it all day long and it wouldn't ping a bit. I never had the need to but I believe I could have gotten away with 87 octane without a problem.

The primary role of the trike was traveling, with a good deal of that being on the interstate. I ran it out west twice where I traveled at speeds on averge of 80 - 85 mph for hours on end. We would stop every 100 miles to top off the gas and stretch for a couple minutes then hit it again, our stops where never more than 10 minutes which ment little to no chance for the engine to cool down. Of the close to 22,000 miles road it I would say 90% of those miles were on the freeway.

Aside from mine and my dads and some other folks who have posted up some pictures that show some of the powder coat burned away I've never seen anything like this. I have a couple sets of heads laying around with between 20,000 and more miles on them and the powder coat in that are is still like the day is came from the factory.

 

[Greydog]

Another thought might simply be contaminated aluminum during the head casting process. I worked in an aluminum mill for several years and you would be suprised at what oil contamination will do to aluminum in the annealing furnace. I don't know what alloy the motorcycle heads are but I've heard of aluminum automobile heads that were cast with iron in them and warped or cracked due to uneven heating of the disimilar metals. Just a thought 'cause if it ain't a hot spot I'm stumped!!:Shrug:

 

[msocko3]

Another thought might simply be contaminated aluminum during the head casting process. I worked in an aluminum mill for several years and you would be suprised at what oil contamination will do to aluminum in the annealing furnace. I don't know what alloy the motorcycle heads are but I've heard of aluminum automobile heads that were cast with iron in them and warped or cracked due to uneven heating of the disimilar metals. Just a thought 'cause if it ain't a hot spot I'm stumped!!:Shrug:

You could be right about the aluminum, this next spring I'll be running some V-Tunes and massaging the EGR tables on my dads. I'll have to monitor rear head temps some and see what I can see.