exhaust heat


Standard Bore
Nov 17, 2006
My Rocket (05) the center cylinder runs 120 degrees hot than the outside 2 cylinder. To me with a water cooled engine this should not be the case. Any ideas as to what might be going on.Steve.
Hi Steve. I am an optimist and going to say that the #1 and #3 cylinders just run 120 degrees cooler.:D

I don't think its anything to be alarmed about. Looking at this photo and seeing that there is not much of a cylinder liner or water jacket makes it easy to see how the center cylinder could be hotter. The center cylinder loses a bit of surface area by touching the other cylinders. Also Wayne from tuneboy has commented in the past that the center cylinder runs leaner than the #1 and #3. Just out of curiosity how did you measure the temp?
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OK... brain fart here... maybe the Pigman can help me remember...

When we were playing with the TuneBoy ect... we discovered that the center cylinder did have a different state of tune than the front and rear... I think it involved ignition timing and it ran leaner. We kind of thought that may be the cause of the popping on decel issue (that lean center cylinder) and low and behold when we richened that up it helped with the popping.

So, if you have a stock "tune" it wouldn't be abnormal for that to run a little hotter. In the greater scheme of things 120 degrees is very little. I get readings on cars (Using a lazer temp gun) anywhere from 900 degrees to 1600 degrees, but you have to remember that the catalytic convertor is right up by the exhaust ports on most cars now.... that cat can get hot!

Why Triumph set it up that way is a mystery to me...

BTW.... get off of that stupid R3 email board... someone needs to turn that off.. You guys need to move over here and drag yourselves into the 90's anyway!!!
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just pulled my exhaust for design of 4th and found lots of black carbon in the port and header on the #2. others are "normal". it's running way richer on 2...gotta get exhaust done and onto dyno and see what that's about.
The R3 email thing is a YaHoo group that someone started back in 2004? Its not really a forum, but you get emails from each user that posts something. If it was busy, you could get 10 emails or so a day. If it was as busy as our site you would have to wade through 50 to 75 emails a day. It gets old fast.

That thing will lay dormant for months without a single hit and then someone will post something and you will get a few emails. Anymore the only thing that triggers it is spammers, and then the two or three people still on it make a comment about the spam. I don't believe the guy that started it originally is even still around.

We tried to use that for awhile and it quickly became evident that the email thing wasn't the way to go. It does have a Yahoo photo album but it doesn't seem to work other than general posting. You are supposed to set up member albums but that feature has never worked...
exhaust heat reply

i am using a laser pointed heat gun and measuring temp as close to the head on exhaust manifold. I also tested the exhaust temp on a Land Rover v8 and a Jaguar xjr v8 on these to cars the temps in a similar point on the manifold all ran within 20 degrees of one another on both banks. The temp issue came up as i lost the timing chain and have noise coming from the head that was not there before the t.chain went out.thinking the heat may have caused a problem? Steve.
Travelguy said:

just pulled my exhaust for design of 4th and found lots of black carbon in the port and header on the #2. others are "normal". it's running way richer on 2.
Carbon doesn't always mean it is running rich. The way you should look at it is that the carbon is due to a lack of complete combustion, which can be caused by being so rich that there isn't enough oxygen to combine with the hydrocarbons present, OR, there aren't enough hydrocarbons to sustain combustion with the oxygen present, the "fire" burns out so to speak and raw hydrocarbons make it into the exhaust port. So being too lean can also carbon things up...