The Evo bikes came before the Twin Cam, of course. Twin Cam riders have complained of heat from the engine. Heat can be caused by a lean running engine, of course. I read the Twin Cam engines are better at dispersing heat than the Evo engines. If an Evo and Twin Cam are allowed to run as rich as optimal for the engines, how much of the Twin Cam's heat is due to it being better at dispersing heat? What other reason's other than lean running and being better at dispersing heat causes the Twin Cam to run hot, if applicable?

 

The Catalytic converter is in the pipes right below your right leg on a twin cam, this is a huge issue concerning heat. Remove the cat and the bike will be cooler, maybe still not as cool as an Evo, but better.

The second is engine displacement, bigger engine is more heat.

 

Anyone know what year they started using cats?

 

Some models in 2009 ( I think CA bikes and CVO's) and all of them in 2010. Which model and year do you have?

 

When you say one motor runs hotter then the other you really need to where they run hotter. Motor temp wise the Evo runs hotter when making the same HP as a TC. What will like be felt tho is more from a TC because it radiates more heat. Since it radiates more heat it appears hotter to the person close by. Compare the fins on an evo to a TC some time.

 

I didn't purchase one yet. I'm looking to avoid things like cats and electronics.


Thanks for the great post, Max.

 

[QUOTE=ShadowforNow;17827903]I didn't purchase one yet. I'm looking to avoid things like cats and electronics.

To avoid electronics you'll have to look at carbed bikes. I think the last year for a carb was 2005. About a dozen years back you could get the same model with EFI or carb, so that might be a starting point for you.

 

Even my new '70s shovelhead had 'electronics', in the form of a solid state rectifier and a factory alarm system. Carb Evos have 'electronics' in the form of the ignition module (plus regulator). Be wary of what you wish for....

 

Anything new Evo wise uses the twin cam style fins on the barrels and heads. Thicker wider gaped fins disperses more heat, and like said above how you measure engine heat will sway the comparison. Best way I would think is to use oil temps, and even then theres issues. Evos run tank to engine to filter to tank which could cool down oil by the time it reaches the tank where you're measuring. While a Twinkie runs tank to filter to motor to tank.
I always felt more heat from my streetglide on my legs while riding than my FXR but that could be because it was doing its job and throwing the heat out instead of keeping it in. Either way if youre running a cat get it the f out of there

 

The heat issues come from the edicts from the EPA. The TC EFI models are programmed in the ECM to run a preset AFR. Unlike the carbureted models,