heads torqued

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socalrider
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heads torqued

#1

Post by socalrider »

re-torqued the heads and cylinders to my 65 flh today . it has only 250 miles after overhaul. heads at 60lbs and cylinders at 40 lbs. only the bolts to the front head turned . they went about 3/4 to one full turn each. i used a click type torque wrench , i know they suck but its all i got and figured it should get me close since its pretty new. does that seem right that only the front head bolts would turn? i did remove the upper motor mount before i did the re-torque.
gracias ,
arnulfo
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Re: heads torqued

#2

Post by Bosheff »

Are ya sure ya torqued the front cyl. head to 60 ft. lbs. the first time? Did ya torque in three stages?....bosheff
Cotten
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Re: heads torqued

#3

Post by Cotten »

Arnulfo!

If we give the clicker the benefit of the doubt inspite of its nature,
and assume you had all the right extention adapters to torque them equally, then the first thing that would come to mind is that the front head saw more heat than the rear.

It might only be that you have been so gentle in the break-in that the rear has not reached its full temperature, particularly if limbering up the machine in short hops.

The front head runs hotter than the rear.

....Cotten
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Re: heads torqued

#4

Post by Mark44 »

Cotten wrote:Arnulfo!
It might only be that you have been so gentle in the break-in that the rear has not reached its full temperature, particularly if limbering up the machine in short hops.

The front head runs hotter than the rear.
....Cotten
Hmm, that's interesting. I would have thought that the rear head would run hotter, being as the front cylinder is more exposed to the cooling airflow, plus it somewhat blocks the flow of cool air to the rear cylinder. Do you know why this is so?

I did some work on VW engines years ago, and the buses were prone to burning the exhaust valve on #3 cylinder (at the left front of the engine), especially if the valves weren't kept religiously adjusted. The reason was that the oil cooling tower partially blocked the airflow to #3 in the engine shroud. To correct for this problem, VW engineers adjusted the cam timing for #3 cylinder, in effect retarding the timing for that cylinder. Is there anything like this going on that explains why the front cylinder would run hotter on Harley engines?
Thanks,
Mark
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Re: heads torqued

#5

Post by Motorcyclemike »

Why would the front head ever run "hotter" then the rear?
Thats sure strange that the front lower cylinder bolts were that loose.......if it leaked oil....it sure would break the seal in the cylinder base gasket....did it?

I really doubt thats it a cam timing issue.
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Re: heads torqued

#6

Post by Cotten »

Folks,

I don't know why the front runs hotter than the rear, but it does.

Having 'autopsied' dozens of sets of heads, the heat signatures were most often greater on the front than the rear. For example, heat distorts exhaust valve seat inserts over the port, and most often the front will be more egged than the rear.

Ever wonder why front Knuckleheads have so much more finnage than the rear?

....Cotten
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