engine case temps

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seattle##gs

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what temp are the engine cases when up to operating temperature? I realize there will be quite a difference between Phoenix and Seattle.
 
Never checked them properly but the timing side gets up to 80c+ ie bloody hot.
 
I was into checking temps on all my bikes when I got my new infared gun. Most cases seemed to be in the 250-300 f range regardless of which bike. Heads and barrels were in the 300-350 range. Oil tank temps around 180-200. Tried checking exhaust pipes but didn't respond well on the chrome. Air temps were in the 70-80f.
 
interesting. That's the temp bearings are installed. So what keeps them from becoming loose in the cases at operating temp?
 
seattle##gs said:
interesting. That's the temp bearings are installed. So what keeps them from becoming loose in the cases at operating temp?
Click to expand...

When installing, only the case is heated .... bearing is cold. Removing, heat is directed at the case and heat to the bearing avoided.

At operating temp, both bearings and case are at same temp. Although aluminum expands more than steel, the difference is not as dramatic as heating aluminum only.

Slick
 
There are signs on old bearings taken out of housing on the OD that they do walk around the housing.
 
Is it not the level of the oil in the timing chest that creates all that heat? And you could drill the return hole a little lower to help with the heat?
 
texasSlick said:
When installing, only the case is heated .... bearing is cold. Removing, heat is directed at the case and heat to the bearing avoided.

At operating temp, both bearings and case are at same temp. Although aluminum expands more than steel, the difference is not as dramatic as heating aluminum only.

Slick
Click to expand...
Hah, not when using the wife’s oven to heat up a crankcase to remove main bearings.
 
Hortons Norton said:
Is it not the level of the oil in the timing chest that creates all that heat? And you could drill the return hole a little lower to help with the heat?
Click to expand...

According to some knowledgeable people yes, the oil contributes to timing chest heat. I drilled the lower drain hole, which also happens to undermine the utility of relocating the OPRV blow off hole that AMR does as part of the wet sump mod... oh well
 
at about .003 interference fit the bearing feels lumpy when turning with my fingers so about .002 fit is needed. It seems to me that the bearing is held
none too securely and very likely creeping around the bore when the motor reaches operating temp. Now, if you are riding in 95+ degree temps I would think the bearing bores would be loose perhaps, in some instances, be ready to fall out of the cases if that were possible.
 
seattle##gs said:
at about .003 interference fit the bearing feels lumpy when turning with my fingers so about .002 fit is needed. It seems to me that the bearing is held
none too securely and very likely creeping around the bore when the motor reaches operating temp. Now, if you are riding in 95+ degree temps I would think the bearing bores would be loose perhaps, in some instances, be ready to fall out of the cases if that were possible.
Click to expand...
Then you will want the Dunstall pinned bearing mod.
 
If you want to keep the 3 thou interference fit then if the bearing feels lumpy go for a bigger internal clearance ie CN to C3.
 
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