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BikeVice
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Joined: Oct 2012
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knuckle head
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knuckle head
Joined: Oct 2012
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The often quoted 10 psi per 1000 rpm is just an an opinion from years ago. Many engines would not be happy with 30 psi at 3000 rpm during heavy power loading. And many engines never need more that 60 psi no matter what the rpm or load...It's really a matter of engine design...


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Big D Cycle in Dallas can do your triple crankshaft correctly. They did mine several years ago. I was at the same point at that time. 35-40 psi hot at 4000 rpm, around 10 at idle. John Healy responded on another forum to my post and recommended redoing the bottom end. On tear down the main saddle bearings were worn but not completely shot. Crank was reground 10 under and new bearings fitted. Also an NOS oil pump and new OPRV from SRM. Oil pressure is now 75-80 hot running and 30 at idle. I wouldn't say a triple engine was any harder to work on than a twin. Only tricky part was fitting middle piston. Install in block first then put the rod cap on through the sump opening in the bottom of the cases.

Last edited by htown70; 02/14/21 5:49 pm.
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Hi

For what it's worth, I recently purchased a oprv spring from LPW 1.5"

Regards


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3000 rpm on a triple is lugging it--they do not come on the boil until about 4500 rpm.
So--warm up the engine slowly and then ride it keeping it on the boil at over 4500 rpm and you will be able to postpone bottom end work for a while.
If you have 35 psi at 4000 rpm then you are under the level of the rule of thumb and should seriously consider getting the bottom end done before you have a disaster.
Fine judgement required!

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I appreciate everyones insight and opinions, good stuff. Thanks. I can't wait for Summer

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