| Moderated by: Greg Fletcher | ||
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Jon Plowe Member
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Hi, I have previously read about restricting the oil feed to the top of the engine is a worthwhile modification but can't seem to find it on the forum. Could somebody point me in the right direction. Cheers Jon |
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Greg Fletcher Administrator 
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If you have a very early 907 engine in your JH, then you might want to swap out the cam towers with later ones. Very early cars had some issues and the factory mitigated the problem in mid production by swapping towers that had a large, funny looking epoxy plug into the part of the end of the housing to slow down the oil drain back. My old car (VIN 13301) had this modification. Later cars had the housing manufactured with more material inside to do the same thing. Something to take a look at during rebuild time. |
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Jensen Healey Super Moderator 
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The early cam towers had the too-tight tolerance that required the use of STP. Of course once they're broken in and have no chance of seizing, these towers should limit oil flow and eliminate the need for the oil restrictor. One man's trash.... |
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Judson Manning Member 
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Jon, Restricting flow to the head is basically a racer's modification and MUST be done in conjunction with different main-bearings. The stock JH bearings 'leak' too much under pressure and restricting flow to the head only causes them to 'leak' more. This side-leakage actually starves the rod bearings long term. If you switch to the Holden bearings available through JHPS or x-drill the crank and use Esprit bearings, restricting flow can be helpful. These bearings can make better use of the increased pressure to feed the rods under high loads/rpm. Judson |
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