.650+ solid rollers.... low oil pressure
Just this week I found out the cause of the problem while in west Houston.
It seems that when using the Crain solid lifter on a large lift (.650+) cam the reduced base circle enables the lifter to travel to far down uncovering the lifter bore oil galley thus causing an internal oil leak. The amount of the leak will be different from cam to cam depending on the base circle and the block machining. For instance in one block a .700 lift cam was ok and a .750 lift traveled .020 to far.
In my iron block a .615 was ok and .650 is marginal.
The fix!!!! Comp Cams part number 859-16 lifter.
It requires a little grinding on the link bar for clearance but other than that it's a drop in.
<small>[ March 07, 2003, 10:00 AM: Message edited by: Joe Kizzire ]</small>
I have the "drop-in" Crane lifters (don't remember the P/N), and haven't seen any kind of problems.
20lb pressure max.... They removed the head and pressurized the oil system and found the problem when oil poured out between the lifter and the bore. If you've got a block sitting around slide a lifter in and you can see how it would happen.
The part number I posted is for a 455 Pontiac. It allows for about .400 inch futher travel down the bore before uncovering the oil galley hole.
All the testing was done at SAM on the engine dyno.
I'll email you my number. Call me if you need anymore info.
I haven't experienced any oil pressure issues (just oil leak issues <img border="0" title="" alt="[Razz]" src="gr_images/icons/tongue.gif" /> ), and I don't plan on swapping cams anytime soon.
I just found your post to be interesting/informative...
<strong> How could you see what was going on from where your head was?
Tim </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Unlike you Tim I have no need for a step stool to see what other people see.
I will be checking on this to see how my car does since it will be running a pretty high lift.
Greg
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<strong>Unlike you Tim I have no need for a step stool to see what other people see.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Just an extractor. <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" /> <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" /> <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />
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