Response to a question on how a re-built Poly runs with a Hydraulic cam.	
		
												
	The cam seems to run fine at all rpm,s. However, since I’ve had the cam in 
since, I rebuilt the motor I don’t know what a rebuilt engine was like with the 
solid lifter cam. 
The motor runs about 68 psi of oil pressure at anything above an idle so I have 
a hard time following that “runsflat above 2400 rpm”(per letter from Larry Jenkins) 
thinking. I mean if the lifters are good at 1500 rpm 68 psi wouldn’t the be good at 3000 rpm with 68 
psi? But then again, I am not exactly known for a superior mind.						I actually researched it a little prior to having the old cam reground and 
found a guy who did a lot of work on Poly 318’s. I made a call to him and he 
swore up and down that a hyd. Cam was compatible with the old 318. But on the flip side, since 
doing this, I’ve noticed some problems which may lead up to something eventually:			I’ve had to replace two lifters and two pushrods. One got some dirt 
or something inside and the plunger locked in the down position (which destroyed 
the cup end of the pushrod) and another had a retaining ring that failed and basically came 
apart(and destroyed the cup end of the pushrod).							I don’t think the lifters spin like they should. During the last 
disassembly for lifter problems I checked a couple of lifters and noticed the 
wear pattern showed the lifters were not spinning.							This setup requires a custom length pushrod. I attempted to maintain the 
factory geometry by comparing a factory lifter/pushrod with hydraulic lifter and 
measuring for thecorrect length. I don’t know if I actually got the correct 
length or not but I believe at least a few of the valves are being sideloaded from bad geometry.	
				
	
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