blower motor cam recommendation

A little low on the RPMs for me, but shouldn't have been that bad. Time spent setting the timing could be the culprit, the first few minuites are the most critical. I get the timing close enough to get them started, keep the RPMs up, varying it around for 15-20 min, then check the timing.
 
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I agree the rpm during break in is a little - you need splash lubrication that a higher rpm will provide. Always worry about "idea" timing later in the piece; the goal is to get the rpm up pronto and get oiling to the parts that are breaking in asap.

I have broken in both milder, "mid" range and "big" cams in FHs in both /NA and blower engines, always at 2K rpm and varying from 1800 - 2200 to mix it up/vary the break in on the cam/lifters.

Never had an issue - perhaps the diff in rpm made all the difference?

BFD
 
khschs said:
Re: break in,
Started engine,checked timing at 700 rpm and then moved it up to 1200 rpm. I changed engine speed from time to time never going over 1500 rpm and never letting it idle very long. The engine temp ran 185+- oil pressure never below 50 psi. The plan was to run it for 20 minutes, shut it down, drain the oil and change the filter. I almost made it.
Keith
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The problem may have been caused by not having enough RPM during the break in period - as others noted, I try to stay between 1500 and 2000 and move the speed around a lot. You need a lot of oil splashing on the cam to get it and the lifters broken in. If it starts to gall, things go bad very fast!
 
My '34 coupe has a 296" 3/4 Potvin cam with SS Chev valves. I am running a B&M 144 blower at 5psi. MSD ignition with boost retard. This engine was built by Mark at Motor City Flathead in 1998. It now has 25,000 miles with no problems. This engine pulls like a freight train and I run it regular to 6000 rpm. Mark Kirby did a lot of research and came up with the Potvin, I believe Flathead Jack carries these cams..
 
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