Pushrod Not Spinning

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T56MaxTorq

T56MaxTorq

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I have one pushrod that isnt spinning at all after a cam change on the Duster Broke it in with moly grease, zddp oil and some additive, 2500 varying rpm for 35 min. Took 3 tries to get there, never cranked and cranked..always started up fast. Runs and pulls good. Idle has a slight miss but maybe it's the cam..? MP 284/284 .528 solid flat tappet. 11-12" vacuum. It's too late tonight to do any measurements. I was going to do a compression check (it's #6 intake valve) Measure lift, and maybe run another pushrod. Should I really be worried about toasting that lobe?
 
Might mean the lifter isn't turnin either. That would suck.
 
you can pull the lifter with long needle nose plier and give it a look.
u may have to back the intake bolt out just a lil to clear.
Also make sure the push rod isnt bent.
 
Hmm I didn't think about long pliers. I can get a set of those quick. Or a good magnet? I have one thatll pick up the oil pump drive. While at idle The pushrod spins freely and feels straight when give it a little help. But I can't feel any real resistance spinning the opposite direction. It may be running flat..I've put an hour or so on it today and again it runs good but this may be that miss at idle. I'll try tomorrow

Oh and my hot lash, all around is good. The problematic intake valve isn't being held open by any means.
 
Well I think it may be done. I pulled the lifter and it wasn't screwed up or worn but it appeared to have a shiny area where you could tell it wasn't spinning. Swapped pushrods, doesn't spin. Ran without the valve cover and I could for sure tell the lifter wasn't spinning. I think I'll buy 1 loose lifter and hope for the best.

Oh and I measured max lift and the lobe hasn't gone flat.
 
A new lifter should fix it right up then. But make sure you can spin it by hand in the bore. That bore may have a bur in it.
 
Good eye and attention there. When it's assembled, lifter rotation and lifter to bore clearance should be checked. Any that dont rotate need to be swapped around until they all do.
 
Well hopefully tomorrow I can lube the lobe haha. Then install the lifter, pushrod, and rocker, change the oil and pray it spins.

If it doesn't it's doomed. I'd love to get it going before snow hits but another cam would take months from all I free time I have. Although this was my first flat tappet cam and I wanted to get it right.

I'd probably pull the engine this winter. When I prime the engine I get 35 psi oil pressure - steady, at idle it says zero. I know that's impossible, the oil pump is spinning and there is oil in the top end. Over 2k it's 35ish but never goes higher. Autometer gauge. It's always been a screwy gauge, it jumps from zero to 15 often, changed the copper tube, no help; old one was pinched at the flare on the fitting. Also noticed no massive amount of oil being applied to the rockers, not usually what I see when priming. So that's been a worry.

The valves looked like the stem seals have been leaking but the ports are nice, maybe need a little cleanup from the last porter.

Thanks for the help guys!
 
I would check lifter bore diameter and check it for burrs/out of round/anything that would cause the lifter not to spin, before I tried another cam.
 
I will for sure. The lifters all spun freely when installed but I didn't check diameters.
 
It spins!! At least initially it is during break in. The pushrod was spinning ever so slightly. I couldn't see the lifter cause I just lifted the valve cover a bit to look at the pushrod. Oil loves to go all over the headers and make a big mess with the cover off and at a higher than idle rpm. I'll check again at idle soon and report back. Thanks again guys! All of you have been a major help!
 
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