I'm helping a friend with his engine (roller 408), and he is hearing a slight valvetrain noise. Now he had his engine rebuilt at a performance shop with a decent reputation, however the more we look at it, the less we think of the reputation. On breaking it in we were a little disapointed in the oil pressure, 25 psi at 3000 rpm, upon inspection found that they used pushrod oiling, as well as shaft oiling. He then put solid pushrods in and had the lifter bores sleeved. Now with the high pressure pump we were looking at over a hundred. Next went back to stock pressure pump, everything seemed fine 527 HP at 6000 rpm, drives great.... but. There just doesn't seem like enough oil is getting to the rocker shaft, which is a Harland sharp setup. We ran the engine with the valve cover off , actually cut up a valve cover not to make a mess, didn't need it, oil only seemed to drool out of the rocker shaft, under the rockers. Now I've run stock chevy engines with the valve covers off and there is plenty of oil going everywhere, not on this 408. The oil feed seems clear. Are these like this with poor oiling to the upper end? Or do we still have some sort of issue here. I'm planning on building an engine very much like this for my Barracuda and want to avoid issues such as this, and help a friend. Thanks!
upper end oiling question
- Thread starter mar-tay1
- Start date
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360duster
Well-Known Member
normally there´s plenty of oil fed trough the cylinder head into the rocker shaft, when i did some oil pressure tests with my new engine (still on the stand, using my electric drill to drive the pump) there was a lot of oil there. The oil flow is timed trough passages in the cam, but with your engine running this does not matter.
Could be that the cam bearings are not exactly lined up with the holes in the block, restricting the oil flow to the heads. Or do these HS Rockers have very little clearance on the shaft?
Ask the engine builder if there´s a reason for the hollow pushrods....maybe you can get some more information there.
Michael
Could be that the cam bearings are not exactly lined up with the holes in the block, restricting the oil flow to the heads. Or do these HS Rockers have very little clearance on the shaft?
Ask the engine builder if there´s a reason for the hollow pushrods....maybe you can get some more information there.
Michael
moper
Well-Known Member
You need to verify the cam bearing alignment... I usually add a small bevel to the back of the cam bearing to help the passage align better but really there doesn't need to be gallons of oil up top and it only gets oil pressure for a few degrees each camshaft rotation. If each rocker and each pushrod end are getting oil from the shaft and the ends of the pushrods look good I'd say it's probably fine.
We were thinking that the cam bearing alignment was the problem. There is very little oil getting to the pushrod cup, I would expect to see more, especially on a cam with over.600 lift. I know on Chevys there is a problem with too much oil in the top end at high revs, this seems just the opposite. I guess we're pulling the cam to check the bearing alignment. Thanks!
moper
Well-Known Member
Pulling the cam and the heads... You have to peak down the passage from the deck surface into the cam bearing bore.
1wild&crazyguy
Banned
Mopars don't push a lot of oil to the top, they don't need it. And if you run needle bearing rockers that are known to bleed a lot more oil off...why would you want that?
Those harlands come with shafts that imo I'd rather have fit a lil tighter than they do, I use the rocker specialties shafts that are a lil larger, like .002, and are 3/8 thick wall induction hardened.
Those harlands come with shafts that imo I'd rather have fit a lil tighter than they do, I use the rocker specialties shafts that are a lil larger, like .002, and are 3/8 thick wall induction hardened.
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