TO30 no oil to valve train

Bobcat07

New User
I bought a good running to30 from my wifes best friends FIL. He had a drop in oil pressure and put anew gauge on to confirm. I never got to talk too much to him so....
I put a oil pump in and sealed the oil pickup arm and now i have 20 psi cold fast idle. Checked one main w plastigage n was w/i specs. Like a good mechanic I'm going to check the valve lash quick b4 i set this out for sale and one rocker is worn so bad its cocked on the rail but... has been adjusted. So someone knew about the problem and ignored it. Now i can't sell it and keep a straight face.
I ran it the other day with the plug out of the far end of the rocker tube... nothing. Ran it for 5 min and then pulled the plugs and rocker assembly off quick and spun it w the starter n have 4-5 psi but no oil up top.
Could a cam bearing(s) be so bad to not allow 20 psi of oil to get up top? Does the oil have to flow thru the last cam bearing on its way up so a spun bearing would block the path?
What would you do first?
The valve cover and original rocker assembly was dry, like sitting out in the driveway dry. But... that was with no oil pressure due to a worn pump.
 
I have a manual that shows the oil galleys and paths that th oil travels till it finally gets to the rear and heads up to the valve train. Seems to me that 20 psi should pump oil up to the ceiling of the garage. The guage port is in the rear of the engine too, away from the pump so if there was a drop it should be read fairly accurately ima thinkin...
The oil makes a 90 after going straight up from the main galley and heads horizontal for a few inches till its below the pedestal that is drilled out to receive that flow. There is plug, on the end of the head, to plug the drilling that went on for the horizontal run. Think there could be debris or tar at that 90 thats blocking the flow?
I just dont know where to start.
Maybe a rod or main that i didn't check is so loose it pours out there, but 20 psi worth?
 
Can you get the oil gallery plug out that is in the head and see if you get oil coming out there while cranking? I have a Z134 engine that someone tee'd off from the oil pressure port on the side of the engine and ran an external line up to the plug in the head to feed the rocker assembly. I haven't taken the engine apart yet to try and find out why the normal route is plugged... You could try going that route for a quick fix if you don't want to tear into the engine any deeper at this point.

Dan
 
Aaaa! Brilliant!
I get my long weekend starting Thurs, that's what I'm gonna try.
Wow, that actually sounds like an easy fix and im positive that will feed enough oilx if too much i can pinch the tube or do an orfice and adjust the hole size.
Waaa Thanks a bunch!
 
If no oil to rocker arms, the rear main bearing was possibly in wrong or has slipped to block the oil from
entering the galley that supplies the rocker assembly.
 
The rockers oil from the rear main. It meters oil as the crank turns, so you won't get oil up there cold
cranking it.

The first thing to try is poking down the oil galley with a wire from the top where the rocker stand bolts
on. Possibly the head gasket was installed with sealer and the sealer could have blocked the passage.

The other possibility, the rear main was installed backward, or it has spun and blocked the oil passage.

Once oil flow is established, you'll need to replace the rocker assembly. Either a good used set, or a
reconditioned one. It can be reconditioned with a new shaft and replacing the bushings, but it is a tedious
job, the bushings must be reamed to size, much easier to buy the reconditioned assembly. BTDT!
 
I remember putting my Honda big red back together and there was a pill that went in the oil hole that fed the rear final drive. The pill had a small hole in it and the manual warned to make sure the hole was clear but, also to make sure to install the pill or the upper half of the motor wouldn't get oil due to the easiest path etc.
Im betting that either the bearing has spun, as was mentioned, or.... over time, crud has built up in an orfice that finally plugged resulting in no flow at all.
 

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