low oil pressure on stock rebuilt motor

[LePore]

just completely rebuilt my motor and only have 10psi @ idle will rev up to 25psi. no oil thru push rods to rocker arms. i primed the oil pump with drill. reused old oil pump that held good pressure (50psi) before rebuild.

what could be the problem?

also motor has only been on start up. has not been driven.

 

[leroy]

Re: low oil pressure on stock rebuilt motor

Remote oil filter lines crossed?

They forgot to install an oil galley plug?

Jim

 

[LePore]

Re: low oil pressure on stock rebuilt motor

what is an oil galley plug? and where does it go? did not remove one.

 

[Don W.]

Re: low oil pressure on stock rebuilt motor

Galley plugs live at both ends of the oil galleys which run through the lifter bores lengthwise through the motor. If the back ones were out you'd have a horrendous oil leak. If both fronts were out I'd be surprised you'd have any oil pressure. One front? Might be the issue.

Same as Dave... You say "you" just rebuilt your motor. Any details? What was changed/replaced? Any strange noises from the motor? Did you change the cam bearings? Was the block machined? Betcha they removed the plugs, but, depending, they should have put them back also. Sometimes you get all that stuff in a little bag.

My guess? Front galley plugs. Reason: Not enough oil pressure to push oil through the lifters up to the rockers.

IMHO Yur gonna have to check by removing the timing cover and chain, although you'll prolly be able to see as soon as the cover is off.

 

[LePore]

Re: low oil pressure on stock rebuilt motor

Where are you measuring the pressure at?
What kind of gauge are you using?
What are the bearing clearances? Or did they even get checked?
Are you using the same distributor as the old engine? Or has it been changed?
Are there any noises?
Did you have to grind the front of the block for timing gear clearance?

using a mechanical oil pressure gauge @ the stock pressure switch on the block next to the distributor. machine shop pollished the crank and installed .010 rod and main bearings. cam bearings are standerd. clearances checked by machine shop. distributor is the same. no noises except rockers because lifters are not pumping up. block was not ground.

 

[LePore]

Re: low oil pressure on stock rebuilt motor

Galley plugs live at both ends of the oil galleys which run through the lifter bores lengthwise through the motor. If the back ones were out you'd have a horrendous oil leak. If both fronts were out I'd be surprised you'd have any oil pressure. One front? Might be the issue.

Same as Dave... You say "you" just rebuilt your motor. Any details? What was changed/replaced? Any strange noises from the motor? Did you change the cam bearings? Was the block machined? Betcha they removed the plugs, but, depending, they should have put them back also. Sometimes you get all that stuff in a little bag.

My guess? Front galley plugs. Reason: Not enough oil pressure to push oil through the lifters up to the rockers.

IMHO Yur gonna have to check by removing the timing cover and chain, although you'll prolly be able to see as soon as the cover is off.

no oil leaks so if the front plug was pulled i did not realize it when i got the block back. i guess i'll be pulling the timing cover tomorrow.

 

[Don W.]

Re: low oil pressure on stock rebuilt motor

You could confirm with another ga., but... Sorry, to save it and before I ran it ANY further I'd pull the front cover and check. Oil is getting away somewhere. If you lower the pan just a bit you can get the front cover off without dropping the pan entirely.

 

[Don W.]

Re: low oil pressure on stock rebuilt motor

no oil leaks so if the front plug was pulled i did not realize it when i got the block back. i guess i'll be pulling the timing cover tomorrow.

The two fronts are press-in not screw in like the rears. Its remotely possible that the the plugs were pushed out by oil pressure. Or the wrong size was put in and they just came out. UGH.

 

[LePore]

Re: low oil pressure on stock rebuilt motor

The two fronts are press-in not screw in like the rears. Its remotely possible that the the plugs were pushed out by oil pressure. Or the wrong size was put in and they just came out. UGH.

i did notice that i had some oil on the driver side rockrers but the passenger side was dry.

 

[REVEREND HARMON]

Re: low oil pressure on stock rebuilt motor

stock main caps?........i had similar problem.....kinda a fluke though, a main cap was cracked.

 

[LePore]

Re: low oil pressure on stock rebuilt motor

Call the shop and alert them to the problem. Sounds like it's on them. At least in your mind.

You didn't check the clearances yourself, did you? Or look it over after you got it back and as you assembeled it, did you? Or you would know whether the plugs are in it or not without having to pull the cover and look.

I'm not bagging on you dude. Just making an example that others can learn from. It's the details that count. When inexperienced people assemble engines, stuff like this seems to come up.

i did not think i needed to check clearances, thats what i payed the machine shop to do. i may have made a rookie mistake but you dont learn by having others do the work for you.

 

[LePore]

Re: low oil pressure on stock rebuilt motor

stock main caps?........i had similar problem.....kinda a fluke though, a main cap was cracked.

yes they are the stock caps. they where checked along with the pistons wich i had to replace two of them.

 

[LePore]

Re: low oil pressure on stock rebuilt motor

If the crank was already .010 undersize, and not in need of re-grind, then the above makes sense.

It can also be construed from the sentence-structure you used above, that the shop assembled this engine, and not you. If this is the case, take it up with the shop. Both you and us here trying to help you will only be guessing as to what the problem might be.

If someone else put this engine togeather, they're responsible for the low pressure.

yes the crank was .010 they pollished the crank and honed the block.

 

[turbodig]

Re: low oil pressure on stock rebuilt motor

I use a machine shop that does 90% of the race motors in the area, and has been doing motors for 30 years +.

I still re-check all bearing clearances myself. Everybody has a bad day once in a while... I'd rather it not be on my dime.

It kinda sounds paranoid, but you're much better off not trusting anybody's work, *even* your own.

Most good shops, if they built the short block, will stand by their work.

 

[LePore]

Re: low oil pressure on stock rebuilt motor

This is the engine in the Conquest. Now I remember your screen-name, and the context. You're not a rookie. Not if you can do this swap. Sorry for being a little hard on you.

The oil to the RH lifters has to go by the distributor. If the distributor isn't seated properly, or has been replaced with a unit that isn't machined properly, this oil flow may be impared. But to only have 5 psi at idle seems like a big leak.

My Typhoon had 8psi at hot idle. (30W oil). It also knocked. The mains had to be turned .020 to clean up the damage. The clearances had to have been in the .015 range. I didn't check them upon disassembly.

Let us know what you find.

no problem Dave, you and turbodig have a good point. if i would have checked the block better and not assume it was right i would not be having this problem. i'll be talking to the machine shop in the morning.

 

[cloneman315]

Re: low oil pressure on stock rebuilt motor

im sure its there fault.....I know you dont want to hear this but pull it back out....

 

[ghettosled]

Re: low oil pressure on stock rebuilt motor

pull the oil filter off or the remote filter adaptor and check for a shiny little ball to the side of the screw on fitting. These often get removed for cleaning out the oil gallies and will do the same thing if not re-installed. thats an easy check without pulling the motor all apart.

 

[Don W.]

Re: low oil pressure on stock rebuilt motor

With all due respect to Mike (I've met him :tup:and done business with him:tup with that ball removed all that happens is oil does not go through the filter.

Which brings up a point. Some sort of serious restriction in the external system? There is a bypass at the block and in the remote filter housing but if they got plugged (not uncommon to intentionally plug the one in the block) then I don't know.

A remote possibility is that the oil pump is not attached correctly or has some other issue but that requires pan removal. Yuk.

 

[ghettosled]

Re: low oil pressure on stock rebuilt motor

need to stop posting at 1am i guess... pretty sure a couple years ago we left one of those out on a motor, and it was down like 20psi on oil pressure. I remember at the time i thought the same thing (that it had nothing to do with the oil pressure, just filter). Put it back in and it went up.. could still be totally dillusional though.

 

[Don W.]

Re: low oil pressure on stock rebuilt motor

Ya Mike, I'm just going by the oil circuit diagram in the manual. That ball just works as a diverter forcing oil over to the element or adapter in our case. For those watching don't forget it's a press fit. You can't just use any thing and, BTW a plug is available if the ball is gone.