KILLER-LS1

iTrader: (18)

Hey so i started my new motor, and I only have like 5-10 psi at idle and 15-20 psi whn i revved it to 3,000 RPM

Before you ask:

i set 1/4" of clearance between the pan and pickup
i made sure that the o-ring went in fine
i ported and shimmed my new pump. (added washer under the spring)
yes the oil gallery plug is in the block

I cant figure this out for the life of me... everything else seems to run great!

Anthony Williams

iTrader: (3)

Possibly too much main bearing clearence the buiilder should have given you a spec sheet?

mike13

iTrader: (27)

I was reading another thread about low oil pressure on a new motor, he swapped out the oil pressure sender and his pressure was normal.

butler

Just a suggestion. To check for mechanical oil pressure break off the upper plastic part of the oil sending unit drill and tap for fitting in mechanical unit and fire it up to see what you get. Sure it will cost you a sending unit but you will know the truth.

totalengine

iTrader: (3)

Try oil pressure sender i have had 2 or 3 cars do the same thing and thats what it was

Sales2@Texas-speed

iTrader: (5)

What kind of clearance do your main and rod bearings have?

SSPerformance

iTrader: (76)

Who built the motor?

Tony Mamo @ AFR

iTrader: (13)

Verify with a mechanical oil pressure guage....if good replace sender....if still bad keep digging.

Assuming the pressure is in fact low its likely excessive lower end clearance or your lifters are possibly designed wrong and your hemorrhaging oil in every lifter bore. Not likely in a hydraulic....seen most of the problems there with some solid lifter designs.

-Tony

NC98Z

iTrader: (1)

It would be easier to tap it out here than to drill on your sending unit that might be good. If its good here then replace your sending unit. If not, carry on!!

Attachment 215059

butler

True. I'm carbed so the sending unit is easier for me and besides I would rather have a mechanical gage especially for oil presure.

HUNTER02SS

iTrader: (24)

Isn't there a small freeze plug that go's behind the timing chain as well.

KILLER-LS1

iTrader: (18)

no there isnt. i have a spare block sitting next to my computer

and I built the motor... but i had my machinist size the bearings for me, and i installed them. this machinist is top notch, been in the biz for over 60 years.

the only thing i can think of is maybe when i put together the pump, i tightened the cover too tight? could this cause rubbing and damage the pump??

TS6

iTrader: (41)

Doubtful. My money is on excessive bearing clearance, but until you verify psi with another gauge we're just guessing.

KILLER-LS1

iTrader: (18)

found my sheet from the machinist....

clearances were between .0032 - .0035" of oil clearance on all 8 rods.
clevite bearing 663 HN

i dont see the info on the mains but im sure they are within spec

NastyC6

iTrader: (77)

did you install the dumb bell in the oil galley at the rear of the block?

NastyC6

iTrader: (77)

yes it's in the block,the oil gally plug.that might be it?

KILLER-LS1

iTrader: (18)

yes, see first post.


and as far as the freeze plug, thats not behind the chain, there is a tiny dime sized freeze plug under the front cover but its to the very left, and yes that is still in place

NastyC6

iTrader: (77)

then hopefully your pump took a ****,put a gauge on it,then you'll know.

KILLER-LS1

iTrader: (18)

well im the douchebag. i never removed the freeze plug so i assumed it was still there. i guess the machinist took it out its all good,


thanks so much for all the advice everyone, i totally overlooked that!

butler

Very good. I think the rod bearing clearances are a little loose. .002-.0025.