Back story 92 ultra, motor just reassembled/reinstalled with new lifters, lifter blocks, cam, rings, cam bearing, gaskets, new oil pump(AFTERMARKET, NOT HD)

My problem is when the bike reaches full operating temp I am getting 0 lbs from the oil pressure gauge in fairing at IDLE, idiot oil light stays on until above 1600, and Im lucky to see even close to 10 lbs at 3k rpm on highway, results in top end tapping after a bit of riding.

The breather gear bore is fairly damaged/scored from lifter/lifter block failure. Engine builder said it was an ok fit with new stock sized plastic breather gear, so I didnt think about boring it out to fit .030 over S&S breather gear.

So I am trying to figure out if this problem is coming from the poor seal between the breather gear/bore, or if I just got a shitty aftermarket oil pump that just doesnt have enough pressure. I honestly dont understand how the breather gear issue would cause the pump to not have enough pressure to get oil up the lifters to the top end and cause tapping. EDIT: Actually its very possible that the breather gear thing is my problem, if its supposed to be sealed during piston upstroke, but its not, it could cause negative pressure in camchest robbing oil marked for the top end into the camchest

Couple Q's:
Could the probem be the aftermarket oil pump? Its brand new, but not HD
Could the problem be the poor seal in the breather gear/bore?
Cannot think of anything else it could be

Im about to pick up one of those s&s reed valve breathers to save myself from boring out the breather gear cavity. This is the best solution I can come up with for this, short of buying an HD oil pump.

Any help is greatly appreciated

 

Did you prime the oil pump? Also I've only heard real good things about two types of oil pumps, S&S and oem.

 

I should think my indy primed the oil pump, but I guess I cant be sure, will try that tomorrow.

 

EVO's are more about flow than pressure although the light should go off at idle around 1,000 RPM ..

 

The breather must be timed correctly with the cam & crank so it breathes at the proper time of the pistons stroke. It would have been good to at least hone the breather bore & mike it for tolerance. there is a reason that the engine designers want it to fit snug!!
Running a bike with insufficient oil volume or pressure can cause damage quickly. Can you tell if you have oil at the rocker box's?
I don't know your indy so I can't comment on his workmanship but a second opinion by another qualified wrench about your oil issue would be your best move before you take the chance on damaging a new motor!
Hatch.

 

Are you running the HD synthetic? reason i ask,, When i had my fatboy i liked a low idle, and had a pressure gauge mounted near the lifter block so i could see the pressure when i wanted. low idle and dino oil = Very low pressure at low idle. switched to HD synthetic and low idle or not, pressure increased to over 10psi all the time. Might be something to consider,,,

 

The gear breather clearance has no effect whatsoever on oil pressure, at that stage its just clearing the combustion pressures.

Although many people have correctly pointed out that Evo's are about flow rather than pressure...the readings you are getting would suggest that the flow is compromised.

An un-primed pump will bleed itself once running, it won't pump at half volume for more than a few minutes, its not able to work like that..... in your case I would recommend having the pump off and apart to check its all together properly....OEM or S&S are the recommended options as the pump is the heart of the motor....also look for a blocked or kinked feed line.

Don't ride it again until its fixed......if an Indy put the whole motor together you need to take it back to him and don't let him fob you off with BS about flow.

There has been a comment on here that the oil pressure light should go off after 1,000rpm.....in 35 years of fixing Harleys I have only once seen one (an Ironhead) that had the oil light lit up at idle....and that bike crapped itself soon after.

The light should go off while the starter is turning, Evos' need 900rpm to get oil up to the rocker gear, if the light is on past 900rpm then you aren't getting sufficient flow to the rockers as even though flow is the go....0lbs pressure means no vertical (or horizontal) flow.

I suspect a bad or mis-fitted seal in the oil pump....keep us posted please.

 

there's a reason you're not getting any pressure.... it has to have something to do with the pump....like others have said, either it wasn't primed or that breather gear bore is so far gone that there's too much space in there for the stock one and it's compromising the pressure and flow, i suspect

get it bored out .030 over and put the steel S&S in there...i did

 

About priming the pump...I did prime the pump again today didnt help, but even before the bike has normal oil pressure upon start up, its only after about fifteen minutes of running the pressure drops off and the top end starts tapping. If it had not been primed I believe it would have no pressure immediately upon start up, correct?

I am quite sure my problem is coming from the poor seal of the breather gear. Correct me if Im wrong, but if the breather gear is not completely sealed when its supposed to be closed(upstroke of pistons) wouldnt the negative pressure in the crankcase from piston upstroke sneak past the non sealed breather gear/bore and cause negative pressure in the camchest as well? Hence pulling oil that should be going into the tappets and up the pushrods directly into the camchest? Causing almost a suction from the feed side of the oil pump... and causing my problem. I think ill be ordering a .030 over s&s reed valve breather

 

that's what i'm thinking