Rebuilt engine, low oil pressure

[dtw]

So this is frustrating. I finally got my 2.7 together and installed. Fired right up! That was the good news. When I spun the motor to build oil pressure before firing, the oil pressure light went out. The light stayed out when the engine started. At idle to 2k, the gauge just flutters around between zero and 20 psi. Beyond 2k, it goes to maybe 25 or 30 psi, no matter how high the revs. Tonight I put a mechanical gauge on it, similar results but not as much 'fluttering' on the needle and it got to 30 psi no problem, but that was it. With the mechanical gauge on, which had a fitting that didn't fit very well, oil was pouring out of the fitting pretty strong.

Other details:
-I am running Brad Penn 30wt break-in oil
-I did an initial fill of 7 qts.
-There is a remote cooler, installed new & bone dry
-Oil bypass pistons are brand new (could they be stuck open??)
-I checked oil pump seals just before closing case, they seemed fine
-The engine is otherwise making strong, healthy sounds

Any thoughts? If I have to tear this thing down again I'm gonna lose it...

[TimT]

You sure the sender is working correctly?

check the pressure with a mechanical gauge before doing anything drastic.

[Jeff Higgins]

Are you sure you put the right springs in the right holes for the bypass pistons? This can be a little bit confusing. That's about the easiest thing to check without really tearing into it.

[dtw]

Tim - Yep, see above - I put a mechanical gauge on it. BTW I've got a 3.2 on the way to you soon -

Jeff - pretty sure, yes, but I'll check it.

Could it have anything to do with the 30 wt oil??

[TimT]

One thing though, you mention "oil pouring out of the fitting" if that is so, you aren't seeing the true pressure..

[dtw]

Originally Posted by TimT

One thing though, you mention "oil pouring out of the fitting" if that is so, you aren't seeing the true pressure..

Yep, kinda what I thought. It made a big puddle under the car and fast.

[cgarr]

I am not sure if this could happen but the bottom (plug) Oil bypass piston which uses the longer spring should also have a guide installed since it is longer, if not could it be binding? Does the pressure come up with RPM? if so you may have some piston squirter's stuck open too.

[Flieger]

It should take 11+quarts to fill a dry engine plus a remote cooler and lines in order to have the dip stick in the tank read between the marks.

[al lkosmal]

I agree with Flieger. You're low on oil.

[Flieger]

You will have to wait until the car warms up enough to open the secondary thermostat to the front cooler, of course. You need to put in 9 quarts, warm up the car, then add the rest. If you check oil before that, it will be up to an OK level on the dipstick but the front lines will still be empty.

[dtw]

Guys, I hope you are right and it is this simple. You think I am sucking air into the pump? I'll add 2 more quarts tonight and give it a shot.

[304065]

Tim is correct, you need a mechanical oil pressure gauge that has absolutely no leaks. You can take the pressure from the top of the engine near the thermostat or at the rear if you have the steel block fitting like a later car.

What exactly did you install along with the bypass pistons? There is a short spring and a long spring and a spring guide. Did you get them in the right locations? Are you positive?

[dtw]

I took the mechanical gauge reading from the steel block on the right-side cam tower/oil pressure sender fitting. The adapter was the right size, but was unable to thread deep enough into the fitting, it interfered the the hollow bolt passing through the block.

All relief parts were brand-new. Updated pistons, springs, guide, hex-style fittings. Pretty darned sure I got them in the right spots, but I can check if topping up the oil doesn't help.

[dtw]

Alright, I feel really stupid but really relieved. Added two more quarts and fired it up. Oil pressure is now right where it should be. I can't believe the difference that made. I gave it ten more minutes at 2krpm to bed in the rockers. Next is to button up the rest of the car and get it on the road. It seems really dry so far, one drip from the right side, but I think it is just where I was diddling with the right-side cam tower fitting. I'll snug that down now that everything is in order.

It is putting out copious amounts of smoke. Not smogging the neighborhood but a good steady stream. Guess I just need to beat the rings like redheaded stepchildren?

[kenikh]

Originally Posted by dtw

It is putting out copious amounts of smoke. Not smogging the neighborhood but a good steady stream. Guess I just need to beat the rings like redheaded stepchildren?

From LN Engineering: http://www.mototuneusa.com/break_in_secrets.htm

[sww914]

With a dry oil cooler and a dry engine I'd expect you to need 11-12 quarts total.
There are very specific break in procedures that should be followed. Th forst step is to break in the cams properly and the second is to seat the rings. The smoke that you are experiencing isn't abnormal at this stage.

[dtw]

I've got DFL-coated cams and have logged about 15-20 mins total around 2krpm for bedding in the rockers. I'm not going to start the car again until it is road-ready (gotta do axles/sway/clutch/valence etc..). I've got brand new rings, pistons and nikasil cylinders, with a very light coat of moly grease/motor oil during the build. Then I will drive hard on and off the throttle, max 5krpm, to get the rings bedded in - basically like the mototune site (thanks Kenik, hadn't read that in a couple years, good to re-read for me now).

Sound good sww914/all?

[cgarr]

Dave, are you running those top secret rockers I did in that engine?

[dtw]

Originally Posted by cgarr

Dave, are you running those top secret rockers I did in that engine?

"I don't know what you're talking about, Craig."

(SSssssssshhhhh).

[cgarr]

Originally Posted by dtw

"I don't know what you're talking about, Craig."

(SSssssssshhhhh).

GOOD ANSWER