Feed Restrictors and Short Travel Hyd Lifters?

[Chipper Chapman]

Had issues this year with flooding top of engine (350/255) with oil. With 6.5 qts in engine (chevy II pan) I was still losing oil pressure erratically in top end. Not dropping to zero but from 50-55 down to 25-30 and back for last 200 or so. After each run the valve covers were in need of a wipe down. I run a stock gm oil pump no high volume or pressure trickery. But what I noticed was that since changing to scorpion short travel race hydraulics I had this issue, and they seem to push lots of oil up even when we hand primed the engine upon assembly. So I'm left wondering if it's possible to use the galley feed restrictors to keep some oil down at the pump, and hopefully get to use a little less oil.

Opinions? Ideas? Experience?

[Alan Roehrich]

I've never used those lifters, so I can't say what they require. For Stock I've only sold and used Schubecks or Trend, and never run a restrictor, I do not like restrictors, there are too many components up there that need the oil.

If you're going to try restrictors (I'd try a different lifter instead, but that's just me) I'd suggest doing it on a dyno for short pulls until you can get the restriction where it "needs" to be. With restrictors, you run the risk of giving some critical stuff less oil than it needs, and you could have valvetrain failures as a result. Even if you only do it for a pass or two at the track, the damage might already be done, and not show up for a while.

[Grant Eldridge]

Originally Posted by Chipper Chapman

Had issues this year with flooding top of engine (350/255) with oil. With 6.5 qts in engine (chevy II pan) I was still losing oil pressure erratically in top end. Not dropping to zero but from 50-55 down to 25-30 and back for last 200 or so. After each run the valve covers were in need of a wipe down. I run a stock gm oil pump no high volume or pressure trickery. But what I noticed was that since changing to scorpion short travel race hydraulics I had this issue, and they seem to push lots of oil up even when we hand primed the engine upon assembly. So I'm left wondering if it's possible to use the galley feed restrictors to keep some oil down at the pump, and hopefully get to use a little less oil.

Opinions? Ideas? Experience?

We had this occur with our big block stocker, also just for an instant on launch showed up on the datalogger. We welded in a shelf with a slight lip facing down across the inner rear wall of the oil pan sump just above the pickup and a few inches forward along either side to control oil climbing the rear of the pan. I'd be very cautious limiting oil that lubricates the cam, lifters or springs if you run agressive profiles or high spring pressures, might cause other unwanted issues. Just my thoughts, but worked on my car to solve this problem...
Grant Eldridge
E/SA 6650

[Alan Roehrich]

Also, I've seen some engines that lost oil pressure several seconds into a hard run. It actually turned out to be a problem with windage that was exacerbated by pressure in the crankcase. If your ring package isn't sealed up dead tight (ignore a leak down test, the correct test is a running blow by test with a Dwyer style air flow guage hooked to the crankcase vent at WOT and max RPM), you get pressure in the crankcase, and the windage from the rotating assembly will literally blow the oil up the sides of the pan. You can cure it with some sort of windage tray, but the real cure is to seal the ring package up better.

[Jim Kaekel]

I had similar problems years ago but cured it by using oil restricted pushrods from Smith Bros.

[Adger Smith]

Take the screens out of the oil returns in the back of the lifter valley.
Not familiar with those lifters. Pull one apart and take a look at what is in the lifter for oil control. They might have left a part out when blocking the lifters. Like the little dimpled plate that sits under the pushrod cup.

[Chipper Chapman]

Engine has the rear baffle sandwiched between pump and rear main, no screens in the return holes. I haven't got it out of the car yet check how the lifter is built. I took schuebecks out to run these, I have seen the effects of ceramic going through an engine! They seem to work great, just having this oil problem. Also I should note, although I had alright oil pressure last season the pump was nfg so this is a rebuilt 'blueprinted' stock pump now. I've only seen this issue on soild roller engines before and restrictors solved it. Many other local class racers run the same lifter with no issues so I'm baffled! The ring seal/blow by issue may be some of my problem however. But it just seems like way too much oil is coming up top via the valvetrain. I mean, I noticed a huge difference from normal engine while priming the pump by by hand.