Guest EPS Posted January 31, 2001 Share Posted January 31, 2001 With a hi-vol oil pump, (1979 Chev 350) on very hard acceleration, the pressure drops low to 5-10 lbs. I believe this is because the oil gets pumped up in the head and does not have have enough time to flow back to the pan. An extra quart seems to help. But the other related problem is that the electric fuel pump cuts off when the pressure drops this low (you know, the little switch behind the distributor that is pressure activated to turn on the fuel pump and the auto choke. So short of drilling the return holes in the head or installing a standard pump, any bright ideas? Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted January 31, 2001 Share Posted January 31, 2001 IMHO, I don't think its putting that much oil in the top end. If it did, I think it would overwhelm the valve oil seals, just a opinion mind you. I would suspect that while alot of oil is going upstairs, whats left over is running back away from the pickup. Are you using any baffling in your oil pan, it could be cavitating on hard acceleration causing the drop in pressure. The stock Chevy pickups and pans were never designed for the G-forces the cars run now ( I doubt a 55 bel air ever launched that hard on 5-6" wide white walls in 1955). Just a thought. Respectfully, Lone Quote Link to comment Share on other sites More sharing options...
Guest EPS Posted February 2, 2001 Share Posted February 2, 2001 Lone, Thanks for the thoughts! I have a Corvette pan and the pickup is, of course, back toward the firewall and thus should be able to "pickup" under G force. Is this true to your experience? As for overwhelming the valve seals, if that were the case I assume there would be plug fouling and smoke, which is not the case, so your point is well taken. There are no windage screens or baffels. Is cavitation really that big a deal? The after market pumps seem to have standard type pickups. Are there any you know of that might do a better job? Keep it coming. Best suggestions to date. Quote Link to comment Share on other sites More sharing options...
Mikelly Posted February 2, 2001 Share Posted February 2, 2001 EPS, Check Pete Paraska's thread on oilpresure and oil pans further down this topic list. The conversation covered this very issue. You need an adequate pan with the appropriate windage tray, baffles and trap doors arounf the pickup tube. My system uses a remote filter made by Catnon, an accululator with electric solenoid made by canton, and a Moroso 7 Qt pan with the above mentioned goodies {windage tray, scraper, trap doors, baffles) in it. I never got lower than 10PSI in my motor with a hivol pump. Mike ------------------ http://hometown.aol.com/dat74z/myhomepage/auto.html "I will not be a spectator in the sport of life!" mjk Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted February 2, 2001 Share Posted February 2, 2001 Yeah as Mike was saying, there is a thread on here about oil pans and what might be the best solutions. If its doing it in the lower gears right during a hard launch and doesn't do it in taller gears, I would suspect its like I was saying. Other causes, perhaps the pickup tube is loose on the pump (many times people braze these in place on a Chevy if I recall correctly), although if that were the case I would expect low pressure most of the time. Moroso, Canton, Milodon, Hamburger and probably several others should have what you need, pan wise, a deeper sump with baffles should put things right. One other thing, just to be sure the gauge is correct , I had a T-bird with a FE 390 in it, the sender wire was loose and it would show low oil pressure on the gauge when I got on it. Sounds like a silly thing, but its worth a glance, eliminate the cheap stuff first, you know. Good luck with it, Lone Quote Link to comment Share on other sites More sharing options...
Guest EPS Posted February 3, 2001 Share Posted February 3, 2001 Mike, From what I've seen you are The Man. Your Web Sit is great. Thanks for the suggestions. I'll let you know how it turns out. ED Quote Link to comment Share on other sites More sharing options...
Guest EPS Posted February 3, 2001 Share Posted February 3, 2001 Lone, Between you and Mike, I'm sure to come up with a solution. It is obviousely in the pan and pickup and not a "pump up" in the head, especially since I'm running Mobile I and you know how that stuff flows. Thanks! ED Quote Link to comment Share on other sites More sharing options...
pparaska Posted February 4, 2001 Share Posted February 4, 2001 The stock SBC oil pan is about 7.5" from the block rail to the bottom of the sump. WIth the JTR mounts, that places the bottom of the pan about 1" below the crossmember! That's why I'm looking for a SHALLOWER pan. The Canton 15-240 is 7" deep, holds 6 quarts and is set up for road racing. Pricey though. I'm not sure which way I'll go. The Corvette pan (78 and later - watch the dipstick placement though) is supposedly a good pan/pickup/windage-tray to use for road course stuff. Another thing to add is a baffle that goes across the back of the pan. These go between the pump and rear main cap, where those two pieces bolt together. You can get them from Milodon, Moroso, others, for less than $10. Pretty easy to make your own as well. Anyway, this helps keep the oil from climbing the back of the pan and up into the back of the block on hard acceleration. ------------------ Pete Paraska - 73 540Z - Marathon Z Project pparaska@home.com Pete's V8 Datsun 240Z Pages Quote Link to comment Share on other sites More sharing options...
Guest EPS Posted February 5, 2001 Share Posted February 5, 2001 Peter, Have pretty much decided my problem is in the pan. The windage tray and other suggestions will help. Thanks! Quote Link to comment Share on other sites More sharing options...
Mike Mileski Posted February 5, 2001 Share Posted February 5, 2001 With all this talk about oil pressure, has anyone ever installed a dry sump system on their car? This is something I've thought about doing down the road but would be interested to see if someone's already done it and hear their lesssons learned. Mike Mileski Tucson, AZ Quote Link to comment Share on other sites More sharing options...
Guest EPS Posted February 11, 2001 Share Posted February 11, 2001 Mike, Have given the dry sump consideration after the problems I have had with dropping oil pressure on HARD acc.. May take a look at it again. Would like to hear what you find out. Quote Link to comment Share on other sites More sharing options...
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