460 Ford Forum banner

More oil system woes

60K views 94 replies 50 participants last post by  BBF Newbie 
#1 · (Edited)
More oil system woes, with pix

We have been dyno testing a 598” Boss 9 hemi, and seeing some strange oil system behavior.
Engine data:
4.6” x 4.5”
Our Boss 9 Hemi heads…. (The set from our 2009 Engine Masters 511” entry), Ported
Unported 4500 Kaase intake
1150 dominator carb, by Dale Cubic @ CMF
13 to 1
282-288, .457” lobe, 112 CL Comp Cam
Wet sump pan with our pump
Best power, 1100 HP @ 6900, 875 Ft/Lbs at 5500
This engine is built for a friend to take to Maxton, NC , for the 1 mile speed runs

This has been a great engine, except for the oil system. It has a Moroso road course oil pan. The pickup is ¾ toward the rear, in a 4” x 4” trapdoor box. There is directional screen over most of the bottom. The pan is mostly flat, front to rear, with a trapdoor divider half way back. During a dyno pull, it loses oil pressure, 5 to 10 lbs or more. We tried jacking up the front of the engine to help more oil get to the rear. We tried thinner oil, Mobil 1 0-W50. We tried more oil. Started with 8, then 10, then 12. Then I really got pissed and threw in another 4 Qt, total of 16. Didn’t hurt the power much, but didn’t help the loss of oil pressure. It would start at 60 psi, and go down to 48. When we ran it from 4500 rpm to 7000, the oil gauge would nose dive at 6500 and over. 6200 to 7000 and it still fell at 6500, 4000 to 7000 and it still fell fast over 6500. The length of the dyno run didn’t seem to matter, it was when it reached 6500 rpm and over that the oil pressure went to hell.
The block is aluminum, which has lower head oil drains, so the heads don’t hold much oil in the valve spring area. The lifter lines are restricted. We took it off the dyno and pulled the pan. Bearings were OK.
Because we needed to know whether the problem was the pump or the short block, or the pan, we decided to change pans to my EngineMasters pan and pickup. It’s a 12” deep front sump with no baffles or screens or covers anywhere. Just a big, deep, open pan.
Well, we ran it today, and it was perfect. Even when the oil was hot. It started at 72 psi and would gain a pound or two at 7000. The pressure gauge was perfectly steady, where with the other pan it would bounce a little. We only had 7 qts of oil in the pan!
So, the oil pressure problem was obviously the oil pan. I think most people would have blamed the pump. I had my doubts about it. Now we have to figure out what’s happening in the customer’s pan and fix it. There is a square hole in the screen for the pickup to fit through when the pan is installed. I think maybe all the windage and pulses from the pistons above are disrupting the oil around the pickup.
Next week we’ll work on the pan, and I’ll post some pictures and dyno sheets here.... Kaase
 
See less See more
#93 ·
I just looked at Kaase's web site and I don't see any windage tray offerred, so it appears this issue continues. I just built a drag race 598 with an eliminator aluminum bloack and Trick Flow heads. I got it on a quarter mile track a couple weeks ago and noticed oil pressure dropping to zero when braking. When I let off the brakes, pressure returned. I have 12 quarts of 10W-40 in the pan so the primary thoughts I have is poor drainage back into the pan? I've read this whole thread and while the windage tray or better pans may help, I was braking and off the gas so obviously, at least in my case, RPM isn't the issue. I just ordered a GZ vacuum pump kit and am wondering if hooking the vacuum to the fuel pump blockoff plate would do a better job of sucking the oil from the top end back into the pan, or just succeed in sucking a bunch of oil into the pump? GZ recommended hooking vacuum to both the valve cover and the blockoff plate. I may try both to see what works best. As far as this thread goes, though, I don't know if the Eliminator block changes the issue versus a standard Ford block.
 
#95 ·
It's a Moroso drag race pan (p/n 20625). Rear sump with a hinged baffle and a metal screen. The pickup was 0.25" from the bottom of the pan. I'm considering a windage tray (if I can find one for the rear sump pan) and/or an accumulator. I've read many threads about this issue and have yet to read any solid fix to it. I'm a bit disappointed in this Eliminator block. If someone was going to make a race-oriented big block from scratch, I would have assumed they'd use the Windsor oil system.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top