Late Model Oil Problems

[DK1]

421sbc with 2 nights on it since built. 5 stage dry sump(3 pick ups in pan 1 in valley) Steel block with alum heads. Pop off valve in valve cover, tank is vented to a catch can. Tank is about 1/2 to 2/3 full when running. running joe Gibbs xp4 oil.

Heres the problem...My motor is pushing oil out of the crank snout (calies) and leaking between the balancer and the pulley. It also is burning oil and pushing oil out of my vent can. Oil leak only happens at idle it seems. Between the leak and burning of oil I'm loosing about 1-2 qrts a night.

To me it seems like either my pump isn't sucking as strong as it should be causing to much pressure in the motor or the rings haven't sealed even though the motor had break in time plus 2 nights.

What are your thoughts? Thanks!

[let-r-eat]

Oil pressure fluctuating any? Oil temperature? Are you 100% on condition of pump and plumbing?

[DK1]

30psi when warm and at idle about 70-80psi at the end of the straight away.PSI stays steady. Oil and water temp are both around 180. Plumbing is all brand new. Not sure condition of pump. Did look to see if the gears were scarred and they looked ok but I did not take the pump apart.

[DK1]

60 psi when first fired

[perfconn]

Does not sound like the pressure section of the pump but rather one or more of your scavenge sections.The gears are on the shaft with a small woodfuff key and you may have one sheared.I would guess it to be the one on the valley scavenge section.

[sj valley dave]

If it was a used pump, I would certainly have it gone through...As Perfconn said it could be an internal issue on the suction side...Get hold of Ed Wulff in Tennessee and have him go through it...very reasonable and very good! IMO

[DK1]

I talked to my engine guy today and he said that the vent line from the tank to the breather/can needs to be 1" since the 5 stage moves so much oil. I was only running about a 3/8 line from the tank to the can. So I'm going to run a different vent can and larger line and see if that solves the pressure build up issues.

[TBRE]

Does not sound like the pressure section of the pump but rather one or more of your scavenge sections.The gears are on the shaft with a small woodfuff key and you may have one sheared.I would guess it to be the one on the valley scavenge section.

Exactly.
This is the reason you HAVE to dyno a new engine.
We check the AMOUNT of vacuum, from start to finish on each pull. If your engine/pump combo won't hold a vacuum, the check valve is HARMING your engine. If there is nothing wrong with the engine, meaning the right ring pack w/gas ports, and gaskets, meaning no CORK ones, then check your pump. It may be something as simple as a couple of scavange lines collapsing. TB

[dynoman14]

Tony is right.
Now what you need to do is purchase a couple vac/pressure gauges, good ones are about 25-50ea. If you put a T in line on your line back to the tank and one in line on the peterson vacuum popper, you can see what is going on. I migtht also install an extra gauge on the oil tank as it should be under vacuum and not pressure.

I have had so much vacuum on a BGN Plate engine that it sucked the valve cover in to the point the engine started knocking like hell and we thought we hurt the engine after about an hour of looking everywhere we found the Moroso covers sucked past flat and the rockers were banging on the valve covers. Peterson valve was defective and not popping off.

You might need to rev your engine up to 7000 slowly and have a couple folks help you get the readings but at least you will start to figure out what is wrong.

I would guess the seal in the engine might not be set up for high vacuum and either you are pulling in air out of the snout and then on decel resulting pressure with the popper not opening will push oil out at the weakest and lowest point.

How much total oil do you have in your oil system??? If you change it and don't count the quarts in and out after a couple changes you can have 5-10 qts too much in the engine.

[DK1]

Well I ran it with the bigger vent line and can and I'm still having the same problem. The problem is not as bad but it's not fixed.

The guy who built my motor is very old school and was not very familiar with a 5 stage dry sump system. How would I know if he used the right ring pack? The motor does have cork valve cover gaskets. All the lines are braided steel, could they really suck shut? I have a -16 line going back to the tank so putting in a T might be hard. Haven't changed the oil yet so the system has 12 quarts. It seems like this is a pressure issue not a vacuum problem.

Here's what I'm thinking and please tell me if I'm wrong...since I had to small of a vent line when breaking in the motor, the increased pressure in the motor prevented the rings from sealing properly since I raced it 2 nights before increasing the vent size. Now I'm getting blow-by into the crank case pressurizing the tank and causing the same problem.

What do you think?

[perfconn]

Possibly but I would jerk the pump off and send it to be checked.It is really hard to convince an engine builder they did something wrong when you don't know how good your bolt ons are.

[giffordracing]

sound like the rings on 1 or more cyl...

run a compession check on the cyl..

[sj valley dave]

If your builder is not familiar with a 5 stage, not much different than a 4 stage, except 3 out of pan instead of two, did he use the seals for a "vacuum" engine as for as front cover seal, etc?? We run a #16 suction and a #16 return to the tank, with #12's everywhere else and run 14 quarts in the system due to a 2qt filter and deck cooler and never push oil out...

[DK1]

If your builder is not familiar with a 5 stage, not much different than a 4 stage, except 3 out of pan instead of two, did he use the seals for a "vacuum" engine as for as front cover seal, etc?? We run a #16 suction and a #16 return to the tank, with #12's everywhere else and run 14 quarts in the system due to a 2qt filter and deck cooler and never push oil out...

When I say hes not familiar with a 5 stage I should of said hes thinks running a dry sump if overkill for a small local track. Like I said he is VERY old school and as I've come to find out not very up to date on current technology. So as to using the right seals I'm going to assume that he didn't.

My lines are set up the way 16s too and from the tank and 12s everywhere else.

I'm going to do a leak down test tomorrow and see how things are sealing up.

[TBRE]

A leak-down will just tell you if something is bad wrong with your engine, it is NOT, going to tell you if it's sealed up good enough to hold a negative in the crankcase, when running, under a load.
Modern ring combo's leak as much as 15%, after the best pull on the dyno, because of wider gaps now used, and 100 lbs of cold air will not seat an .043 ring properly against the cylinder wall (like 1400 psi, at 1250degrees, which they are designed to operate at).
Put a vacuum gage on the valve cover, or fuel pump hole, anywhere, and see if you're holding 8 inches of vacuum. If not, install breathers on the engine to let it breathe the old school way.TB

[DK1]

Thanks for the help guys. I called Ed Wulff today and was talking to him about my pump and the problems I've been having. First let me say this Ed is a super great guy and spent over 2 hrs with me on the phone while in the shop trying to figure this thing out. In the end all 8 cylinders have 80-100% leakage causing the crankcase to pressurize. Obviously there is a piston to cylinder wall issue either with the rings and or bore. Looks like its time to rip this thing apart and see what's messed up. Thanks for all the help!!!

[let-r-eat]

That will do it!!!!!!! Hate that for you.

[sj valley dave]

Glad to see you got hold of Ed. He can work and rebuild any brand pump, is quick and reasonable and will take the time and discuss your situation with you...Glad you figured it out, sorry to hear you have to pull it apart again..