Air bubbles in ATS/Petersen LS7 dry sump tank. - Lateral-g Forums

Bowtieracing · #1 08-21-2018, 02:10 PM

Guys please advice.

Why I am having a lot of air bubbles in oil in my ats/peterson dry dump tank after 10 minute drive. Engine temps are okay around 190 and suddenly oil temp begun rising close to 200. Then I can see oil pressude dropping. When I look in the tank after shuting the engine, there is a lot of air bubbles in the oil.

My tank is from botton to top of the fill neck 18” height and 6” diameter. I have ats / peterson breather can. All lines and fittings are earls size 12. Adapeter on the
Stock oil pan is GM.

Tank is on right front corner tucked front of the wheel. Botton of the tank is higher than oilpan.

I have there now about 9 quarts of correct oil. When oil has bubbles and I have shout the engine, oil level is about 3/4 of the tank. After it has cooled down and bubbles are gone, oil level is about 8” from the bottom of the tank.

what is wrong here?

Blake Foster · #2 08-21-2018, 05:27 PM

i would call Peterson direct (800) 926-7867

get the answer direct!!
there will always be air in the oil, the tank is designed to help control the air. it is just a product of pumping oil.

but call them

**Flash68** · #3 08-21-2018, 05:53 PM

18" tall x 6" wide? Isn't that the 2 gallon tank? If so, I say that is too small for an LS7.

http://www.petersonfluidsys.com/drys...d-2gallon.html

dontlifttoshift · #4 08-21-2018, 06:16 PM

Meh, a customer has been running a (that exact) 2 gallon tank on a 416 for years without issue. Blackstone keeps telling him all is well. Car is on street tires and doesn't run the big boy tracks like VIR so it doesn't see 6000 rpm, high g sweepers very often.

Oil level should be just below the screen after the engine has been off for approximately 5 minutes.

Pressure will drop as the oil warms up, without numbers it is hard to say if your situation is abnormal. 200* oil temp is nothing to be concerned about......300* could be.

Like Blake said, there is air in the oil, that's why it swirls around the tank the way it does, to deaerate.

As was posted on the other site, your vent line to the catch can is a poor layout. You want that line to run uphill to the vent can.

**Flash68** · #5 08-21-2018, 06:39 PM

Quote:

Originally Posted by dontlifttoshift

Car is on street tires and doesn't run the big boy tracks like VIR so it doesn't see 6000 rpm, high g sweepers very often.

No big boy tracks?

Bummer.

Blake Foster · #6 08-22-2018, 09:12 AM

also i would try and route the breather hose so it in not the low point otherwise it will fill with oil

meant to post this last nigh

Bowtieracing · #7 08-22-2018, 11:59 AM

Thank you guys a lot!

I will reroute the line between tank and brather tomorrow. And Iwill take about one quart of oil away. It is two gallon tank and I did put there 9 quarts of oil.

I found it bit confusing if the tank is too small, it was advertised as an LS7 tank.

Blake Foster · #8 08-23-2018, 09:51 AM

Keep in mind some of the issue is the space allotted to mount the tank becomes a design criteria as well.
the 2 gallon number would include the filter lines and residual in the pan and engine. i know on the drag race stuff we check the level with the car running and it typically is the tank 1/2 full +/-

Che70velle · #9 08-23-2018, 08:13 PM

Sounds elementary, but make sure your scavenge lines are all tight.

Bowtieracing · #10 08-24-2018, 12:18 PM

Guys, I think I know what is the problem.
As engine and oil gets hot, oil pressure starts dropping until it goes to zero.
Then I stop the engine and the dry sump tank is about 3/4 full.
Could it be that the oil pump creates a vacuum and causes the hot oil softened intake hose to collapse?

I have earls 12 hoses and fittings. That hose dont look very strong to hold vacuum.