About Us

TCSGTO · 08-20-2019, 07:42 PM

Quote:

Originally Posted by redhawk44

I am reading to learn I don't really think I need this . The one question I have is , sorry if this is a stupid one, why can't you just return it to the oil pan like they do with turbos?

The oil pulled out by a vacuum pump has water vapor and is contaminated with blow by gasses. If you saw the stuff that comes out of a catch can you probably wouldn’t want it going back in the engine.

redhawk44 · 08-20-2019, 07:57 PM

Quote:

Originally Posted by TCSGTO

The oil pulled out by a vacuum pump has water vapor and is contaminated with blow by gasses. If you saw the stuff that comes out of a catch can you probably wouldn’t want it going back in the engine.

Okay, I figured there was a reason why it wasn't being done. Thanks

Keith Seymore · 08-21-2019, 06:47 AM

Quote:

Originally Posted by 455 pontiac

The leak point at the dipstick actually will make the pump pull harder to compensate for the vacuum leak which can result in excessive oil being put into the catch can.

Thank you; I'll try that too.

K

chuckies76ta · 08-21-2019, 08:34 AM

Quote:

Originally Posted by 455 pontiac

The leak point at the dipstick actually will make the pump pull harder to compensate for the vacuum leak which can result in excessive oil being put into the catch can.

I disagree. The pump will only pull as much vacuum as it is set too. The leak will relieve the vacuum on the engine.

chuckies76ta · 08:52 AM

Quote:

Originally Posted by Mike Fowke

I pulled a quart of oil through the evac pump during a recent autocross in just two runs. See picture for my set up.

I have a 3/4" spacer under the factory covers for total of 3 1/2". The bottom of the Moroso breather is 3" from the rails.

I can switch to a 3 3/4" cover and move the pick up point higher. Do you guys think this will solve the problem?

I didn't realize how much oil pools in the heads under high RPM.

455 w/ 4.25 stroke / .060 overbore
Kauffman heads

Attachment 518242

I'm running 2 of these vacuum pumps. No issues. Like others have said you need a vacuum control to set the amount of vacuum the pumps pulls on the engine.

https://www.gzmotorsports.com/VCV101...rol-Valve.html

They are mounted on the pump on mine like this one.
https://www.gzmotorsports.com/VP104-vacuum-pump.html

You just can't install the pump and away you go!

You need to then seal up the engine as other have stated. Plug dipstick, Remove PCV valve and plug. You then have to install a vacuum gauge temporarily, I made a setup to use on the PCV port. Then take car for a drive and find out what the vcuum is on the engine at WOT. From here you now set the Vacuum Control Relief that is installed on the pump. Somewhere around 10" to 12". The other thing that can affect the vacuum the pump makes is the size of the pulleys. In other words, speeding the pump up or slowing it down.

Also, the vacuum pump inlet on the valve covers usually works best mounted up front on valve covers as the oil migrates to the rear of the engine on hard acceleration. your looking at pulling vacuum with just oil mist.

As others have also stated, the oil in catch can is junk. Water vapor, oil, combustion products.

Hope this help. Not good at explaining through Keyboard.

chuckies76ta · 08-21-2019, 09:27 AM

Pic of pump

surfsama · 08-21-2019, 02:29 PM

Quote:

Originally Posted by Mike Fowke

According to GZ, it pulls 19"-22" at 3500 rpm.

Did you actually measure that much vacuum on a gauge or are you going by what the literature says the pump is capable of pulling?

If you can get the pick-up away from the oil with taller valve covers or spacers and better baffling that would help situation.

455 pontiac · 08-21-2019, 06:14 PM

Quote:

Originally Posted by chuckies76ta

I disagree. The pump will only pull as much vacuum as it is set too. The leak will relieve the vacuum on the engine.

I run a star machine pump that is adjustable. Before I plugged my dipstick I had the pump set to pull 12" at 6000 rpm and it put 5- 6 oz in my can each 1/4 mile pass. As soon as I plugged the dipstick my guage went to 20" at idle so I had to turn the pump way back. After it was reset to 12" at 6000 I get about an ounce every 12-14 1/4 mile passes. I agree there is a lot to getting a pump set up but plugging the dipstick was the only change I made to stop the oil problem. I pull from the front of the value cover with a baffle.
Hope this helps

Mike Fowke · 08-21-2019, 06:44 PM

Quote:

Originally Posted by 455 pontiac

I run a star machine pump that is adjustable. Before I plugged my dipstick I had the pump set to pull 12" at 6000 rpm and it put 5- 6 oz in my can each 1/4 mile pass. As soon as I plugged the dipstick my guage went to 20" at idle so I had to turn the pump way back. After it was reset to 12" at 6000 I get about an ounce every 12-14 1/4 mile passes. I agree there is a lot to getting a pump set up but plugging the dipstick was the only change I made to stop the oil problem. I pull from the front of the value cover with a baffle.
Hope this helps

The gentlemen I spoke with at GZ gave the same explanation: Any air pulled into the system will take a lot of oil with it thru the pump. He said I didn't need to restrict or regulate the vacuum. I'm going to test for and resolve any air leaks first. I may have to relocate the pick-up and reduce the vacuum anyway, but I'll start there.

Mike Fowke · 08-21-2019, 07:02 PM

Quote:

Originally Posted by chuckies76ta

Pic of pump

I'll try the vacuum control valve before I buy taller valve covers. It looks like your pick up point is only 1/4" higher.

Mike Fowke · 08-21-2019, 07:04 PM

Quote:

Originally Posted by surfsama

Did you actually measure that much vacuum on a gauge or are you going by what the literature says the pump is capable of pulling?

If you can get the pick-up away from the oil with taller valve covers or spacers and better baffling that would help situation.

Just going by their literature.

chuckies76ta · 08-22-2019, 08:11 AM

Quote:

Originally Posted by 455 pontiac

I run a star machine pump that is adjustable. Before I plugged my dipstick I had the pump set to pull 12" at 6000 rpm and it put 5- 6 oz in my can each 1/4 mile pass. As soon as I plugged the dipstick my guage went to 20" at idle so I had to turn the pump way back. After it was reset to 12" at 6000 I get about an ounce every 12-14 1/4 mile passes. I agree there is a lot to getting a pump set up but plugging the dipstick was the only change I made to stop the oil problem. I pull from the front of the value cover with a baffle.
Hope this helps

I understand what your saying.

I just got stuck with you saying, The pump pulls harder. You were introducing air at the dipstick which allowed the pump to do it's job, but now sucking more oil vapor with it. Hence why you had to turn it down when you plugged dipstick..

That's all.

catc · 08-22-2019, 08:38 AM

what speed are you running the pump, maybe your crank pulley needs changed..i had that happen when i was spinning the vacuum pump too fast...

Keith Seymore · 08-24-2019, 10:32 AM

Update from Norwalk:

a). Added gortex patch at pickup point in valve cover: didn't work. Made huge mess.

b). Cleaned mess. Plugged dipstick, added "outerwear" cover to outside of tank breather element: perfect. Cleaned it right up, with a tablespoon of liquid in the can.

By way of reference I'm at about 6" vacuum at 6000 rpm.

K

Mike Fowke · 04-28-2020, 03:38 PM

Thought I'd update this since I've run a few events since August. I capped the dipstick tube which made a big difference, but I was still getting more oil in the catch can than I wanted. So, I installed a control valve on the pump and set vacuum to 10 psi @ 3k rpm. The combination solved the problem for me. There isn't too much in the can during events but a little during normal driving.

Menu

About Us