Best vac pump inlet location?

Where have you guys put your inlet for your vacuum pumps? I got an Aerospace pump for my big block and they recommend the front of the valve cover with no baffle, but I was thinking of installing it mid valve cover on the intake side. Any suggestions and pic's of your set ups would be great, thanks!

I tried several things till I found the right spot ..

Middle of V/C ..intake side , I no longer have pics but, did a little fancy gizmo to make it look neat ..

Not what works for one will work for another, your lost without a gauge, took lots of trial and error

On dyno worked great if front of v/c .. at track it did not

I put mine at the front of the passenger side valve cover as far forward and on top of the cover with the bypass valve beside it per the instructions from the manufacturer.
I did make and have a flat aluminum baffle welded under them, but the welds broke, and the motor didn't seem to suck any more oil into the vent tank after removing the baffle and racing it without the baffle

Mine is in the upper corner of the front surface of the right valve cover. No baffles. 25 passes before maybe 5 oz of oil. .Doug

Vacuum at the valve cover interferes with oil drain from the head.
Ideally, it should be in the air space above the oil in the pan.

Lot cheaper option...
https://www.moroso.com/crankcase-evacuation-system25900/

In my opinion not near as effective.

What will those pull a couple of inches of vacuum as opposed as much as you want with a good pump setup.

Also for what its worth I pull from the top front of the driver's side valve cover, no baffle and little oil in the tank.

IMO it depends on the heads being used. We have them in the front of the cover, top of the cover, intake side of the cover, depending on cylinder head being used. Our current engines have two in the front of the cover with no baffle and one in the top oft he cover. None of them pull any oil really usually just some condensation and maybe a drop or two of oil. But we don't have any external leaks either.

Thanks for the replies. I am ditching the existing Moroso pan evac set up for the vacuum pump. This engine is a 499 lo deck with -1 heads and Harland Sharp rockers. My 582 BBC that was in my dragster had a breather style inlet on top of the valve cover and it provided almost no oil to the pump at all. My routine with that one was to squirt some oil in it every race day. I guess no matter where it goes, if I have too much oil going to the puke tank I will baffle it. Thanks!

With a =1 head and Indy oiling, which I assume you have it will make little difference where it is. We have run that combo a few different times with just a fitting in the cover with no issues at all.

This was a -1 headed 446 with the fitting in the top of the cover at 11" of vacuum never any oil in the tank.

I did notice that the oil now stays a lot cleaner a lot longer than before using a vacuum pump

Switched mine from valve cover to lifter valley, and it filled the catch can every time I stood on it lol. Switched it back to valve cover.

Not being a ass but i have a older aerospace pump i find them to be junk i would sell it and get a moroso or star , not sure if the new ones are any better though, mine was plumbed into top of valve cover and tried in the valley plate too .

FWIW I have NEVER seen the valley plate to be a good location. Alot of oil flying around in there at RPM and if you are pulling any real amount of vacuum its gonna make a mess in short order.

Agree 100%

Can the valley plate area be used for the relief?

Why not?

IMO no reson to regulate it unless you are the paranoid type. Especially with a 3 vane pump, in that case there is ZERO reason to run a regulator

that kind of example would be the breather/oil fill tube on chevy engines over many years. i have even seen PVC valves plumbed into oil fill tubes [with no breather] on certain POBC engines over the years.

Second reason to not use valley for relief woudl be why woudl you want to pull outside air through your engine. Best place for one if you must is on the pump itself.

X2!

Yep ! I've seen a lot of motors with the relief on a valve cover, and then they wonder why they keep filling the catch tank

My suction hose fitting is mounted on the right front valve cover next to the bypass valve and it gets moisture only in the tank after a day of racing using a enhance GZ pump that pulls only 5.0 inches of vacuum

I was told you wanted to get a little amount of oil back to the tank that way the vac pump is getting lubed ??

Who told you that?
I'm thinking there are a lot of tiny oil droplets in the motor being slung around, especially after 4500 RPM
I had a 12.0 inch long baffle welded into my right side valve cover with a lot of 3/8 holes drill in it to act as a trap to help not let a lot of oil be slung into the fitting going to the pump. It vibrated loose the welds and I removed it this year, it has less oil in the tank now after 5 or 6 runs than it had before with the plate: confused:

Fred Flintstone loved his.........

I ran one of those systems for a short while on my old A/SA M.W. NHRA stocker a long time ago, it would suck in a lot of moisture after every run and condensate in the valve covers making a milky mess with the oil, NOT GOOD: down :

My contribution to this thread......

I dyno tested a 557 BBM with -1 heads on it that the owner was trying a vac pump on.
He had the fitting in the valley cover.
We had made several pulls with valve covers that had breathers and no belt on the pump.
Swapped covers and hooked up the belt.
I barely got to WOT and the puke tank was over flowing.

Took the hose off the puke tank and had it aimed into a bucket.
At WOT it looked like a fire hose amount of oil coming out.

Valley cover = Not a good place for the fitting.

Good for you helping on this post

How about a 4 vane Moroso pump? My machinist told me to not even worry about regulating it with an aluminum block. Your thoughts Al?

I use a Moroso 4 vane and I am happy with it.

I do regulate it.

How much vacuum to run is a whole other discussion. I limit mine to 12".

However I know that the more vacuum I let it pull the more horsepower it makes.

I think Star is considered the top of the line.

I personally do not regulate them. Never have cant make enough vacuum to hurt it. But your results may vary. We have pulled 20"ish with a 4 vane enchanced in BBM aluminum block stuff with one. That number scares alot of guys who read magazines and internet forums though. I have NEVER hurt a wrist pin in any of my deals to date. Nor have we in the red car which is the same set up and results.

IMO a 3 vane is PERFECT for those folks, why I suggest it for most. Throw the regulator away or dont buy one and save some money for something else. We have pulled 12+- with a three vane in the dragster back when we used one. Also have one on the street car doing the same.

Same deal here….. morose 4 vane w/t Star regulator. ……but I don’t have a top shelf aluminum block so I’ll get back on the porch.

(Disclaimer: jeff and I will make any snide comment available at each other’s program, but it’s all in jest and we usually learn something in the process….. carry on )

I think the Star pump is very nice quality but on a quieter street car annoying from the vanes -clack -clack -clack -clack.....

Second to that, the regulation of pressure was at the pump itself but they recommended using a separator between pump and engine. Soooo, as the foam media gathered oil the amount of vacuum between pump and separator remained at whatever you set it at, but between separator and engine would quickly go from negative to positive as the media became more restrictive. I felt with that design the regulator should have been on the hose between the separator and engine (as to maintain negative pressure on the crankcase consistently) but Star did not agree. (so I moved on)

Now using a GZ pump as it has more of an oem appearance and is quiet.

I have a Moroso vacuum pump fitting like pictured in my valve cover oil fill cap with no issues and a Moroso enhanced 4 vane pump.

IMO wherever it ends up I woudl use the Star baffle where it attaches...

In the most forward area of the valve cover!

I have a Moroso 22641 pump (4 vane). Pickup on top the valve cover b/t rocker arms. Just a straight fitting w/ no baffle. I use a regulator mounted on the pump, but it's as tight as it'll go...might as well remove it. Pulls 10-12" or so and no issues filling the tank w/ oil at all.

I have that valve cover fitting with the holes in the front top corner of the drivers VC. I also fitted a baffle under it after getting oil but it made no difference.

I have 7" of vac with a gauge plumbed into the rear of the drivers VC with a GZ pump with a reg in the pump - I cant get anymore vac regardless of the reg adjustment. The hose from the VC goes into a Moroso oil/air separator, into the pump, then the"OUT " hose into a catch can mounted under the fender.

BOTH the separator and catch can still get a fair bit of oil after a street drive at diff speeds both fwy and city streets.

The dipstick is removed and a threaded plug added/sealed as is the locked out distributor and the oil pan is well sealed, so it must be still pulling air from somewhere hence the oil.

Kinda stumped really.

Valve covers with evac fittings