Looking at some of the regulator valve for vcuum pumps. Mostly look like a check valve that has a pressure setting about same as enderle poppet. I have cpl 8AN aluminum poppets and figuring with pressure set at desired max vacuum they should work fine.

Any reason they will not so same thing? Yes I know they have to be positioned so as to open under suction not under pressure. Sure as he11 be cheaper than 150 bucks for something that would do same ting.

If it works I can machine the blank off in right side burn down tube plug to have it built in. That way if it opens it will pull thru entire engine. Plus Have to plug it anyway and this way no weight gained on car. Got to get drivers fat azz to drop about 15 lbs.

I bought one on EBay for like $12 shipped then drilled and tapped my Vacuum pump in a safe area and put it on the pump.

Mine is positioned at the inlet side of the pump. Engine pulls into a vacuum and if it pulls deep enough to unseat the relief valve, it then sucks air through the valve and straight into the pump. Doesn't need to pull dirty air through the engine. I simply put a tee fitting at the pump inlet. The one I use has a calibrated spring that you can change opening vacuum with shims. If the pump never pulls enough vacuum, the valve never opens. It's more of a safety valve to prevent pulling too much vacuum.

Honestly if it's a 3 vain most engines don't even need one. I now run 4 vains and even sealed up real good they barely need it and they're on gas. I'd worry about it if you need it.

change pulley for desired vac

quote:

Originally posted by rusty:
change pulley for desired vac

BINGO


.970
3.89
6.05 @223

Not really worried about it.More of safety valve since no data recorders to know vacuum. Also doubtful would be issue until I get to smoke engine to find leaks and sure there are some. Old reworked oil pan is already safety valve I guess. LOL I am working on new pan that is o-ringed and should seal lot better.

Mainly safety valve thing because I am help with some R&D on bushed lifters for this style engine where there is no pressure feed thru lifters. Don't want to screw up on my end and give bad feed back since they where nice enough to give me cpl sets to test out.

Still looks like a simple poppet on vacuum side and taped in to line from pump to VC would work. Plus easy enough to set a poppet. While number 8 not huge it should relieve the pressure if needed after engine gets sealed tight.

The poppet valves are about $50 plus the cost to mount it in line and the vacuum valves are about $12 shipped and smaller and work better.

You probably do not need any valve at all in first place. Motor has to be sealed up really good and have good pump to pull over 15 inches of vacuum.

I've never used a vacuum regulator on any engine with either a Moroso 3 vane or a Star sportsman pump....

Never saw any engine wear issue inside an engine....460-509-565.....Injected, carbureted, alcohol or gas...

Adjustable Pressure and Vacuum Relief Valves for Air and Inert Gas

https://www.mcmaster.com/catalog/126/545

I always thought that anything over 15" of vacuum could pull oil from wrist pins or whatever and cause failure that way? I would think if engine is sealed up well and pump is spinning fast enough I would want to limit it to around 15" at finish line or so..

actually poppet cost nothing, except lifting lid to fuel box. As for 12 buck deal I have not found any such item..
Agree probably don't need, but then I have insurance and hope to never need. Simple drilling of hole and tapping is not really that much effort.

quote:

Originally posted by NC3x58:
I always thought that anything over 15" of vacuum could pull oil from wrist pins or whatever and cause failure that way? I would think if engine is sealed up well and pump is spinning fast enough I would want to limit it to around 15" at finish line or so..

internet hearsay, rumor and myth

quote:

Originally posted by rusty:
change pulley for desired vac

That's what Tracy Dennis told me years ago and did on his engines.

That said, both my current engines use Moroso's Vacuum Relief Valve #22636

quote:

Originally posted by Rodney Pryor:
Adjustable Pressure and Vacuum Relief Valves for Air and Inert Gas

https://www.mcmaster.com/catalog/126/545

Thanks looks like what I need and cheap enough that if does not work can toss it and say oh well.

quote:

Originally posted by 1320racer:

quote:

Originally posted by NC3x58:
I always thought that anything over 15" of vacuum could pull oil from wrist pins or whatever and cause failure that way? I would think if engine is sealed up well and pump is spinning fast enough I would want to limit it to around 15" at finish line or so..

internet hearsay, rumor and myth

quote:

Originally posted by rusty:
change pulley for desired vac

That's what Tracy Dennis told me years ago and did on his engines.

That said, both my current engines use Moroso's Vacuum Relief Valve #22636

So what do you have yours set to? I thought those relief valves were min. 10" and max 16" or something like that in 2" increments with shims? Also, what pulley do you use on the dragster and what pump?

quote:

Originally posted by wideopen231:
actually poppet cost nothing, except lifting lid to fuel box. As for 12 buck deal I have not found any such item..
Agree probably don't need, but then I have insurance and hope to never need. Simple drilling of hole and tapping is not really that much effort.

Here you go.
https://www.ebay.com/itm/Contr...5:g:qToAAOSwieZZd96n

I really don't know how much vacuum my pump pulls but I think the main benefit is that after a run, I drain off all the condensation from the puke tank. With alcohol, it really keeps the oil clean.