My custom Electric Crankcase Evac

[KEVINS]

I'm not going to get into a debate with those who think an electric crankcase evacuation system is not or should not be needed b/c I have my own reasons for wanting one: To minimize any oil leaks....and they work but instead of running it off a hobbs switch I wanted it to run all the time.

The electric GM smog pumps that people have used to evacuate the crankcase work great but they do NOT like to be run all the time. I discovered this for myself when the electric motor failed after a few days due to heat which caused some of the plastic parts inside the motor to melt. I needed a 12v motor that is designed to run continuously and decided a heater fan motor may work.

I found several on ebay for around $25-$30 and bought a few with different housings giving me several options to make an adapter to mount the motors to the pump housing.

Here are pics of what I came up with and it has been working great for a week so far. Only time will tell how long it will actually last but this motor is designed to run continuously so I have high hopes.

The below pic shows the fan motor on top of the adapter I made then the fan portion of the pump housing bolted to the adapter.

Both v-covers are sealed off except each has a hose that runs to a canister to separate any "liquid". Then a valve cover breather is mounted on top and a hose runs to the vacuum pump. I discovered that the breather had a foam element in it and this quickly got saturated with moisture so I removed the foam and it's been working great so far.

Before, with both valve covers vented to atmoshere, I always got a dribble of oil out of the v-cover fill hole just driving around town for 5 minutes. This evac system creates enough vac that I get absolutely NO leaks even under boosted runs.

The next thing to do is move the canister under the bumper b/c this draws a LOT of moister from the crankcase and I will probably need to drain it often. I also drilled a .06 hole on the bottom of the plastic hose elbow so any moister will drain out of the hose.


ks

 

[Nick Micale]

Not only is that a neat approach for improving your car, it shows a great deal of initiative for someone to solve an issue by thinking how to do it better!

I had the same problem with the electric smog pumps, so it is impressive that you have worked out an inexpensive and reliable solution, good job.

I am going to give it a shot on my street car which I am finishing, thanks for the info.

 

[KEVINS]

Not only is that a neat approach for improving your car, it shows a great deal of initiative for someone to solve an issue by thinking how to do it better!

I had the same problem with the electric smog pumps, so it is impressive that you have worked out an inexpensive and reliable solution, good job.

I am going to give it a shot on my street car which I am finishing, thanks for the info.

Thanks Nick.
Here's the motor I bought.
http://www.ebay.com/itm/331126793709?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649

This motor only runs around 3200 RPM and I think it's "just" enough to work. Do some research and see if you find one that runs at a minimum of 5000rpm which I feel would be a better motor.

Here's the company that makes the motor and it looks like they could custom make one but I haven't received a quote to see how much it would cost.
http://www.dcm-mfg.com/pdf/dcmotors/dc_motors.pdf

ks

 

[Fast4Ward]

Thats neat way ta go.

 

[TurboSmart]

So you used a gm smog pump but with another motor?

The connections are...
Valve cover - breather - catch can - pump...
Where are you dumping the pump exhaust?

What about the pcv...still running one?

Posted from the TurboBuick.Com mobile app

 

[KEVINS]

So you used a gm smog pump but with another motor?

The connections are...
Valve cover - breather - catch can - pump...
Where are you dumping the pump exhaust?

What about the pcv...still running one?

Posted from the TurboBuick.Com mobile app

I bought a new 12v fan motor.
I removed the original motor off the pump.
Made an adapter.
Bolted the new motor onto the adapter then bolted this to the existing GM smog pump fan housing.

Connections:
V-cover to catch can. On top of catch can is a breather with a hose port on it. I ran a black heater hose from this breather to the inlet side of the pump and it just dumps into atmosphere. I may dump it into the air filter but for now I haven't.

No PCV at all.

ks

 

[larry33kc]

Nice setup

 

[Nick Micale]

Connections:
V-cover to catch can. On top of catch can is a breather with a hose port on it. I ran a black heater hose from this breather to the inlet side of the pump and it just dumps into atmosphere. I may dump it into the air filter but for now I haven't.

No PCV at all......

You keep on peaking my interest and motivation on the higher HP street engines that have too much crankcase pressure at high RPM and I have been looking for a method that is simple and inexpensive.

My thinking has been to use the PCV to evacuate crankcase pressure and possibly sealing the valve covers like is done on my race car?

Since it is boost that greatly increases this pressure, my initial thought was to trigger the pump with a Hobbs switch at 5-10 psi, but with a reliable pump it could run continuous especially if the VC's are sealed.

Hopefully I can finish and clear out some customer GN's so I can have time to experiment with these options.

Thanks for your information as it has been very helpful.

 

[KEVINS]

Glad it's been helpful.
This system could work on any engine if the electric motor is durable enough to last and move enough air. I'm going to try and contact the motor MFR Monday and see if they can offer me something that spins faster..

ks

 

[Evaddave 87gn]

Nice job! I'll be doing basically the same approach.

 

[ijames]

Nice job on the motor. There has been lots of discussion on vacuum pumps over on speedtalk.com where several top engine builders hang out, and the very short version is that with standard rings you usually don't see any more hp but with skinny low tension rings it can be 50+ hp on a 700 hp small block chevy. Definitely helps with weeping oil leaks. Check the vacuum with a gauge and limit it to about 10 in Hg. Less than 10 in Hg makes less power if you have skinny low tension rings, more vacuum doesn't make more power and some have run into lubrication issues on wrist pins running over 15 in Hg vacuum. Oh, if you are running on alcohol running the pump all the time will help keep the oil dry and make it last a lot longer, according to our own Don Wang . This is all hearsay, I am not a lawyer, your mileage may vary, etc .

 

[Pronto]

So how much vacuum does this motor pull?

 

[KEVINS]

So how much vacuum does this motor pull?

Almost none. It's not really a "pump" so it doesn't pull much of a vacuum at all but just enough to prevent oil leaks..
I'm still working to find a motor that spins faster.

ks

 

[Pronto]

A 2002 T/A pump that I tested pulled 3" HG. It spins pretty fast. Don't know the exact rpm though. That is probably enough to stop leaks. Would probably be better at 6" HG.

We are just using the intake side of the pump. The original design uses the exhaust side to push air into the exhaust system. Vacuum cleaners are not a real vacuum pump but pretty much work the same way as these evac pumps. There are small pumps that pull more vacuum but they don't move enough volume to evac an engine.

 

[TurboSmart]

Those pumps help pump the oil vapors... they dont actually pull enough volume to create vacuum but enough to prevent crankcase presurization while on boost.

Posted from the TurboBuick.Com mobile app

 

[Pronto]

Does anyone have a good idea what kind of pressure is built up inside an engine that has a decent ring seal?

 

[KEVINS]

Does anyone have a good idea what kind of pressure is built up inside an engine that has a decent ring seal?

That could be difficult to determine. If the v-cover is vented it may not develop any pressure. If it's completely sealed then pressure could continuously build up while the engine is running.

ks

 

[TurboSmart]

Dependa on cyl leakdown.
Is more ventilation required by the rotation assembly.

Posted from the TurboBuick.Com mobile app

 

[Pronto]

So the pressure of the churning air moved by the spinning parts plus the blowby would need to be less than what the evap pump can draw. If not the block would still be pressurizing as the pump is overwhelmed. If you had one vented valve cover, the extra pressure overwhelming the pump could still escape. At lower rpms fresh air could be circulating through the engine and still be drawn out by the pump.

 

[KEVINS]

So the pressure of the churning air moved by the spinning parts plus the blowby would need to be less than what the evap pump can draw. If not the block would still be pressurizing as the pump is overwhelmed. If you had one vented valve cover, the extra pressure overwhelming the pump could still escape. At lower rpms fresh air could be circulating through the engine and still be drawn out by the pump.

Yea, Pretty much. However, the reason for this on my application is b/c without an actual vacuum oil can still seep out of the joints and cracks of the valve covers and ?? so there doesn't need to be "pressure" to push the oil out of these areas. In my case a vacuum does prevent this seepage.

ks