Vacuum pump routing.

[LaVelle]

Looking to delete the PCV on my BBC.
I'm not interested in performance gains as much as evacuating the crankcase.
I have a electric smog pump for the vacuum source over the usual belt driven.
The electric pump has a centrifugal style compressor that pulls 8" deadheaded on a gauge.
Being it only has 8" of vacuum I don't see the need for regulation.

Questions;
Should I run it as a closed system as normal pulling a vacuum, or as a flow through system like the PCV would with a inlet breather?

Is it possible to use the fuel pump block off plate for attachment as it is closer to the crankcase over the valve cover? (also makes easier install)

What is the best placement on the valve covers if the fuel pump plate isn't an option?
Right vs left, and front vs rear due to internal windage?

[Ted Gerstenslager]

fuel pump is low and the pump will probably suck oil. The hole in there is just small enough to allow the oil to return to the pan.

[MadBill]

Such pumps are usually quite sensitive to oil; probably will need a good separator to get decent life from it.

[LaVelle]

fuel pump is low and the pump will probably suck oil. The hole in there is just small enough to allow the oil to return to the pan.

There are actually 2 holes around 1/2" diameter from the fuel pump boss, 1 to the cam for the fuel pump rod and the other for oil drain back.
Had an anticipation that oil pick could be an issue.
Correct baffling of the pick up could possibly address that issue with ease.
I was more interested in evacuation and oil drain back effects.
The plan was to run it as a filtered open system like a PVC does.
Either in one cover with a breather and out the other to the pump, or a breather T'd to both valve covers pulling from the fuel pump plate.
Was thinking that having the air enter the valve covers and pulling down through the crankcase would help oil drain back, instead of drawing upwards hindering oil return.

[LaVelle]

Such pumps are usually quite sensitive to oil; probably will need a good separator to get decent life from it.

I 'm not sure how oil sensitive this pump will be, being it is centrifugal and not a vane style.
It's like a turbo with an electric motor instead of exhaust impeller.
The air oil separator has already been addressed and purchased. ( even got one for the PCV on my other car )
Motor heat will from continuous duty will probably be more of an issue for long life, and am looking into addressing that issue also.

[Circlotron]

You might be able to set it up with a throttle switch that shorts out a resistor so that the pump runs at a slower speed most of the time and full noise when the throttle is above a certain point.

[LaVelle]

You might be able to set it up with a throttle switch that shorts out a resistor so that the pump runs at a slower speed most of the time and full noise when the throttle is above a certain point.

I'm going to run it dual speed, with a rpm switch for speed control and a small computer fan for cooling it.

My big question has to do with internal windage and airflow within the crankcase area, for best evacuation source point.
Wither or not drawing from the block off plate with valve cover breathers would be better than, in one valve cover and out the other with breathes like a PCV does
If the in one out the other is better, which valve cover would be best to draw from, do to internal windage. (I may be over thinking all this)

[n2xlr8n]

You might be able to set it up with a throttle switch that shorts out a resistor so that the pump runs at a slower speed most of the time and full noise when the throttle is above a certain point.

I'm going to run it dual speed, with a rpm switch for speed control and a small computer fan for cooling it.

My big question has to do with internal windage and airflow within the crankcase area, for best evacuation source point.
Wither or not drawing from the block off plate with valve cover breathers would be better than, in one valve cover and out the other with breathes like a PCV does
If the in one out the other is better, which valve cover would be best to draw from, do to internal windage. (I may be over thinking all this)

I've been using these for years on my cars.

I run mine 100% DC on a good relay, with the output to a ventilated catch can- not deadheaded.

Only failure I've ever had was when it ingested some engine shrapnel. Street driven every weekend.

[LaVelle]

You might be able to set it up with a throttle switch that shorts out a resistor so that the pump runs at a slower speed most of the time and full noise when the throttle is above a certain point.

I'm going to run it dual speed, with a rpm switch for speed control and a small computer fan for cooling it.

My big question has to do with internal windage and airflow within the crankcase area, for best evacuation source point.
Wither or not drawing from the block off plate with valve cover breathers would be better than, in one valve cover and out the other with breathes like a PCV does
If the in one out the other is better, which valve cover would be best to draw from, do to internal windage. (I may be over thinking all this)

I've been using these for years on my cars.

I run mine 100% DC on a good relay, with the output to a ventilated catch can- not deadheaded.

Only failure I've ever had was when it ingested some engine shrapnel. Street driven every weekend.

Good to hear they will do 100% duty free flowing.

I figured heat might be a problem for the motor trying to pull a vacuum full time.

I'll just add a cooling fan to the motor for extra measure, and screw the extra cost and hassle of making it 2 speed.

I adapted/converted an air/oil separator for air compressors for a filter before the pump, and have a JAZ breather tank for the pump exhaust.

I'll try drawing air from the fuel pump block off plate with the valve covers vented and see how much oil comes that way for ease of install.

If I get to much oil in the filter that way, I'll change it to in and out through the valve covers

[n2xlr8n]

I think this has been mentioned, but I'd suggest not using the FP block off as a pump input location.

Don't believe? Do a test:

Remove the block off plate and fire the engine

[LaVelle]

I think this has been mentioned, but I'd suggest not using the FP block off as a pump input location.

Don't believe? Do a test:

Remove the block off plate and fire the engine

Yes it's been mentioned, along with in the research I've done. ( might have been one of your posts )

Going to try it anyway, to get a clean tight installation.

I have a baffle idea for the plate pickup.
If it works, then great, if not I'll use the valve covers. ( nothing ventured, nothing gained )