Evacuation pump street usage
 

I'd like to install a Morosso 3 vane pump on a street/strip 455 motor. My concern is that the car will be driven to races and cruised, how will the pump hold up to roadmiles, or should I just plan on rebuilding it every year. I have asked the company (Morosso) via e-mail but they don't reply. Anyone using these on the street?

You're probably going to have to rebuild it every year, or at least take it apart for inspection.


That's the safest way to operate.

65gofast,

If you are going to run it on the street, you need to be carefull how much vacuum you develop. After talking with several people, I got a wide range of answers - one supplier indicated you can not run them on the street period. It appears that for street use, you do not want to have to much vacuum or you run the risk of starving your bearings of oil. The difference is on the street you will run alot longer than just a 1/4 mile. You may also have to add oil and drain your catch can often.

This Butler engine is going in a "regularly street driven 1967 GTO" and it has a evac pump.:confused2

The amount of vacuum pulled corresponds to how fast the pump is driven. Since there are so many different pulley combinations, its a vague question and answer.


Use a McClintic valve to automatically limit the amount of vacuum that any pump and pulley combination can pull.

Helluvadriver,

The pump on the Butler engine is most likely thier low end kit that they sell. They indicated that this kit pulls approximately a max. 6 inches of vacuum and typically runs around 4 to 5.

Goatman,

The vague answer I got when investigating this subject is what vacuum is safe for street use. The answers I got ranged from you can not use one to 13 inches. I feel that the safe value would be around 3 to 6 inches, but have no data. So the valve is a great addition, but what do you set it at. That's maybe why Morosso did not answer. If someone has the number I would be interested as I have a pump for my street car.

65gofast,

I would suggest you call a couple of other suppliers such as Aero space (they will most likely tell you not to run one on the street - gave me a 3 -4 inch after discussion) and talk with Butler (They have a complete kit that they feel is suitable for the street - I have this kit for my car).

Is this a concern with running header evac on a street car as well?

John

We ran a 3 Vain Morso Vacuum pump on Franks 1971 T/A 535 cu. Tiger Head motor last weekend. It would pull a full tank of oil out of the motor in 4 miles. We tried front of the valve cover, middle of the valve cover, and two valve cover e-vac hoses. We are pulling 11 inches of vacuum on the street.

After many weeks of trying different devices, we have developed a oil vacuum separator that works. We drove the car for 38 miles and got less then 1/2 teaspoon of oil out of the catch can breather. Our new device will catch the oil and return it back to the motor automatically. This will work on any make or model motor. Our plan is to make it at a affordable price.

There is nothing wrong pulling a safe vacuum of less then 12 inches on the street. Anymore then that you my starve the wrist pins. We tried the max to prove a point. A negative pressure will help in sealing oil leaks and will prevent the pushing out of the rear main seal. And will gain around 18 Hp. as a by product. The extra oil in the valve cover will cool the valve springs and give them longer life.

Now, I have to find the time to do another project

By the way it got 8 1/2 miles to the gallon.

Ponjohn;
You would'nt really want to run a vacuum pump system in combination with a header evac set-up,the crankcase needs to be sealed well for a vacuum pump to work correctly.

You'd run the risk of the vacuum pump overcoming the check valves for the header evac and loosing the crankcase seal.

One or the other,not both,JMO.

That sounds like great news Bob. Keep us posted. I have an idea as well for an oil separator.

To clarify- I meant is too much vaccum a concern when using header evac? I have all the parts to convert over.

John

Mark We will be glad to show you what is needed on your end of the valve cover, But..... and I hate a but in a sentence. We have to kill you after we tell you. Just kidding.

The valve cover is not the working part of this system. But a baffle will help. We will try it on a non baffled valve cover to prove a point.

The system is a two part deal not including the baffle in the valve cover.

We have looked at many systems out there that claim to work and don't. The Morso E-Vac fitting is useless. This is the one that has a hex head with holes inside of the cover.

Ohhh,OK,my mistake,I misunderstood what you were asking.

It's highly unlikely any header evac system will pull enough vacuum to be a "problem",especially on a car with any sort of exhaust on it,as well as being driven at "cruising" RPMs,it's just not designed for that situation.

It's meant to be most effective with open exhaust/racing RPMs.

Bob,

Thanks for the value for street use and I am looking forward to try your oil separator.

That would be great if you could solve this problem. I have people ask me about that all of the time.

Mark it is solved. Finding the time to get them made is the better question.

FWIW - when I was putting together my 600hp street/strip motor I spoke to David Butler and asked his opinion on a street EVAC pump. He recommended the base kit they sell. It is a remanufactured Ford pump (?) with a Moroso pulley, -12 lines and I used the Moroso valve cover adapter.

While on the dyno we hooked up the manifold pressure line to measure crank case vacuum. My readings were as follows...

RPM inHg
1500 -1.5 this what I recall at idle

The dyno run sheet showed the following

3000 -2.9
3500 -3.1
4000 -3.7
4500 -4.2
5000 -4.7
5500 -5.4
6000 -6.1
6300 -6.8

I didn't use the system to pick-up any real HP...I'm using it for better gasket sealing and a cleaner intake charge. Incidentally vacuum signal got stronger as the pump broke in.

Also, there was a interesting HPP article about a month back that can answer additional questions.

Hope this helps.

Dan

GTO Dan,

Thanks for the great data. This is the same pump I purchased for the same reason - oil leak control.

Any more info on this vac pump situation? I am trying to solve a oil blowing problem on long WOT runs. A vac pump seems like a definite fix, but I want to make sure it is good for a street car. Seems to me like just a small amount of negative pressure would be all you would need to maintain to control leaks and be better that a stock PCV system.

Could you convert a vacuum pump to use an AC Compressor style clutch? You could have a valve or two (maybe an idle air control valve) that opens the system to just vent while cruising on the street, then use a RPM switch or WOT switch to shut the valve and apply the clutch to pull vacuum?? I have no idea how to do this, but it works perfectly over here in Fantasy Land :)