ELECTRIC VACUUM PUMP RESULTS
 

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I bought two of them off of E-bay for 20 bucks apiece. You just have to watch for them, they are always on there for 50 or 60. Here is one for 60 right now. Item number 360182675334 on E-bay.

I'll try to post up some pics of the installation next week. And again this is with a 16v battery not sure of the results we would get with a 12v system.


Curtis

How much more hp will you get putting on a vac.pump?

I had bought 1 that only pulled 1.5inches on 12v

I don't expect to pick up a single one. If we do great, but we are running it to keep the moisture out of the motor. If it will at least keep the motor in a neutral pressure situation we may pick up a few. This motor made 702hp on the dyno and seems to have a really good ring seal so who knows?

Curtis

Those are actually auxillary air pumps used on later model GM vehicles.

TS1955

Yeah, I know.

I'd be curious to know what type of vacuum, if any, you see at 7000-8000 RPM with it under full load.

Just make sure you don't get into a positive crankcase situation, or you may find out which seal is the weakest on the motor.

You might want to consider something like a roll over check valve in the valve cover. Something that will seal with vacuum, but vent with pressure. It'd be some cheap insurance to do that and not worry about pushing oil pan gaskets out and spraying the tires with oil.

Just food for thought.

WJ if we are pushing gaskets out we need to work on our ring package. :lol: :lol: .

I hope that was a joke.

5" of vacuum isn't that much, especially with no engine load, and that electric pump isn't going to scale as RPM increases.

I'm dead serious when I say make sure and monitor that vacuum level during your first couple passes. If it loses vacuum at any time, you need to get out of it and ditch the pump.

From all of the stuff I've read, dead minimum vacuum you want is 10", and most regulators are pre-set to 15". Most pumps can pull up to 25-30" of vacuum and their volume scales with engine RPM since they're belt driven.

I'm just saying... be careful. I have nothing against doing things on the cheap, and this may work well for you. Just don't put yourself at risk if it doesn't keep vacuum on the crank case at max RPM.

x2 on what he said, I set mine to pull min of 12"

x 3

I had to buy the biggest star vac pump they make to accomodate a 632 bbc mine was set at 11. There is a big difference when your running at idle approx 1500-1900 rpm to when your on the top end of the track, wide open pulling 7500 to 8500 rpm.

And for the small cost of a check valve, I would certainly recommend it.

Don't get me wrong, In sincerely hope you have came up with an idea that is not only mechanically effective, but cost effective as well,

Good luck and keep us posted with your results.

It was no joke, I think everyone is losing sight of what we are doing with this and I do understand the positive crankcase situation. This engine, as many across the country does, ran fine with just a pan evac system. This pump moves way more volume than that ever would. it is only to remove moisture I don't think it will pull over 1 or 2 inches of vacuum on a pass.

Just to clarify something though. I have a mechanical pump on my car and we have one on the dragster that we have also. I posted this for the guys who always ask questions, which I have seen a hundred times, about how these work on an engine. I do appreciate the concern for our safety but we are not a bunch of newbs trying to do something with $12.00 dollars in our pocket.

AGAIN guys don't lose sight of what we are doing with this we are not trying to pull vacuum to make power. This car is tire limited with a 14-32 so we have to kill some bottom end as it is. I am not trying to be adversarial about this I just want everyone to understand that we do have a pretty good idea and knowledge about what we are doing, this was just for the guys who can't buy a Star or Moroso and would like some info.

Curtis

Keep in mind that a pan evac system is an open system. It's not being limited by the speed of that impeller within the electric pump.

The problem is that you never mentioned (unless I misread the post several times) that you also have a mechanical pump on the same motor. Nobody ever called you a newb or insinuated that you were poor.

Look at it from an outside perspective. If nobody knows you also have a mechanical pump, and you say this thing works, but because you know what you're doing it's not explained thoroughly in the post, someone who's wanting to do it on the cheap may want to try it (run on sentance, sorry).

Some young adult Johnny may try and put this on his big block street motor that has 14%+ leakdown when cold, push all the oil gaskets out at the top of the track, spray oil under the tires and wreck his car and hurt himself.

I'm glad it works for you. The hazards if it doesn't work for someone else also need to be pointed out so the end reader can determine if the reward is worth the risk.

You win.

I didn't know we were competing.

I think you have a good idea. At the price point, it's certainly worth exploring. It just has some risks that needed pointing out.

I see what WJ is trying to point out, in order for a vaccum pump to work properly the engine must be sealed up air tight. (With exception of the vaccum system plumbing)

When you do this, your vaccum pump must be up to the task of pulling more vaccum than the engine creates the oposite of (positive crankcase pressure). If that is not achieved, you will have problems with blown seals and pushed out gaskets.

IMO a pump that will only achieve 2" of vaccum will never do this.

I think he took his ball and went home.

Haven't gone home, still have all my balls in play. :lol: :lol: First passes on this car will be tonight.

Mud This pump is not positive displacement so pressure can pass through is even if it is not running.

I tried to us a electric vacuum pump to eliminate the condensation in my engine due to short intensive bursts on the street, getting ready for the drags, but encounted the problem pointed out previouly, that under full load and high RPM I had a positve crank case pressure and blew out the rocker cover gasket and the sump gasket is now leaking with standard breathers, I now have a oil patch on my drive way and had a second degree burn to my arm from accededently touching the pump to remind me of the electric vacuum pump.
Now I am saving for a mechanical vacuum pump, I should have done in the first place IMO.

The pump did pull out the condensation as expected. Car ran a best of 6.04 in 2800' of air. The pump did quit running after 3 passes and I haven't had a chance to pull it apart and inspect it. The three passes made after it quit were just fine no blown out gaskets of any kind. These are just our results do not try this at home we are trained professionals.

We have another pump that we will change out with the one that quit and I will report what I find wrong with the bad one. All in all it did what we wanted it to do. If it turns out that one will not last I will put it on here so no one wastes their time with it. Had a blast yesterday and made some rounds with both cars, 80° day, great racing, I think I heard there was 8 perfect lights through time trials and the first two rounds :shock: :shock: . Tough day.

Curtis

Not sure yet. None of the other motors such as water pump have had a problem with it. I don't believe that was it but I will post up what I find.

Curtis

I did a lot of looking around at different forums for information about a electrical vacuum pump. Most folks are using Delphi GM pumps either used or buying new. Some people are modifying them and claiming they get more vacuum. One of the best sources of information is turbobuick.com. I have a 383 in a 69 camaro street car with a D!SC procharger on it. The motor was never meant to be a forced induction motor and has 10.4:1 compression , so I only run 10-11 lbs of boost. However, this is a street car and most of the time, oil leakage is not an issue. When I go racing on the weekend though, I have lost about 1 quart of oil because of higher crankcase pressure(3-4mmHG) measured off a line plumbed into the valve cover.The car already has header evac system(vacuum is not measureable with a vacuum guage) The back of the motor and the transmission tunnel would be soaked with oil and when I opened the hood at the end of a run, the sky would turn blue from the oil smoke(ran on to the headers). I put a Delphi pump with a Racetronix harness that includes a Hobbes switch(motor only on with positive pressure) and ran this weekend. Not one drop of oil and no blue smoke. The system only pulls 2 inches of mercury but it stops the crankcase from pressurizing and pushing oil out of every orifice it can go. This electric system is not meant to be as good as a belt driven system, but in my application it helped to clean up the messy oil blowouts from cylinder blowby. Hope this information helps.

If your evac tubes are not plumbed in behind your mufflers, they aren't doing you any good, and in fact are holding in pressure.

Any resistance in the exhaust behind the evac tube will not allow it to function.

dftaylor, very good feedback. I figured out what burned up the pump motor yesterday. Our engine is sealed up very good so the pump was working very hard, since we had no relief valve on it, and was building heat internally. This heat caused the brush mount to distort allowing it to short out inside. We have already changed motors and we are going to install a relief valve for the next test.

Curtis

I have used an electric pump on a couple of different cars now..The 1st couple I did have some issues with reliabliltiy. I do run the pump when the car is going down the track, but the primary use is to get moisture out of the motor after a run. Alcohol injected. I also have a blowoff valve set at 12" just in case

I found on a website that to make the pumps live you have to do some mods to it. I took one apart and did what was listed. That was 4 years ago and have not had a problem since then.

If anyone wants the information on how to modify an electric pump please send me you email address and I can forward it to you...It will be 2 Word Doc files (4 pages in total )

Good luck

Dean

Here you go Earl. Took me a while, sorry.

http://i242.photobucket.com/albums/f...iscpics003.jpg

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http://i242.photobucket.com/albums/f...iscpics016.jpg

http://i242.photobucket.com/albums/f...iscpics031.jpg

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Thanks Again, Curtis.

I have one on my car and I don't think it works very great especially at high rpm I have oil all over after I beat on it, I think I'm gonna have to bite the bullet and go belt driven. Just my thoughts.