Vaccum Experiment ?'s

[VetteKilla]

I am currently on to my next mod and it includes installing a 12 VDC electric vacuum pump that will put 22Hg of vacuum from idle to 5000 RPM.

I know high vacuum is good for the engine but how much is too much?

I have a 2 barrel Autocraft, 360, AT.and low gears.

I picked up two of these electric vacuum pumps at the local wreckers there mostly on 4 cyl engines.

I am currenly experimenting with the mod now and have awesome response once it kicks in but I am experiencing a slight hesitation.

I have moved the pump to its fartherst slot and have checked the timing its all fine. I think some of the rubber vacuum hoses might be collapsing because at 3000 RPM I had 25 hg's and at 4000 I had 30 hg's.

The car pulls real strong and my engine runs quiter and the exhaust is bearly audible.

The car just wants to keep on pulling and loves higher RPM's.

Has anyone else experimented with this mod?

I know moroso has a crank driven one but that too pricey for me.

I am experiencing no detonation at all.

Well if I'm on to something let me know all tips help links surely would be appreciated, Thanks.

[rumblefish360]

Where or what did you get these pumps off of? And are you useing it for crank case evac. , or power brakes?
Either way, as long as your not sucking oil through it, I guess more the merry. Power brakes too.

[moeflo]

Vettekilla. I'm currently doing the same to my beater. Installing
two of them, in a 150K mile mustang, with procharger. One is to be reserved, by a vac-switch, ported to the intake, to click on only under boost. Although the car uses no more oil, etc, than it did at 50K, the boost has always shown to "swell the oil-pan"... How much Vac is too much?, I've never heard of anyone complaining to getting to much. many have taken pains to seal the motor against "reverse-leaks"(outside-to-inside), in an attempt to get more.

I think when your valve covers collapse.

[moeflo]

Rumblefish,, late(96-97-up) mustangs, and camaros have them. I think alot now use these things.
. Mustangs are in the front- inner fender, can't recall where he camaros are.

[VetteKilla]

http://www.calgarydragracing.ab.ca/index.html

This is the link that first got my interest.

I then modified one to push out more vacuum as needed like on demand.

Yes mine is from a 4 cyl car you can run it on a 24 volt battery and get more vacuum out of it.

I'm running mine on the intake and it is greatttttttt!!!!!!!

There's so much room for tweaking and all out experimentation, I love it.

I 'm always carefull to check to see if the vacuum is pulling oil from the system but when I look at turbo's and Superchargers I don't feel so afraid to push the envelope. I have yet to find signs that the engine is indeed pulling oil.

There is a down side I had to disconnect some vacuum operated devices because the hoses were collapsing, but I'm getting stronger hoses. I 'm in desperate need on a 4 bbl intake and 4 barrel carb with mechanical secondaries.

I 'm currently seeing much higher vacuum readings as I tweak away.

The car is definitely running more efficiently at lower RPM's now.

Tips greatly appreciated.

[AAR4fun]

I have been researching this and have the following links:

At the bottom of this link is a Chevy test with a Moroso Pump. Interesting how much HP is gained by evacuating the crankcase.

http://216.239.51.100/search?q=cache...en&ie=UTF8</a>

Article below mentions effects of vacuum on oil pressure in the crankcase.

http://www.rehermorrison.com/techTalk/24.htm

My understanding from research is 15 inches of vacuum is the threshold from where oil starvation begins. This link is a mechanical adjustable valve that can be incorporated into a crankcase system as a relief valve. Here it is described to control boost but the principle can be applied to control vacuum.

http://www.xmission.com/~dempsey/perform/grainger.htm

I understand the Moroso units cannot be used on the street, because they are designed for racing and will generate an enormous amount of heat during a short run. Therefore not have any lifespan on the street.

Smog pumps will not last over a period of time either because they were designed to take in cool air and pump compressed air into the exhaust. Pumping hot crankcase vapors will cause the pump to generate too much heat and drastically shorten the pumps lifespan and ultimately seize.

The electric pump sounds like the best alternative although it was not designed for hot vapor or continous running. A long hose and a simple innercooler could take care of the temp.

I would be interested in knowing how long your pumps are lasting and what is the driving conditions.

[VetteKilla]

Thanks for all the info AAR4fun and great links, excellent!
I am currently running 1 pump which I run with a toggle switch.
The longest I ran it was about 3 hours it was hot. I have located it on the intake near the middle.

I am surely going to have a good read tonight, thanks again

ablazing

[VetteKilla]

AAR4fun the second link doesn't make sense is it the right link?

Article below mentions effects of vacuum on oil pressure in the crankcase.

http://www.xmission.com/~dempsey/perform/grainger.htm

[VetteKilla]

AAr4fun this link is dead also help you have my complete and uttermost attention.

http://216.239.51.100/search?q=cache:JVa1NNruoOMC:[url]www.theengineshop.com/feature7.shtml+moroso+vacuum+pump+installation&hl= en&ie=UTF8

[AAR4fun]

I guess the Merlin page was stored on my machine and the link has died. Here is the text at the bottom where they test the Moroso 3 vane pump.

__________________________________________________ _

VACUUM PUMP: WORTH 25 HP!

Builder John Scialpi equipped the Red Line Merlin 540 with a complete March Performance five-rib serpentine pulley system, but with a catch: he also used a Moroso street vacuum pump. This made 25 hp on the dyno by helping the piston rings seal (it sucks the rings out against the cylinder walls, as opposed to the normal crankcase pressure, which does the opposite) and makes for cleaner conditions under the hood. One other advantage is that you'll see less oil leaks anywhere on the engine! This three-vane pump (as opposed to a four-vane like Moroso offers for a racing engine, which pulls more vacuum but wears out quicker) helped to produce an average of 11.9 to 10.3 inches of vacuum-solid figures. We slowed the pump down by using the largest smog-pump pulley that March makes (from a late-model Mustang set), to run it slower and avoid wear. The cool little tank and filter are from Moroso, like the pump (Scialpi made his own bracket). Remember, with a system like this you don't run a valve cover breather (that would defeat the purpose) and can pull your vacuum from either the back of a valve cover or the back side of the manifold. If you do the latter, don't do like we did--build the baffle inside the manifold (to take air and not water) big enough so that a ton of oil doesn't come through into the tank too quickly! We had to service the canister after every few pulls, and rig a rag on the filter to stop from making a mess. A bigger baffle would have solved the problem.

[AAR4fun]

Originally posted by VetteKilla
AAR4fun the second link doesn't make sense is it the right link?

Article below mentions effects of vacuum on oil pressure in the crankcase.

http://www.xmission.com/~dempsey/perform/grainger.htm

The second link is an article published in National Dragster on oiling systems. Toward the end of the article the author discusses the effects on crankcase vacuum on a wet sump system.

The 3rd link (quoted above) is information about a grainger valve.

This is an adjustable relief valve used to control boost/vacuum. I added this because you may want the ability to control the maximum amount of vacuum in the crankcase. Installing one of these relief valves somewhere in the system (valve cover or T into the hose leading to the pump) will allow you to control maximum vacuum and keep your hoses from collapsing.

[VetteKilla]

I guess I should read more carefully. Thanks again AAr4fun.