I heard today that if you reverse a factory smog pump so it sucks out air from the valve covers it will work way better than the pcv valve and the guy told me he picked up 3/10 of a sec
he said he used an electric motor to run the thing to prevent draw from the crank
has anyone else tried this
please let me know what you think as I am interested in trying it at some point on my tpi

 

People do it all the time. I find 3 tenths a bit hard to believe, but it does definitely make a difference, because the pistons aren't having to waste as much energy moving air around underneath themselve as they go up and down. Professional racers quite commonly do it, in fact there are vacuum pumps specifically marketed for the puropse.

 

It does help. I have been thinking of a way to do that on my motor. I'm leaning towards an electric air pump from a 4th gen. The V6's and V8's have the same one.

 

Would'nt it be easier/cheaper to get the crank evacuation system from Moroso? Doing the same thing plus you lose the weight and clutter of all the crap under the hood.

 

part number?

 

The Moroso one driven off a pulley? I like the idea of it being electric. Also the price of the Moroso is $359.99. The mounting bracket is $39.99. The pulley ranges from $29.99 to $49.99. Then you have to buy the belt. I think I'll just get one from a 4th gen for $10 or $15 from a salvage yard and be done with it. If you mount it in a good spot it won't look like a bunch of clutter. It's just a small black box with a hose.

http://www.jegs.com/cgi-bin/ncommerc...80&prmenbr=361

 

An LT1 electric A.I.R pump, perhaps?

 

New newer fourth gen and caddy electric pumps work well. The trouble with most belt driven smog pumps including practically all the GM ones is that they're only designed to spin in one direction. If you look at the pump it has an outlet port to pump air into the exhaust. The inlet port is the little fan behind the pulley. There's no way to connect the pump to the valve covers to pull the crankcase down into a vacuum.

I have seen 2 belt driven smog pump that have inlet ports. One is on ford vehicles with V8 engines especially the trucks. The other is on Toyota. I saw one on a Toyota pickup that could work. They both have the inlet air hooked up the the air filter assembly for a clean air source. I guess the clean air doesn't wear out the pumps.

The early 80's electric vacuum pumps found on 4 cyl Cavaliers for power brake assist can pull the crankcase down into a vacuum however they can't pull enough air when the engine is under load.

Using any sort of pump to put the crankcase in a vacuum must be regulated to no more than 12-14 inhg. A belt driven smog pump can easily pull 30 inches of vacuum. This can actually suck the oil out of the wrist pins and seize the engine.

3 tenths is possible on a 700 hp engine. All the prostock cars run vacuum pumps.

 

I made a mistake, it's the Mr. Gasket Crankcase Evacuation System. Jeg's p/n 720-6002 for $32.99. Everybody and their brother runs these at the track. They're made to pull out of each valve cover, but they have a warning that for street driving only hook one side up.

 

All an exhaust crankcase evac system does is pull the vapors out of the crankcase and into the exhaust system. If your engine is blowing oil out the breathers then you're going to be putting that oil into the exhaust (mufflers).

This system will not put the crankcase into a vacuum. All it does is keep the engine clean if all you've used before is just a couple of breathers in the valve covers.

 

Um I hate to disagree, but an evacuation system can put the crankcase in vacuum. The scavenging affect of the exhaust system and pull of the exhaust flowing past create a suction effect. It's similar to the things used to drain waterbeds and such, where you hook a valve up to a faucet and hose, run the hose into the waterbed, and turn on the water at the faucet. The setup will suck the water right out of the waterbed. These setups are not for the street though.
If you aren't running enough cam to need a vacuum pump for your power brakes, you probably don't need one to create crankcase vacuum, you're normal pcv and breather system will relieve the pressure just fine. If it's not something's wrong and you've got to much blowby.