JRracing

iTrader: (35)

I posted this in Internal also to get more feedback.
I'm not real sure how I will be venting my motor. I am getting the GMPP valve covers and my valley cover is a custom peice that is a think aluminum plate with a bow tie etched into the front of it.

I was thinking of welding a -6 or -8 AN 45 degree fitting on the rear and venting it to a fitting on the header. Like some race cars I see. Or should I consider a vecume set up? I'm not really trying to buy one of those right now. They are salty.

But I will be sraying this set up after the first year on motor.

TLewis4095

iTrader: (10)

If you are only running on the track you could do a collector evac if you pull from one valve cover & have a breather in the other.....it will pull the combustion byproducts, water, unburnt fuel out with a good cross-crankcase flush.

If using Methanol a belt driven vacume pump is a must due to the amount of moisture the Alky wicks into the crankcase.

With either race gas or Alky, a vacume pump will help seal the rings & reduce the forces working against the pistons going up & down thus resulting in more HP. You need to have a vacume relief valve in one valve cover, pull to the vac pump from the other, and exit it through a overflow can that is vented (NHRA & IHRA require 1 qt minimum).

Also, if pulling vacume with a belt driven pump, keep the vac relief valve so you do not pull more than 12-14 inches of vac in the crankcase or you start to pull oil off the wrist pins & mains.

If street driven, then a good PCV system mod with the proper oil seperating catchcan is best allthough there are some electric vac pump set-ups that work on the street for daily driving.

JRracing

iTrader: (35)

The car will be street driven very little. So a pvc system would be the way to go for my aplication?

mrdragster1970

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My 2 cents. If you spray, you need a pump. The header evacs barely pull anything.
We used them, because that's all we had back then. You must keep the charge clean.
Oil & N2O do not play well together. If you can afford it, get one.
It gives you much less windage which gets you 10-40 HP, depending on size & wildness of engine.
I just tried running without one for the 1st time in ~15 years. I had a vacuum stage added to my dry sump.
Will know more when I get some pass' on the new combo. Also helps with little nagging leaks & gasket sealing.
All good from using a vacuum pump, if you can afford it, of course. Good luck.

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JL ws-6

iTrader: (50)

I would NEVER use a pcv on anything again, after taking my first intake off and seeinf the coating of oil on the inside of the intake, I'm all set with the PCV.

Run breathers at a minimm... what I did was the aftermarket valve covers I got had a -10 fitting on both, I ran a line around the back from the drivers side to the passenger's side, put a T on the passenger's side valvecover, then ran a -10 line up to a catch can.

This will work perfect for when I do finally get a vacum pump on the car, the line will just come off and run from the T to the pump, rather then teh catch can I put it to, and I can reuse the catch can with the pump.

It's on my list of things to put on the car when I get it back out (taking a break for a while after the end of this season)

TLewis4095

iTrader: (10)

How are you evacing & flushing the harmful vapors from the crankcase with your set-up? If you do not use a proper set-up PCV system or a vacume pump you will need to change oil after every race to avoid damaging the motor over time.....

JL ws-6

iTrader: (50)

It's vented to the atmosphere via the breather/catch can.

And I do change the oil after every race day, wether I make one run or 10.... something everyone with a race car should be doing anyway. Best way to make sure there's nothing bad going on in there, is to drain the oil and cut the filter open.

150 runs and counting, no problems. in the power department

TLewis4095

iTrader: (10)

Venting to the air only releases the excess crankcase pressure, it does not remove the damaging combustion byproducts that re-condense in the crankcase after cooldown. But if you change your oil after every race you are good to go with the set-up you have as the condensed liquids will come out with the old oil.

JL ws-6

iTrader: (50)

Pretty much what I've been going by. Generally, I will start the car, warm it, and change the oil while the engine/oil is hot, that way all the contaminents are in the oil. When the car sits for a long period, I put a plastic bag and ziplock it over the vented breather can just out of habit so that no additional moisture can make it into the engine.

The whole factory PCV system though, is 100% garbage. Even on my car when it was a street car I rippped that nonsense off and vented the engine thru a catch can. Never had a problem with it this way, but I've always been a 1500 mile oil changer with it so that might have something to do with it. I can not and will not support the concept of contaminating the intake charge with crankcase gasses... it's a real good way to junk up your intake tract, get alot of added buildup on valves and ports, and generally do WAY more harm to the performance then it's good for.

All of my atv's over the years, all that were always vented, everything I've pretty much owned that's been performance orientated has been set up to vent into the air rather then back into the engine's intake tract, and I've never once, in anythign I've torn down that has been set up this way seen a sign of bad news.

Vacum pump is the ultimate, but when it's not pratical, venting to the atmosphere, 100% improvment over dumping the crap intake manafold.

Why the factory's didn't just come up with a good electric pump, or a reliable mechanical one is beyond me.

James Montigny

iTrader: (13)

I've yet to find an electric pump that can do the job.
Seems the only choice is to use a mechanical one.
It's really too bad that no one makes a decent bolt-on setup for these cars.

dlove

iTrader: (23)

http://www.racetronix.com/product/RX-CEPH/RX-CEPH.html

TLewis4095

iTrader: (10)

The electirc kits (use a GM electric air pump mounted backwards) will pull some vac but under WOT they cannot come close to a belt drive.

JL ws-6

iTrader: (50)

Ya'd need an electric motor that would weigh 25 lbs to get it to pull 10 to 12 psi of vacm like is needed.... and then you'd have an elec moor that's drawing a ton of current causing charging problems... it's just not worth it when the crank is right there spinning and ya just have to add the drive to it.

It sucks, but that's the truth of it. I'd be all for an electric one if it didn't weigh a ton, but after 10 yeas in the electronics/industrial electronics industry, I know it's just not pratical.

TLewis4095

iTrader: (10)

Agreed!

mrdragster1970

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Pro Stocks use an electric that pulls a bunch of vacuum & is very light.
The problem is what they cost. Big dollar. They also have a drill battery, pump,
no drain on car electric system.

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JL ws-6

iTrader: (50)

They run off a drill battery? Intresting... you have a link to one of these pumps? With my electric background, I bet I might be able to build something myself that will work, just a matter of getting the pump itself....