Installed crank case evac today...

[INSIDIOUS '86]

As the title says. I ordered a crankcase evac kit on summit. Payed attention to the instructions religiously and...

It works on my full exhaust street engine. At 500rpm it pulls 3-4 inches vacuum and I can imagine much greater at higher rpm. The top end feels a little stronger too. And this is only one side done so far haha.

most people at the track in Bremerton report half a tenth to a tenth faster 1/4 mile times with this kit but usually run 11.80 and faster. and this isn't just talk, we did this on our 67 belvedere with a 496. We ran consistant at 10.64 and started running 10.58.

So if your curious about the kit or want to try make sure your running large tube exhaust, good headers and mufflers that are high flow.

Any questions comments or concerns?
Posted via Mobile Device

[68longhorn]

Will this help with moisture problems inside the motor? With a mild cam my pcv doesn't take all the moisture out of the motor, and I get a build up on the inside of the valve covers. Is 2.5 inch exhaust with turbo mufflers ok to run with this? Or do I need higher flowing exhaust than that?

[INSIDIOUS '86]

Turbo mufflers prob not. I get a lot of moisture in my engine as well. If you have an aluminum intake a little known fact is that the aluminum sweats when the engine is cooling. Kind of like a window on a cold morning.

I have not run the evac kit long enough to know if it will help ( just on a couple hours ago) but I imagine it would

If your pcv does not creat crankcase vacuum at idle then either your ring seal is bad or your pcv isn't hooked up right or your like me with bad ring seal and a cam that makes insufficient vacuum
Posted via Mobile Device

[tylervalo]

Something I researched forever when I had my C5, really no reason at all not to run one if you got the money. It's got a ton of advantages.
Posted via Mobile Device

[INSIDIOUS '86]

I was hesitant cause everywhere you search they say it won't work on street cars or full exhaust systems


NOPE THEY WERE WRONG
Posted via Mobile Device

[stock75]

Pardon my ignorance, but anyone wanna put the crankcase evac in a nutshell?

[tylervalo]

Basically it hooks into your PCV system, is run by a belt attached to a something (idler on my C5, not sure on a SBC) and pulls a vacuum from the crankcase into a catch can. It helps to seal the piston rings and helps with oil consumption.

[Firebirdjones]

What we usually do for those that are junkyard savy and want to save some coin, is pull the electric vacuum pumps from newer fords.

You don't need high flow exhaust for this one to work. Just wire it up, hook it to the PCV system, and you have a vacuum pulled all the time. Usually hide the electric pump up inside the wheel well or somewhere inconspicuous, they run fairly quiet and don't draw much amperage,,,very stealthy for those trying to keep stock appearance Ooops, you didn't hear that from me.

[king-918]

Originally Posted by tylervalo

Basically it hooks into your PCV system, is run by a belt attached to a something (idler on my C5, not sure on a SBC) and pulls a vacuum from the crankcase into a catch can. It helps to seal the piston rings and helps with oil consumption.

Also helps prevent oil / carbon in the combustion chamber i.e. predetonation
Posted via Mobile Device

[INSIDIOUS '86]

Originally Posted by stock75

Pardon my ignorance, but anyone wanna put the crankcase evac in a nutshell?

There at three ways to evac the crank one is with a pcv going from the intake to the valvecover

The other is belt or engine driven and is a vacuum pump

Third is an exhaust system the had a tube in the collectors and the exhaust pulls a low pressure area across the tube and crates vacuum. On the end of this tube there is a one way valve and some heater hose that runs to an air oil separator on the valvecover that looks like a breather
Posted via Mobile Device

[Cue-Ball]

Originally Posted by INSIDIOUS '86

I was hesitant cause everywhere you search they say it won't work on street cars or full exhaust systems
Posted via Mobile Device

The reason you're not supposed to run that style on a street exhaust is because there is too much pressure in the system. If you have open headers or headers and dumps (no mufflers), then the air rushing past the connection creates a vacuum. But on a muffled system you often have the opposite; pressure building up inside the exhaust. In these cases you get exactly what you're trying to avoid, which is an INCREASE in pressure inside the crankcase.

I definitely would not hook up a system like this to a muffled car. On a street car you're much better off to use an electric system as mentioned by Firebirdjones. The additional weight is negligible and it works 100% of the time, not just when conditions in the exhaust stream are just right.

[tylervalo]

Originally Posted by INSIDIOUS '86

There at three ways to evac the crank one is with a pcv going from the intake to the valvecover

The other is belt or engine driven and is a vacuum pump

Third is an exhaust system the had a tube in the collectors and the exhaust pulls a low pressure area across the tube and crates vacuum. On the end of this tube there is a one way valve and some heater hose that runs to an air oil separator on the valvecover that looks like a breather
Posted via Mobile Device

Originally Posted by Cue-Ball

The reason you're not supposed to run that style on a street exhaust is because there is too much pressure in the system. If you have open headers or headers and dumps (no mufflers), then the air rushing past the connection creates a vacuum. But on a muffled system you often have the opposite; pressure building up inside the exhaust. In these cases you get exactly what you're trying to avoid, which is an INCREASE in pressure inside the crankcase.

I definitely would not hook up a system like this to a muffled car. On a street car you're much better off to use an electric system as mentioned by Firebirdjones. The additional weight is negligible and it works 100% of the time, not just when conditions in the exhaust stream are just right.

That's why exhaust evac systems are ususally reserved for turbo cars, they seem to be especially popular in Supra's.

[INSIDIOUS '86]

Originally Posted by Cue-Ball

The reason you're not supposed to run that style on a street exhaust is because there is too much pressure in the system. If you have open headers or headers and dumps (no mufflers), then the air rushing past the connection creates a vacuum. But on a muffled system you often have the opposite; pressure building up inside the exhaust. In these cases you get exactly what you're trying to avoid, which is an INCREASE in pressure inside the crankcase.

I definitely would not hook up a system like this to a muffled car. On a street car you're much better off to use an electric system as mentioned by Firebirdjones. The additional weight is negligible and it works 100% of the time, not just when conditions in the exhaust stream are just right.

Well if you look at the kits the come with a one way valve so the pressure def does not increase. And I'm sure part of the reason they don't want street cars running it is increased tailpipe emissions.

However I'm pulling vacuum all the way up to 3000rpm (didn't rev it higher in consideration of neighbors) but it seems to work all the way
I have a three inch xpipe system and spintech mufflers so that seems to be working. But I think anything smaller prob wouldn't work
Posted via Mobile Device