HomemadeTurbo - DIY Turbo Forum

HomemadeTurbo - DIY Turbo Forum (https://www.homemadeturbo.com/)

- Forced Induction (https://www.homemadeturbo.com/forced-induction-7/)

- - catch can (https://www.homemadeturbo.com/forced-induction-7/catch-can-12307/)

i was thinking hook up one to bottom end of engine also and pull air mass out the lower end also should work right?

Quote:

Before going on to diesel engines, we should mention the pumping action of the underside of the pistons too. As a piston descends, it must displace the crankcase air under it. Similarly, when it rises it draws crankcase air behind it. At low speeds, the movement of air under the pistons balances out since on most multi-cylinder engines there are always as many pistons moving down as are moving up. At very high RPM, the crankcase air really doesn’t have time to move back and forth from cylinder to cylinder. Instead, it just compresses and expands under each piston, but again, expansion balances compression and there’s no pumping loss as a result. One of the benefits of a crankcase evacuation system that depressurizes the crankcase is that the density of the air beneath the pistons is reduced, further minimizing pumping actions.

info provided by:
http://www.bankspower.com/Tech_todaysdiesel.cfm

now does this prevent the oil from going all over the place? but i still dont understand why its need and how its caused?

sooo then wouldnt any oil just go into the exhaust and burn off then? id rather just have it slowly collect in a catch can rather than brun it all off in my exhaust.

i think i would rather have no chance of oil going back into my intake to lower my octane and gum up the intake track. but that is my opinion. also this is suppose to help out in high rpm situations. i guess its all up to you and what floats ur boat

The oil that would be caught in the catch can would be blown out the exhaust. However, it would also relieve the pressure that was put on your rings by excessive crankcase pressure. Its whatever you want but an evac kit would actually free up horsepower instead of an overpriced catch can that does nothing

they are calling those things that go on top of valve covers "oil seperators" i wonder if they do that or if thats just their name. because it would be a much cleaner job just to run the hoses off the nipples already provided

Well a friend of mine tried using an evacuator like that on his car, said it didn't work. He has a 3" pressbent exhaust and one large straight-thru muffler. I know these evacuators kick ass with open headers but for some reason they run belt driven vacuum pumps on race cars that are required to have mufflers.
Does this stuff really work with an exhaust system or is it a open headers/downpipe only thing?

They work fine with open exhaust or full cat back. the exhaust is creating the same amount of vaccum pressure

I know they work fine with open exhaust, but I wasn't sure if they worked at all if there's some sort of a muffler.
I'm thinking about putting in an alternator from a diesel truck. Those have vacuum pumps attached to them for powering the brakes since diesels don't have a throttle. I need a bigger alternator on my off-road truck anyway, to power a set of 120W halogen projectors, an added bonus is it can back up as a welder for off-road repairs.

I see two downfalls. 1. emissions 2. gumming up your cat