Krank Vents

Im interested in doing the same thing to my 84 308 GTS, can you send pictures please if possible? thank you.

Mike

 

Hey John,

I've heard that those things fail. If you're routing it to the exhaust how are you getting a vacuum? Wouldn't you have positive pressure? Right now I'm just venting to atmosphere after the oil separator. I've got individual filters. I'll probably just stick a "breather filter" on the end of the separator and call it a day.

Henry

 

if there is vacumm at the exhaust then it wouldn't need a check valve. the check valve keeps exhaust from pushing back up to the pump. at best you'll get a scavaging effect. the EGR operates under the same principle, the exhaust pressure for a given load and rpm is diverted back to keep cruising speed temps down.

also why divert crankcase oil fumes onto the back of hot exhaust valves? just run a catch can and vent that with a std. pcv.

 

also by feeding it to the exhaust side you're re-introducing the vapors to the combustion process. at least when it went in under vacumm from the intake the fuel wash kept the valve clean. if you don't have catch can prior to the venting you will deposit oil.

 

Tommy Cosgrove found the same thing with one of his Krant Vents he'd purchased from Kermit at Durable 1. Kermit replaced it no charge. Nick may (should?) be willing to do the same.

 

if your feeding the crank emmisions into the air nozzels the only vacum is from when the exhaust valve is still open on overlap, hence the scavaging. it still puts an oily residue on the back side of the hot valve which can build up deposits. exhausts do not run under vaccum which is why they have a one way check valve that allows the air pump to pump in air but not the exhaust pressure to push exhaust air into the pump. if you removed the valve then exhaust gas would push back into the seperator causing all kinds of trouble.

 

I am pretty sure that the Fchat detectives did some testing on the Krank Vent thing a few years ago and determined that they are useless!

Birdman

 

so what you're decribing if i got this right, is a cross over pipe between both exhausts. if so then you would get a vaccumm due to bernoulis principle, the high pressure exhaust flow on both sides of the tube would create a low pressure system in the tube thus a vacumm.

that setup is not found on the normal cars and thus why i was saying you wouldn't have a vaccumm. my appologies. interestingly enough if the pipe was angled enough you'd loose the vacuum. so where in the stream is the pipe welded in?

you may know this already, the air injection system is pumped directly into the head, the tubes on the headers are for the CO2 testing.

 

Useless is not a problem. Harmful would be. Are they harmful?

 

I inquired and rec'd a reply from, can't recall who now, I'll search when I get home, and the reply was you don't need them unless you have a problem...or something like that....

 

the way the PCV works is it allows crankcase pressure to exit and atmoshpere not to enter, or under the rare occasion of vaccum in the crankcase it won't allow it to loose vaccum.
becouse of the loose tolerences we get blow by into the crankcase, this causes oil to be pushed out of the valve covers, the OEM set up collected it all and used a seperator with a hose runnig to the intake to create a vaccum.
if the PCV fails then air will flow freely in&out, no real harm but not ideal either. i switched over to the krank vents and the only issue i have is oil spray on the motor becouse i vent at the valve cover thru a filter. i probably run a catch can with an electric vacumm pump in the future.

 

just for humor here, who's steve???

 

it's alright, happens alot.

 

I don't think anyone ever said they were harmful, just didn't do anything to improve the engine or performance at all. I have never been able to understand what is wrong with the factory solution?

Birdman