[Mk2] [Turbo] Crank Vent/Breather Modifcations

[^Trickster^]

Since taking the head off and having it reconditioned and back on the engine I have come to the conclusion that my ring gaps are too large causing my crankcase pressurisation.

I had 175psi on all cylinders previously and it ran sweet, I now have 190psi and still running sweet.

I have had it pretty much since i built the engine.

I get alot of breathing but the catch can doesnt really fill up quickly, I get more condensation in there than anything else.

However it does annoy me because it smokes like hell.

I am considering installing another vent port into a old oil cap to give the crankcase more breathing toreduce the pressure, if it works ill put a permanent one into the rocker cover.

I have also considered instaling a breather system into the exhaust but would prefer other ideas if anyone has any? I am just sick of seeing the smoke, I have seen the Krankvent system but am yet to hear of anyone using one with first hand experience.

I am going to end up just extending the pipework and ditching the smoke out somewhere I cant visible see it!

Has anyone else got this issue.

[jimGTS]

There is a sump pcv on my rev5. Many phoenix power cars have secondary pcvs off the sump to relase pressure on the other side of the piston.
My sump has literally been tapped for the turbo oil line on my apexi ihi turbo, and the standard oil line sump adapter is used to vent the sump gases via a large 3-4foot line that connects to a second catchcan that in turn can be plummed into the intake.

I presently have both my oem gen3 and this additional catchcan venting to atmos via breather filters. Will be installing a third filter for my isc off the throttle body so I have zero pipework to the intake.

Anyway the sump way is how most of the PP mr2s have been setup, and same as mine. I don't know whether PP ever had there hands on my car, but is setup very much the same. (along with the tons of other PP mods that's on it).

[greeny]

There is a sump pcv on my rev5. Many phoenix power cars have secondary pcvs off the sump to relase pressure on the other side of the piston.
My sump has literally been tapped for the turbo oil line on my apexi ihi turbo, and the standard oil line sump adapter is used to vent the sump gases via a large 3-4foot line that connects to a second catchcan that in turn can be plummed into the intake.

I presently have both my oem gen3 and this additional catchcan venting to atmos via breather filters. Will be installing a third filter for my isc off the throttle body so I have zero pipework to the intake.

Anyway the sump way is how most of the PP mr2s have been setup, and same as mine. I don't know whether PP ever had there hands on my car, but is setup very much the same. (along with the tons of other PP mods that's on it).

The only reason that you'd want or need a secondary Breather from the sump is if the crankcase is overpressurising, the standard single/double breathers should be sufficient, unless the engines breathing too heavy for some reason.

[jimGTS]

am just going by the info ive been told/found in relation the PP cars..
they may or may not breath heavy, due to what ever reason, crazy piston sizes or whatever (i dont know alot about that), but it seems its what PP do to there mr2s. lockeys PP car for example, his has it, i have it, hes the one thats given me alot of info.

my ring gaps are too large as per tricksters comments

this could be the case with mine, hense the reason to sump it.

ive heard of other reasons as well, gives quicker revving due to less pressure for the piston on its downstroke....
how much of that is true i dont know, but heard that as a reason as well.

[JJ]

Jim... Do you work for Pheonix Power ??!! Fair few plugs there !!!

I'll let you into a little secret... alot of the original PP kit/gear is from a HKS parts bin... predominantly HKS tuning gear. In other words, a PP engine is practically a HKS engine..... styling and stuff is all unique to PP.

Like Bang & Olufsen electrical components are predominantly Philips !

[jimGTS]

for sure. same deal with the TRDs, didnt Tonis real TRD have a ton of HKS parts, tho put together by TRD.

[bobhatton]

The crankcase vent on the turbo engine are far too small for increased boost. The sump is the wrong place for a vent, too much oil moving around and could get blown out of the vent. I am going to use two 15mm vents in the cam cover to a large catch tank then one 25mm filter on the catch tank.

If you have a heavy breathing engine then there must be too much blow by. It will be piston and or ring clearance too large. It could also be a broken ring land. I only use total seal piston rings.

Bob

[JJ]

I am going to use two 15mm vents in the cam cover to a large catch tank then one 25mm filter on the catch tank

^^^^^^ As Bobs notes.... Have to do this on Supras otherwise they start blowing crankshaft oil seals out on a regular basis... a real damn inconvenience I can tell you !!

I visual smoke often points to a ringland cracked or broken ring - but as tricksters mentioned.. good compression all round.. and theres a set of forgies rattling around in there.

The rev 3's manifold does have a constant pull via a non return valve from the cam cover to the intake.. probably takes away a lot of the visual from what the rev 1/2's maybe suffering.

[cantfindausername]

The crankcase vent on the turbo engine are far too small for increased boost. The sump is the wrong place for a vent, too much oil moving around and could get blown out of the vent. I am going to use two 15mm vents in the cam cover to a large catch tank then one 25mm filter on the catch tank.

If you have a heavy breathing engine then there must be too much blow by. It will be piston and or ring clearance too large. It could also be a broken ring land. I only use total seal piston rings.

Bob

Similar in set up to what I've got. 2x -8AN breathers installed in the cam cover. Not sure on the "output" of the catch can yet though. Not really discussed that with my tuner.

[^Trickster^]

Thanks for the replies.

I certainly wont be venting from my sump, If anything ill be venting the crankcase like I mentioned before, I think the problem is ring gaps and the increased crankcase pressure is too much for the small single vent on the rev1/2 cover, I am going to bodge up the old oil cap with a filter on it for a trial before I start drilling holes in my rocker cover tho.

I dont really care about it breathing, as long as i makes power it can breathe all it wants lol

Graeme

[bobhatton]

Get some total seal rings in there.

Bob

[^Trickster^]

I wont be pulling apart my full bottom end to fit rings unless something goes wrong, the engine runs strong as it is, I would rather address the breathing for the time being.

Graeme

[JJ]

Think you can find a decent air pump with good flow rates ??!! Channel it to the base of the car !! It'll place the block under vacuum all the time and divert the smoke ??!!

I'm sure one of those ebay superchargers would help ( turn it around )... Might need a 14mm to 3 inch hose reducer !!

No point putting it back into the intake, will only push hot air / oil particles right through your intercooler back into the intake creating an additional cocktail for detonation.

[kameleon]

im using 2 dash 12 fittings to my catch can.

ive seen people fit catch cans to their engines with smaller then factory hoses...........