[kittyboy]

Kindly requesting feedback regarding personal experienced issues directly caused by excessive crank case pressure in the 800hp plus neighborhood. Thank you in advance for mod suggestions, products, shared personal experiences? Preemptively trying to avoid potential issues such as blown seals, etc... Not sure exactly what else may be common to expect at this power level? LSX-B15, 3.8 pulley ratio, etc...

 

[Racerfox]

My 418 has this issue. The fix is to run a mighty mouse catch can.

 

[Lt1z]

You need a breather can with check valve like the MMS wild

 

[theheder]

I use one of these in the oil fill tube and a dual catch can setup. Might be overkill but problem solved.

 

[Lt1z]

I use one of these in the oil fill tube and a dual catch can setup. Might be overkill but problem solved.

That is ok if SD tuned but I would not use one when a MAF is being used. On the higher power stuff we generally run a -10 from each valve cover to a mms wild can or fabricated breather can with check valves

 

[jcmgt]

Another option.
Peterson 2 psi pop-off valve

 

[kittyboy]

That is ok if SD tuned but I would not use one when a MAF is being used. On the higher power stuff we generally run a -10 from each valve cover to a mms wild can or fabricated breather can with check valves

Yes, I have a MAF only tune, high power setup, noted some oil blowing out from around the rubber-stop style oil fill valve cover fill cap, I'll check-out this setup. Became a bit concerned, no blown seals or gaskets at this time thankfully. I've read about some using -10 lines and figured I better get-up to speed!

 

[kittyboy]

I went ahead and added a breather to my existing catch can setup with 3/8" line, see if the vent might help.

 

[jcs003]

Call motion Raceworks and discuss with them your situation. They likely have a solution.

 

[RedTXV]

That is ok if SD tuned but I would not use one when a MAF is being used. On the higher power stuff we generally run a -10 from each valve cover to a mms wild can or fabricated breather can with check valves

Hello,

That's fine if it's SD tuned, but I wouldn't use one with a MAF. We usually connect a -10 from each valve cover to a mms wild can or built breather can with check valves on the higher power things.

 

[Blown376]

🤔

 

[random84]

Note that the valves also have a bit of latency and are ultimately a restrictive orafice (giggity) so it's not just "2psi." It's 2psi after an oil coated valve 3-4 feet up stream opens, but that still may leave quite a bit of crankcase pressure to push out seals.

You also want larger hoses as there is inertia of the air / oil vapor when you go from a vacuum to blow-by in the crankcase. -10 AN is a good rule of thumb.

I have some Motion Raceworks valve cover adapters I have been meaning to install for a vented setup.

Sent from my SM-G991U1 using Tapatalk

 

[SilverELEX]

That is ok if SD tuned but I would not use one when a MAF is being used. On the higher power stuff we generally run a -10 from each valve cover to a mms wild can or fabricated breather can with check valves

If the valve cover breather has a check valve, wouldnt this be ok? Mighty mouse sells one that is fantastic and seems to work well for me in in conjunction with a normal can in line with the factory routing. I went this route because i would always end up with oil in my blower with the mms wild can.

 

[Rubber Duck]

If your moving 1000 cfm above the piston, your
also moving 1000 cfm below the piston.

This is called 'Windage'.

We are fighting crankcase pressures developed by high windage,
which is amplified with these engines, as these engines use a
'Y' Block construction to aid in strength as the engines are made
of aluminum which is not sufficient for high hp output levels without
having the 'Y' Block construction.

-regarding a reasonably sealed engine-
While some leakage of the piston rings will occur on the
compression stroke, as well as the power stroke, this will
most likely not define the entire issue.

-windage issues-
If the crankcase pressure is sufficiently high when the piston
moves down on the intake stroke, the engine will inhale some
of the air in the crankcase, which is an oily film.

Any oil entering the cylinder will decrease the octane rating,
and will pose a high risk regarding destructive self detonation.

Relieving the pressure in the crankcase can help 'Band Aid' the windage issue. . .

Cheers