Crankcase ventilation options for supercharged Rover V8?

SuperV8 · Post by **SuperV8** » Thu Apr 14, 2011 11:35 am

What options are there for crankcase ventilation with a supercharged rover V8?

I understand a PCV system is a good thing but not sure how it works when you have positive inlet pressure?

I have a centrifugal supercharger and don't really want to feed oily air past it.

Also do you think i'd need a flame trap on each rocker cover or just the 1 as standard? It is a 4.6 & I'm aiming for 400bhp, my engine has been re-built with new rings and tophat liners so I have no idea how much blow by i'll get? once the rings have bedded in.

With my last engine (3.5 supercharged) i didn't get round to sorting out any PCV type system, just had a pipe with a u-bend in it from the flame trap, I used to get out my car (Dax Rush, with no doors/roof) after a journey and have a sore thoat and eyes due to I guess the fumes!

Tom.

Wotland · Post by **Wotland** » Fri Apr 15, 2011 6:02 pm

Evacupan system http://www.v8tuner.co.uk/product.php?id=589

mgbv8 · Post by **mgbv8** » Fri Apr 15, 2011 7:00 pm

Give it some thought before you fit anything.

Are you happy that the existing breather pipes are big enough?
Can you show us some pics of the existing breather system please.

SuperV8 · Post by **SuperV8** » Mon Apr 18, 2011 11:39 am

Sorry for my slow reply had a hectic wknd.

I don't really have a current breather system. The photo shows where it would be going

i don't know what size pipes should be used? Would standard dia be enough? One or two flame traps? Would just using a catch tank be enough?

Tom

stevieturbo · Post by **stevieturbo** » Mon Apr 18, 2011 8:13 pm

Keep it simple.

Just route as many breathers as possible into a properly designed oil/air separator ( catch can ) which will have adequate venting ability.

If this is designed right, this air can then be vented into the intake tract before the blower, as the air will be pretty clean.

Ideally this catch can will return to the sump, below the level of oil.

I'd say a 1" breather from each rocker cover would be a good start. Kind of hard to source breather take offs anywhere else on a rover. Flame traps arent required with a proper catch can.
In fact I think they are more for old carb systems in case of backfires etc.

You can try and add PCV etc, but it just adds complication.

A proper catch can simply needs to have adequate volume inside. And to be baffled in such a manner than any liquids or deposits find it impossible to escape out the vent, yet air can still pass through relatively easy.
Then any fluids caught can either be drained off the bottom, or returned to the sump.