SPOHN'S Journal II Track Demon Reborn

Sh0velMan · 06-26-2013, 12:47 PM

Quote:

Originally Posted by Red__Zed

You get the same purge everytime you go into boost, as the crankcase is positive relative to atmosphere, with none of the pressure build up while under boost (which can actually be rather substantial).

I've not messed with this on a VHR, but just offering my opinion from the bit of experience I have with FI.

You can go pre-impeller and probably get something working, but that likely gets you into other issues.

It's only positive relative to atmosphere if there is, in fact, substantial blow-by. This engine is not like older examples where there is a mechanism at work pressurizing the crankcase with intake manifold air so that all you need is a single vent, it requires vacuum from the manifold to draw out said air. Without that vacuum, there is no evacuation of the crankcase, as I've said over and over.

And as I addressed in my reply, any true pressure buildup would exit via the breather, so that's a non issue.

Red__Zed · 06-26-2013, 12:49 PM

Quote:

Originally Posted by Sh0velMan

It's only positive relative to atmosphere if there is, in fact, substantial blow-by. This engine is not like older examples where there is a mechanism at work pressurizing the crankcase with intake manifold air so that all you need is a single vent, it requires vacuum from the manifold to draw out said air. Without that vacuum, there is no evacuation of the crankcase, as I've said over and over.

And as I addressed in my reply, any true pressure buildup would exit via the breather, so that's a non issue.

If you logged pressure in a VQ crankcase over boost, I bet you'd be surprised.

Here's one for you:

Crankcase Ventilation Mod w/Pics - Page 18 - MY350Z.COM Forums

Sh0velMan · 06-26-2013, 12:52 PM

Quote:

Originally Posted by Red__Zed

If you logged pressure in a VQ crankcase over boost, I bet you'd be surprised.

Here's one for you:

Crankcase Ventilation Mod w/Pics - Page 18 - MY350Z.COM Forums

Wow, 15psi got him a 1.5psi crankcase pressurization.. that's loose as hell.

Red__Zed · 06-26-2013, 12:53 PM

Quote:

Originally Posted by Sh0velMan

Wow, 15psi got him a 1.5psi crankcase pressurization.. that's loose as hell.

with a drilled out PCV...

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