Mopar Muscle Association UK

What do people think?

Can you run a breather pipe from the Rocker boxes (or a breather port in the valley) directly to the Full manifold Vacuum port beneath the Carb throttle plates?

I would have thought that this would have an impact on carburation mixture as you are introducing more air into the incoming charge AFTER the carb boosters, Jets, etc.

I want to reduce crank case pressure and I can think the only other (safe) alternative is to route a breather pipe into the Air filter so it does not disrupt the carburation mixture.

Any views?

Thanks

Pete

Why not use a PCV valve?

Mick70RR wrote:Why not use a PCV valve?

I would have to engineer one in but as this is merely a one-way valve, the question still remains - would you connect this output to the large port on the carb that is under the throttle blades? I am concerned about affecting the fuel mixture. I do not have an AFR so I cannot easily see the impact.

Cheers

Pete

You would certainly be drawing in oil vapour if not oil itself, you would need good baffles. Better off plumbing into the headers, you might see a little blue smoke but it won't contaminate the intake charge. Why is crankcase pressure an issue?

I am trying to reduce the crankcase pressure as the engine is susceptible to leaking on the manifold to block seal. It is a Stage VI inlet so no bolts across the valley.

Gotcha, in which case assuming you have sufficient valve cover breathing, sounds more like a straightforward leak rather than a pressure problem. Assume you are using silicone on the block rails? If the intake is a very tight fit, or metal to metal you will need a different sealer, silicone doesn't work very well unless there is a bit of gap to fill.

I have found that the high temperature Silicon used on Glass Oven doors works bet, the "normal" Silicon lasted about 30 minutes, but as there was a port welded into the inlet at the valley I put a simple air breather filter on it.

That started puking oil within 10 minutes.

I can block it off, but I was looking at other alternatives.

There will be a lot of oil getting chucked around the valley, if you have a breather on there it's probably best to run a hose up to a small breather tank to allow it to puke and drain back.