Thanks for the responses: Bob, Marc, Sid...
My main problem (of course) is I dont have "stock" air-cleaners for
these mikunis.
I dont even know if they are still available ...does anyone know?
I had intended to use aftermarket air filters... k&n cones or such,
but I see that without routing it properly, it may not be setting up the
correct (exhaust port to intake) pressure.
hmmmmmm
-ed
Marc Sayer wrote:
> aryasura wrote:
>
>> I installed Mikunis on my 311 this weekend, and I wanted to find out
>> what to do with the blow off on the top of the engine
>> which is hosed into the SU airfilters.
>>
>> Excuse me for ignorance of the correct part numbers, terms etc...
>>
>> Can it be plugged ? If not where should I re- route it?
>>
>> ed
>> in NYC
>
>
> No it can't be plugged. It is a crankcase vent and if you plug it pressure
>will
> begin to build up in the crankcase. This causes the rings to seat poorly, as
>it
> is the pressure differential across the rings that makes the rings seat
>against
> the bore and ring lands (and not the static ring tension as many folks think).
> Excess crankcase pressure buildup will also cause the engine to leak oil.
>
> The best solution is to recreate the original venting system, however with
>some
> carb conversions this is more difficult than the avg. DIYer is willing to deal
> with. At the very least all stock breathers should be vented to atmosphere
> through some sort of filter. If you car had a PCV system originally and you
>opt
> to go with simple venting to atmosphere, you may find you develop oil leaks,
> don't quite get the power you expected and/or start burning a bit more oil. If
> so, what you have done is not adequately venting the crankcase and pressure is
> building up.
>
> There is a system racers run (though most racing bodies have outlawed as an
> unfair performance advantage it for some reason) that uses both manifold
>vacuum
> and the draw of fast moving exhaust gases to actually draw down pressure in
>the
> crankcase. The system is called an evacupan system and it really works if your
> exhaust system doesn't develop back pressure. It can create a significant
>vacuum
> in the crankcase, and this can boost hp figures quite a bit due to better ring
> sealing. So, do not discount this issue as unimportant, as the crankcase must
>be
> properly vented for the engine to run properly.
>
> Marc Sayer
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