Heymow - Lawnmower Racing Forum

Engine Help => Briggs Flathead => Topic started by: matthewfortson on December 01, 2013, 12:22:40 am

Title: air filter adapter help
Post by: matthewfortson on December 01, 2013, 12:22:40 am
My standard air filter has a connection to the rectangular cover for the valve springs, I just ordered an air filter from bmi and the adaptor that supposed to go with it doesnt look like it has a connection for the cover, any ideas?
Title: Re: air filter adapter help
Post by: royalblu68f100 on December 01, 2013, 01:11:37 am
We normally just leave it hanging. You could attach a piece of tubing to it and run it down the frame if you like ( this would be to prevent a mess if any oil came out).
Title: Re: air filter adapter help
Post by: matthewfortson on December 01, 2013, 01:37:19 am
O so there wont be any damage done if I dis connect it? And thanks
Title: Re: air filter adapter help
Post by: Huffy044 on December 01, 2013, 07:29:01 am
Early on I made a plate to cover this, installed a fitting and ran a hose over to a collection tank. I was able to keep an eye on how much oil was pushed out. Later I hooked this line to a vaccum fuel pump. This created negative pressure in the base of the engine which gave more power. As long a ring seal is good, this is a power adder.

As George says, "A lot of little things add up to a big thing"
Title: Re: air filter adapter help
Post by: matthewfortson on December 01, 2013, 06:28:08 pm
Could I just point some tubing upwardly
Title: Re: air filter adapter help
Post by: DeereRacer on December 14, 2013, 12:34:58 am
Later I hooked this line to a vaccum fuel pump. This created negative pressure in the base of the engine which gave more power. As long a ring seal is good, this is a power adder.

Forgive my ignorance but how does a vacuum fuel pump make a vacuum in the crank case? I have thought about creating crank case vacuum for more power but was not sure how to do it on a mower engine.
Title: Re: air filter adapter help
Post by: royalblu68f100 on August 28, 2014, 07:40:14 am
They plumb it in to the side of the crankcase and pull air out. This will pull almost as much vacuum as it will provide pressure.
Title: Re: air filter adapter help
Post by: Huffy044 on August 28, 2014, 11:24:38 am
Correct Royleblu, the vac signal comes from the intake which has little to do with crankcase vac.
Title: Re: air filter adapter help
Post by: DeereRacer on August 29, 2014, 12:44:11 am
Didn't think a fuel pump could pump enough volume to make a vacuum in the crank case. Do you use a standard stock pump or something else? Would you plumb the pump into the stock crank vent and close the valve cover hole?