Crank case moisture with E85
Pistons are set with .0045 clearance and rings are gapped 28/32 as I am intending on spraying it down with 300-400hp on n20.
I have also installed a vacuum pump with catch can.
The tune was fairly rich up until now, I have aprox 50-75miles on it getting part throttle leaned out and working in to WOT. When first driving I was collecting a lot of moisture in the catch can, as much as 3oz with in 6-8 miles. That has now been reduced to roughly 1oz in roughly 15 miles.
I pulled the oil filler cap off tonight and there is a good amount of foam collected in the cap and filler neck.
My vacuum pump pulls from a modified LS3 valley cover using a -12 line to the pump but there is nothing tieng to to the valve covers which are technically the highest point. I think the moisture is collecting there for that very reason.
Thinking about hooking the valve covers up the the pump as well but I am curious as to what others are doing.
Everything is sealed and I can only attribute the moisture to the fuel and blowby.
Thought, ideas and suggestions are definately wanted.
You will need a spectrometer (Science Beaker) to check gas Just like they do on Moonshiners for Alcohol content with a little water to see the EXAct amount of Alcohol the fuel has. Different shipments has higher or sometimes lower Alc. content. I did pull the valve covers. The filler neck had a lot of foamy condensation but the covers had very little and rockers/heads has none.
I might just drill a hole in the top of the cap and run a line from it to the t-fitting on the pump (t-fitting attaches the -12 from valley cover, vacuum adjuster and pump).

You can tee the two VC ports into the front valley cover port for some extra circular breathing if you think the VC are becoming stagnant, but truthfully there's no reason water should be going up there at all. If you have condensation at the filler neck (bad) it leads me to believe you have a vacuum leak there. I have my vac relief valve on the fill cap (pictured), so thats the last place water would collect on my setup. I have the valve covers looped together. The idea is through the vac relief valve the engine pulls in a slight amount of air creating a flowpath from top to bottom to evac out the valley, although its all negative pressure.
Last edited by DietCoke; Jul 31, 2013 at 06:32 AM.
I thought about mounting mine on the valley cover at first, but I didn't want it pulling dirt in to the motor.
Not a bad idea the way you have it set up, might do that with mine and put a filter on it.


