LIL SS

iTrader: (9)

I recently tore my 418 LS motor down and made some changes. One big change is I am on 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.

lil john

I may be wrong,but Boss Hogg said something about this to me and I went and asked my uncle James about it, you will have to check gas ea. time before fill up with E85 (Jim at Comp Sale quote 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.

LIL SS

iTrader: (9)

I have a tester, it does not tell you water content, at least not that I am aware of, just alcohol/gas content. The alcohol attracts water, the blow by contains alcohol, gas and water. If i am correct the alcohol and gas evaporate an moisture collects. The steam wants to rise and the valve covers/filler neck are the highest points. The vacuum pump isn't pulling that moisture due to its location.

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).

DietCoke

iTrader: (18)

My setup is similar, pull from valley, VC highest point... my valve covers don't collect moisture though. Lots of moisure and water vapor out the can, but thats normal with e85.



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.

LIL SS

iTrader: (9)

Is your vacuum relief filtered?

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.

DietCoke

iTrader: (18)

It's not filtered, but you'd be hard pressed to pull in dirt there I think. They do make filtered valves, I've just never honestly been concerned about it since I've never gone WOT on a dirt road.