David Dickson

Ok, just a little background on my setup:

Fully built engine with pauter rods and OE size CP pistons.
Custom ring gapped by me for copious amounts of boost.
Street ported and polished head with stock valvetrain
Perfect Power TF10 with 310cc primaries and 670cc secondary injectors
Running Ethanol E85 Winter Blend

Now on to my question. I'm currently running 12psi for winter driving and everything runs smooth for about 45 minutes. AFter that things get a little weird. The engine seems to run a little rougher and I seem to get more junk in my catch can than normal. A while ago I removed my PCV valve and replaced it with a straight thru barb fitting. I have both the PCV and Breather line going to a catch can with a filter on top. I have one line going from the catch tank to the turbo intake.

Now on to some of my personal theories.

1) Worn valve guides. Maybe as the engine heats up it allows the valve guide tolerances to slip and allows some combustion gases to seep into the head? Is the only way to check for worn valve guides to pull the head? I know a leak down checks for worn valve seals but I'm talking about the guides themselves. Either way I'll do a leak down test to check valve seals.

2) Worn piston rings? Maybe all the dyno and track time is finally taking its toll? I'll do a compression test to verify that.

3) Tappet to cam lobe clearances outta whack? I check them a few weeks ago and only a couple of intake valves were too tight. I fixed those with new tappet shims.

Naturally I meant Newbs Need NOT to reply....lol

Regit

My guess is the piston rings., all the lands were totally destroyed in mine when I pulled her apart (all Garys abuse lol),but ran amazingly at 15 psi with not much issue,when people see the pistons ,they are astonished the car worked that awesome let alone even worked! , the catch can did use to fillup quite quickly with frapp too, not now since I rebuilt her.. sounds like the same pcv/catch can set up as mine,but what does "I have one line going from the catch tank to the turbo intake"mean?,your blowing frapp vapors through your turbo?, I'm confused......... I'd like to know if E85 all the time on a daily is wise?,cant be good for overall longevety?must end a engine life way quicker than reg gas?, I know dick all about E85 and its good/bad points.

'treezy

From what I know about e85 (not much) it burns cooler than gasoline and doesn't leave carbon deposits like gasoline IMPROVING longevity.

Regit I think he means vac line..

Since the problem starts to occur after 45min of drive time my guess would be more towards valve guides and less towards rings. How new are piston/rings?

Post the results of your leak down

Denisst99

sensor or voltage/ground to a sensor that is going out of whac?

David Dickson

I wasn't able to do the leak down this weekend. Hopefully today. smile.gif

I've been running E85 for over 3 years with no problems, but maybe I should do my research on longer term affects on things like valve seals and guides. wink1.gif

I didn't think about it possibly being an electrical issue. I'll have to look into that.