Sy99T/A

iTrader: (34)

I built a 416 a few years back for my 99 T/A, goes 10.90's full weight. I am feeling the itch again to squeeze a little more power out of it. I have decided to go from 93 to E-85. The engine has uncut 5364 heads, pistons are Wiseco -3cc with valve reliefs, Wiseco shows compression range to be 11.0-70cc or 11.3-68cc. I'm going to pull the heads, get them decked and put some mid runners in my FAST. The car is primarily a street car and I have easy access to E-85 fuel. How far down should the heads get machined? Should I continue to use the factory .051" head gasket or go with a .040" cosmetic?. I understand after a certain point the inserts in the manifold will need to be removed for the bolt's to screw in so I'm keeping that in mind along with rechecking for new pushrod length.
Thanks to all those who help out.

eaglegoat

You can't mill the heads enough for it to matter. For it to be worth it good need to run a domed piston and push your compression over 13. This is the type of thing you do during your build, not so much after. You're looking at 5hp tops from a compression change.

dogsballs

I've done the same thing with 5364 heads a few times as im a big e85 convert. First engine took 100thou off with factory cam and plastic manifold, up to 11.8 and loved it. Built another engine with same heads for drag car and 236/246 615/615 110 cam, factory pistons, needed pistons flycut a fraction (easy to do in block and pistons are 320thou thick anyway)

Gone up to 125thou now off same heads and monster solid roller 257/268 840/804 112+2, with domed wisecos but already valve reliefs.

Plastic manifold (and single plane alloy) will bend a fraction to fit. Main thing is to check port match.

don't listen to guy above obviously never done it

eaglegoat

You can run 11.8:1 on 91 or 93 octane. Increasing from 11-12 :1 gives a very small increase on power. Theoretical max of about 2%. Unless you're octane limited is not worth it.
​​​​
You're taking about bending things to fit. Doing something and doing something the right way are very different. Best of luck smart guy.

dogsballs

Lol, the right way. Its called hot rodding. Making do what you got.

I ran 10.0@135mph using a cam only shaved head 6.0 using that technique, on e85.

Now have a 720hp 6.0 with factory block, heads and crank. Lol

Dyno Junkie

Last year I had .075" milled off of our LS3 heads and flycut the pistons .100".
This took the LS3 to approximating 12:1 compression, which got another couple of mph in the quarter.

pantera_efi

iTrader: (1)

Hi, I would fit a Felpro 1041 HG.
I would "true" the heads.

My reason IS the strength of the OE casting, the push change, port angle.
I would fit studs that grow to match the head growth.
I would check for Bus Fuel in your area. (E-95)
I would check for E-98 and E-100 in your area.

Lance

Sy99T/A

iTrader: (34)

Thanks, I will look into those other fuels, as for E-85 I know where I can get that or AV fuel at least

I talked with camster a bit after the initial post about how much he did his heads and what else would be needed so I'm feeling like I will be pulling my heads here real soon, it is starting to get miserably hot here in Florida and I won't enjoy driving the car for much longer. Summer here sucks mid to upper 90's with crazy humidity in the day and even at night it stay's in the upper 80's