How much can an a6 head be milled?

[exratedaccord93]

well guys, I'm probably going to go all motor until I build for turbo. I'm going with the delta 272 regrind ($115+ shipping- the price went up! ) and going to mill my head to bump compression. I've heard that I should only mill it .030" at the most. I've seen a stock ls head milled .060" and had no clearance problems. Is it possible to mill more than .030" for the F22 to get a higher CR? BTW, I'll be running stock bottom end and valvetrain. What are your opinions?

[ACC0RD22]

if your going turbo dont mill the head . . . i mean . . . unless you want to buy low CR pistons or buy a new head to lower the comp back to stock (which is like perfect for turbos . . . . )

[d112crzy]

any compression is good for turbos, its all in the tuning, that why ppl run away from high compression when dealing with turbo, its more complicated to tune, thats all.

as far as milling the head, find out first how much .030" would do to ur compression and then go from there. i wouldnt get a compression higher than 9.5, i think thats good enuf, for me anyway. then, when it comes to turbo, u can just get some h23 8.0:1 cr pistons and call it a day, well, if thats all u wana do, i guess.

[ACC0RD22]

any compression is good for turbos, its all in the tuning, that why ppl run away from high compression when dealing with turbo, its more complicated to tune, thats all.

as far as milling the head, find out first how much .030" would do to ur compression and then go from there. i wouldnt get a compression higher than 9.5, i think thats good enuf, for me anyway. then, when it comes to turbo, u can just get some h23 8.0:1 cr pistons and call it a day, well, if thats all u wana do, i guess.

unless you want to run race gas on teh street then i would avoid a high compression turbo set-up

[d112crzy]

u can make ur own race gas, its not hard. and like i said, i wouldnt suggest running over 9.5:1 compression, just to be on the safe side of things. just, always take ur time on tuning the car, and dont cheap out on tuning parts. u'll pay in the end, and so will ur car.

[d112crzy]

k, after a few math problems and lots of reading, ive come to a conclusion, getin a thinner head gasket is a lot safer than millin the head, or so say the techs at h-t. a thinner HG would have the same effect as milling the head, but its a lot safer, duh. and if ur still now happy with ur results after the thinner HG, then mill the head like .010", and and should a good cr bump. o, and i found that milling the head .030" will give u a compression of ~9.2:1, i had to do some rounding, so its not accurate.

[HondaFan81]

My F22ax head was milled by DH Racing .020" , he has 16 years of Honda experience.

[d112crzy]

do u know ur compression with the whole set up?

[exratedaccord93]

I don't plan on going turbo with this motor. This is just a fun project while i build my turbo motor. My concern isn't with the compression being too high because i want to bump compression significantly by milling the head. a forum member @ nonvtec.com says that milling .030" will bump it to 9.3:1. I'm trying to get the cr in the high nines or maybe low tens with out new pistons. I'm just seeing if anyone has had experience in milling more than .030". Thanks for the feedback already guys

[TÜNE.FREE]

well, i am am going the piston rought, expensive but very affective.... on F22parts.com u can buy forged pistons from 8.5:1 compression to 17:1 compression, so i am ganna replace the head gasket (OEM), and then i am going with a 11:1 compression piston set, rebuilt OEM bottom end, micropolished crank, 282 Delta cam ( a little hotter than the 272), socketed and chipped ECU for tuning, and basic ported H23 IM, TB, then AEM cold air for prelude, Megan header with modified 2 1/2 inch collector, 2 1/2 inch CAT, and 2 1/2 inch exhaust with one APEX N1 style muffler... very affective setup.. rest goes towards drivetrain...

[exratedaccord93]

Not to be a jerk, but can we stick to the topic please.

[d112crzy]

he's really not off topic, he's just stating the route he's going, since u want a higher cr, but the harder way, and he is gettin it the easier way. remember, cheap does not equal reliable, cuz sure, u can get ur head milled for around 30-50 bux, but if u dont know what issues its gona cause, and how to fix them, ur gona fuck up ur engine. u do know that its gona affect the timing right?

[hatchninja]

High comp pistons, turbo, etc etc are off topic, here's what's on topic, Head milling, Claying, Cams.. Timing is fixed with a timing gear (1 degree advance for every .012 milled), and milling the head for cheap and easy compression is not at all a new or crazy idea.

A lot of people i know have their heads milled to add some compression. A friend of mine has an LS that keeps up with GSR's with just I/H/E and the head milled .040. Another friend of mine has an LS/VTEC with 11:1 pistons, his b16 head is milled .050 (GSR cams.....no clearance problems). My GSR head is milled .030 with ITR cams (stock c/r is 10.6:1....again no clearance problems)

Although no one has apparantly tried it, I'm pretty convinced that there will be no clearance problems with milling the F22a head .050 on the stock 8.8:1 compression ratio. However, it's always, always necessary to clay the motor. If there's not enough clearance (unlikely IMO) just use a layer or two from a stock head gasket. In the end you will have a more useable compression ratio for a mild n/a build.

Here's the question that needs to be answered. Does anyone have EXPERIENCE milling an F22a head more than .030 or claying an F22a?

[hatchninja]

Here's an idea. Take off the head...remove the HG, put the head back on and clay the motor for clearances....the stock HG thickness is appx .030, that will give you a rough idea of how much you can or can't mill.