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View Full Version : what is the maximum mill limit on the head.


patrik.johnson
01-12-2005, 07:10 PM
and is it the same limit on evrey f22a engine head?.

TÜNE.FREE
01-12-2005, 11:11 PM
well ya, but u can mill a head to any reasonable point, usually companies try not to do any milling to where u cant run pump gas.... i know a lot of people that use 11.0-11.5:1 compression, thats safe for 91oct. and some booster.....

patrik.johnson
01-13-2005, 07:31 AM
well ya, but u can mill a head to any reasonable point, usually companies try not to do any milling to where u cant run pump gas.... i know a lot of people that use 11.0-11.5:1 compression, thats safe for 91oct. and some booster.....
the lowest in sweden is 95oct and the highest 98oct so that wont be a problem.
i heard that 0,05mm is the maximum limit on milling the head before the piston starts to kiss the valves.
can any one confirm?

ZigenBallZ
01-13-2005, 08:38 PM
I can tell you what the Highest confirmed amount is in inches... no metric system in our machine shops... you'd have to do your own conversions...

but I took part in creating an F22A1 with .050" milled off the head... it's running that with an .043" copper headgasket and there was zero interference when it was clayed...It's been running since last year in a friend's car and is still doing fine... and he beats the shit out of it... He is also using my first chipped ECU with a Hondata copied bin program and a 7k rev limit which he does hit quite quite often... there have been zero problems with rod stretch... gotta love ARP... :D

but there's a pretty big cam in there and we clayed at both 5 degrees retard and 5 degrees advance on the cam gear and Zero interference... but I asume ZERO liability as far as anyone reaading this is concerned... you had better clay to be sure... the valves you save may be your own...if you don't and something breaks... it's your own fault...

I would play it safe though and clay anything over .040-045" used with a stock thickness head gasket...alot depends on the specs of the cam it will be used with...

When you increase lift and duration you have to take every measurement into account...

patrik.johnson
01-14-2005, 06:55 AM
can you make a guide how to clay the engine?.
i would like to learn my self about how to do that.

90AccordEXR
09-26-2005, 11:28 AM
how thick is a stock head gasket?

HondaFan81
09-26-2005, 01:03 PM
how thick is a stock head gasket?

From what I've read & have had knowledgeabe people tell me compressed F22 headgaskets run .026-.028 inches.

Of course, I do have a used one at home that I could mic...

exratedaccord93
10-02-2005, 12:27 AM
word on the .050 and chipped ECU

alb_accord
10-05-2005, 09:30 PM
to be on the safe side its .45

ACC0RD22
10-05-2005, 10:01 PM
the lowest in sweden is 95oct and the highest 98oct so that wont be a problem.
i heard that 0,05mm is the maximum limit on milling the head before the piston starts to kiss the valves.
can any one confirm?
I think the way europe measure octane is different than the way we measure octane . . . I think 98 octane from europe would correlate to around 94 octane here . . . ill try to find rationalization for my claims . . . but i dont think their gas is much better than ours.

EDIT: found it . . . read a few paragraphs down http://en.wikipedia.org/wiki/Octane_rating

hatchninja
10-07-2005, 04:28 PM
can you make a guide how to clay the engine?.
i would like to learn my self about how to do that.

http://www.c-speedracing.com/howto/claymotor/clay.php

done

Jarrett
02-10-2006, 12:27 PM
The octane rating me refer to is actually the average of two ratings come up with by two seperate entities The Research Octane Number and the Motor Octane Number values are averaged to get what we call the octane rating. Also, a question about the gasket thickness: I you mill the head are you not defeating the purpose by putting a thicker gasket under it?

HondaFan81
02-10-2006, 03:01 PM
I can tell you what the Highest confirmed amount is in inches... no metric system in our machine shops... you'd have to do your own conversions...

but I took part in creating an F22A1 with .050" milled off the head... it's running that with an .043" copper headgasket and there was zero interference when it was clayed...It's been running since last year in a friend's car and is still doing fine... and he beats the shit out of it... He is also using my first chipped ECU with a Hondata copied bin program and a 7k rev limit which he does hit quite quite often... there have been zero problems with rod stretch... gotta love ARP... :D

but there's a pretty big cam in there and we clayed at both 5 degrees retard and 5 degrees advance on the cam gear and Zero interference... but I asume ZERO liability as far as anyone reaading this is concerned... you had better clay to be sure... the valves you save may be your own...if you don't and something breaks... it's your own fault...

I would play it safe though and clay anything over .040-045" used with a stock thickness head gasket...alot depends on the specs of the cam it will be used with...

When you increase lift and duration you have to take every measurement into account...

You all have to remember just because .050" was milled off the head, this doesn't mean it is a TRUE .050". Mike mentioned using a .043" thickness headgasket ...this counteracts the mill...I think i calculated your exact situation for a .035" true mill

Jarrett
02-10-2006, 03:16 PM
To set the record straight are we referring to max mill specs on a cammed F22 or a factory cam? Cisco, PM sent.

ACC0RD22
02-10-2006, 05:36 PM
The octane rating me refer to is actually the average of two ratings come up with by two seperate entities The Research Octane Number and the Motor Octane Number values are averaged to get what we call the octane rating. Also, a question about the gasket thickness: I you mill the head are you not defeating the purpose by putting a thicker gasket under it?
yep

In most countries (including all of Europe and Australia) the "headline" octane that would be shown on the pump is the RON, but in the United States and some other countries the headline number is the average of the RON and the MON, sometimes called the Anti-Knock Index (AKI), Road Octane Number (RdON), Pump Octane Number (PON), or (R+M)/2. Because of the 10 point difference noted above, this means that the octane in the United States will be about 4 to 5 points lower than the same fuel elsewhere: 87 octane fuel, the "normal" gasoline in the US and Canada, would be 91 in Europe.