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Old 10/03/2011, 11:31 AM   #1
Charlie Moua
JDM King
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Charlie Moua is offline
Join Date: Mar 2011
Posts: 1,156

Default b20b rebuild...milling head

This if for my kid brothers build...

after the rebuild we are hoping to make about 145whp and 140tq on e85
Keep in mind I will be boosting it next year with garrett T3 super 60 & make 250whp @ 7-8psi

So far this is in the rebuild :

- jdm b16 s1 tranny (4.4 Final Drive FTW !!!)
- exedy 9lbs flywheel
- exedy clutch
- arp rod bolts
- arp head bolts
- oem head gasket
- npr rings on stock pistons
- fresh hone
- stock cams (might go with 62403 later on)
- tri-y replica header (2.5" collector)
- 2.5 exhaust
- chipped po6 crome
- walbro 255lph fuel pump
-e85 with pte 780cc injectors

Looking to get compression to about 10.1 but no higer than 10.5


1) can I shave the stock head down to 0.075?
says that if I milled head by 0.075 it would bring my cr to 10.45cr.

2) is 0.075 enough to affect timing issue where I would not be able to correct it by adjusting the distributor?

3) when you shave the head, do you have to take off the valve springs too or just the cams & rockers?

LMK - charlie Moua

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Old 10/04/2011, 10:43 AM   #2
The Tranny Guy
H22APWRD94 is offline
Join Date: May 2007
Posts: 2,007

Default Re: b20b rebuild...milling head

In regards to question #1, I would have to check the service limit on that head. On most Honda heads, the max that can be milled without the piston hitting the combustion chamber is .030 That is what they call the service limit. You can actually check it yourself if the head is off. I need to see if I can find a picture of what I am talking about, if not, I will take one and show you.

#2 - any milling will affect timing. Anything more than a couple thousandths honestly requires adjustable cam gears so that it does not affect the cam/crank timing. I had that b16 head I got from you milled .005 and it offset my cam timing on a ls/vtec with CTR cams almost 2 degrees.

#3 - I have taken fully assembled heads in to be milled, but it is best to take out as much as you feel comfortable with. After the first one, I learned it is easier to take them apart, then it is to try and clean the debris out afterwards.

Hope this helps man and I will check on that service limit.

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