I have been trying to get a definitive answer for a while on this, and i have searched my *** off also. I have found not much useful info yet, someone please help me out with this.

I don't want to sleeve. Yes, period, no sleeving. (period)

I want to get 12:1 compression with the stock jdm pistons, if i can't get that, then i can go with type s pistons.

I was thinking just to mill the head enough to do it. If that isnt sufficient, then i guess i will go with as high as i can get, becuase i dont have the money for jun pistons.

How much does the head need to be milled to hit 12:1 with the stock jdm piston?
How much does the head need to be milled to hit 12:1 with the type s piston?

If the head is milled this much is there room for a cam as big as jun?

I will probably run RM cams for a while, and switch to jun sometime next year, just want to be able to expand to bigger things in the future.

Thanks guys.
Matt

edit: also, i have never been able to find any info on what you need to do rod-wise to get the type s pins to work.

 

why dont you search and calculate the numbers? Although I have not run any numbers 12:1 is probably to aggressive of a milling especially for stock jdm pistons, you'd most likely have clearance issues especially with large cams, and even more so if you decided to run oversized valves or make any timing adjustments. You would also have to have adjustable cam gears to correct the timing that you would be offsetting so much by milling the head. I think 12:1 even on type-s pistons is ambitous, and again more so with high lift cams and possibly oversized valves if you so choose

 

i havent been able to find anything on search that i can use, everything so far that i have found has been for other situations....

if you could point me in the right direction that would be great....thanks

 

well, the most you can safely mill/deck an H22 head is .030", right? otherwise you run into timing problems because the autotensioner cannot adjust.

 

well,I have crower rods,type-S postons,.030" milled head and 3 stage crower cams,Skunk2 cam gear,this give me ~12:1 CR and not have any problem
not sure about JUN cams:
jun cam valve lift: IN .480'' EX .468''
crower stage 3 lift:IN .468'' EX .468''


Modified by raser5050 at 4:39 PM 2/22/2005

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by mgags7 &raquo;</TD></TR><TR><TD CLASS="quote">edit: also, i have never been able to find any info on what you need to do rod-wise to get the type s pins to work.</TD></TR></TABLE>

Use 5th gen rods..

 

I figure with Type S pistons, 0.02 milled head, thin head gasket and flat valves, compression would be about 12:1

But I have concerns whether this setup have enough clearance for my Jun valvetrain, does anyone have a definitive answer?

 

Clay it and find out. People here do not really have Jun cams. They are more expensive than what most people are willing to pay.

Pirate

 

geez, talk about back from the dead....

clay is the way....

 

I have Jun cams, type S pistons, 1 layer headgasket, block decked (slightly, can still make out the cylinder code letters) and head milled (twice, just enough to make it flat) No clearance issues.. I'll do a compression test to see what I'm running..

 

Lots of ppl suggest to clay the motor, but it cannot replicate the same situation at high revs...

Corey, your setup has the closest specs to what Im shooting for. Seems like your setup has even less cleanrance than my proposed, and still running good.
When you say the head is milled twice, do you have the exact measurement?


<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Honda318dx &raquo;</TD></TR><TR><TD CLASS="quote">I have Jun cams, type S pistons, 1 layer headgasket, block decked (slightly, can still make out the cylinder code letters) and head milled (twice, just enough to make it flat) No clearance issues.. I'll do a compression test to see what I'm running..</TD></TR></TABLE>

 

vsbb6, if you have appropriate valve springs, high rpm clearances should be the same as low rpm.....just lock the cams into vtec and clay away....

 

wouldn't high rpm clearances be a little tighter due to more thermal expansion?