i was woundring what will happen if i put h22a head on f20b block will that give me more power?and what C/R would i get

 

https://honda-tech.com/zero...age=2

It looks like the heads have the same displacement, so compression ratio would stay the same.

 

from what i understand about r/s ratio and air velocity it would be a worthless thing. the smaller valve design on the f20b is to aid the r/s ratio of the f20b bottom end. it creates more air velocity to get more air into the cylinders. the larger valve area of the h22 would hinder this and create less power.

 

so its worthless even thought if h22 head has bigger vlaves

 

yes, the f20b head was designed to work best with the f20b bottom end. the f20b head is more than capable of flowing enough air for the bottom end and considering valvetrain and cams are interchangable they have the same aftermarket. can i ask why you want to do this head swap.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by sedracer &raquo;</TD></TR><TR><TD CLASS="quote">can i ask why you want to do this head swap.</TD></TR></TABLE>
more air sence i'm having 100 shots direct port

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by CiViC SiR &raquo;</TD></TR><TR><TD CLASS="quote">so its worthless even thought if h22 head has bigger vlaves</TD></TR></TABLE>

I've measured f20b head cc to be smaller than the h22, so you may lose compression putting a h22 head on a f20b. I'll try and get more accurate measurement before i post the numbers.

 

was reading a page on the development of the f20b and f20c...jdogg has also pointed this out

the bore on the f20b is only 85mm and the valve spacing is pretty much the smae as the h22 ..there for if you were to go with a bigger valve ,the outer radius on the valves would be to close to the bore hendering flow since there would be no room left for air to flow around it

 

If anyone was ever willing to sleeve there F20b and bore it out to atleast 87mm(I would go to 89mm though) then you would benefit from an H22 head... Or if someone were to simply swap crank/rods into an H-series with H-series pistons as well...

 

^^^^
i'm still not 100% sure of this, i believe some dyno time would be needed. the velocity and volume of the ports and valves has more to do with the stroke and r/s ratio than the bore.

 

wait, i know that the f22's have cast iron sleeves, but do f20s?