Just got a call from Jim Galto of Greracing.com who did a flowbench test on my DH racing head. The intake was 275cfm and exhaust was 195cfm. He actually had nothing bad to say about the headwork, other than to simply say "there's always more you can do" and that he could, with different valves and some refining of the portwork, probably get that number up above 300cfm. He has an in house CNC and Superflow 600. He's not a Honda guy specifically, he's got EVO Supra and small block heads all over his shop, so I'm turning to you guys to let me know if I should continue with my F23 head or just grab an H23 and do a Frankenstein.

 

I've just been checking specs and it looks like this is about where an H22 head is stock. A stock F23 flows in the 230's Again, this was tested by someone who REALLY knows heads and he gave it a big overall. If I can get this to flow 300cfm and fit it with the proper cam springs rods and pistons can I hit 200whp? That's been my goal all along. I see the Frankenstein build with the F23 block pretty much stock with a pretty much stock H23 head making the power I want. Is that doable with the sohc F23 with these flow numbers? Or is the better to have a dohc head with the same flow numbers? Really trying to figure this out.........

 

200whp is do able. It will require ALOT of work though. The flow numbers are ok. Don't get caught up on those though. You will need good aftermarkte rods to rev it reliabley. Good header is going to be hard to come by and you can mod. a H23 IM or have your F23 re-worked. The F23 IM is not really that bad.

If you want to get that head done better look at contacting Combustion Contraption or if you want IM me and I will give you the name of the person who did mine. If you are really hell bent on getting over 300cfm then these would be your best people to contact IMO.

 

Ported H23 runners and DH plenum. Crower maxi light rods and some forged pistons. Will probably run 11-11.5 compression, going to spec out the pistons after the math has been done. I'm assuming the maxi light rods and light forged pistons will it rev a lot more effeciently?

 

If those flow numbers were at 28"

275/1.05 x .272 = 71.2 hp/cyl x 4 = 284.9 hp at 100% ve

However, that only works if everything else in the combination is optimum (intake, cam, compression, fuel....).

 

could you explain your math to me. is that just general math for NA heads that flow 275cfm ? Remember I'm trying to use the G23 frankenstin build for comparison purposes. There's nothing optimum about that build, and it makes the power I'd like to make. So, considering we're using the same block, and the head and its flow are really the only big difference between the builds, I should be on the right track considering the H23 head doesn't flow any better than my F23 now does correct?

 

Yes and no. Easy way to remember it, The bottom end holds the power and the head will produce the power. General terms of cores.

Question for you, Is an H23 head wider across its ports of the head (front to back) then a F23?

This can effect volacity, volume, and speed of the air that enters the cyl head.

 

The h23 has wider ports. If two heads flow the same CFM, the one with the smaller ports front to back has to be flowing faster. Certainly CFM doesn't mean everything, but mine doesn't produce high CFM because its been hogged out, the ports are still smaller than an H23, but a bit larger than an F23.

 

was that done @ 28"

 

i would say the biggest limiting factor on a f23 is the cam selection

 

I'll ask about whether or not it was at 28" I don't honestly know. I'm going to the shop tomorrow morning to find out. As far as cam selection, I had a custom cam reground by crower.

 

yep 28"

 

search for Pirates build....

 

Flow a F22Ax non-vtec head, and I hope you sit down when the number come through. With some decent porting, the F22Ax will give you numbers north of 340cfm at 28"...more than an H22 will even muster. I hope that helps.

 

it does bisi. i'm starting an f22a project as well..... buying another accord to drop in the engine.

 

F22a head Cam selection is also very important depending on what the head end up flowing.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Bisimoto &raquo;</TD></TR><TR><TD CLASS="quote">340cfm at 28"...more than an H22 will even muster. I hope that helps.</TD></TR></TABLE>

I'm not so sure about that. I just finished a H22 head with 35.5mm valves that did 333cfm @ .550" and that was with leaving some flow on the table.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Bisimoto &raquo;</TD></TR><TR><TD CLASS="quote"> With some decent porting, the F22Ax will give you numbers north of 340cfm at 28"...more than an H22 will even muster. I hope that helps.</TD></TR></TABLE>

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Bisimoto &raquo;</TD></TR><TR><TD CLASS="quote">Flow a F22Ax non-vtec head, and I hope you sit down when the number come through. With some decent porting, the F22Ax will give you numbers north of 340cfm at 28"...more than an H22 will even muster. I hope that helps.</TD></TR></TABLE>

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Bisimoto &raquo;</TD></TR><TR><TD CLASS="quote">Flow a F22Ax non-vtec head, and I hope you sit down when the number come through. With some decent porting, the F22Ax will give you numbers north of 340cfm at 28"...more than an H22 will even muster. I hope that helps.</TD></TR></TABLE>

my h22 head was &gt;300 w/just a valve job

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by JDogg &raquo;</TD></TR><TR><TD CLASS="quote">

my h22 head was &gt;300 w/just a valve job </TD></TR></TABLE>

That doesnt count cuz I bet Brad did it.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Combustion Contraption &raquo;</TD></TR><TR><TD CLASS="quote">

That doesnt count cuz I bet Brad did it.</TD></TR></TABLE>

im just sayin haha

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Bisimoto &raquo;</TD></TR><TR><TD CLASS="quote">Flow a F22Ax non-vtec head, and I hope you sit down when the number come through. With some decent porting, the F22Ax will give you numbers north of 340cfm at 28"...more than an H22 will even muster. I hope that helps.</TD></TR></TABLE>

i keep hearing this from people that simply repeat what you say

and ive been searching for this answer to the question for awhile:

exactly waht head is the best one? or are they all the same?
i found that these are all non-vtec. the f22 heads that were used in the prelude or accord are better?

* F22A1: 125 hp (93 kW) @ 5200 rpm
* F22A4: 130 hp (97 kW) @ 5200 rpm
* F22A6: 140 hp (104 kW) @ 5600 rpm
* F22A7: 150 hp (110 kW) @ 5900 rpm (147hp/108kW with automatic transmission)

thanks in advance man

 

Don't know about the a7 but the a1, a4, a6 are all the same head.

 

Bisi sells F23 grinds also. I'd say that since you already have a decent flowing head you should just put a cam in it and see what it can do.