Since there is not much tech on this site I thought I’d make my little contribution. The goal of this thread is jsut to get as much H/F info in one place as possible, instead of spread out all over the internet. All the info I post is the result of about 6 months of sifting and compiling. Much (pretty much all) of the info comes from various forums which I know can be crap, but everything I post is things I’ve seen reiterated several times and confirmed. While most of the info is accurate, I by no means guarantee any of it. If you’re building a motor don’t go by these specs, but measure and clay it yourself.
Also, feel free to add to this what you know.
NOTE: The F20C and F22C (s2000 engines) are not really part of the F series line of engines. They are totally different in just about every aspect.
Lets start off with block and head specs. The following is quoted from Honda-Tech (here) and is fairly accurate.
Blocks
Block Type
H22A4 Block = Open Deck
H22A block = Closed Deck
H23A block = Open Deck
H23A1 block = Closed Deck
F22 block = Open Deck
F23 block = Open Deck
F20B block = Open Deck
Deck Height
H22A4 Block = 8.643
H22A block = 8.643
H23A block = 8.643
H23A1 block = 8.643
F22 block = 8.643
F23 block = 8.643
F20B block = 8.643
Bore
H22A4 Block = 87mm/3.425
H22A block = 87mm/3.425
H23A block = 87mm/3.425
H23A1 block = 87mm/3.425
F22 block = 85mm/3.346
F23 block = 86mm/3.385
F20B = 85mm/3.346
Note:
Due to various available piston diameters (A/B) actual bore diameter may vary
Rods
Length
H22A4 = 5.633
H22A = 5.633
H23A = 5.572
H23A1 = 5.572
F22 = 5.572
F23 = 5.551
F20B = 5.709
Width
H22A4 = .935
H22A = .935
H23A = .935
H23A1 = .935
F22 = .935
F23 = .780
F20B = .935
BE Bore
H22A4 = 2.008
H22A = 2.008
H23A = 2.008
H23A1 = 2.008
F22 = 2.008
F23 = 1.890
F20B = 1.890
Pin Bore
H22A4 =
H22A = .8649-.8654
H23A =
H23A1 = .8649-.8654
F22 = .8649-.8654
F23 = .8649-.8654
F20B =
Pistons
Bore
H22A4 = 87mm/3.425
H22A = 87mm/3.425
H23A = 87mm/3.425
H23A1 = 87mm/3.425
F22 = 85mm/3.346
F23 = 86mm/3.385
F20B = 85mm/3.346
Note:
actual diameter may vary depending on code of piston (ie, A B)
Compression Height
H22A4 = 1.221
H22A = 1.221
H23A = 1.203
H23A1 = 1.203
F22A1 = 1.203
F22A4 = 1.203
F23A1 = 1.181
F20B = 1.221
Dome Volume
H22A4 = 53.8cc
H22A = 53.8cc
H23A =53.8cc
H23A1 = 50.0cc
F22A1 = 50.5cc
F22A4 = 50.5cc
F23A1 = ??
F23A4 = ??
F23A5 = -18cc
F20B = ??
Wrist Pin Diameter
H22A4 = .866
H22A = .866
H23A = .866
H23A1 = .866
F22 = .866
F23 = .866
F20B = .866
Crankshafts
Stroke
H22A4 = 90.7mm/3.570
H22A = 90.7mm/3.570
H23A = 95mm/3.740
H23A1 = 95mm/3.740
F22 = 95mm/3.740
F23 = 97mm/3.818
F20B = 88mm/3.464
Main Journal Diameter
H22A4 = 55mm
H22A4 = 50mm (1997 Only)
H22A = 50mm
H23A = 55mm
H23A1 = 50mm
F22 = 50mm
F23 = 55mm
F20B = 55mm
Rod Journal Diameter
H22A4 = 1.888
H22A = 1.888
H23A = 1.888
H23A1 = 1.888
F22 = 1.888
F23 = 1.771
F20B = 1.771
Cylinder Heads
Combustion Chamber Volume
H22A4 = 53.8cc
H22A = 53.8cc
H23A = 53.8cc
H23A1 = 50cc
F22A1 = 50cc
F22A4 = 50cc
F23A1 = 50cc
F23A4 = 50cc
F23A5 = 50cc
F20B =
Intake Valve Diameter
H22A4 = 35mm
H22A = 35mm
H23A = 35mm
H23A1 = 34mm
F22 = 34mm
F23 = 34mm
F20B = 34mm
Exhaust Valve Diameter
H22A4 = 30mm
H22A = 30mm
H23A = 30mm
H23A1 = 29mm
F22 = 29mm
F23 = 29mm
F20B = 29mm
Head Gaskets
Bore
H22A4 = 88mm
H22A = 88mm
H23A = 88mm
H23A1 = 88mm
F22 = 86mm
F23 = 87mm
F20B = 86mm
Thickness
H22A4 = .026
H22A = .026
H23A = .026
H23A1 = .026
F22 = .026
F23 = .026
F20B = .026
Note:
Gasket thickness measured after crush
Bearings
Main Bearing Thickness
Blue: 2.013 - 2.010mm / 0.0793 - 0.0791
Black: 2.010 - 2.007mm / 0.0791 - 0.0790
Brown: 2.007 - 2.004mm / 0.0790 - 0.0789
Green: 2.004 - 2.001mm / 0.0789 - 0.0788
Yellow: 2.001 - 1.998mm / 0.0788 - 0.0787
Pink: 1.998 - 1.995mm / 0.0787 - 0.0785
Red: 1.995 - 1.992mm / 0.0785 - 0.0783
Rod Bearing Thickness
Blue: 1.510 - 1.507mm / 0.0594 - 0.0593
Black: 1.507 - 1.504mm / 0.0593 - 0.0592
Brown: 1.504 - 1.501mm / 0.0592 - 0.0591
Green: 1.501 - 1.498mm / 0.0591 - 0.0590
Yellow: 1.498 - 1.495mm / 0.0590 - 0.0589
Pink: 1.495 - 1.492mm / 0.0589 - 0.0587
Red: 1.492 - 1.489mm / 0.0587 - 0.0586
Main Bearing Width
H22A4 = .784
H22A = .784
H23A = .784
H23A1 = .784
F22A1 = .784
F22A4= .784
F23A1 = .784
F23A4 = .784
F23A5 = .784
F20B = .784
Rod Bearing Width
H22A4 = .762
H22A = .762
H23A = .762
H23A1 = .762
F22A1 = .762
F22A4 = .762
F23A1 = .609
F23A4 = .609
F23A5 = .609
F20B = .762
(Another, similar listing can be found here)
Hybrid Builds
If you actually looked through all that you’ll notice that the H and F series blocks and heads are VERY similar. Because of this stroking your H22 or building a F22/H23-Vtec is actually pretty easy. Some people have even gone as far as using the F23’s 97mm crank. Below are a couple break through build threads that are good reads (although very long).
F22-Vtec (F22/23 Block and H22 head) : Here and Here
H23-Vtec (H23 block and H22 head, or H22 block and head with H23/F22 internals) : Here
F23 block and H23 head (160whp/160wtq with all OEM parts, 200whp/175wtq with cams) : Here
This next one is an on going H23-Vtec build. Started out as a 12:1 cr build but has evolved into a 14:1 cr track monster : Here
Been looking into this one just recently. Turns out K20 pistons work pretty well in F22/F23 motors. The compression hight of the K20 piston is a little shorter than that of the F22, but the F22’s rods are longer. Turns out that K20a3 pistons give you about 10:1 cr and K20A pistons result in about a 12.2:1 cr. More info can me found here.
Note on Cranks
Another think you might notice if you really read the information quoted above is that the cranks changed mid way through the H22s lifespan. Older H22s have 50mm mains and newer ones have 55mm mains. Here is a post that details offset grinding and a few other things specific to the H/F series : Here
FRM Sleeves
Little bit of sleeve info specific to the H series: The sleeves in ALL H series motors are made of a material called FRM. FRM prevents us from running a forged piston(with a few exceptions that I will talk about in a minute). The sleeve and the pistons just don’t get along well and eat each other. This is due partly to different heat expansion rates and partly to the strength of the sleeves. A few companies have designed forged pistons that will not get eaten by the sleeves. These companies are JUN, Mahle, and Wiseco. More info on both why the sleeves don’t like forged pistons and on the FRM compatible pistons here. Again, this does not apply to F series motors, they have iron sleeves and can run forged pistons just fine.
Ditch your auto-tensioner
Now on to tensioners. The H22’s auto tensioner is notorious for failing and causing bent valves, dropped valves and grenaded motors. Thankfully the H23’s manual tensioner swaps right over without too much work. A write up can be found here.
Trannys. (No…not the guys that have turned into girls…pervs)
All H/F transmissions are interchangable between any H/F blocks with 1 exception. The exception is the H22A4 that comes out of a Prelude SH. Both the tranny and the block have light changes to accomidate the ATTS. Here is a listing of the gear ratios of all the different H/F transmissions.
Budget F22 Turbo Info
Happen to have a spare F22 or an Accord or Prelude S that is just begging to be boosted? On a tight budget? Then you want to look to the DSM guys. The 2nd gen Eclipse/Talon turbo manifold to be more specific. The ports line up perfectly with the F22’s ports, all you need is to redrill the mounting holes. Slowboy Racing even has a 2g DSM “turbo solution” that includes much of what you need to boost your F22. Check it out here.
Header choices
H22 choices: If you want to make any decent gains you are pretty limited in choices for a header. Companies like DC Sport and Megan racing produce rough copies of the stock H22 header, but in stainless steel and sometimes with a ceramic coating. These headers produce no gains to very minimal gains. The headers that do make good power are the made to order peices you can get from HyTech, Sigma Six Racing, and SMSP. These peices make good power, but they also put a large dent in your pocket, whith prices ranging from $800-$1400. If you are looking for something in-between an off the shelf header and a full blown custom race header then you might want to look into Vibrant and Camp1430. They sell headers in the $500-$700 range that make alright power gains.
F-Series choices: Unlike the H22 Megan, DC Sports, and other “off the shelf” brands do make headers that will provide some gains. If you are looking for big gains out of your F22 build then you might want to shoot Bisimoto and email. He currently holds the record for the fastest all motor SOHC honda and he is using a heavily modified F22. His headers are top notch.
Builds
Just for shits and giggles here are two all motor builds and one turbo build on H and F motors:
NA F22A
NA H22A
Turbo H/F hybrid
Thats it for right now. I’ll most more later.
