# Honda H-series/F-series Motor Tech **URL:** \ **Category:** Shift518 Automotive\ **Created:** [February 4, 2008, 9:30pm UTC](https://forums.speedlife.net/t/honda-h-series-f-series-motor-tech/235583 "2008-02-04T21:30:11Z")\ **Posts on this page:** 9\ **Page:** 1
**Author:** ![SlackJ94](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/slackj94/32/6325_2.png) [@SlackJ94](https://forums.speedlife.net/u/SlackJ94)\ **Post date:** [February 4, 2008, 9:30pm UTC](https://forums.speedlife.net/t/honda-h-series-f-series-motor-tech/235583/1 "2008-02-04T21:30:11Z")
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**](http://www.honda-tech.com/zerothread?id=1232811)) 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**](http://www.cb7tuner.com/vbb/showthread.php?t=41915)) **_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**](http://www.honda-tech.com/zerothread?id=1069869) and [**Here**](http://www.honda-tech.com/zerothread?id=776837) H23-Vtec (H23 block and H22 head, or H22 block and head with H23/F22 internals) : [**Here**](http://www.honda-tech.com/zerothread?id=510617) F23 block and H23 head (160whp/160wtq with all OEM parts, 200whp/175wtq with cams) : [**Here**](http://www.honda-tech.com/zerothread?id=1046336) 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**](http://www.honda-tech.com/zerothread/2030543) 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**](http://www.cb7tuner.com/vbb/showthread.php?t=83362). **_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**](http://www.honda-tech.com/zerothread?id=1245350) **_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**](http://www.honda-tech.com/zerothread?id=416069). 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**](http://www.collectiveracing.net/crforum/index.php?topic=9.0). **_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**](http://www.cb7tuner.com/vbb/showthread.php?t=37839) 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**](http://www.slowboyracing.com/estore/product.php?productid=4939&cat=195&page=1). **_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**](http://www.cb7tuner.com/vbb/showthread.php?t=26368) [**NA H22A**](http://honda-tech.com/zerothread?id=1646948&page=1) [**Turbo H/F hybrid**](http://www.cb7tuner.com/vbb/showthread.php?t=71285) Thats it for right now. I’ll most more later. ---
**Author:** ![dc2nick](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/dc2nick/32/6289_2.png) [@dc2nick](https://forums.speedlife.net/u/dc2nick)\ **Post date:** [February 5, 2008, 7:42am UTC](https://forums.speedlife.net/t/honda-h-series-f-series-motor-tech/235583/2 "2008-02-05T07:42:26Z")
Nice write up Jake Should be a Sticky its amazing the motors you can build just by using oem parts from a different series ---
**Author:** ![Vovchandr](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/vovchandr/32/6275_2.png) [@Vovchandr](https://forums.speedlife.net/u/Vovchandr)\ **Post date:** [February 5, 2008, 8:17am UTC](https://forums.speedlife.net/t/honda-h-series-f-series-motor-tech/235583/3 "2008-02-05T08:17:52Z")
Great write up :thumb Lot’s of stuff I didn’t know is in here. ---
**Author:** ![SlackJ94](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/slackj94/32/6325_2.png) [@SlackJ94](https://forums.speedlife.net/u/SlackJ94)\ **Post date:** [February 5, 2008, 8:20am UTC](https://forums.speedlife.net/t/honda-h-series-f-series-motor-tech/235583/4 "2008-02-05T08:20:08Z")
Thanks guys. Formated it a little better and added a little more information. I’ll keep adding more as I sift through my massive pile of saved links. ---
**Author:** ![Phate](https://avatars.discourse-cdn.com/v4/letter/p/e0b2c6/32.png) [@Phate](https://forums.speedlife.net/u/Phate)\ **Post date:** [June 18, 2010, 10:42pm UTC](https://forums.speedlife.net/t/honda-h-series-f-series-motor-tech/235583/5 "2010-06-18T22:42:36Z")
should probably mention that they changed the F22’s cylinder head design in 1994. The 90-93 F22’s (F22Ax) have huge ports that are evenly spaced (like this 0-0-0-0), flow awesome, and line right up with the DSM mani. In 94 they switched to the F22Bx motors which have uneven port spacing (like this 0-00-0), and smaller ports with crappy flow. On those, the DSM mani will not fit. The F22B2 (SOHC), F22B1 (SOHC VTEC), and F23A use this style of head. ---
**Author:** ![Eatonualive](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/eatonualive/32/6442_2.png) [@Eatonualive](https://forums.speedlife.net/u/Eatonualive)\ **Post date:** [June 20, 2010, 5:49am UTC](https://forums.speedlife.net/t/honda-h-series-f-series-motor-tech/235583/6 "2010-06-20T05:49:41Z")
i remember seeing that info on honda tech a while ago. good write up either way man, the f22a is a great motor and ppl dont realize it. im doin an f2b swap in my civ ---
**Author:** ![freakLS7](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/freakls7/32/6298_2.png) [@freakLS7](https://forums.speedlife.net/u/freakLS7)\ **Post date:** [June 20, 2010, 5:57am UTC](https://forums.speedlife.net/t/honda-h-series-f-series-motor-tech/235583/7 "2010-06-20T05:57:12Z")
this could be a big help to me very shortly!!! great write up thanks for sharing ---
**Author:** ![pitman](https://avatars.discourse-cdn.com/v4/letter/p/4da419/32.png) [@pitman](https://forums.speedlife.net/u/pitman)\ **Post date:** [April 5, 2011, 12:16pm UTC](https://forums.speedlife.net/t/honda-h-series-f-series-motor-tech/235583/8 "2011-04-05T12:16:00Z")
what about a k24 crank in a h22 hybrid 2.5 stroker? and the s2000 motors are pretty much k series…and to sollve the frm sleeve on h blocks get a f22 block from accord or prelude they have factory iron sleeves. also a k series bolts to a s2000 trans and vice verse ---
**Author:** ![Phate](https://avatars.discourse-cdn.com/v4/letter/p/e0b2c6/32.png) [@Phate](https://forums.speedlife.net/u/Phate)\ **Post date:** [June 19, 2011, 7:18pm UTC](https://forums.speedlife.net/t/honda-h-series-f-series-motor-tech/235583/9 "2011-06-19T19:18:13Z")
Guy named ghostaccord on CD5tuner did a good comparison. F22A on top, ported F22B2 on the bottom. The red highlighted area is a water jacket completely surrounding the exhaust ports that prevents you from opening them up some more. The F22Bx ports are also all curved, while the F22A ports are straight shots. ![http://i133.photobucket.com/albums/q71/GhostAccord/Odds-n-sodds/A6-vs-B2-exhaust-01.jpg](http://i133.photobucket.com/albums/q71/GhostAccord/Odds-n-sodds/A6-vs-B2-exhaust-01.jpg) The F22A’s intake port is on the left, fairly heavily ported F22B2 intake port on the right. ![http://i133.photobucket.com/albums/q71/GhostAccord/Odds-n-sodds/A6-vs-B2-intake-01.jpg](http://i133.photobucket.com/albums/q71/GhostAccord/Odds-n-sodds/A6-vs-B2-intake-01.jpg) Don’t know if you can run K-series cranks in the F/H blocks. Here’s the fun combo I put together on paper, and will be going into my car if I don’t just boost the F22B2 that’s in it: -F23A1 bottom end (you need to install the oil control orifice from a non-vtec motor) -Run the stock pistons for a still boost-friendly 9.3:1 CR, or put OEM K20A3 pistons in for 11:1 all-motor goodness -F22A6 cylinder head (stiffer valvesprings stock) -Delta 272 regrind cam -H23A intake manifold (dual runners ftw) and throttle body (one of the larger ones honda made. -F22A4 exhaust manifold (factory tubular header, with a bigger collector welded on its about as good as most aftermarket headers. No idea what kind of power it would end up actually making, but it would make for a decently torquey motor for a daily driver (so hilarious fun in a light ass civic, and about perfect for a 3000lb accord). If I had to guess, probably somewhere in the 170-190whp range based on builds of F22A’s with similar parts and compression. A guy on the 4th gen accord forums did almost that exact build, and he said it ripped pretty good, although never dyno’d it. The funniest part is that it would look like a bone stock motor under the hood, and possibly even would still fall into the SCCA’s stock class.