F22B DOHC Compatibility

[Jarrett]

I'm replying instead of editing so that this thread gets bumped.

Anyway, I got results very similar to those posted by grumpys93. The are camshafts that came with an F22B PT2 head purchased from a member on here. I suppose the possibility exists that the member sent H23A1 cams because he or a previous owner swapped them out. I don't know, nor do I remember who I purchased this head from.

My measurements:

IN - 1.326"
EX 1.327"

These measurements were taken with the Pittsburgh dial caliper from Harbor Freight, as many measurements provided on this forum are.

I suppose the only way to definitively prove that they're different is to have Colin, or another member to Japanese part number database, look up the numbers from the F22B and compare them to the known H23A1 part numbers or the JDM part numbers for the non-VTEC H23A in the 2.3L Ascot Innova.

That's my contribution. It may mean nothing.

[Grumpys93]

I'm replying instead of editing so that this thread gets bumped.

Anyway, I got results very similar to those posted by grumpys93. The are camshafts that came with an F22B PT2 head purchased from a member on here. I suppose the possibility exists that the member sent H23A1 cams because he or a previous owner swapped them out. I don't know, nor do I remember who I purchased this head from.

My measurements:

IN - 1.326"
EX 1.327"

These measurements were taken with the Pittsburgh dial caliper from Harbor Freight, as many measurements provided on this forum are.

I suppose the only way to definitively prove that they're different is to have Colin, or another member to Japanese part number database, look up the numbers from the F22B and compare them to the known H23A1 part numbers or the JDM part numbers for the non-VTEC H23A in the 2.3L Ascot Innova.

That's my contribution. It may mean nothing.

Ill see if I can measure the cams on the f22b, Im sure I can get a micrometer in there and I am 99.9% positive these are f22b DOHC cams.

[deevergote]

What I find interesting is that the H23A1 and F22B both make 160hp (Wikipedia says the F22B makes 166, but I feel that may not be accurate...) The H23A1 has a slightly higher compression ratio (9.8:1 compared to the F22B's 9.3:1). Since the H23A1 has those advantages, wouldn't it be more likely to make more power? Especially if the H23A1 camshafts are a bit more extreme than the F22B's. I would've assumed the F22B's camshafts were more on the wild side, in order to make equivalent horsepower from a smaller engine with a lower compression ratio.
Kinda like how the cams from the 200hp F20B are similar or identical to H22A Type S cams.

[Jarrett]

So much of that could be in the tuning of the P39 vs. P14 ECUs as well.

[deevergote]

That's very true.

[preludeNinja]

Possibly a more economy based tune?

[H311RA151N]

I'm interested in seeing what gains adjustable cam gears can provide on the F22B DOHC. That and how well it responds to boost.

I don't know what it is about the H23A1 but it's undoubtedly a bearing spinning mofo. I've seen more H23A1's spin rod and main bearings than all other Honda's combined. And listening to others over the years I've heard many many Honda enthusiast make similar statements.

H23A1 / F22A

Rod Length: 5.572 / 5.572
Rod Width: .935 / .935
Rod Big End Bore: 2.008 / 2.008
Rod Pin Bore: 21.97-21.98 / 21.97-21.98

Piston Bore: 87mm / 85mm
Piston Compression Height: 1.203 / 1.203
Piston Dome Volume: -9.9cc / -14.5cc
Wrist Pin Diameter: .866 / .866

Crankshaft Stroke: 95mm / 95mm
Crankshaft Main Journal: 50mm / 50mm

Cylinder Head Combustion Chamber Volume: 50cc / 50cc

Main Bearing Width: .784 / .784
Rod Bearing Width: .762 / .762

So the pistons being the only difference from the F22A bottom end wise, why is the H23A1 such a bearing spinner while the F22A is not? I always wondered if the larger (thus heavier?) pistons contributed to it's bearing spinning characteristics or if it was possibly something with the manufacturing process.

[preludeNinja]

Well i definitely plan on boost but i have to bring the chassis up to par first but this is all great info.

[deevergote]

If you plan on boosting, plan on forged internals.

[preludeNinja]

For sure thats really what my question was regarding was the internals because I want to have a really reliable yet fun car to cruise around in. I turbo'd the d16 in my 91 civic and learned what not to do so it should be cool to see what a larger engine can do and how well it will do when properly done. For the civic I used a way to large turbo and didnt get boost till around 4.7 to 5k rpm. It was still pretty sweet but I literally did everything wrong. Didn't upgrade my brakes or suspension at all so the ride was terrible. Didn't do anything with the internals and tuned it myself with my laptop and a piggyback tune. But made 214hp on a 1.6L so that was cool.

[Rilas]

I'm still looking for a final answer on this as well. I have an F22B DOHC and I can pickup an entire H23A1 for $100. I think this would be a good deal for the cams as well as a spare head. But I'm not sure if the cams are actually an upgrade and would like to know.

[deevergote]

Whatever differences, if there are any to confirm, are going to be so minor that they will barely be noticeable.

Honestly, given the grater displacement and higher compression ratio of the H23A, it's more likely that the F22B camshafts are actually the wilder ones. Common sense would dictate that with two similar engines, the one with the greater displacement and higher compression ratio would make more power. Since they both make 160hp (Wikipedia says 166 for the F22B, but that's the only place I've ever seen to say that...) then the F22B would likely have something leveling the playing field, so to speak. With lower compression and smaller displacement, it would stand to reason that the camshafts were wilder in order to make more power.

Much like the F20B vs. the H22A. Both make 200hp, but the F20B needs the camshafts from the H22A Type S to do so. The F20B also has higher compression than the H22A as well. Not to mention a superior (Type S) intake manifold and throttle body.

[Jarrett]

The H23A1 head is not compatible. The combustion chamber diameter is 87mm and not the F22B's 85mm. Also, the oil drain ports share the same pattern as the H22A and not the F22A. The F22B DOHC follows the F22A pattern.

I'd save the money. Sure it's only $100, but I don't think there's anything there you'll really ever need. The camshafts are not a definite upgrade, I don't think. Not until more measurements have been taken verifying the difference.

[deevergote]

The combustion chamber / cylinder diameter mismatch isn't as big a deal as once thought. That was my soapbox topic of choice for a while when people talked about doing headswaps... but there are a few Honda engines that come with that mismatch from the factory. The oil drain issues aren't supposed to be a big deal, but I feel if Honda designed them a certain way, there was a reason for it.

But yeah, the F22B block is essentially the same as the F22A block, so any full H head swap would cause the same potential issues with the F22B block as it would the F22A... and anyone who has been around for any amount of time has learned that those things are commonly unreliable.

[H311RA151N]

The bore being smaller than the combustion chamber of the head is worse than the combustion chamber of the head being smaller than the the bore. At least that's how I understand it to be.

It's a 1mm difference and is in the better of the two ways it could be however I still don't thinks is a bright idea and I'd never consider building and engine with that combo. 85-85, 87-87 or whatever it may be I'd be sure they matched. I couldn't bring myself to put blood sweat and tears into something that wasn't right. Even if it's only a little bit not right.