H23 Head Swap and Boost

[bruno8747]

I've seen quite a few people who want to do projects that involve swapping a h23 head onto a f22 block and then adding boost.

Now the best advice for I will give is, Don't. The h23 head swap is by far not the best swap.

First off, Head gasket problems. I don't know about you, but I don't want any part of my head gasket in the combustion chamber. Adding a turbo to the already stock engine is stressing everything and now you have a head that does not directly fit will just stress things even more.

These is no reason not to use the F22A head. The F22A head has been proven many times to make great power. The intake and exhaust ports are great size for many applications.

The main problem with the F22A engine and boost is the pistons, NOT the head. The head is able to rev past 7k rpms easily with no problems. So instead of wasting money on a head swap, I would highly suggest upgrading bottom end components.

That is my advice for the month.

[d112crzy]

Can't you use an f23 headgasket for the head swap, thus eliminating this headgasket issue?

[bruno8747]

Can't you use an f23 headgasket for the head swap, thus eliminating this headgasket issue?

It doesn't completely eliminate the issue. Is still going to be some missing space between the sleeve and the head. And you still have to modify the head gasket still.

If you really want to go dual cams, I would strongly say hold out for a F22B head.

[Dep22build]

a yea f23 gasket works fine just need to cover up a coolant passage or if your not cheap have one custom made

[10thcb7]

well what kind of head gasket does the f22b use?

[gdout90accord]

well what kind of head gasket does the f22b use?

f22a

[d112crzy]

You can use F22A head gasket

[whitejdmcb7]

then what is the diff between the f22b head and h23 head i know there is a oil passage or something but a side by side comp would be nice

[wed3k]

then what is the diff between the f22b head and h23 head i know there is a oil passage or something but a side by side comp would be nice

the CC's are shaped a bit differently. the h23 has some material on the side, is it called quench?

but that material would also raise compression.
pistons and rods definitely need to be addressed, i dont trust those at all. plus, a lighter rotating assembly will help in engine efficiency and freeing up power.

[d112crzy]

the CC's are shaped a bit differently. the h23 has some material on the side, is it called quench?

but that material would also raise compression.
pistons and rods definitely need to be addressed, i dont trust those at all. plus, a lighter rotating assembly will help in engine efficiency and freeing up power.

I believe its the f22b that has those quench areas.

[wed3k]

i have two h23 heads sitting in front of me

[d112crzy]

I believed wrong
h23 on left, f22b on right

[quickangel93]

so your theory is that the h23 head is bad on the f22 because of the headgasket?

come on bro, you could give us a little more info. the reason people swap head is for tunning purposes. on the h23 (DOHC) they have 2 cams. one for intake one for exhaust. you could adjust the valve overlap, so that you constantly have boosted pressure in the cylinders.

im going to be starting a new turbo project soon with a 16g turbo and h23 head on f22a6 bottom. the reason i went with the h23 was because:

a: i dont want to deal with vtec (h22)

and

b: i want 2 cams to control valve overlap.

to much boost on a stock head, is going to crack it, blow a valve, or tear a spring. it most likely will happen because of high reving and to much pressure on the valves.

so in your theory, you could just replace the gasket to a copper one and be set. im not saying your theory is wrong, but in it i dont see why the h23 head is bad. or maybe im blind.

on a f22a head you got one cam to play around with, so something will eventually break. why do you think most guys who run high boost have 2 cams? awnser : better tuning. its not about the turbo, or block or head, its about how tuning is going to give you the power you wished for.

end of my rant.


btw even if you go boost, you will go big or go home. so eventually you ill be replaceing the bottom end for stronger parts.

[d112crzy]

The idea of doing an H23 head onto an f22 block is bas BECAUSE of the headgasket issue.

If you want 2 cams, then it is best you go with an f22b dohc head instead. The combustion chamber is 85mm, just like the f22a. You can even use the stock headgasket.

Now, if you can find a much better headgasket, or a custom one, then go ahead and do the h23 head swap.

The reason people run high boost on 2 cams is because they are ignorant to single cams. They have no clue about what is available and choose not to look into it because of the much easier available parts for the h22 or any other engine.

I've tuned 3 single cam d series so far that will all make it into the low 11's in the 1/4 mile. The f22a is no different.

All you're theories on stock heads are wrong. An h23 can't handle any more then an f22a head can.

[deevergote]

Dual cams provide easier tuning. With a single cam, you have to adjust the intake and exhaust valve timing at the same time.

Now, with a carefully planned system, and intimate knowledge of the SOHC engine, this isn't a problem. Just order a custom ground cam to do what you need it to do.

Even a sub-optimal SOHC setup with a good turbo will make plenty of power.


You won't crack an aluminum F22A head any faster than you'll crack an H23 or F22B head. They're made of the same stuff... and none of them were made with turbo in mind.

The head gasket issue IS a big deal... on NA or turbo. Not only does it interfere with port flow and combustion, but it also provides a potential hot spot for detonation. When dealing with turbo, that's even more of a threat than with NA. If the edge of the gasket, or the edge of the head, whichever is exposed to provide a sharp edge, will eventually heat up and provide a point of ignition. You'll ignite your mixture before the spark. The rising piston will smack into an explosion. Do that a few times, and you can kiss that motor goodbye.