HEAD SWAP: F22B DOHC on F22A1 BLOCK .. PICS**

[Grumpys93]

i used the gsr belt on mine worked like a champ.

[Mishakol129]

I wanna do this but I can't find the jdm f22b head. What I would do if I ever got one is mill the head a little to make more compression so I could use the P39 ecu to its full potential.

They're rare to come buy I suppose, if anyone has one pm me. Maybe better off swaping the whole engine though.

[fstacrd]

I wanna do this but I can't find the jdm f22b head. What I would do if I ever got one is mill the head a little to make more compression so I could use the P39 ecu to its full potential.

They're rare to come buy I suppose, if anyone has one pm me. Maybe better off swaping the whole engine though.

just order the whole motor and make 2 motors lol.. they're very cheap so might as well get the motor.. you can save one or build one long term

[deevergote]

Agreed. The whole motor is easy enough to find, and it's dirt cheap. Milling the head is dumb... throws valve timing off, and renders the head useless if you ever warp it due to overheating (a blown head gasket could do this easily.)

The F22B head fits perfectly, but why bother doing it when the F22B itself is so cheap and easy to obtain and install?

[Accrdwgnguy]

There is really no point in swapping out a whole motor or even a head for 20hp unless your F22A is dead. You could achieve that goal for less money with bolt-ons, a bigger cam, and a tune. Engine swap sounds like fun until you are doing it.

Remember to look at your mounts, stock squishy torn mounts will hurt your power transfer, Get some ESP mounts or fill your stock mounts.

[HappyGilmore]

I wish I hadn't lost my F22B DOHC head that I had now...SMH...

[cb7_530]

Would this work with a h23a1 head or does it have to be a f22b?

[Accrdwgnguy]

Would this work with a h23a1 head or does it have to be a f22b?

Has to be the F22B PT2 head. You can use the H23A1 head, but it'd not 100% bolt on. Ports don't match up, it's doable but it's a hack job.

[cb7_530]

Has to be the F22B PT2 head. You can use the H23A1 head, but it'd not 100% bolt on. Ports don't match up, it's doable but it's a hack job.

Okay thanks for clearing that up!

[HappyGilmore]

Has to be the F22B PT2 head. You can use the H23A1 head, but it'd not 100% bolt on. Ports don't match up, it's doable but it's a hack job.

And the bore is bigger on a H23 too if memory serves as well. Deff alot more work for such a gain.

[Mishakol129]

So this swap isn't all that worth it? I don't get it how this can get you any gains at all if you compression ratio isn't increased. And you can't run the P39 ECU either unless you up the compression with a thinner head gasket (do they even make those for our engines?). I was thinking about doing this swap only because I need a new head gasket and if the head is off why not change it for the dohc. But if I don't raise the compression then what's the point, little or no gains to be made. Maybe it will feel faster but I would doubt it actually will be. Dohc vs Sohc is not that different, not like dohc makes it faster. What makes the F22b dohc faster is the raised compression... Am I right or am i right?

[Mishakol129]

There is really no point in swapping out a whole motor or even a head for 20hp unless your F22A is dead. You could achieve that goal for less money with bolt-ons, a bigger cam, and a tune. Engine swap sounds like fun until you are doing it.

Remember to look at your mounts, stock squishy torn mounts will hurt your power transfer, Get some ESP mounts or fill your stock mounts.

Yeah the F22 I got is healthy, that's the thing. The f22b dohc in my opinion is a baby H22a not really worth the swap from a healthy F engine. A healthy H22a would be though.

I have a question though, has anything ever ran a P39 ecu in an F22a and noticed any gains? I am having a hard to learning how to get an ecu tune at a reasonable price and an assured quality.

[toycar]

So this swap isn't all that worth it? I don't get it how this can get you any gains at all if you compression ratio isn't increased. And you can't run the P39 ECU either unless you up the compression with a thinner head gasket (do they even make those for our engines?). I was thinking about doing this swap only because I need a new head gasket and if the head is off why not change it for the dohc. But if I don't raise the compression then what's the point, little or no gains to be made. Maybe it will feel faster but I would doubt it actually will be. Dohc vs Sohc is not that different, not like dohc makes it faster. What makes the F22b dohc faster is the raised compression... Am I right or am i right?

DOHC cylinder heads tend to flow better and have better control of valve timing since there is a dedicated cam to the intake and exhaust. Yeah, they do move air more efficiently.



Does that equate to more power? Who knows. Its an engineering crap shoot. Some companies make a better flowing SOHC engine.


Others, DOHC or bust.


In this scenario, yes I do think DOHC would equate to more HP. Why? HP is a measure of how frequently torque is reproduced. Its easier for an engine to breath with two cams, you get better valve timing/valve overlap control. So, HP would most likely increase but tq wouldn't do shit.


Food for thought.



As previously mentioned, it would be pointless for 20hp because you can get that out of the f22a with a cam, header and intake changes + tune.


What happens when you change a cam, header and intake though? The engine flows better-right? So, there you go. No point in swapping when you can just bolt on some shit and go and get the same results.

[deevergote]

But you could swap the head for 20hp, and THEN add cams, intake, header, and a tune

A P39 ECU could be used with such a swap. It just won't be 100% right. The lower compression will cause the gain to be less than 20hp, obviously. I'd be curious to see exactly what the compression ratio ends up being, as the head can have an impact on that as well. An engine's compression ratio is not just a function of the pistons.

Also, it's arguable that DOHC flows better than SOHC. In most cases, probably. In bone-stock applications, also probably. But I do believe Bisi (you can take his word as you will...) said that a modified F22A head can outflow a modified DOHC VTEC head, be it B18 or H22. Port design and valve angle come into play. Stuffing 2 cams into a head, along with all the hardware and mounting points, can reduce area in which to plumb effective ports.

Regardless, the flow capabilities of modified heads are beyond the needs of most average tuners anyway. A street car will never see such limits... and some restriction is actually useful to keep the powerband in a useful RPM range.

[honda2014]

But you could swap the head for 20hp, and THEN add cams, intake, header, and a tune

A P39 ECU could be used with such a swap. It just won't be 100% right. The lower compression will cause the gain to be less than 20hp, obviously. I'd be curious to see exactly what the compression ratio ends up being, as the head can have an impact on that as well. An engine's compression ratio is not just a function of the pistons.

Also, it's arguable that DOHC flows better than SOHC. In most cases, probably. In bone-stock applications, also probably. But I do believe Bisi (you can take his word as you will...) said that a modified F22A head can outflow a modified DOHC VTEC head, be it B18 or H22. Port design and valve angle come into play. Stuffing 2 cams into a head, along with all the hardware and mounting points, can reduce area in which to plumb effective ports.

Regardless, the flow capabilities of modified heads are beyond the needs of most average tuners anyway. A street car will never see such limits... and some restriction is actually useful to keep the powerband in a useful RPM range.

Well said deev.. You also have to consider the ability of the f22b compared to the f22a. Just doing research for a few hours I've noticed that on street n/a setups, the dohc f22b beats the f22a price wise. If you want non-vtec n/a power, I would suggest the f22b over the sohc f22ax/bx. Sure, you have 2 cams, but from what I can tell, the money to get the f22a to 200 hp is better spent in the f22b, as long as you can get the head for a relatively cheap price. But then, you have variability in prices, so, I'm not 100% sure. Either way, boost is a better way to spend money on the f series, but priorities, you know?

I'm planning on buying an DOHC F22B and think that it is a wiser decision than rebuilding my f22a6. It has just as much boost potential as the f22, and is more powerful in stock form, as well as more potent with mild upgrades to have fun with while you/if you save for turbo. Pretty neat motor. So is the H23.

My .02.