reality on H22 engines

Can someone, please, tell me what is the real difference between a U.S. h22 engine vs a japanese model. I have heard that injectors are bigger, or there is no rev limiter, one has top speed cut off the other one not... I'm confused. I want to buy one but I don't know the differences because everybody i asked always contradict each other and so whatever.......

Thanks in advance.

Peace y'all, Raph...

Japanese engines are less restictive than American versions. As far as I know, you will be better off with a Japanese version...unless you are planning on passing an emissions test.:mad:

Originally posted by praxis
Japanese engines are less restictive than American versions. As far as I know, you will be better off with a Japanese version...unless you are planning on passing an emissions test.:mad:


another lie.

japanese motors have higher compression.

so that's it, japanese engine only have higher compression?
do they have more hp or more torque?
is there another difference because it's about 800$ to 1000$ more expensive.

thanks again Drift and all the others who answer...

Peace y'all, Raph...

Drift throwing down the knowledge and puttin' the liars to bed once again.....

Keep up the good work, Drift.

IMO - Get the USDM engine and add hicomp pistons of your choice. Are you going FI?

Originally posted by drift



another lie.

japanese motors have higher compression.

I don't think thats true. For b16 its the same compression. I'm not sure about H22's but i know for sure that the SIR and USDM b16's have the same compression from what i read. So not ALL japanese motors have higher compression.

Drift, as always is right.

The only diffrnce between a JDM and USDM H22 is compression. oh and the fact that it has to get shipped all the way from Japan, and becuase of the extra few hp, they are in higher demand. Hence the higher price.


The JDM and USDM B16a is a differnt story.

The 1st gen (160hp) JDM B16a like the one in my car which was never sold or made avliable in the US had a CR of 10.4:1.
The 2nd and 3rd gen JDM B16a made 170, but used differnt Cams, OBD I and OBD II ECU's and a CR of 10.6:1

The USDM B16a use's a differnt set of cams again, and a differnt ECU but useing either OBD I or OBD II depending on year. They do however have the same CR and hp as the 1st gen JDM B16a.

All the engines should meet US emissions laws. After all the current Japanese Laws are currently tougher than any of the US laws, and Japan has always been ahead of the US in this regard.
The only engines you might have any trouble with are the early B16a's which thanks to thier age might not meet the requirments. maybe. if your unlucky.

Originally posted by Moppie

The JDM and USDM B16a is a differnt story.

The 1st gen (160hp) JDM B16a like the one in my car which was never sold or made avliable in the US had a CR of 10.4:1.
They do however have the same CR and hp as the 1st gen JDM B16a.



Yeh what i meant was the first gen b16. I know the compression rates and HP are the same as the us specs.sir2 is a different story. My point was not ALL jdm engines are higher compression than the U.S. model.

Originally posted by mellowboy


Yeh what i meant was the first gen b16. I know the compression rates and HP are the same as the us specs.sir2 is a different story. My point was not ALL jdm engines are higher compression than the U.S. model.

And my point was that the 1st gen B16a is not the same as the US version. It only shares a block, head and crank and rods.

:biggrin2: no... more like :eshooter:

'again'? :what:

I don't believe that a JDM engine will pass US emissions. A JDM build up will have less restrictions than that of a US version. Do JDM ECU's communicate with all the same emmissions sensors as that of a US version?

And I think it's worth the 20 extra horses:

Originally posted by mellowboy


Yeh what i meant was the first gen b16. I know the compression rates and HP are the same as the us specs.sir2 is a different story. My point was not ALL jdm engines are higher compression than the U.S. model.


actually it does in a way... the SiR I motor wasnt offered here in the states, so it cannot be a basis for comparison. as for the SiR II motor, the static compression ratios may be the same, but dynamic compression is different since the JDM SiR motor runs more advanced timing to produce 170hp, whilst the USDM B16A runs retarded timing that only produces 160hp.

Originally posted by praxis
I don't believe that a JDM engine will pass US emissions. A JDM build up will have less restrictions than that of a US version. Do JDM ECU's communicate with all the same emmissions sensors as that of a US version?

And I think it's worth the 20 extra horses:


first off, most JDM motors will pass most states' emission requirements... only CARB states will it not. this is due to compression... the higher compression combined with lower octane fuel will create lean detonation, which will trigger the knock sensor and force the ecu to run more fuel in combination with timing retard. it's not a "degree of retard"... it's a set retard point that creates more hydrocarbons in the exhaust due to unburnt fuel.

JDM ECU's have all the same sensors as USDM ECU/motor combinations... it would be retarded to add/subtract sensors as it would require Honda to have different versions of wiring harnesses for just one assembly line... not very efficient. plus, JDM ECU's are plug and play, therefore debunking the thought that JDM motors have less sensors.

lastly for the "extra 20 horses", because of poorer grades of fuel here, the 20 "extra horses" will never be realised if used in America due to our low grade fuels. the "20 extra horses" come from more efficient combustion and optimised ignition timing... it's not borne of thin air.

There you have it.

Drfit as always is right. In fact right about now he is your god! and you should all bow down and worship him. :smoker2:


Now, wheres that add to favorites button, this is one of those threads that could be very very usefull.

Originally posted by Moppie
There you have it.

Drfit as always is right. In fact right about now he is your god! and you should all bow down and worship him. :smoker2:


Now, wheres that add to favorites button, this is one of those threads that could be very very usefull.

Yeh i guess so . Oh well, on the bright side i've gain more knowledge :finger:

The JDM has a speed limiter.

Oh, and the JDM has closer gear ratios also.

Alright, I find an H22a J's for 3500 bucks canadian and a US version for 3200$ can. should i get the japanese one or it's gonna be too complicated when the time of changing parts will come? Drift, when you talk of low octane fuel in America, does a 94 octane fuel is still poor for those engines? I can even full my tank with 96 octane fuel.

Peace y'all, Raph...

Japanese engines are less restictive than American versions. As far as I know, you will be better off with a Japanese version:)

they also have more horsepower some of them come with atleast more than an extra 30 horsepower except for the new 2001 models they r also coming as the japanese engines and that i'm still on the look out :confused:

Originally posted by H22-Civic Si
Japanese engines are less restictive than American versions. As far as I know, you will be better off with a Japanese version:)

they also have more horsepower some of them come with atleast more than an extra 30 horsepower except for the new 2001 models they r also coming as the japanese engines and that i'm still on the look out :confused:


why do people keep insisting on believing a lie about japanese spec motors when i just debunked it about 12 posts ago in this very same topic? read the whole topic, and get educated


as for Canadian fuels, 96 octane should run it decently, and still produce near spec power advertised for J-spec motors.

as for changing anything... like i said, there's nothing to change.

Is that true that JDM's H22a can rev near 11 000 RPM?

And if I buy the JDM, will I get any problem changing the pulleys, finding headers, throttle body or any other improving parts? And also, does the flywheel and the clutch could be changed for better one or are they just fine as original?

I really don't know which one is the best here in North America. One of my friend tell me not to get a JDM and he says that USDM are easier to tune here in Canada, but another one told me that the JDM is also easy to tune, that it's just a little more expensive changing parts.

What do you think?...

Peace y'all, Raph...

The parts are just as easily interchangeable for a USDM and a JDM. I have a JDM in the shop right now and I bought a flywheel, clutch, and Quaife LSD so far all for a 'US' engine and they fit fine. You should've been able to read by now that there are no structural differences really between the US and JDM ones except for the compression ratio, gearing, and whatever other little things there could be.

How would putting a low compression head gasket on a JDM H22 affect the HP and torque or how would lower the compression affect the engine in general?

http://www.h22a.com/specs.html Maybe this will help you answer some of the questions that you have about the difference between USDM and JDM.. I have a JDM H22 and have no problems putting USDM parts on it..

Originally posted by dominate9
How would putting a low compression head gasket on a JDM H22 affect the HP and torque or how would lower the compression affect the engine in general?

compression is a form of power. power comes from compression. the more you compress, the harder the pistons move up and down, making more torque, and horsepower is derived from torque. when you add a thicker head gasket, the volume of the cylinder chamber increases, putting less pressure in the cylinder chamber, and when there is less pressure, less air will be sqashed, meaning the compression will be lower.

Originally posted by GSteg


compression is a form of power. power comes from compression. the more you compress, the harder the pistons move up and down, making more torque, and horsepower is derived from torque. when you add a thicker head gasket, the volume of the cylinder chamber increases, putting less pressure in the cylinder chamber, and when there is less pressure, less air will be sqashed, meaning the compression will be lower.

SAo basically, lowering the compression of a JDM H22 will decrease my HP and torque, but will make the engine better to turbo, right? I should be able to make the decrease in power by the addition boost I'll be able to run because of the lowered compression too, right?