H22 head on H23 block

[bb2h23a1]

after getting abotu 20 emails from people asking me how to do this and what they would need i figured i would just research it a little more for myself and find out what is needed and what needs to be done so here is what i found.

h22a head with all internals and valve cover
h22a power steering braket (h23 doesn't line up right)
h22a thermostat housing
h22a waterpipe
h22a waterpump
h22a lower crank gear
h22a headgasket
h22a plug wires
h22a timing belt
h22a headbolts
h22a header and downpipe
h22a intake manifold (injectors perfered)
h22a top timing belt covers
h22a cam gears



you will need to swap out all the parts and sensors from the h23 to the h22a intake manifold.

you can keep the same distributor mounts but you need to use the manual tensioner. The wires are deeper in the h22a.

you need to remove the oilcontrol plug in the block before putting the head on.

you will need to run wires and the ecu, for the vtec solenoid and knock sensor

[XboxFPSKing]

Great post, this should be stickied.

[black_h23]

Ugg this slipped though my fingers:
ebay auction for 1999 prelude h22 head

too bad I didn't have the money would have been a hell of a deal.

[f22b_lude]

from whut i hear the head swap will definately limit your engine reliability.

[black_h23]

depends if you do the extra stuff to the lower end.
Yes most hybrid motors will never be as reliable as a stock motor.

[f22b_lude]

whut extra stuff?

[black_h23]

Having the crank balenced and possibly cryo treated. Also having the rods shot peened or replacing them with stronger aftermarket rods. Also using h22 type S pistions in it increases the CR to 11.5:1.

Also there is a debate on wether or not to use the lower end oil squirters on the h23 hybrid block too.
Oil pressure is also key most builders that have built this kind of motor suggest shimming the oil pump for more pressure or getting a high output oil pump.
Honestly someone should talk to a honda engine engineer and find out exactly why they were added.

I have a sort of theroy on this:
Likely at high rpm's the crank's centrifical forces sqeeze the oil off the bearings and it seeps past them resulting a drop in oil pressure to the crank and bearing wear and it produces heat. The oil squirters likely just spray on the rod ends to keep them cool.
I am just speculating here might be sort of correct.

Don't think building one of these is cheap.
With any build if you do it cheap likely down the road it will fail early and you be crying about how this h23 vtec is crap, it sucks man I am out blah, blah, blah, yaddah, yaddah, yaddah...

If you don't like what you are getting into build a h22.

Most people wreck h23 vtec's by reving it way higher like past 8500 way more than crank or bearings can take resulting in failure.

Also remember the reason someone is building this type of motor is to develop low end torque more quickly so you don't have to rev it past 7,000 rpm unlike the h22 with a shorter stroke.


If you get a ECU programmed to change the vtec engaugement curve or get a VAFC or VAFC II.
Definately have it dynoed and tuned.
Also limit the rev's if you keep that in check it should last a long while likely as long as it is built right.

I gathered most of this info from reading and talking to others about thier experinces and failures on this motor in other forums.

Before you build one definately do your homework on it first don't jump into just building it.

[bb2h23a1]

Originally posted by black_h23@Jan 11 2005, 09:29 AM
depends if you do the extra stuff to the lower end.
Yes most hybrid motors will never be as reliable as a stock motor.

i dunno about that in my opinion the ls vtec is the best motor that honda never made but did if you get what i am saying

[Ice_man]

What is the weakest part of the h22 engine? And what woulds be the weakest part of the h23 vtec?

[B00stN H23VTEC]

Lets put it this way.
Weakest part of a h23 is loss of top end power
Weakest part of h22 is you wont make your 200 hp until 6800 rpms or whatever, plus displacement isnt as high as a h23

weakest part of a h23 vtec...no complaints here..ive got 14k on my built h23vtec and ive abused the hell out of it..still runnin strong...compression gauge still shows 215psi in each cylinder!!

in my personal opinion H23VTEC=BEST OF BOTH WORLDS