PSPEC

Im building an h23aVTEC and I've got some questions. I realize that alot of you guys say its not worth it, but I have both motors and I need parts from both of them to make 1 working motor. Anyway, here's the setup.

I have a 1995 accord lx (it has an external coil distributor). I have a complete 1992 h23a swap (has external coil). I also have a 2000 h22a4 longblock (has internal coil).

The h22a has a busted crankshaft. Some idiot that worked on the motor before me snapped the flywheel bolts off inside the threads at the end of the cranshaft and managed to crack one of the threaded holes too.

So I want to take the pistons and rods from the h22a and put them into the h23a block and use the h23a crank. And then take the head from the h22a and put it on the h23a. I like the fact that the h23a is closed deck vs. the 2000 h22a open deck.

I heard that the F22a crank in my stock motor has the same stroke as the h23a crank. Can anyone verify this? If so, then why arn't you guys swapping over your cranks when you swap motors? If it does work to make a 2.3 VTEC out of an h22a, then thats free torque from a motor that you are going to throw out anyway.

I also realize that I need to take components from the timing belt side of the h22a and place them on to the h23a. Seems to me like the only h22a part that needs to be used on the timing belt side of the h23a is the water pump (since it has more teeth) Everything else looks the same, but I have all the parts from both motors so I'll figure it out when the time comes.

I have a question about the timing belt tensioner. The h22a has an "automatic" tensioner and the h23a has a manual one? I will provide pics in a later post in this thread. Which one should I use and why?

I also have heard that the the oil squirters will bolt up to the h23 block, but they will contact the pistons. I have read that you can bend the squirters out of the way though and I will try this. Anyone running without squirters?

The h22a also has a sensor on the crank (where the timing belt gear is) The h23a does not. Do I need to swap this sensor over if I have a 1995 accord?

I don't have an ECU at the moment, but I plan on buying a JDM P13 ecu since its OBD1 and my car is OBD1. The h22a head is OBD2 though since its from a 2000. What issues am I going to run into with that? Injectors? Can I use the h23a injectors? Distributor? Since my car is external coil and the h23a is external coil, can I run the h23a distributor on the h22a head?

That pretty much sums it up, if I left anything out I will add it later. I know its alot of info that I'm asking for, but if all the experienced guys chip in their thoughts, we can eventually turn this thread into an h23aVTEC FAQ. And I'll have a working motor to testify that the FAQ is correct. I will also start posting pics to clear up some confusion in my questions, which can also be added to the FAQ. Thanks in advance.

drift

didnt bother reading the whole story, but here i go..

the F22 is 2.2 litres because of the bore diameter of 85mm. the H23 does share the same crank and rods as the F22, but the 87mm bore of the H23 is what gives it the 2.3 litre displacement.

putting H22 rods and pistons on an H23 crank will result in TDC being a few millimetres above the block's deck, therefore severly increasing compression to the point of not operating. the only internals that swap between the H22 and H23 are the pistons. you can put the H22 pistons into the H23's block with H23 rods and crank... combined with the H22 head, you'll get 10.1:1 compression. if you use a whole H23 block with VTEC head, you'll get 9.3:1 compression since the H22's head has larger volume combustion chambers (approx +3.8cc) than the H23 head.

the F22's rotating assembly is identical to the H23's assembly... it's where Honda used shelf parts to make a different motor.

some measurements you'll need:

H23A1 stock compression: 9.8:1
H22A4 stock compression: 10.1:1


H23A1 block piston bore: 87mm
H23A1 block stroke length: 95mm
H23A1 rod length: 141.5mm
H23A1 rod/stroke ratio: 1.49:1


H22A4 block piston bore: 87mm
H22A4 block stroke length: 90mm
H22A4 rod length: 143.0mm
H22A4 rod/stroke ratio: 1.59:1


H23A1 head chamber volume: 50.0cc
H22A4 head chamber volume: 53.8cc

H23A1 stock piston displacement: -5.1cc
H22A4 stock piston displacement: 1.3cc

H22A4 head with H23A1 block: 9.3:1

F22A/B block stroke length: 95mm
F22A/B block piston bore: 85mm

F22A/B rod length: 141.5mm

F22A/B features same rod and stroke as H23A1


you'll need to use the H23 dizzy you have, as the H22A4 is OBD II, and will require a rewiring of the motor harness should you go that route. using the H23A block, H23 dizzy, H22 pistons, and H22 head will provide you with 10.1:1 compression, with 2.3 litres of displacement. the H23 bottom end isnt great for revving high due to excessive lateral force from the poor rod/stroke ratio, but you should be able to gain a few more ponies over an equivalent stock H22 setup.

for simplicity sake, i assume you're going to put this setup into your Accord.

here's what you have that you'll use:

H23 block
H22 pistons
H23 dizzy
H22 head
H23 engine wiring harness
P13 ecu
H22 head gasket
H22 timing belt
H23 balancer belt
H22 timing gear
H22 water pump

the P13 ecu is the H22A1 93-95 OBD I ecu. you can use a 94-95 Accord EX ecu, but you'll lose the secondary runner function and knock sensor. 94-95 P72 GSR ecu is also capable after reprogramming the fuel map for H22/H23 duty.

the reason why i chose this parts list for you is to keep it simple and stay with OBD I. no sensor swapping or rewiring (except VTEC, since the H23 harness has no plugs) since both motor and the car are OBD I. the H23 block is also a solid deck, much more durable than the H22A4's open deck. you can swap over the H22's oil squirters into the H23, but it really isnt worth it... they require a bit of bending to fit properly.

you'll need to change everything that touches the timing belt, too. the H22 cam gears have a different amount of teeth than the H23's, so you need to get an H22 timing belt, water pump, and the timing gear off the crank, and swap those to the H23 block. as for the intake and exhaust manifolds, obviously use the H22's setup, as the H23 exhaust manifold wont bolt up to the H22 head.

MNY2BRN

Good luck with the swap man. I got some info about it too, but Drift took the words out of my mouth. We did a H23 vtec in my buddies Accord, and it huals ass when it's running good, but thats only 20% of the time. good luck:thumbup:

PSPEC

what do you mean only 20% of the time? Whats wrong with it the rest of the time?

Also, I read somewhere that there are injector issues. OBD1 injectors are "peak/hold" while OBD2 are "saturation" and that if I don't change the injectors to OBD1 they will fry either the ECU or the injectors. Any input on this? Can I use the H23 injectors? whats the flow for h22a and h23a injectors? thanks

PSPEC

About the balancer shafts.

One guy was saying you can get your crank/rods/pistons balanced and remove the balancer shafts all together. 15whp gain on a stock setup. How will this affect the life of the motor?

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Are h22a and h23a balancer shafts the same? Since my h23a has 160,000 miles on it and my h22a only has 32,000 I would like to use the h22a balancers.

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What about balancer bearings? are they all the same size, or do you have to order the different color coded bearings like with the rod/main journals?

Thanks Drift, you have been a BIG help.

PSPEC

Will Type S pistons fit the h23a block/crank/rods - H22a head? What will my Compression Ratio be then?

F22's rotating assembly is idencticle to h23a? So the Rods are Identicle too? or just the stroke? Im just wondering if the F22 rods are as strong as the H23a.

PSPEC

Should I use the manual belt tensioner from the h23a or the automatic one from the h22a? Why?

I know Im flooding this thread with questions, but drift knows his stuff and I just keep thinking of new questions to ask.

v4lu3s

actually most of your questions are answered in drift's long post above...

PSPEC

Not really....

there is nothing about the balancer shafts....

i assume you can use type s pistons, but what will the compression be.....

still don't know if F22 rods are identicle in thickness (strength) as H23, not just length....

nothing about the timing belt tensioner either....

I just read throught his post again and none of those questions were answered....

drift

not worth changing the balancer shafts. i didnt bother with "balancing" the internals since the internals come balanced from Honda. if they werent, the motors wouldnt last. i didnt install a balancer shaft belt on my setup... the additional vibration is minimal. balancer shafts are designed for driver comfort... it doesnt hurt to disable them. H22 and H23 shafts are different, but there's no blocker plate design to remove them for weight reduction... so i suggest you just not install the belt.

the compression on the Type-S pistons will obviously be the same as when installed in a Type-S motor. piston wrist pin placement is the same, along with deck height. the only reason why this setup produces a different compression ratio is due to the H22's head having more volume in the combustion chamber. stock for stock, the H23 is 9.8:1, and the H22 is 10.1:1 the H23 head has less chamber volume, and in combination with a dished piston, still prodecues 9.8:1 compression. the H22's head having more volume requires a domed piston to increase compression a mere .3

F22 and H23 rods are identical. if you dont trust me, tear down both motors and compare them. if you're planning a real build up tho, you're going to replace the rods.

obviously, the timing belt tensioner doesnt mesh with the teeth on a timing belt. it merely applies tension on the backside. you can use either one. i chose to use the H22's autotensioner, but you can use the manual tensioner from the H23 if you choose. if this section causes you difficulty, you need to find someone else to do the job.