Well, I just bought a prelude and I am about to start working on it, was wondering if the H23A that is in it is worth the time to work on, or if I should start with a whole new motor.
I am a bit new to Honda motors so any info would be appreciated.
I think it depends on what YOU want out of it. I have an SI and I have bolted on i/h/e...and now I am doing the swap. I love my SI but I wanted a 5 speed. It was going to cost me almost the price of the H22 to convert it. If it wasnt for that I would have kept the SI.
well its a good motor...but the only thing about it is the availability of aftermarket parts...compare to the h22...best way to get more power out of it is to put a turbo kit and work on the internals....look at XES setup in hondaprelude.com......he's pushing alot in the h23 of his.....
Its a good motor and yes its worth spendin time on it. alot better than others i think. i just killed a porsche 2 days ago on the highway so it works for me they are very strong and have very good low end around 3-5k. youll be whooping some asses trust me
__________________
-Lewis-
Si Prelude with H22 swap
i/e/hi-flow cat/clutch/motor mounts/thermo coolent mod
Originally posted by Fast&furiuslude Its a good motor and yes its worth spendin time on it. alot better than others i think. i just killed a porsche 2 days ago on the highway so it works for me they are very strong and have very good low end around 3-5k. youll be whooping some asses trust me
Wut kind and wut yr/body type Porsche? If you don't mind...
Originally posted by Fast&furiuslude it was an old 944. i posted it in the street racing.
The one with the VW engine?
Honda makes some pretty good motors, but you have to look at what they were made for. The H23 was built for torque via stroking the H22, at the expense of things like the oil squirters and the rod ratios. Everyone loves to talk about how great the H23 is for boost with it's closed deck, but the H22 was also closed deck from '93-'95.
If you work on the H23, do NOT raise the rev limit... with the rod/stroke ratio and lack of squirters, you will likely run into reliability problems over time. How long? Don't know. I DO know that from a standpoint of design, it's a bad idea.
With FI or NOS you will develop much more power more cheaply than NA work. If you want to make the car stronger, drop in an H22. If you are looking at absolute power levels (like, 300+WHP), then you'll need to go FI. I'd suggest only going FI on a closed deck motor with the H22 internals, or even improving on the internals to make a better rod/stroke ratio, or even destroking the motor to spin it faster.
Might want to check out the FI forum for more info.
Originally posted by marcucci
If you work on the H23, do NOT raise the rev limit... with the rod/stroke ratio and lack of squirters, you will likely run into reliability problems over time. How long? Don't know. I DO know that from a standpoint of design, it's a bad idea.
Sorry to say that I haven't had problems with a rev limit of 8500+ rpm on an h23a (with a modified valvetrain, oil pump, etc). I will admit that the VTEC head does lend itself alot better to these higher revs.
How many miles? I wouldn't expect a problem if driven lightly or not for very long. I've seen firsthand what a VTEC head and higher rev limit will do to an H23 and I would suspect a turboed version to be even worse.
The H23 is a good motor, but I think it's primarily because it's an H22. You can bring the H23 to H22 power levels with very little work, but I think from the standpoint of "what motor to get" the H22 is a much better foundation.
Back to the original question, it depends on the power levels this guy wants. I'd recommend a closed-deck H22 for turbo, NOS, or super-NA application. If you just want a little more grunt and don't plan on spending much money... stick with the H23.
XES, I have a h23 block getting worked now. What did you do to raise your oil pressure, is there a high pressure pump available?
I am getting about 165+ to the wheels now, and I suprise allot of cars. I am thinkin of morphing but it requires electrical stuff to switch out that I am not familiar with.
Originally posted by marcucci How many miles? I wouldn't expect a problem if driven lightly or not for very long. I've seen firsthand what a VTEC head and higher rev limit will do to an H23 and I would suspect a turboed version to be even worse.
The H23 is a good motor, but I think it's primarily because it's an H22. You can bring the H23 to H22 power levels with very little work, but I think from the standpoint of "what motor to get" the H22 is a much better foundation.
Back to the original question, it depends on the power levels this guy wants. I'd recommend a closed-deck H22 for turbo, NOS, or super-NA application. If you just want a little more grunt and don't plan on spending much money... stick with the H23.
so you talk about the h23a with a vtec head, but what about raising the rev limit on the h23a without the vtec head? I wasn't planning on raising it that much, maybe to about 7000, but that's when i get new rocker arms, cams, valves, retainers, and all that good stuff! Also i heard bad stuff about going turbo on a vtec motor, how at high revs the vtec interferes with the spool of the turbine and confuses the computer?? any comments?
Originally posted by rybred
so you talk about the h23a with a vtec head, but what about raising the rev limit on the h23a without the vtec head? I wasn't planning on raising it that much, maybe to about 7000, but that's when i get new rocker arms, cams, valves, retainers, and all that good stuff! Also i heard bad stuff about going turbo on a vtec motor, how at high revs the vtec interferes with the spool of the turbine and confuses the computer?? any comments?
Yes you can easily go to 7000 on an h23a (that is where the stock fuel cut is). If you raise it, it'll probably be to around 8000rpm, at which point new valvetrain components are needed (i.e. new valves and titanium retainers). Cams will just help you make power higher up in the power band.
As for turbo and vtec interfering, where did you here that? That is false. At the vtec point more air will be pushed into the turbo thus providing more power (on a properly sized turbo). It will not affect the computer in any way at all. Vtec and turbo do mix. And they mix very well.
The weakness of the H23 isn't in the valvetrain. The weakness is in the Rod/stroke ratio. It also dosen't have oil squirters. Merely slapping an H22 head, and ECU on an H23 is one of those things like, "Let's put a 427 in a VW Bug!" but with less technical problems.
The Rod/stroke ratio would compromise piston ring life, and oil seal. You'll need VTEC oil squirters, forged rods, and balanced crank, VTEC oil return line, and anything else a CR-VTEC or LS-VTEC requires to run up that high of an RPM.
As for VTEC and turbo, VTEC loses in a few areas:
1) Transmission. Short gearing takes you out of boost often
2) Too much overlap: Good for N/A. Bad for FI.
VTEC wins in other areas, though:
1) Revs quickly to build boost
2) Extra backpressure to build boost (I think)
When i first got the Si, my friend (who's been building engines forever) was like... whats your fuel cut-off? I said, i dunno i shift at redline.. he said .ohhhhh no, you can take it to the limiter to see.. h23's are strong..and he drove it and hit it @ 7k as was told... so now that ive owned it for a good 6 months now. I don't take it past redline often, but i know it can handle it easy, and it seems like it WANTS to go higher.
I'm gonna keep my h23 and do valves, retainers, springs this summer. Then save for some rods and such (maybe xmas) then turbo after all thats on. But in the process re-build it cuse im at 129k miles now. If it blows, oh darn. H23's arent as expensive as h22's =]
Thats like my friend, he has a turbo sohc non-vtec engine.. he has 3 waiting to go in after it blows... just runs itinot the ground and swaps the other one in... their cheap. hehe
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