So some people are gonna see the title and think I’m a uneducated ricer kid, but let me start with clarification on what I mean by H23A “Type R” clone. I will be using a number of H22A7(True Type R H series) parts along with various other rare OEM H parts that are “better” then the common ones in some way or another to build a very aggressive (by street OEM parts standards of course) H23A PDE without removing the head at all, only bolt ons and likely Type R/Euro R cams.

This engine will be for a 1993 Prelude S with beautiful rather hard to come by in good condition Type C Midnight blue interior, dash and all in near mint condition no rips at all. This car is pretty cool and I was sold on the fact that it had a full bolt ons F22A1 that was every bit as fast as h23a1 cars I had in the past.

Now seeing as these days I am not making this my race car, my race car being a Twin engine 1995 Subaru Impreza with a EG33D H6 SVX engine w/3.90 trans in the front and a H23A blue top P13 VTEC JDM Accord engine w/P2T4 lsd trans in the back, I’ll be trying to make a street car that makes me as content as my typical race cars do. My last daily being a SN95 New Edge with a 5.4l PI v8 running on a Predator 5000 Positive control induction fuel system no FI or true carb, as PCIs are different then carburetors and FI despite being commonly called “carburetors”. It made far more hp then then the 5.4l was rated for stock on the dyno and I’ve considered running the H23A on a PCI but for the sake of an “OEM” style build I’ve scrapped the idea of running a Predator 5000 on the Honda. But it got mediocre gas mileage at times, great at others, despite me tuning with a wide band so I sold it recently because 10mpg sometimes and 50mpg with the fast cruise fuel shut off averages out to only 23mpg real world from my tests and I drive 80 miles a day some times so that didn’t cut it for me. I believe I can pull 30+mpg with this new build to be realistic.

With that said here’s the build list of parts, the goal is 217+whp, the number claimed by the Euro R/Type S on paper. 30mpg minimum is what I hope for when daily driving out of vtec shifting at 3200RPMish.

2000 H23A SIR PDE engine, 100+K miles on it

H22A7(Type R) Exhaust manifold

PCBX intake manifold with functional IABs

H22A7(Type R) cams from the UK

H22A7(Type R) U2Q7 LSD Transmission

JDM Type S exhaust slightly modded to fit a 1993 BA8 Prelude S

The only non OEM H/F series Honda parts being a P28 that will be Dyno tuned on 450cc injectors, and a lengthened custom 2.5” outlet down pipe for the H22A7 Header as the stock A7 down pipe is too short.

I’m at 5000ft above sea level so E85 may be implemented as well as bigger injectors if needed aka if the goal is not hit, e85 is super common around me so it’s easily viable.

The engine was ordered as a 40-60k miles engine and was had for a good deal price wise but after disassembly I’ve noticed carbon/sledge build up and wear average of a 150-200k miles engine. So I know I’m working with a sub par setup to begin with, leaving my goal in the pipe dream range at best, but regardless I’ve planned this build for months before knowing the condition of the engine so I must continue despite the bad odds. Here are a few pics for starters, I’ll post more as the build progresses, still need a few things and need to give the engine an intense cleaning inside and out. Cleaned the inside of the cylinder head a bit and forgot to take pics but everything from here on will be documented to see if the 217hp claim of Honda’s best stock H engines are realistic. I know the H23A is rated at less then 217hp factory but it’s also only found in automatic cars with a mild tune and a poorly built exhaust manifold/exhaust system as a whole so I am confident it will pick up some power just from better tune, flow, gearing and more carful assembly.

So let’s begin, the H23A after mild cleaning and a few parts for it:





The H22A7 exhaust manifold, very meticulously built, and has no drop downs after the flange like the rest of the OEM H headers as well as most after market ones. It also has functional expansion chambers at the merge points of all 4 pipes and is smoothed from the factory with none of the dead heads that are present in all other H series manifold including the Euro R and Type S.





The PCBX intake manifold, smoother and better designed then all the other H series IAB intake manifolds, possibly better then the PDE but that’s not known for sure due to the lack of experimentation done on the PCBX. Also the bigger throttle body same as on Euro R and Type S.







I’ll take more pictures as the build progresses, maybe some of the car in the next day or 2 just to show the beautiful interior. So stay tuned I’m thinking I may actually meet the power goal with some extensive tuning and carful assembly, attention to detail on port matching everything best as possible in stock form/no sanding or porting. We will see👌

 

Looks like it's going to be a very neat build.

You didn't mention valve springs. Are you planning to swap them since you're using A7 cams? I'm pretty sure even the PDE head H23As just have standard springs.

 

Should be interesting, I’m older now so I’m not looking for massive power but I do want at least what Honda claims from factory Honda R / S H series engines.

Until I actually spec the springs for myself I have not decided if I’ll put the A7 springs in or not. I have a set though as I bought a cracked A7 head some years back just for the cams. People claim the H23A has typical h22a springs but I have yet to find someone who actually took them out and tested them, haven’t done much looking on the subject either though. I have a spare H23A head already off so I’ll take those springs out and test them this week.

I can do springs with the head on but don’t want to as it’s a pain to lock the valves in place safely so they don’t drop into the cylinder. Some people put the piston at TDC on the cylinder you’re working on and let them sit on the piston, I’ve tried it before with success but for obvious reasons I’d prefer not to do it that way.

 

Almost forgot, this thread is about an all motor OEM parts build but here’s a fun little add on to the build. I didn’t want to spend $500+ on wheels and this Prelude S came with base model plain wheels with the hub caps missing so I found myself a full nice set of late 1950’s 15” Rambler Z1 wheel covers for just $30.00! Plus they have an “R” on them and we all know R’s and Honda’s go together like Subarus and spun rod bearings. Here they are:

 

What I normally do is pressurize the cylinder using an adapter that threads into the spark plug tube and my air compressor. Air pressure keeps the valves in place.

I think the only difference is the intake springs. The F20B manual version has the Type-S/Euro-R cams and just has heavier duty intake springs. Exhaust springs are the same. Probably the same situation with the other engines. If you plan to rev it high I would definitely consider swapping them at least. Would suck to drop a valve. The H23A pistons have pretty lackluster valve reliefs too. Piston-to-valve contact is fairly common with high rpm applications. Mostly with aftermarket cams but it's not something I would personally take a risk on regardless.

Either way I'm excited to see how this turns out.

 

Some PCBX pictures after some paint.

 

An idea for a high TQ setup, probably won’t use it for this build but it looks cool and should work well if it’s all port matched and smoothed. Only the top plate has IABs, the bottom is gutted.

 

That looks completely ridonkulous (would you need hood risers to clear that beast?), but a dyno comparison would be interesting to see.

Any pictures of the Prelude, by the way? I just picked up an Accord, but I daydream about fourth-gen Preludes all the time. By far my favorite of Honda's FWD bodies. One day...

 

Same. One of my favorite cars from the body lines and styling to the awesome spaceship dash. Had cash in hand to buy one once. Unfortunately I'm 6'5" and couldn't fit in it comfortably. Leg was jammed between the steering wheel and console, head was touching the ceiling.

 

yeah....Preludes and tall people aren't meant together. Hence why I've stayed with Accords lol.

 

Well the Prelude was stolen 2 nights ago, I woke up instantly and chased them in my truck but couldn’t catch them, then the cops got in a chase with it. In the end the guy got away, and they found my car dumped, mechanically it’s destroyed, physically it looks pretty bad too. The person who stole it must of jumped it or hit a curb super hard because there is unfixable damage to the frame in the front, heavily tweaked. So the project has come to a screeching halt till I can save up and find another clean prelude to do the build in. Very sad days...

 

That's a real shame. Sorry to hear it. Hope you can find another one to build soon.

 

Sorry to see the thread end like this. Good luck finding a replacement!