Welcome to 21st Century Restomod, the still-ongoing story of the transformation of my 2001 Honda Prelude. I initially wrote this months ago, but I got busy with my 3rd gen.

In my previous entry, I’d bought a new engine for my project car and had removed the old one. By August 2014, I was getting the new engine prepped to put into the car. The engine bay had been cleaned and I’d bought a bunch of new parts to install. The H23A, while at its core is essentially a stroked H22, has enough different parts on it due to being from a JDM-only Accord that to get it to work properly in a Prelude you need to take several things off the old engine and switch them over. Here’s a list of things you’ll need for the swap.

I had a couple friends come from out of state to help. They’d done this swap a few times in the past and knew what to do, whereas my dad and I were doing all this for the first time. By the time they came, in August 2014, we’d gotten the engine partially ready.


At the last minute, we switched from the H23's original blue valve cover to the H22's black valve cover after finding a crack in the blue one.

Rest period. Mr. Coal is tired from being up all night with strangers.


There were complications. We’d stripped a few of the holes where the transmission bolts to the engine, so the engine sat for another month waiting for parts (taps and Heli-Coils) to remedy that to come in.

Parts came a few weeks later, some of them having been shipped from overseas. One of the out-of-state guys came back.

Ready for an engine. Sorry for the glare.

Time to drop the engine in.

It wasn’t going onto the mounts properly so I stood on it to help get it in there the right way.

Finally in.

Over the coming days I slowly put the peripherals back together.

The box said 10 horsepower.

Finally, in early October, I got everything ready and started the car for the first time. It was a minor success, although there were still a few issues to fix. The idle surge was still there, and there were a couple of leaks, oil at the oil pan and transmission fluid at the passenger’s side axle-differential seal. After fixing the leaks and tracing the idle surge to the fast idle thermo valve, a common issue for Hondas, it was ready for the road.

After a few days of just driving close to home, I got the car inspected, checked the timing belt, changed the oil, and broke everything in, then started driving it around and taking various photographs.

The H23 swap was well worth it. The car pulls harder than either of the H22s I’ve owned, due to the longer stroke providing more low-end grunt. I stayed with the stock ECU for the time being, since a manual ECU for the H23A doesn’t exist. They work just fine together, VTEC coming in around 5200 RPM and rev limiter in the high 7xxx’s. I’ve never revved it all the way up to the max, since the engine’s original redline was 200 RPMs under the H22’s. Either way, the engine wakes the car up a little bit more, and is recommended for the mechanically-inclined owner of an H-powered car. With the engine refreshed, it was time to move on to other things the car needed. I could do several different things, but the junkyard helped me out a bit.