Hello all. Was on here years ago when I built an FI F23 setup making just under 300hp. Welp, after cracking a cylinder wall, I finally got a replacement motor. I found it locally for $100 however it’s the F23 straight from Japan with less than 100K on it. Pretty fortunate actually to have come across it as I’ve been looking for the right deal for quite some time. I essentially only need the block and crank (as I’d like to keep them together) and completed my teardown yesterday. I’m reusing my head, as it wasn’t damaged, and will be again using Wiseco K20 pistons with the cylinders 0.5mm overbored and Molnar rods.

I have the complete 6th gen service manual in pdf form and was looking at the bearing charts tonight. Although I’ve read the JDM F23 is pretty much the same as the US F23A1, the chart is confusing because they only list the bearing codes for the A1, A4 and A5, both Japanese, US and Canadian built. My question is does anyone know if I can even use these charts? I have 44334 stamped on the block and 25444 stamped on the crank.

Anything else about the JDM I should know before I start buying parts and assembling?

Also what’s everyone’s opinion on ACL race bearings? I went OEM the first build, but am thinking it might be easier to go that route this time. I was thinking their standard size or 0.025 over? I’m running a balance shaft delete kit so oil pressure is already a lot higher than normal.

 

The benefit of OEM bearings is that you can dial in your oil clearances since they offer them in a range of thicknesses. You can't do that with ACL unless you buy a bunch, measure, and then pick and choose. However, for my build I had the crank, block, rods, and bearings measured and the ACL bearings gave an acceptable clearance. I recommend having your engine components measured and then you can calculate what bearing thickness you should run.