questions on building a "g23"
 

Me and a friend are putting together an engine for his accord using an h23a1 bottom end and an h22a head, uppon further research we found out that the h23a1 block isn't very good with boost (frm sleeves). So what im wondering is, can we use an h23a1 crank into an f23 block (iron sleeves) overbored to 87mm with an h22a head?

Re: questions on building a "g23"
 

Also reason to do this is because we already got some h23 h-beam rods and noticed that the h23 and f23 deck height are identical as well as the 55mm mains

Re: questions on building a "g23"
 

bump! need to get some responses, my local junkyard has a 50% special and we're trying to make this work, thanks.

Re: questions on building a "g23"
 

All H/F series(minus the F20C/F22C) share the same deck height and a lot of other things. FRM sleeves don't make an engine any worse for boosting, just to clear that up. They just make it difficult to run a good piston. The H23A1 you have is from a 96 Prelude I'm assuming? I believe that's the only year they came with 55mm mains. Prior to that it was 50mm like everything else.

Boring out an F23 block to 87mm is going to substantially weaken the stock sleeves. Since you seem to want boost that's going to be a very bad thing because boost is going to increase cylinder pressures by quite a bit. Even if you threw in a good set of pistons with the rods you have, the engine is only as strong as it's weakest link. The FRM sleeves in the H23A1 are actually stronger than those cast iron sleeves anyway. Honestly, all the frankenstein crap is going to end up costing you more money in the long run. I've been messing with H/F series for over a decade now and I've never recommended them or really seen the point. May as well just get an H22 and boost it. You can throw whatever internals you want in it and not have to worry about this headgasket or that headgasket, oil leaks, fitment issues, etc etc. But I digress, with what you're working with, the best option I can see is keeping the H23A1 bottom end. Check the cylinders for scuffing or taper, get a new set of rings and open the top and second ring gaps a bit to combat the thermal expansion introduced by boost(which is one of the big causes of busted ringlands on cast piston engines), throw in your H beams with new bearings and all that. You'll have to get a machine shop to fit the factory pistons to the rods since the pins are different(press on the stock vs floating on the aftermarket rod). Get a good, professional tune from a reputable tuner using good quality fuel and keep it conservative. Keep any and all detonation out of the engine and it should do just fine in the 350-400whp range. I would trust that more than I would a bored out stock sleeve F23 block even if it had forged pistons.

Re: questions on building a "g23"
 

ok, h23vtec seems much more simple