hotaccord243
Well-Known Member
Re: Accorman722's G23 Build.
That is true the FRM sleeves are a PITA to get to seal up especially with new lower compression pistons. It's even harder I have heard to have it re-sleeved as some companies won't even touch them.
I am almost positive that the same goes with the f23a4 motor of ours that those sleeves are not cast iron and have the same issues but the f23a1 does not. When I was building mine I found out that you basically can't resleeve the f23a4 due to this same issue or similar as the H22.... That, along with an open to deck block and a head designed for a closed deck block.
I've heard as far as mating the Fseries block with an H head they bolt directly up no problem, but the kicker is in the coolant channels and it takes a bit of leg work to either modify to get them to line up and so forth and some have to be plugged (from what I read a LONG time ago, but could be wrong as I am going off of memory from a few years back).... I know either way it cools it's just trying to improve that cooling for better flow is a bit tricky.
I have also heard about the MAHLE FRM pistons as well, and I believe people are having much better luck with those than anything else. It's a great solution to what little options you have for that too.
The problem with H22's and boost is the fact that their sleeves are FRM. That and the H22s inherently have a higher compression ratio. Between the two of those even 10psi on a smaller turbo will not last very long. The biggest problem is that forged aftermarket pistons will not seal properly in an FRM sleeve...so lowering compression and strengthening the internals is not an option.
I have heard, but do not have experience myself, that the Mahle FRM compatible pistons will work in FRM sleeves. They say it has a special skirt coating that allows it to be functional in the sleeve. Like all piston coatings, it will not last super long. Here is a link to the pistons.
http://www.inlinefour.com/mahle-motorsports-forged-racing-pistons.html
Hopefully Darksideaccord chimes in to clear this up. I would not think it has cooling issues, since the coolant channels are around the cylinder and the f23s are open deck (i.e even if it didn't line up exactly with the passages, all the passages would still get coolant).
That is true the FRM sleeves are a PITA to get to seal up especially with new lower compression pistons. It's even harder I have heard to have it re-sleeved as some companies won't even touch them.
I am almost positive that the same goes with the f23a4 motor of ours that those sleeves are not cast iron and have the same issues but the f23a1 does not. When I was building mine I found out that you basically can't resleeve the f23a4 due to this same issue or similar as the H22.... That, along with an open to deck block and a head designed for a closed deck block.
I've heard as far as mating the Fseries block with an H head they bolt directly up no problem, but the kicker is in the coolant channels and it takes a bit of leg work to either modify to get them to line up and so forth and some have to be plugged (from what I read a LONG time ago, but could be wrong as I am going off of memory from a few years back).... I know either way it cools it's just trying to improve that cooling for better flow is a bit tricky.
I have also heard about the MAHLE FRM pistons as well, and I believe people are having much better luck with those than anything else. It's a great solution to what little options you have for that too.