Help with Piston and bottom end choices.

[dwhacks]

Is anyone aware of someone who has either tried boring the f22aX to 87mm or stuffing k20a2 pistons in there? It seems like the k20a2 pistons would be ok, but harder to tune and need high octane gas. I can only get 91 octane around here.

Other then that it seems like I am all out of "budget" f22a options and have to go with forged pistons which is a lot less fun for my bank account! (an extra $400+ USD)

[Jarrett]

It seems like you're talking about two different things, or you're not listening.

K20A2 pistons (or any "K20" pistons, for that matter) are an 86mm bore, 30mm compression height piston with a floating 22mm pin. The F22A pistons are 85mm bore, 30.55mm compression height pistons with a 22mm press-fit 22mm pin.

To fit a K20 piston into an F22A block you'll need to bore match the cylinders to the K20 size (piston in hand, but the method isn't what's being argued here). You'll also need to address the floating vs. pressed-fit wrist pin issue. Then, you can get aftermarket F22A rods or have your factory rods rebushed for a floating bushing.

K24A2 pistons (or any "K24" pistons) are an 87mm bore piston. The F22A cannot be bored out to 87mm. A machinist member on here abandoned the project of trying to get it done with a torque plate, so I would abandon any idea of that happening. It would be much cheaper and much more beneficial to purchase an F23A bottom end to accomplish an 87mm bore if that's what was truly desired.

[dwhacks]

Oh yes, I understand completely the problem.

What I'm saying is, I have private messaged jdm92_accorn and asked him what to do. He claims that 87mm would be fine on and f22a and that k20a2 pistons would cause hot spot issues.

So I was just wondering if there is any info on anyone ever trying either, and you've just told me someone had tried the 87mm and gave up so that's a good bit of info. Now is there any info of someone actually installing the k20a2 pistons in an f22a?

I'm just trying to compile as much info from as many sources as possible so I don't miss anything.

[Chrisnick]

Are you planning on a camshaft or headwork to take advantage of that extra compression? If your answer is no, then just a regular ol' F23 bottom end will be plenty. I bought my swap for $300, and it came with an auto trans and a TON of extras, almost enough that if I sell the extras, I could easily make my money back. Extra compression is all fine and dandy, but just look at what jdm92_accorn has already done with a STOCK F23 block and a STOCK F22A head casting. If it wasn't for the fact that there's nearly zero options on the VTEC heads for a camshaft, a full drop in F23 would be the way to go if you don't plan on porting/valvetrain, as they flow a little bit better(especially on the exhaust side and at lower lifts) than the F22A heads. I'm trying to source someone who's willing to regrind the F23/F22B1 cam at a decent price and see what I can put down with it. There's really no need for a build, if you really think about it, you can accomplish your goals easily without having to dump a bunch of money into a build if you're willing to look around for a good deal on something that's in good health. Just refreshing an F22A longblock would probably cost northwards of $500 with decent/OEM parts and machining, it's easily another $500 ontop of that for something of a performance build. Personally, I'm not willing to dump that much money into something that MIGHT make the same power as a stock H-series, when that's an easy drop in to make 60 more HP. I say start with a cheap, healthy F23, add some bolt ons, and go from there. They seem to respond better to modifications than the F22A's without a camshaft change, just think about what it'd be able to do with a ported intake manifold, decent header, and camshaft? I know for certain there's at least 30-40hp that can be added without changing the camshaft on an F23 with proper parts selection and tuning. Here's a quick example: my car with a very stock F22B2(similar power levels to the F22A's in stock form), did 16.3's at 83-84mph with me driving the nuts out of it. It would not go faster. With the F23 swap and adding bolt on's, I'm a better launch away from a 14.9 at 91+mph, still on a stock tune. Nothing else changed with the car, although the 60ft time improved by .1 second. Same suspension, same tires, same gearing, etc. Another member on here, with a shorter geared trans+LSD, gutted interior, more drag friendly suspension, fresh F22A+cam and what's supposed to be a better engine combo that I have, is running 3-4 tenths SLOWER than what I'm running- and he's not a bad driver from what I can tell from the videos he's posted(no disrespect to him at all, he's done great with his setup, IMO). I still have yet to try it with a tune, still have yet to put on my ported intake manifold, still have stock engine mounts, still need to get a clutch that can take the launch/shifting, still need a traction bar, so on and so on. Are you starting to see why I'm recommending just dropping in a healthy F23? It's VERY restricted in stock form and shouldn't be passed on just because of poor information that's been regurgitated about it for many years. Building something like you're suggesting is WAY over complicating things when there's much easier, better options.

[dwhacks]

You're probably right, and I have been leaning more towards the f23a. I just liked the idea of giving my current engine new life.

I do already have a port matched h23a intake with 68mm throttle body, Delta 272 cam, cheap header and custom 2 1/4 exhaust with cat delete. So I really think I should do decent with a healthy f23a bottom end.

[Chrisnick]

I'd just take you're head and slap it on an F23 block then. It'd simplify things a bit wiring wise, and you as long as your head is in decent shape, you should be able to make pretty decent power. Gut those lower runners and port it like jdm92_accorn has done, and it should be pretty decent. Only your header and exhaust should be a restriction at that point.

[ol blue]

I would also like to mention to get a new collector on the header. I would keep the iab plate operational but port match everything and clean up the webbing. I do agree on just putting your f22a head on the f23a block, maybe even machine it down a little to bring the compression closer to 10:1.

[dwhacks]

Ok, well it seems you've all convinced me that f23a is the best budget N/A way to give my engine new life. I will be on the search for an f23a short block so if anyone has one in northern Washington let me know!

I'll save the f22a and one day maybe do forged pistons.

Has anyone seen the new Chinese 4-1 headers on ebay? I'm wondering if they are any better then the 4-2-1 headers.

[Chrisnick]

Probably not considering how short the runners are and that collector design. Out of all the off the shelf choices there are/were, the Bisi was probably the best. If you don't mind hacking off a head flange, there's some nice opportunities from an H22 that could work.

Also, check to see if you have an LKQ pick and pull local to you, I've gotten some great deals out of my local LKQ.