KdrewsBB6

Just wanted some conformation before I make my purchase. I want to lower my compression and build my block a bit for my turbo set up. I don't want to sleeve or bore (unless it looks bad down there) so I was gonna go with mahle gold 9:1 87mm pistons
http://m.ebay.com/itm/291187758893?nav=SEARCHI want to confirm that I should get 87mm not 87.25mm if I don't want to bore right?
Then I was gonna get some eagle h beam rods
http://m.ebay.com/itm/271545487890?cmd=VIDESC&gxo=trueJust want to make sure that these will work with these pistons. Also gonna replace bearings, any advise or recommendations is greatly appreciated.
Thanks!

KdrewsBB6

I'm pretty sure I'm right but can anyone confirm this?

AznBlueBoy

you have to look at your block to see if its A or B block.
itll be stamped AAAA or BBBB
if its B then you need 87.25 size.

KdrewsBB6

Awesome thank you; rods should be the same though right?

Yeret

Are you going to have the cylinders checked? To me it seems ill-advised to dial-up the power in any engine that has any cylinders even slightly out-of-round. Why spend thousands on souping up an engine that's just going to leak a bunch of said power?

Also, are you going to have the lower-end journals checked? If those are out of round and you crank up the horsepower, even with new bearings, you could have anything from an engine that knocks after a few thousand miles and throwing a rod the first time you stomp her down.

Machine shop work can be crazy expensive, but there's a big difference between a beater build and a turbo build, especially if you want any kind of longevity...

dagle

iTrader: (1)

When you get your drop-in pistons, you/your machine shop will still have to check piston to wall clearances, but yes the Mahle's should be fine assuming its responsibly put together.

The rods for H22's are all the same size with 50mm rod diameters, it's the bearings that you will need to be measured/fitted. A good machine shop that does work on Hondas will have them in stock, my local lube/mechanics shop keeps bearings stocked.

the171

Is this true? First I've heard this. While there are certainly 2 oem piston sizes, jumping 0.25mm on a b cylinder seems like a bit of a guessing game. Measure the cylinders with a dial bore gauge and then decide what size piston you need.

H engines are tricky because its hard (sometimes impossible) for a machine shop to hone the frm cylinder to the correct clearance for the new piston. You can leave stock bore but then you're fighting the ridge and wear pattern from the original pistons. Even though these cylinders wear very little, there will still be wear.

Lots of people have had trouble with aftermarket pistons in a frm engine for the above reasons. I personally would start with a new block from honda, and a new set of std size mahle pistons. Then check or have your specs checked by someone reliable. Once everything checks out you can be confident in your short block.

on another note... leave the bearings alone if they're not damaged. replacing with std bearings will be decreasing the quality of your engine, not improving it.

snobordboy

Nope, the A and B are not .25 difference, the .25 is first overbore size, and Honda sells distinct pistons at this size. If you look into the part numbers, for say a type-s piston from Honda, you will find a part# for the standard 87 mm bore A, the standard 87mm bore B, and the 87.25 OS piston.

dagle

iTrader: (1)

Well I mean if the OP could afford a new OEM block, he could afford to simply install sleeves into his motor and do away with the FRM compliant pistons altogether lol.

The only reason I would go with a new set of bearings is because there's no way the OP has a low mileage engine. I would feel better with a new set of bearings with uniform measurements, but that's just me personally. :p

I have a bare H22A4 lying around that's BBBB I believe, I'll measure it later with a micrometer (don't have a bore gauge, but I do have the pistons so it shouldn't be off by more than 0.25mm)

gstrudler

B is not the .25mm oversize, but it is slightly bigger than the A. I would strongly suggest you get the 87.25mm and get the cylinders honed. The FRM walls are known to go out of round, and especially if you want to go boost if you don't touch them you'll have tons of blow-by.

There are instructions for how to correctly hone FRM walls in the Helm's manual, plus numerous places online (including here in the FAQ I believe); print them off and take them to a couple machine shops and see if they have the equipment to do it correctly. You can also contact a couple local Honda dealers and ask them where they would send their blocks if they needed work.