nuezdaman44

Well my '00 prelude has definitely seen better days... Not only have I been getting random misfires on all four cylinders (#3 and #1 mainly), but I recently started hearing rod knocking. So I decided it was time for the H22 to get rebuilt...

Everything has gone fine, the head removal was a breeze, but once I got it off I discovered the likely cause of the misfiring... The second closest cylinder to the flywheel is scratch and scarred like a motherf***er and its definitely the quickest to throw the misfire code. Cylinders #4 and #2 are fine, #1 has a few scrapes as well but nothing like the one shown...

Looking at the damage I'm thinking that new piston rings wont quite be enough to get back full compression and maybe not even stop the misfiring... So I have two questions I'm trying to figure out:
1) whats causing it... and 2) aside from getting it bored out by a machinist, is there anyway to smooth out the cylinder walls

They all appear to be lined with some kind of low friction coating, the metal is definitely shinier inside the scrapes... So is that something I could reapply? I really don't want to have to take it to a shop cause I'm strapped for $ but once I get everything back together I definitely don't want to see the engine still running like sh*t... I've spent years staring at the same yellow CEL and burning a quart of oil every 2-3 weeks, so if anyone has seen this before or if you just know your stuff I could use some help, I'm kind of a noob with engine blocks...

vinuneuro

How deep are the scratches? If they're not deep enough to catch a finger nail AND the bores' roundness and taper are within Honda spec (this is important), you can just put new pistons in there (whatever your block piston code is).

Most important would be to understand why this happend.

nuezdaman44

You can just barely feel them with your finger... To me it just looks like the coating on the walls got scraped away, with no real damage to the metal... But that could just be wishful thinking

vinuneuro

There's no coating. You need to bore/hone .25mm+ and go to oem oversize pistons.

Dl the helms from here if you don't already have it and go through it thoroughly: Helms Download

This is extremely important: Regarding honing FRM that's used in these blocks: How to have FRM honed

nuezdaman44

Yea I have do a manual, I would have destroyed my engine by now if I didn't, definitely key...

Good looks tho it definitely looks like the cylinders need to be honed... If I'm reading this correctly I'm going to need a special RPM controlled honing machine? Any idea how important the RPMs are to the process cuz If I got the stones I was thinking I could just use a really slow drill...

vinuneuro

Honda revised the honing procedure when the S2000 came out, 150rpm is now the max rotational speed. I would send the block to one of the shops I mentioned in that thread. Cylinder finish is the most important thing for ring seal. Most shops will screw it up.

nuezdaman44

Well I just tried the "fingernail test" and couldn't seem to get my nail caught in a scratch, although the scratches do go all the way down the wall...

I know we're talking about fractions of a millimeter when it comes to cylinder finish but it seems like if I just got a really fine finisher, like 800-grit or less, and very very lightly smoothed out the bore that a fresh o-ring would seal... I really do not want to have to send it to a shop but if that's a really dumb idea I just might have to consider it

Apex1972

hey man this guy is trying to help you out. If you aren't gonna listen justt go ahead and just get a new motor. FRM has to be honed correctly.

mattsnooz

Its not like he's trying to say "no I don't like your ideas". He's saying his wallet isn't fat enough to send the block into for a honing. Its not exactly a cheap process. Especially if he overbores and than has to buy oversized pistons.

I'm assuming the OP has to buy new pistons anyway or what, or are the rings / seals just fuked?

TwizT

If you are really strapped for cash, it's probably more cost effective to drop in a JDM H22A instead of rebuilding your H22A4 motor.

bluedlude

very true.

you are going to have to tear the block down regardless so i would just measure the cylinders to see if they are within spec and if they are hit them with a ball hone for a second or two and see how it looks. but thats just me.

nuezdaman44

yea I am still trying to figure out whats causing the scarring... but I'm hoping its just f'd up o-rings and not something more serious. This is definitely more than I was hoping to get myself into, I'm attempting to do all this without even pulling the block. I might just try to gently hone the bad cylinder and see how it looks, I can always ship it somewhere if it doesnt work and get it bored out.

bluedlude

I think you are making more work for yourself trying to rebuild the block with it in the car. has your car ever overheated? ran low on oil?

nuezdaman44

Yea actually alot of sh*t has happened that I'm sure hasn't helped things... I let my brother drive the car for about two years while I was away at school, which I kinda regret... I came home one time, noticed the VTEC wouldn't engage, and checked the oil and saw it was below the dipstick... ended up adding 3 or 4 qts to get it back up to the top dot, and who knows how long it was like that.

I also blew out the cam seal a few years back and ended up having to drive it 5 miles or so with oil shooting out of the engine. And it has been burning **** loads of oil for as long as I can remember, but it is an H22... Never had any overheat issues but I'm sure any one of the other things could have some impact on the overall health of the engine block.

I'm just playing it by ear as far as removing the block, I do not have an engine puller so I'm doing what I can with it in the car until I absolutely need to take it out... The only thing is I'm not sure if the rod and main bearings can be replaced - I've searched but haven't found a straight answer on if it's possible, I've seen people that swear both ways. Has anybody successfully done a full rebuild without pulling an H22??

hondaZvic

U can remove the rods with it in the car.. But removing the crank, NO. Its attached to the flywheel..
By the time the tranny is off and then the clutch flywheel u would be able to pull the block straight out with a buddy if not by urself.

kornerk12

I never really understood how the s2k runs forged pistons in an frm block but we cant, besides the mahle gold pistons.

vinuneuro

S2k oem pistons are supplied by Mahle. It's the same alloy as the H22 Goldseries.

bluedlude

screw mahle, ive got a smoked block to back up my opinion. and S2K pistons are nothing like mahle's. even visibly.

vinuneuro

Many people have used them in H22 NA and high-hp FI builds without problems.

Who cares if the pistons look like each other or not. We're interested in the alloy, they are the same. F2xc, Mahle H22, JunH22 are all made from the 4032 alloy.

Btw, the oem s2k and Mahle H22 pistons do look similar, maybe different skirt size.

bluedlude

the s2k's definitely look more like a cast piston, the mahlesare obviously machined. i have an s2k piston because i had some crazy ideas way back when. but anyway, i would never run a mahle piston again.

vinuneuro

The S2k pistons are forged. It even says so in the Honda press release. And I know for sure that Mahle makes them with the 4032 alloy. I worked with an ex-Mahle engineer in my last job who used to work on Honda apps.

bluedlude

there are different forging processes. the mahle pistons are likely made from a forged blank and the honda pistons a different process, I am no forging expert. but just because they are made from the same alloy doesn't mean the alloy goes through the same process.

vinuneuro

That I have no clue about, I'm an IE. How does the forging process change the characteristics of the piston?

bluedlude

its all about the crystaline structure. forging involves heat and pressure. the smaller the crystal the harder, but more brittle the structure is. the larger the crystal the softer and more ductile the structure is. forging aligns the crystals in a controlled configuration to increase the strength of the material, this is usually done with pressure and a controlled, short cooling process. but the exact method of forging can differ, like i said i am no expert.

gstrudler

so has anyone ever actually put an f20c/f22c piston in an h22? bluedlude, are you still running mahle's, or did you go another direction?