thumper64

I'm not after lots of power, I just used the RS Machines pistons because they're cheap, OEM quality, oversized slugs.

I'm trying to build this engine so it will last like 150k or more miles as a daily driver. Having everything right is important.

DDTECH

1) you can't use 81mm rings on 82mm pistons.. its impossible no matter WHAT ANYONE Tells you on here, for a FACT , you'll just have oil and **** blowing everywhere and it wont hold compression
2) Hasting does make 82mm rings.. call them their there.. dont be stupid.

Garage 808 Hatch

HERE

http://fjdistributors.com/index.php?cPath=53

2nd one down.

raiden571

i think someone needs to have a chat with rs machines if people are getting 81mm rings with oversized pistons. its just dumb.
does it really make sense to put a standard sized ring on an over sized piston? no it doesnt.
using the rings u have isnt an option, and if you do then your just dumb.
sell them/bitch to rs machine/ buy new ones/ something, just make sure you use the right size

mar778c

iTrader: (1)

^^^ How deep does the 1st and 2nd ring actually sit in the lands at the top and bottom of the stroke?

thumper64

Ok, what the crap? The part number for the 81mm rings is "2C 4666" and the part number for the .040 oversize is "2C 4666 040", right above a barcode. But, the box still says "81 1.0 1.2 2.8" at the bottom of the white label on the side of the box.

We have confirmation that RS Machines is sending the correct rings. I bought the rings from the seller "droopie888", and they were willing to send pictures of the different labels to let me make sure I got the right thing.

thumper64

Are you asking how much of the ring will be in the grooves versus outside of them? The piston to wall clearance would dictate that. I think ideally it's supposed to be .004 times x inchs of diameter the piston is. Whatever the diameter of the cylinder is at that height in the cylinder compared to the diameter of the piston, subtracted from the width of the ring would give you the amount of the rings sitting in the grooves of the piston.

The piston sits about flush with the deck, and the top of the first groove is about 6mm and the top of the second groove is about 11mm, measuring from the top of the piston, ignoring any groove/domed area on the ITR piston.

thumper64

Anyone saying I'm dumb to use the wrong sized rings...shut the heck up and read the whole thread. The whole point of the thread was to make sure I either get, or have the correct size for 82mm bore because I'm not going to run 81mm rings in a 82mm engine

90 integra da

Wanted to bump this old thread and ask everyone for more input. I got the exact same thing 82mm pistons with hastings rings. My part number also is 2c 4666 040 but my box says 81mm on it.

jjohn170

i know im late but I was looking for this exact thread just to check so figure id give input.

from reading/searching these seem to be the right rings. 82 mm is 40 over ( 40 thousands of an inch (4 hundreds of an inch)) from a 81 mm piston.

im assuming that an aftermarket 82 mm piston will have a sligly larger ID( inner diameter) for for the piston ring grooves, thus this is why you have to use the 82 mm pistons that are called out on hastings website for aftermarket pistons. AND you have to use the 40 over rings (2c 4666 040) bc the rs machine piston rings groove ID for the 81mm and 82mm are the same.

If that last part is not clear or is incorrect PLEASE let me know or correct.

dester223

You have the correct set.

ef2_civic

iTrader: (1)

i know this is very outdate but I have ITR oversized pistons .25 and would like to know if I could use hastings 81mm rings or any brand 81mm rings at that?

please if anyone knows or has tried this Im stuck until I know

L.D. built

Thanks mar, now I can comfortably build by engine with the 81mm rings sent to me with my 82mm pistins, ima return with how the engine build went thanks again!

Rosko

iTrader: (1)

Is this thread for real??

Easy math says theres .123" in circumference difference between and 82mm bore and an 81mm bore. Thats a few thousanths shy of an 1/8" difference in ring gap!!

raverx3m

iTrader: (1)

i also bought 81.5mm set from droopie on ebay
rings were oversized had to be shaved

but so far after 10000 miles it looks clean and has less than 5% leakdown last time i checked

its a circle it shrinks evenly they have to have tension otherwise they wont seal

EG1834

Jesus, what kind of Mickey Mouse bullshit are you guys building? The rings need to be made for the pistons, most file fit rings are about .005" over the bore. Too far oversized and you are spending hours filing the rings and it could still have excess ring tension and wear the **** out of the rings and cylinder walls. Too far undersized, and you have enormous gaps and too little ring tension resulting in blow by and oil consumption.

Just get the correct rings!

Rocket

I dunno, RS/YCP **** works plenty good, surprisingly good, for slowsleeper.

mar778c is one of the handful of peeps whose input I value and trust. Seen enough of his post to know he's not a regurgitator.

Calling the manufacturer, while not a guarantee, shows the level of thoroughness that helps one figure out if the info presented is reliable.

DDTECH

I stopped along time ago, you'll pull your hair out.

PyroProblem

LMFAO

blackeg

i have run into this issue on the last few motors ive assembled at 81.5mm with rsmachines or nippon pistons. same exact ****, with both gaps coming in about the same at .020" which i have no problem using on an n/a 1/8L 2nd ring, but is too big of a gap for the top imo. it keeps costing an extra 50 bucks for a set of hastings rings. this issue is very annoying.


as for the pistons themselves i have nothing but good things to say.

Dkb20v

how did it go?