PM sent pete

red rider, that's weird. When I looked them over I installed them in a cylinder and on a piston. The piston was .25 over pilot and the cylinder was a .25 over cylinder with some wear. If I made a mistake some where I'm sorry for that. I will get them from stixs if he has them a get pics and measurement to post. I had compared them to a set of .25 over pilot right out of the box. Are you sure you do not have an 80 mm bore ("they measure 79.5mm compressed and overlap when placed in my cylinder"). If I was wrong I will reimburse Stix's for the shipping cost both way if returned and owe you a favor of your choosing.

Had to do in two post sorry.

Pilot rings used in test
RING SET (OS) (0.25) (13012-HE0-305) See pic

Ody ring #'s
RING SET (OS) (0.25) (13012-VM0-681)
(replaces 13012-VM0-305)

Which ones did he send ? I hope 13012-VM0-305

Make sure to check bore before getting the other set of rings just too be sure.

ride_red, is the cylinder already bored to the new piston. If so post up a pic of the piston crown. There should be a .25 mark on the center of the crown in the circle. see pic.

Heres some ring part #'s
Pilot ring.
RING SET (OS) (0.25) (13012-HE0-305)

Ody ring.
RING SET (OS) (0.25) (13012-VM0-681) (These are the one in pic from pilot pete)
(replaces 13012-VM0-305) (These are the ones the stix should have.)

If you could help me undestand the 79.5 reading you took and where. I will help you any way I can. If need be I will come down and look over.

I have a set of 13012-VMO-681 rings will these work for you?

Ok, got some pictures taken this morning and will tell you all what I know and where I'm at right now.

First, the piston:
It is stamped 25 on top, but the weird thing is that I get a measurement of 78.5mm on it. The .25 piston does fit into the cylinder as one would assume (hoser did all the work, so I'm sure its good and true considering he has done many and knows what he is doing...BTW hoser, thanks again for your help!).

Rings:
The rings I received from Stix have the number 130A1-VMO-005 on the box. No idea where this number comes from. Did a quick search at hondapartshouse.com and Google with no luck.

Measurements:
As you can see in the pictures I only have a cheap digital caliper that I use for measuring things. This could be where I develop an error in what I'm trying to measure, and partly what is confusing me. If I have read correctly STD bore is 78.5mm. My .25 piston measures that (#1 thing that's confusing me). If this is what my bore is, that would explain why the next size up, 78mm, rings would overlap when placed in the cylinder.

The only two things that I am 100% sure of is that the piston fits, the rings I have do not lol. I have payed pete for the rings he pictured earlier in the post, but from his tag and ridiculous posting times I believe he lives in the UK....so I have yet to receive them in the mail. If everything is as it should be they will work, if not....I will probably be calling on you adnoh!! Again thanks all for your help and concern!

you need to measure the biggest part of the piston witch is the bottom of the piston skirt

the ringing are not for that bore for sure


SpeedChaser

78.71mm

Just a guess but them rings are for the pre recall 350 he has a post recall piston, I have a set of the .25 over post recall rings here if needed they are TurboTexas rings I can send you can work out the money with him.

On a side note Pilot rings fit the 350 OEM piston just fine.

Thanks hoser...when I get Pete's rings in the mail and compare them I will know then if I need Turbo's....Any thoughts on my measurement on the piston?? If it is the .25 piston wouldn't it measure closer to 80mm?

I might need the rings you have too, as the ones hoser is refering to are too small for my piston... would it be worth the postage to swap out and see how they fit???

Right now I am waiting on rings (should be the correct ones) that I have already purchased from Pete a couple weeks ago...when they get in I will check to see if they fit. If they don't and I still am on the search I would be willing to do a trade turbo...I'll let you know as soon as the rings from Pete come in and I get a chance to slip them in the cylinder.

Hey. I talked with Adnoh today. I tried to make head or tales and am also stumped about the 25 stamped on the piston but measuring like a standard piston. We discussed your situation. He told me to have you give him a call on Sunday evening or better Monday. He wants to help you out. Ill PM you his number. Hes going to be at the lake till Sunday. Talk to ya later

Pete's rings fit!! I'll have to get the feeler gauges out to verify ring gap, looks slightly large, but I'm hoping not...these are stamped "25" on them. I'll double check everything in the morning when I get off work. andoh, I may or may not get a chance to call tonight. If not I'll keep y'all posted tomorrow. Thanks!

JP

hope they fit .....

I'm back. Had a blast at the lake. I see the delima you have there. The ones you have are not the correct ones ( 130A1-VM0-005). As speed noted you take reading at the skirt ( see pic). Since it is a OEM piston this spot should be 20mm up from the bottom of the piston. You can use teh caliper and make two markes on the piston and one on each side ( carfull not to damage new piston) and then take the calipers and measure. Write that number down, Then since its bored take the calipers and measure the inside of the bore att the top. Write this down as well, then you can subtract the larger number from the smaller and get an idea of the piston to cylinder clearence. Using calipers will not be as accuarte as using a boreguage set up but you get the idea. The next step is to place a ring in the cylinder and use the skirt end to push the ring down the cylinder so it set square in the bore and measure the end gap and see if its with in the spec listed in the manual. It must fall with in spec or problems will accure.

Also note that the oem piston and rings are tappered do not install up side down or rut ru. Alos check both rings do not assume there both ok if you measure just one. Post up some more pics later gotta go eat. Need anything else just ask.

I looked over all my data and info and after redeading your post I conclude you have a post recall piston that is .25 over. OEM post recall is 78.5mm standard so .25 over is 78.75. SO the rings you will need is 13 for crank/piston assembly, 01 for rings, 2 for .25 over, VM0 for ody and 618 for post recall bore range. 13012-VM0-618.

Please verify that you have piston 13102-VM0-315 (78.75mm) The flat top kinda telles me you do. No mater what still check the ring gaps. 13 crank /piston assembly,10 for piston, 2 for .25 over, Vm0 for ody and 315 for post recall bore range.

So I took the measurements andoh asked for and this is what I came up with. Piston measures 78.75 20mm up from the bottom of the skirt. I then placed the rings into the cylinder and squared them up with the piston and got these two measurements for ring gap. .58mm for the top and .50 for the bottom....According to the manual only one of these are within service limit....barely lol

When you measure the piston you want the largest OD you can find.

Pistons are cam ground egg shape and tapered from top to bottom, smaller top bigger bottom.

Not good on the end gap for an oem. see pic .2 to .4 mm. Be sure you took good number adn lets re check each after you get your first number check it again this time by reinstalling the piston and pushing a little furture down the bore and get second number. Never hurts to double check. I take it the ring number was 13012-VM0-681 on the package. If same reading concure the origanle numbers then look for markes on the rings (T) to see if one is marked (T) for top. If so I hope its the one with a larger end gap. This will reduce ring flutter and help with land pressure between rings. Also check to see if there marked with a 25 on them. If both are marked the same this should tell you which way is up for the taper and the larger gap for the top should be used for the top ring. Always be sure and look any way. Once on the piston the ring should compress easily into the grove if on right.

Yes the gap is out of the service limits but don't panic yet. Next, lets check the depth of the ring using the tips of the caliper to see if one is thinner is than the other or if one is the top ring with a larger gap.

NOTE: The pilot runs a .45 to.60 with a limit of .70mm. Its not uncommon to open up the top ring for higher compression ratios to help offset the swell of the crown and reduce excess wear.

The rings depth should be around 3.2 to 3.3mm in depth. So let see where yours fall.

"H" is right on with the fattest part of the piston. The book tells you where to measusre but when boring one must find the fattest or largest diamiter to set the clearence to.

Sorry still having posting problems.

I'm sure "H" has your piston to cylinder clearence correct so I would bet its the rings. This is another reason to have the rings when boring so you hone the piston to the minium than check you ring end gap and see if more honing need or can be done ( depending of clearence range) or a different piston or rings need to be installed. If some one has a new set of the same number to compare the numbers to we can be sure. Where nukem when we need him. I wonder if odystable has a set. Might p.m. him and see.

Are you using a feeler gauge to measure the end gap, or sticking the ruler/caliper thingie down therre???
I think Hoser has a set of my rings with those numbers, I think that sounds famliar...

Just got home from work...I am using feeler gauge to check the gap. Only one of the rings is stamped, and it has both "25" and "T" stamped on it. Part number 13012-VMO-681 on box....this afternoon after some rest I will go over some measurements again and double check everything to be sure I'm getting good data. Thanks all.

-JP