Author Topic: Sourcing new rings for 70's NOS Venolia 71mm pistons (Read 5248 times)

gschuld · « **on:** January 20, 2013, 10:11:50 AM »

So if I acquired a set of NOS 70's Venolia 71mm pistons, where might I locate a set of rings for it?

Thanks in advance,

George

cbr954 · « **Reply #1 on:** January 20, 2013, 11:17:19 AM »

Total Seal will make rings. I contacted them about rings for a set of 70mm RC pistons that I have.

gschuld · « **Reply #2 on:** January 20, 2013, 12:36:21 PM »

Interesting, please keep me posted with how it works out.

George

Retro Rocket · « **Reply #3 on:** January 20, 2013, 01:44:40 PM »

APE engineering have 70 and 71mm piston kits, Send member Big Jay {Owns APE} a PM and ask directly...

Jerry Rxman Griffin aka MuthaF'er · « **Reply #4 on:** January 20, 2013, 01:48:20 PM »

Can't say for sure but many aftermarket big pistons can/did use stock Honda rings. Such as CB350/CB450/CB500 Twins or maybe the oversizes for those.

gschuld · « **Reply #5 on:** January 20, 2013, 02:43:32 PM »

I have heard about that. That would just be too convenient... So naturally, can't be possible

!

I just did some looking and found this:

CB500T The bore is: 70 mm CB450 The bore is: 70 mm
Last factory Over Size is: 1 mm over Last factory over size is: 1 mm over
The stroke is: 64.8mm The stroke is: 57.8mm

Sounds like the Honda factory had rings for 71mm cb450/500t pistons.

Interesting...

George

seanbarney41 · « **Reply #6 on:** January 20, 2013, 03:04:09 PM »

do you have any rings to measure?...the thickness is important too, and it may be tricky to accurately measure the grooves in the pistons. I know cb 350 twin rings are 1.5mm top, 1.5mm middle, 2.5mm bottom

754 · « **Reply #7 on:** January 20, 2013, 03:13:08 PM »

Keep in mind some of the honda rings are one piece oil rings and not chrome either..

gschuld · « **Reply #8 on:** January 20, 2013, 03:34:05 PM »

I don't have the pistons handy, but will measure the ring spacing tomorrow. Knowing that 1mm oversize (from 70mm) was a factory overbore for the cb450(around the same timespan as the beginning of the cb750's history is comforting. I presume the fact that RC's 70mm(970cc) pistons match the standard cb450 bore and the 71mm(1000cc) pistons match the largest factory overbore for the cb450 was more than a coincidence.

So is it reasonable to assume that RCs 1000cc 71mm pistons used the same rings as aftermarket high performance cb450 pistons back in the day?

George

seanbarney41 · « **Reply #9 on:** January 20, 2013, 03:45:17 PM »

that is good news, but not definative. You are gonna have to have those measurements and probably talk to your supplier/manufacturers tech departement. They don't always list all the necessary measurements in the catalog or online as they assume most are seeking an oem replacement or, at least, something more common.

Jerry Rxman Griffin aka MuthaF'er · « **Reply #10 on:** January 20, 2013, 03:50:54 PM »

George,

Exactly what I am talking about. Now we need someone that knows/has a 450/500. It's looking like CB450 uses 1.5mm, 1.5mm and 2.5mm rings perhaps. What are the meaurements on your piston lands?

I have my doubts about new Honda rings being 1 piece oil but I could be wrong. NOS rings might be found that are 1 piece.

City Boy · « **Reply #11 on:** January 20, 2013, 07:18:25 PM »

Hi gang.I can confirm that at least in my 1000 RC unit the piston rings were in fact genuine Honda 450 rings as supplied by RC with the pistons and bored and oringed cylinder. Rock On

754 · « **Reply #12 on:** January 20, 2013, 07:55:34 PM »

I bought new Honda rings, 836cc one piece oil ring, but I admit i may have ordered them in before some people reading this were born...back then my new Honda 750 oil pump was around 76.00
I know later cb 750. Had 3 pce oils, and that is probably all they sell, but for 350 (4th over 350 = 836cc), they may not have had 3 pce ever..anyone seen any ?

gschuld · « **Reply #13 on:** January 21, 2013, 04:35:56 AM »

Quote from: City Boy on January 20, 2013, 07:18:25 PM

Hi gang.I can confirm that at least in my 1000 RC unit the piston rings were in fact genuine Honda 450 rings as supplied by RC with the pistons and bored and oringed cylinder. Rock On

Interesting. Do you by chance know what pistons came with your RC 1000 stuff? Arias, Venolia, Alcoa blank MTCs? Perhaps the year RC sold them?

Thanks for sharing. I'm getting smarter all the time

. (need all the help I can get)

George

City Boy · « **Reply #14 on:** January 21, 2013, 05:43:46 AM »

Hey gschuld.No can do on helping identify pistons.As far as I can recall,the purchase was made in the 1975-1979 range. Rock On

Big Jay · « **Reply #15 on:** January 21, 2013, 09:07:48 AM »

If they are the thick rings they would be Honda CB450 ( i piece oil ring ) or CB500 twin ( 3 piece oil )

City Boy · « **Reply #16 on:** January 21, 2013, 01:52:29 PM »

Yes indeed.My 450 rings came with 1piece oil ring.

Bill/BentON Racing · « **Reply #17 on:** January 21, 2013, 05:19:09 PM »

Like these!

13011-292-000 would be stock,13031-292-000 would be .020 inch,.50 mm.

Another use for a RC 71 mm piston!!!!

Will take some pics of pistons...they're soaking,one or two still have the rings on them,so I can measure.Have old cylinder also.

Jerry Rxman Griffin aka MuthaF'er · « **Reply #18 on:** January 21, 2013, 05:32:12 PM »

Bill and his high compression toys!

Bill/BentON Racing · « **Reply #19 on:** January 22, 2013, 06:33:23 PM »

My RC 71 mm pistons, say RC underneath.They have 3 pc oil ring. Doesn't mean they came that way. My RC 71mm pistons Arias ground mostly out underneath,one pc oil ring.Will post some pics tomorrow.Will check out the 450 rings also.Bill
The RC pistons use buttons, the Arias ones, clips.

cbr954 · « **Reply #20 on:** January 22, 2013, 07:23:33 PM »

I have a set of RC 70mm Arias pistons that uses buttons. They have 3 piece oil ring. Total Seal quoted $143 to make a set of 4 rings.

gschuld · « **Reply #21 on:** January 24, 2013, 04:24:14 AM »

Quote from: cbr954 on January 22, 2013, 07:23:33 PM

I have a set of RC 70mm Arias pistons that uses buttons. They have 3 piece oil ring. Total Seal quoted $143 to make a set of 4 rings.

Thanks for the info. Several people have had god things to say about Total Seal making custom rings for them. Could you clarify, a set of 4 custom individual rings to compliment the 8 other rings that you already sourced, or a complete set of piston rings(12 rings). I presume that you sent your pistons to them for the job.

George

cbr954 · « **Reply #22 on:** January 24, 2013, 06:12:32 AM »

Complete set of rings. They had me measure my old rings. Measured the thickness and the radial thickness.

gschuld · « **Reply #23 on:** January 24, 2013, 01:55:31 PM »

Thanks. Good reference for a good option.

George

Red Good · « **Reply #24 on:** March 02, 2013, 09:30:02 PM »

Just ordered a couple of sets of rings for our 900's with Haindst markings from Total seal and they were very easy to deal with and the same price as 954 quoted and 2-3 week turn around , 3 piece oil ring too . Very happy . Red

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Author Topic: Sourcing new rings for 70's NOS Venolia 71mm pistons (Read 5248 times)