Machining piston ring groves

[328FTW]

In my on and off search to actually fix my bike I'm having difficulty locating a 0.8mm 60mm ring for the VT250. 1mm would be fine but 0.8 is lame.

So some of the more tech savvy people here, what about switching to a 1mm ring? The piston would need machining sure but I could get perfect like new ring to piston groove clearance and could go to gapless total seal rings for my top compression rings which would be neat. Only drawback I can see is possibly increased drag on the cylinder walls. As long as I don't machine down the centre ringland don't see it taking away the strength of the piston. Or is there more to it than what I'm thinking?


I'm getting so desperate to put the bitch back on the road I've got the old motor with snapped exhaust cam and I might put an intake cam (all I have) reclocked for correct timing in an old POS head found in the scrap pile to get it running enough to ride. Yes I'm serious But doing my other motor properly would be ideal.

[Grumph]

I do quite a lot of older Jap classics for which rings may not be available - or may be too expensive for the owners.
Here in ChCh there's a very good automotive parts outfit . Cliff Bond Ltd - who can supply aftermarket rings at very good prices.
Frequently OE will be say, 1.0, 1.25 and 2.5mm wide and I can get 1.25,1.5 and 3.0 widths - set up and machine, gap rings and install...
I'm sure there's an equivalent company in the Auck area.

I've never had a comeback on any of the replacement sets I've used - or broken ring lands.

[Motu]

Johnson's wouldn't do under an 1/8'' back in the day, I don't know if they got over that hurdle. I see they are part of Franklin Engineering now.

http://www.franklinengineering.co.nz/johnsons.php

[carburator]

seriously over thinking the issue of lands and drag

there are no COMPEDANT machineshops ( general engineers in pukekohe )
fine for tractors and thats really about it.. bitchy maybe but after you have sent the
same job to three different firms only to have them !@#$ it up each time you really
got to wounder

A. what the !@#$ are your staff smoking
B. What? you are chargeing me twice for your !@#$ up!
C. You can't read a drawing and seriously can't read a digital vernier...

FES would be a good port of call, for getting the work done and possibly supplying the rings.
I have used them a couple of times for clients motors due to being bigger than I can do..

[328FTW]

Johnsons don't do 0.8mm, too thin; I asked. They also only do cast rings which I'd be dubious of at about 14,000 rpm. I feel that a thin cast ring even with the short stroke would be accelerating hard enough to break it. I'd really like steel on a motor like this.

STA parts are actually a total seal stockiest. An FZR600 1mm oversize set is actually right I think. The code I found was for a 2.362 bore (60mm) with sizes .8 .8 1.5. Gapless top is M2362XA, gapless second T2362XA and conventional 2362XA. Might give them a ring tomorrow to see what they stock or can supply. My cousin works there so he can sort damn near anything for me


This isn't a particularly hard problem, I can 100% get rings but I'm just not keen on paying the loony prices I've seen on some of the NOS I've found if I can have a more solid product for less.

[Brian d marge]

With that sort of gap you will have ,no problems , ring weight shows itself at higher rpm , inertially and only will let more usually unburnt carbons through which will kill the rain forest.
Back in the day one used to file ring and lands to all sorts of shapes .
I have the calcs for minimum land depth if you need but to be honest its not a big job ,

Stephen

[spanner spinner]

Have you got a good parts guy at your local honda dealer? There will be another honda in the range that has the same rings, just a matter of if your local parts guy knows what will fit. If not give econohonda a email they can usually help with this sort of stuff or worst off supply you with a full ring set.

[ducatilover]

Getting rings that size should be easy enough, heaps of shit out there running a 60mm piston.

[RoscoP]

[QUOTE=carburator;1130493937]seriously over thinking the issue of lands and drag

there are no COMPEDANT machineshops ( general engineers in pukekohe )


there is a guy near Pukekohe (Doug Smith) used to own a big engineering place, now has an awesome workshop on his farm and does lots of M/C engine rebuilding and he is really good.

PM me if you want his contact details. I was there watching him rebuild a KTM head the other day, he was awesome and didn't charge the owner very much

[manxkiwi]

C. You can't read a drawing and seriously can't read a digital vernier...
..

I'd be checking the groove width with slips. Verniers aren't that accurate below .05mm, not for a high tolerance job anyway.

Not sure if Gouden Gizler in Tuakau does machining? Or maybe has a contact he uses for machining?

Good luck.

[ducatilover]

Jeez, just chuck it on a drill and get the wife's nail file on it