Topic: Fitting 3-Piece Oil Rings

[The Lone Builder]

I learned something today  ; well last night actually, but I put my new knowledge into practice today.

I'm posting it here because a search on what was wrong, or what I was doing wrong didn't reveal an answer. Every day is a school day they say!

Yesterday I tried to fit my newly arrived piston rings. My pleasure at being able to get on with things was short lived; the oil rings wouldn't fit into the lands - which were spotlessly clean.

My measurements did nothing to help, because the lands were wider than the assembled 3-piece ring. 

It was only when chatting to a much more knowledgeable mate in the bar, that I learned that the springy bit has a ridge on one side - see pic, meaning that if you put one of the thin rings in first, as I was doing, the spring won't fit past it.

The trick is to put the spring in first and then the two thin rings. I just tried this out and it worked a treat!

For the experts, this is probably nothing new, but for those of us striving to reach that elevated status ....

[newday777]

I saw that in a youtu.be video the other day. It's been 30+ years since I've been in a motor rebuild.

[Tracksnblades1]

I learned something today  ; well last night actually, but I put my new knowledge into practice today.

I'm posting it here because a search on what was wrong, or what I was doing wrong didn't reveal an answer. Every day is a school day they say!

Yesterday I tried to fit my newly arrived piston rings. My pleasure at being able to get on with things was short lived; the oil rings wouldn't fit into the lands - which were spotlessly clean.

My measurements did nothing to help, because the lands were wider than the assembled 3-piece ring. 

It was only when chatting to a much more knowledgeable mate in the bar, that I learned that the springy bit has a ridge on one side - see pic, meaning that if you put one of the thin rings in first, as I was doing, the spring won't fit past it.

The trick is to put the spring in first and then the two thin rings. I just tried this out and it worked a treat!

For the experts, this is probably nothing new, but for those of us striving to reach that elevated status ....

Pay your mate at the bar to supervise your engine build !!!

[MRieck]

Try fitting an XA oil ring The only thing more fun is fitting the pistons in the bore with the XA rings.

[PeWe]

Try fitting an XA oil ring The only thing more fun is fitting the pistons in the bore with the XA rings.

Order extra rings direct if pistons have XA rings!
Very, very thin oil rings.

I pinched one. Had to wait for new rings. Ordered 4 sets since shipping cost was high.

Good idea to file the inner corner  of those thin ring ends  round to not letting them hook into the expander.
Ring will then not compress completely. Cylinder enter and pinch the ring.

I will have good use of the new rings next time. I used only one oil ring (rail).
Those are now gas ported, one way to increase ring wear

XC rings much easier to handle.
Left XC rings, right XA.
XA rings are all thinner.



If order pistons from a seller that can provide extra rings, order a set to at least one piston.

Dynoman's tech pages have good info for pistons and ring orientations.

Wiseco's description with rings is tricky.

[HondaMan]

Try fitting an XA oil ring The only thing more fun is fitting the pistons in the bore with the XA rings.

Oh, man...I'd forgotten all about those nightmares...
I have a set of 750 pistons, 1st oversize, with those rings. There's a reason they have been sitting on my shelf for almost 10 years, now.

[Tracksnblades1]

Try fitting an XA oil ring The only thing more fun is fitting the pistons in the bore with the XA rings.

Order extra rings direct if pistons have XA rings!
Very, very thin oil rings.

I pinched one. Had to wait for new rings. Ordered 4 sets since shipping cost was high.

Good idea to file the inner corner  of those thin ring ends  round to not letting them hook into the expander.
Ring will then not compress completely. Cylinder enter and pinch the ring.

I will have good use of the new rings next time. I used only one oil ring (rail).
Those are now gas ported, one way to increase ring wear

XC rings much easier to handle.
Left XC rings, right XA.
XA rings are all thinner.



If order pistons from a seller that can provide extra rings, order a set to at least one piston.

Dynoman's tech pages have good info for pistons and ring orientations.

Wiseco's description with rings is tricky.

Which oil ring type do you feel is more effective at oil control..?   ie less oil consumption….🤔

[MRieck]

All IC engines use really thin rings now secondary to frictional losses. Personally I'd say the XC ring pack is better at everything EXCEPT friction. One of the big things is to keep that skirt to wall as tight as possible to prevent piston rock....that will keep compression and oil retention at reasonable levels. At least we are dealing with verticals bores....think about a Subaru etc with horizontal bores and light oil weights.

[Tracksnblades1]

All IC engines use really thin rings now secondary to frictional losses. Personally I'd say the XC ring pack is better at everything EXCEPT friction. One of the big things is to keep that skirt to wall as tight as possible to prevent piston rock....that will keep compression and oil retention at reasonable levels. At least we are dealing with verticals bores....think about a Subaru etc with horizontal bores and light oil weights.

No need to convince me. There doesn’t look like enough space between the rails or enough drain back holes of any size  prevent the oil ring pack from skating. Looks like it would cause the second ring to be real busy on the way down..I always used standard tension oil rings in performance V8s.. I would rather change the oil all at once, instead of a quart at a time.. Thanks for the comparison PEWE..

[PeWe]

About the pistons above.
New 70mm vs used 71.25mm.

** The oil stained piston got oil from above, not via oil rings. **

It was a period of oil leaking heads. First one, head with bronze guides with a short life.

Flexy 5mm stems worn the guides from top to bottom.

Next a ported 392 head with K valves, the thinner part of stem for keepers very tall as they are.
Higher lifting cam made the thinner area of stem to pass thru the guide seal making an oil pump, in valve. Guides machined and sunken deeper for ca 11mm lifting cam

Both heads are restored. 392 head now with the 970cc. The 5mm stemmed head got CycleX iron guides and 34/28mm K valves.

[Tracksnblades1]

About the pistons above.
New 70mm vs used 71.25mm.

** The oil stained piston got oil from above, not via oil rings. **

It was a period of oil leaking heads. First one, head with bronze guides with a short life.

Flexy 5mm stems worn the guides from top to bottom.

Next a ported 392 head with K valves, the thinner part of stem for keepers very tall as they are.
Higher lifting cam made the thinner area of stem to pass thru the guide seal making an oil pump, in valve. Guides machined and sunken deeper for ca 11mm lifting cam

Both heads are restored. 392 head now with the 970cc. The 5mm stemmed head got CycleX iron guides and 34/28mm K valves.

I understand..

 Does your picture  show the 71.25mm pistons ring land oil residue stains washed clean between the the 2nd and 3rd ring, thrust side 90* to pin…?        Or is that just the light or flash washing out the stain…?

It’s good to know you don’t contribute the oil consumption with the XA ring pack… I have a set of (old design) 71.25mm wiseco with the same XA ring packages…

However I’m now more concerned about the cylinder head I was planning on running..
It’s a jmr stage 4 sporting kibble whites Oversized k valves, bronze guides, springs, retainers, caps….?…?

Now I see Kenny is promoting 5mm stems after a bulk purchase or buy out of the same valve kits….but I’ve also previously read somewhere that the cast iron guides were the recommended choice along with the standard valve stem size for OEM length lifespans… Indicating the 5mm stem flexed too much with heavy springs in combination with aggressive camshaft profiles..

May need to rethink….

What does PEWE believe caused or contributed to the bronze guide short lifespan…?
Does your 392 cast iron guide head run the same camshaft and springs combination as the bronze guide counterpart..?
How many miles have you logged on your 392 cast iron guide 5mm valves…?    (as for a comparison)
Was your 5mm valve stem height adjusted prior to lash cap usage..?

Thanks in advance…

Edit::

Did you by chance dykem the top of a lash cap to see where the adjuster tip’s sweep was,  in relation to the valve stem centerline…?     

[Tracksnblades1]

All IC engines use really thin rings now secondary to frictional losses. Personally I'd say the XC ring pack is better at everything EXCEPT friction. One of the big things is to keep that skirt to wall as tight as possible to prevent piston rock....that will keep compression and oil retention at reasonable levels. At least we are dealing with verticals bores....think about a Subaru etc with horizontal bores and light oil weights.

Indeed.
We ride two stroke dirt bikes with my son’s friends who except one rides 4strokes. Mostly all Hondas CRF 450s but there is an occasional crf250 that rides along..

I notice during breaks they’re always checking their oil. Obviously for a reason. They don’t normally hold much oil either and require very frequent oil changes.  My son and his friend has rebuilt several smoking 450s circumventing the dreaded grenading that usually only leaves a usable aluminum roller for a cr500 conversion..😇

I noticed the same XA ring size in the CRF and CBRs and heard the complaints of them being oil burners if ridden in an aggressive way…I really like the piston design in the CBRs and CFR’s. Considering most of them have an oil jet cooled piston to boot, perhaps the XA would better be up to the task in a sling oil only application…

I’ve talked to wiseco in the past. They’ll literally make what ever you want..  Oil consumption in air cooled higher compression engines is just another level of bad. Perhaps the XC would perform better with the air cooled oil viscosities required…

Yea, when you mentioned Subaru flat pancakes, I was thinking inverted v12  RollsRoyces 😁

[88BuckMeister]

I just got done installing the Dynoman 61mm kit in my 550. That was a double treat each time we bent the oil control rings and scratched the cylinders

[PeWe]

About the pistons above.
New 70mm vs used 71.25mm.

** The oil stained piston got oil from above, not via oil rings. **

It was a period of oil leaking heads. First one, head with bronze guides with a short life.

Flexy 5mm stems worn the guides from top to bottom.

Next a ported 392 head with K valves, the thinner part of stem for keepers very tall as they are.
Higher lifting cam made the thinner area of stem to pass thru the guide seal making an oil pump, in valve. Guides machined and sunken deeper for ca 11mm lifting cam

Both heads are restored. 392 head now with the 970cc. The 5mm stemmed head got CycleX iron guides and 34/28mm K valves.

I understand..

 Does your picture  show the 71.25mm pistons ring land oil residue stains washed clean between the the 2nd and 3rd ring, thrust side 90* to pin…?        Or is that just the light or flash washing out the stain…?

It’s good to know you don’t contribute the oil consumption with the XA ring pack… I have a set of (old design) 71.25mm wiseco with the same XA ring packages…

However I’m now more concerned about the cylinder head I was planning on running..
It’s a jmr stage 4 sporting kibble whites Oversized k valves, bronze guides, springs, retainers, caps….?…?

Now I see Kenny is promoting 5mm stems after a bulk purchase or buy out of the same valve kits….but I’ve also previously read somewhere that the cast iron guides were the recommended choice along with the standard valve stem size for OEM length lifespans… Indicating the 5mm stem flexed too much with heavy springs in combination with aggressive camshaft profiles..

May need to rethink….

What does PEWE believe caused or contributed to the bronze guide short lifespan…?
Does your 392 cast iron guide head run the same camshaft and springs combination as the bronze guide counterpart..?
How many miles have you logged on your 392 cast iron guide 5mm valves…?    (as for a comparison)
Was your 5mm valve stem height adjusted prior to lash cap usage..?

Thanks in advance…

Edit::

Did you by chance dykem the top of a lash cap to see where the adjuster tip’s sweep was,  in relation to the valve stem centerline…?   

Hi,
Here a photo of the head  (300 head) upper part during removal.
Guides bad after around 20.000 street km.
-  DP315 cam mostly, not high lift in the reality. 0.368" lift, subtracting the 0.012 lash making it rather tame.
- RC295 profile with 0.395" lift, 0.004" lash.
I guess 75/25 mix of cams.


And lash caps, today in the bags of the leftovers except guides. New guides and ready to be reused.

The lash caps looked OK. No dimples felt by nail.

Valves assembled at my local shop where the spring pressure was measured.
Shim by Kibblewhite recommended pressure. Not much found, only 4 silver colored ca 1mm thick.
Might have been on In or Ex side.
Very light valves need less spring pressure.

That 300 head has now CycleX iron guides and SS valves. They got a temporar batch. Still available, scroll down to SS valves. Only $25US each. (Iron guides for high lift, springs and TI retainers to be added.)
http://www.cyclexchange.net/Engine%20Parts%20Valve%20Trane.htm


Good idea to purchase as plan B. Where to find other 34mm K valves?
F2 IN is possible but slightly shorter.

The later 392 head got stock guides, shortened and reshaped when sunken deeper.
33.5/28.5mm Kibblewhite valves.





Photo of piston today. The dirty sides could also have been affected by rich jetted carbs. Too rich needles. Tried to change all other jets. Always way too rich and lean somewhere.

I used the 970cc setup while finding correct carb setup to not torture the billet block too much.

Found correct needles.
The 970cc setup runs too good to be changed, not even adjust the cam.

I must let it run on the same Dyno to see what not rich needles can provide.