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ReedS

Chrome or not

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ReedS
I recently aquired a 3410 with an overhauled eng that smoked tons. Having some time this week I diassembled the eng to find these. [img]/club2/attach/reeds/dscn0683a.jpg[/img] If I'm not mistaken those are chrome rings and if I'm not mistaken I heard that they sometimes don't seat well? Here a pic of that piston next to what looks like to are iron rings on a model 19 piston. The 10hp piston is on the left and the 7hp is on the right. [img]/club2/attach/reeds/dscn0685a.jpg[/img] While the bore doesn't measure too too bad my guess is that it should honed out to a .010 over std (it measures to std size now). [img]/club2/attach/reeds/dscn0686a.jpg[/img] I guess my questions now are 1) Am I correct in the assumption that the rings on the 10hp are indeed chrome rings? (I haven't until now seen chrome rings before) 2) Is it true that the chrome rings don't always seat well? 3) The best repair here would be to hone the cyl .010 over size install a new piston w/standard iron rings. This may have discussed here at one time or another but I can't remember the answers at this momement. Thanks

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HubbardRA
If the bore measures STD and is not scored, then don't bore it. Just put in standard "Non-chrome" rings. I have two running right now that I did that way, and neither one of them smoke. All you need to do is break the glaze on the sylinder. Use a ball type glaze breaker, hit it a couple of strokes with a hone, or just scuff it up good with sandpaper. If you use sandpaper, make sure your strokes are around the cylinder, not up and down. You don't want to produce any grooves that can start a blow-by path.

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powerking_one
Reed, I would get the cylinder mic'd for taper, out-of-round, and wear. If the bore is true but just worn a little(say up to +0.003" from nominal) then Rod is correct in just re-ringing it and breaking the glaze. I would venture to say that the bore is out of round and/or tapered and is the major contributor to excessive oil blowby. If the cylinder dimensions check out as STD, then I usually buy 0.010" OS rings and file the end(s) a little to make the minimum gap spec. Personally, I like chrome rings better and they wear longer. If you do need to OS the bore, having it bored as opposed to honing it oversize is always preferred. Boring restores dimensional trueness whereas honing just follows the wall contours/distortions. Tom(PK)

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HubbardRA
Tom, From my experience, when I see a beautiful cylinder with no ring groove, the blow-by is usually due to overheating the engine and the rings losing their tension. What you do with the .010 oversize rings will provide additional force between the ring and cylinder beyond stock size ring tension. I'm not sure I would do this on a STD size cylinder, but it is good on one that is .003 to .005 oversize but still smooth and round. Don't see many like that.

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Salthart
I can't tell from your pics as to what those rings are but from the looks of them I'd say have the bore checked by a machine shop. The Chrome rings are harder and take longer to seat but once seated they wear longer ( They are also harder on the bore ) A worn bore needs chrome rings as they take up the slack somewhat ( Up to 10 thousanths I was told in Briggs School ) But if you bore, I would go back with non-chrome rings. Good luck

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powerking_one
"Seeing" a beautiful" looking cylinder is not assurance that it is non-tapered or out of round. Oversizing the rings by +0.010" from nominal has little/nil effective more ring tension than those spec'd for the bore size. Getting the intitial ring gap closest to minimum spec will ensure a lower amount of "normal" oil consumpion and give the highest compression with lowest blowby. The worst offenders of excessive oil consumption are due to the above stated cylinder distortions (with new rings) and very worn rings having huge gaps. Usually empirically opinionated, Tom(PK)

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ReedS
I know that photo's can be a bit deceiving esp when a flash is involved. My take on this eng is that someone tried the quickie rebuild trick (chrome rings) with this eng, how long ago this was done I'm not sure (I was told that the tractor had spent 5 yrs sitting). While the bore is not terribly out of round there is definetly some wear in the center of the bore as well as there a couple of scores that don't show well in the pic. As to new rings afterward I had already planned on using standard rings as what I've seen with (what I think are chrome rings) didn't impress me. I guess I will finish stripping the block and have some machine work done. Thanks guys:)

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ehertzfeld
I just put rings in my 9hp in my LL. All I did was change the rings. I didnt remove any glaze, hone,sand or anything. Just poped it out replaced the rings and poped it back in. I did lap the valves how ever. Oh the reason I did replace the valves, was because of oil blow by. Over the winter I whent thur lots of oil blowing my drive. With the new rings.....no smoke!!! Im sure it would be better to do all mentioned above, but to someone who is a beginer, what I did works. Elon

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