Over sized rings on stock pistons- cylinders?

I'm working on a 1953 Ferguson TO-30. When I got the block back from the machine shop he said it all looked good. I have a 3 7/8 bore and I need three rings that are 3/32 and one 3/16. Based on what I have looked at that means I need oversized rings am I going to be ok running them on the stock pistons in the stock bores? Sorry might be a dumb question but I'm 16 this is my first motor rebuild and I'm confused thanks.
 
3/32 and 1/4 is the width of the rings in inches.
3 7/8 bore is nothing I ever heard of in the TO30 Z129 engine.
Probably 3 3/8" bore but check.
 
Is it possible that the bores are warn to that size? And will I be ok to put the oversized rings on the stock pistons?
 
not likely. if you think you need over size rings the engine will require a lot more work. you need to measure the bore and see how much taper wear you have. plus you need to make sure the ring grooves on the piston are not worn. the rings need .003-.004 clearance for every in. of bore. so you need about .012 ring end clearance for that bore. then when you factor in the wear you will have more clearance yet. put the new ring into the top of bore where the ring wear in cyl. is and measure the end clearance. do the same at the bottom of cyl. you will have less at bottom always, as less wear at bottom. you can not put oversize rings in a standard bore, as they might fit at the top but at the bottom they will bind up . they need a clearance for expansion when running at operating temp.
why are you thinking you need oversize rings?
 
Because I bought std. bore rings I have them all installed etc. and I realized I never measured the ring end gap so I took an extra ring and measured it and I can fit bigger than a .017 feeler in the ring gap. So I'm lost do I finish putting the tractor together and see what happens or do I take it back apart? Thanks
 
took an extra ring? you need to use a new ring. that .017 gap would be normal because you have cyl. wear. new rings are usually close in end gap measurements. when installed in a new bore with no wear. nothing you can do unless your bores are new. also need to measure the gap between the ring lands on piston. should be around .0015 , if you can fit say a .005 feeler guage between ring and piston groove the pistons are worn and should be replaced. if you have .017 end clearance with a used bore and new rings you just have to live with that. or spend more money but you need to take into consideration what you are using the tractor for.
 
well what is the gap? need exact measurements.
are the bores original size? or has it been bored out? I am not familiar with the to-30 engine just giving you advise on an engine rebuild. an engine is an engine and there is spec's to follow. put a new ring in the bottom of bore and measure the gap. I am not getting enough info here. what has the machine shop done to the block. just honed it or bored it?
 
ok, I see. might be measuring the bore with a tape measure also. if it was bored 10-20 thou. never know the diff.
 
knurled pistons have nothing to do with rings. all knurling does is make the skirts bigger to allow for skirt wear and piston slap.
 
What you might need is 'service rings' that are slightly thicker than stock OEM- they are designed with the assumption that the bore has worn .005 but not over .010 requiring a over sized piston and bore job. thickness is also in width to take up slight oversize groove width in somewhat worn stock piston. Some service ring kits have a notched top compression ring assuming no ridge ream to be done. Shafty club had a old R60 quick fix to get on road for May Day rally that used .020 over rings and ground down end gaps to fit with about .010 clearance in stock pistons- it ran rest of season with a bit of rattle and smoke cold but kept up with traffic. SO, measure carefully, see if sizable service rings are available or just use 40 weight oil with your .017 gap rings for light duties if cost is a problem. Wide gap but otherwise new rings usually a lot better than old worn down rings that by that time have end gap about twice what it started with. Tapered cylinders still acceptable a top can be honed extra pass on bottom to remove slight taper- common procedure when boring bar not called for- ridge ream only- on top end first ring jobs. Knurling skirts takes care of .010 over bottom slop for a long while on most long skirt pistons- small block Chevy pistons with cutout get some short term help but only enough for short race or very light duty. RN.
 
Cole, orignal TO 30 is 3-1/4" bore wet sleeve engine,the sleeve assemblies have most likely has been replaced with what they call oversize 3-3/8" assemblies. Most aftermarket ones will have wider ring groves than the standard TO 30 ring groves. The sleeve could not be bored out enough to be 3-7/8". Email should be open
 
I think were gonna go ahead and finish putting it together and
see what happens. If it does not work out and I need new
sleeves is there anyway to get them out with the motor still
bolted on the back half with the crankshaft still in? Thanks
 
(quoted from post at 17:53:59 01/31/15) I think were gonna go ahead and finish putting it together and
see what happens. If it does not work out and I need new
sleeves is there anyway to get them out with the motor still
bolted on the back half with the crankshaft still in? Thanks
can tell you up front it isn't going to work properly. You can't use oversize rings on a standard bore piston. Since stock bore is 3-1/4 and you say yours is 3-7/8 then there is something mismatched or non standard to begin with. Just throwing something together and hoping it works can be expensive and cause non-repairable damage. You need to have definite answers on what size the pistons and bores are before you go any farther.
As for the last question, it should be possible to to remove Pistons and even the cylinders with the motor still bolted up and the crank still installed. You would probably have to do it one at a time though. Never actually done it personally though. If you go to that much trouble might as well buy cylinders, pistons and rings and just swap everything out if your crank and rods are good.
 
I decided to replace them I got all new sleeves-pistons. Another question the pistons on the tractor now say M&W add power are those stock pistons?
 

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