1957 35 Hp Ring Gap

Hi,I have just honed the cylinders on a 1957 35 HP Big Twin and I am left with a problem.My ring gap is .023" which is about .006" over spec(.007"-.017").What to do?Here are my options as I see them,I would appreciate any comments on one or all of them.<br />1.Over Bore and purchase .020 over Pistons and rings.(Pricey but best option)Cost is more than motor is worth.<br />2.Purchase .020 rings and fit to standard piston.<br />I know... not supposed to file ring ends,but I hear it is done and works.May require a little more honing?<br />3.Use standard pistons and rings (which I have)<br /> and hope for the best. <br /><br />Any advice is appreciated,Thanks Jim

Re: 1957 35 Hp Ring Gap

Personally, I would run the standard rings. Since you've got three rings per piston, you're not going to be loosing a lot of compression through the ends.<br />I take it these are new rings right?<br />Finding 0.020 over pistons is going to be difficult. Finding 0.020 rings is not going to be much better.<br />Putting a .020 ring in a standard bore hole would be a bad idea, because the rings are sliced out of a .020 over cast iron 'pipe', broken, opened and heat-treated. So if you filed them to fit, they wouldn't press evenly against a round bore.<br />A better idea would be to have a custom set made by Otto works.<br /><br />How bad is your piston skirt end to bore clearance?<br />How bad are the cylinder walls?<br /><br />Did you hone excessively?<br />Did you square the ring in the bore with the end of a piston before you measured it?

Re: 1957 35 Hp Ring Gap

Hi,The pistons are in excellent condition and the rings are brand new.I honed enough to remove <br />the scoring from the walls,the cylinders were pretty badly scored.It is amazing how much more scoring was evident after breaking the glaze.I didn't check the clearance on the piston yet.I measured around and got a 3.067" bore 3.0625 is spec.So I'd say clearance on the piston will be on the high side also.I used a piston to square ring in the bore.<br /><br />I just checked out OTTO and this may be the way to go...if the price is within reason ($20.00 +/- per hole)Hmm maybe $20.00 per ring Wow.<br />I think I'll be ok with standard set.Otto says up to .008 per 1" of bore is acceptable.So that would be .024" I'll do some more in depth measuring tommarow.Thanks

Re: 1957 35 Hp Ring Gap

I've never delt with them. I was considering it until I found a NOS set for my big twin (28hp). I had found a set still in production made by Hastings that would work, but they wanted $160 a set for them. <br />You would have to machine them for the locating pin and such. Something makes me think they do 4-strokes there. <br /><br />If I were you, and the piston-bore clearance wasn't way out, I'd probably just run the rings you've got. If you were unhappy with the compression after breakin, you could then get the rings, get them all machined, and ready while still running the outboard.

Re: 1957 35 Hp Ring Gap

I guess i'll give it a try especially because I got the rings for $3.00 per set from e-bay .I bought all 6 sets the guy had NOS.Thanks