Filing down .030 piston rings to stock size?

[ultra353]

Hello all, Can this be done with relative ease with a file or not worth the effort and just get the new set of std. rings ? A new stock set of rings is $45-50 where .030 oversize is $15, I`m a tight budget right now( divorce) and was just thinking of saving some $$$. Its for a `75 evinrude 25 hp
On the crank seals do they go on the crank then put the case together or case together then put seals in? and do I use any sealant on the seals? Thanks!

 

[nwcove]

Re: Filing down .030 piston rings to stock size?

get the proper size rings for the bore.

 

[boobie]

Re: Filing down .030 piston rings to stock size?

The last time I heard of filing rings was for an inboard during world war II 'cause the proper ones weren't available.

 

[HighTrim]

Re: Filing down .030 piston rings to stock size?

I don't think it is even possible for that ring, say you were spiderman and able to keep is even. The whole ring spec is different. End gap, ID, etc...

 

[V153]

Re: Filing down .030 piston rings to stock size?

I say go for it! Prove the naysayers wrong! Hee hee hoo hoo ha ha ha, gasp, thud ...

 

[nwcove]

Re: Filing down .030 piston rings to stock size?

I don't think it is even possible for that ring, say you were spiderman and able to keep is even. The whole ring spec is different. End gap, ID, etc...

awe, c'mon Chris! anyone good with an oxy/acet torch could trim those rings up to fit in just a few minutes!

 

[racerone]

Re: Filing down .030 piston rings to stock size?

What is wrong with the old rings ?-------Going with filing down the O/S rings will require removing quite a bit (~ 0.085" ) of material.-It will require work to make sure there is clearance for the wee pin that keeps rings from rotating. Can it be done --sure.--Is it recommended , don't think so.

 

[F_R]

Re: Filing down .030 piston rings to stock size?

You might could get away with filing .010 to std, but .030 is a lot. I wouldn't risk it.

Top seal goes in the bearing before putting the bearing on the crank. Bottom seal assembly goes on after the crank is installed and case buttoned up. You can smear some sealant around the outside diameter of the top one if you want. Just oil on the inside. No sealant except oil on the bottom..

 

[raczekp1]

Re: Filing down .030 piston rings to stock size?

i did this few times.
in my area its difficult to get OEM parts.
I ordered rings in factory(send them old rings for measure)
i got new sets, but had to file ring end gap for right size.
in 9.9/15 ring end gap works fine with ring end gap 0.25mm
i installed file vertically in latch and slowly holding ring in both hands just file them making up and down movement

 

[ultra353]

Re: Filing down .030 piston rings to stock size?

Thank you all, I guess it was an idea I had for trying to same some $$$. I`ll just save up for the standard set.
It had a blown head gasket and water had sat in one cyl for a while and had a small amount of rust. So I tore it down to make sure there was no rust damage to crankshaft/bearings. A light honeing and everything looks good.
Thanks F-R for seal info

 

[nwcove]

Re: Filing down .030 piston rings to stock size?

jmho. but i think that ^ is your best option. sometimes trying to save a buck will cost you two.

 

[cchildr84]

Re: Filing down .030 piston rings to stock size?

I can't speak to filing the rings, but I recenlty rebuilt an 81 25hp and the crank seals go on the crank first and then the crank case cover. I just put some permatex high tack sealant around them and once the everything was put back together tapped all the way around the seals to make sure they were flush.

 

[rolmops]

Re: Filing down .030 piston rings to stock size?

sorry

 

[Bosunsmate]

Re: Filing down .030 piston rings to stock size?

I put the seals in first, maybe im doing that wrong but i figure it is much more kinder on them than trying to push them in when its torqued down. I use permatex aviation form a gasket on the outside of them and I put a bit of two stroke oil on the crank as i slide them on, so they dont burn up on motor initial start up after rebuild too. Make sure you get the seal lips the right way round.

Interesting you considered filing them, id imagine that you must have some rather interesting other ways of cash saving too