Embarrassing Mistake

[stanley]

I admit I put new rings in a RD14 without checking their end gap.It wasn’t until I had the motor fully reassembled that it hit me that I had gotten ahead of myself and skipped that step.Is there any remedy/check I can do and avoid tearing it down for a redo?

[jeff-register]

Had a 1951 Dodge car with a flathead 6 in it. My neighbor “rebuilt” it with rod bearings, valve job & new rings. It was so tight we had to pull it backwards to get enough traction to get it to turn over & finally it locked up & was junk. He too didn’t check ring clearances or taper. Swapped it out for a Chevy 327.
If it was me I would check ring clearances @ the top & bottom of the cylinder. You will end up taking it apart anyway. Sorry!!

• This reply was modified 4 years, 7 months ago by jeff-register.

[Mumbles]

Checking the end gap is the first thing done when rebuilding a motor.

Unless the motor was bored out, chances are the sixty seven years of wear on the cylinders will allow new rings to be installed as is. I’ve never had to set the end gap yet when using original OMC/BRP rings but I do have to when using aftermarket rings such as NOS Perfect Circle brand.

If it was mine, I’d play it safe and tear it down again to be sure and laugh it off as a learning experience. I have enough trouble sleeping at night and having something like this on my mind wouldn’t help any.

[Bob Wight]

Been there, done that. On my current 57 Fastwin restoration, I was just getting ready to put the final torque on the rod bolts when I remembered I had not checked the ring end gap. Pulled it back apart and found the end gap on the NOS rings (OMC) to be at .006 which I found surprising, being just under the minimum spec of .007. I would also play it safe and open it up again just to be sure.

Bob

1937 Champion D2C Deluxe Lite Twin
1954 Johnson CD-11
1955 Johnson QD-16
1957 Evinrude Fastwin 18
1958 Johnson QD-19
1958 Johnson FD-12
1959 Johnson QD-20

“Every 20 minute job is only a broken bolt away from a 3-day project.”
"Every time you remove a broken or seized bolt an angel gets his wings."

[frankr]

Ah yes, that feeling of panic, when the thought comes to mind. Did I torque those rod bolts? Then tear it all back down to find that it was OK. Been there and done that or something similar too many times.

But think about it. I have never found a set of OEM rings to be too tight in the standard bore they were intended for. And it would be impossible to get oversize rings into a standard bore. So, what could be the worst that could happen? Yeah, they might have too much end gap due to a worn bore. It might wind up with some compression loss, but it isn’t going to blow up.

In this case, I’d probably assume it is ok unless proven otherwise.

[need2fish]

My first rebuild was an RD-15. New rings. Didn’t check the gaps, even though I took 3 yrs of automotive shop in high school.Motor ran great until it was completely warmed up, then the rings would bind in the bore and the motor would run slower and slower. Haul it off the boat, up 10 stairs and half a football field lugging the beast to my dad’s shop.Tore it down and took all off 15 minutes with a file to size the gaps. Back across the half football field, down the stairs and back on the transom. All that effort for forgetting to gap the rings.

[labrador-guy]

I too have been in that situation. Over the years I have learned to check that end gap. The latest problem was a mercury m55. The rings came to me with .005 end gap. I check around and some people told me that was OK, WRONG! I settled for .010/.012. Sure glad I did! Another time I purchased some rings and they did not have the cutout for the positioning pins. It was tricky to file those notches but they worked just fine. If the end gaps are to small you will have a bugger of a time getting the piston back in the bore.

dale

get’em wet don’t let’em set

[Tubs]

A "Boathouse Repair" is one that done without having tools or the skills to do it properly.

[fleetwin]

Been here, forgotten to do that, don’t feel too bad….
Did you rebore the cylinder? I’m assuming you did not, and you used standard rings… Tubs picture seems a little strange, can’t imagine ring end gaps being lined up in the ports….This surely is not the case on your engine.
What to do, what to do….You could pull the intake covers and probe each ring to see if it has some give to it…Like I say, I’m thinking you are OK provided you didn’t bore the cylinders and are using standard rings. I don’t think you could jam over size rings into a standard piston/cylinder without breaking or jamming the thing up.
Judgement call for sure…

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