OMC power head swaps (interchangeability of years?)

[shoestringmariner]

Hey everyone, because some of the internals interchange, I’m wondering about the interchangeability of power heads between years and also between Evinrude and Johnson in the 50’s and 60’s?

The reason I’m asking is that I have three QD’s (54, 57 and 58). The 58 is a runner, but the 54 a and 57 are rough. I’d like to get one up and running so I can restore the 58 properly. So basically, is there a number of years that cross over, or do I need to be looking for exact production years? Are Evinrude power-heads identical?

Thanks
Scott

[frankr]

Evinrude didn’t have a 10hp in 1954. But the ’57 and ’58 E/J’s are identical—almost. Small differences to accommodate the different hoods.

[fleetwin]

Well, seems like your 58 is in good shape, so it does not need parts and you don’t want to use it as a donor….
The 54 and 57 QDs are not very similar. Different gearcase, different midsection, different flywheel and recoil. I don’t know if the basic powerheads are interchangeable, might have different driveshaft spline patterns…
So, it does not seem like the two engines that need work have many interchangeable parts…

[shoestringmariner]

Thanks guys.

@fleetwin, I am leaving the 58 alone until I do a full restoration.

I’d like to get the 57 up and running as it is leap years better shape than the 54. I am just wondering though in my search for parts motors, if any years overlap. Ie; Do 53’s interchange with 54’s, or do 56’s interchange with the 57’s etc. Based on what comes along, I’d like to scoop up motors that can donate to either the 54 or 57 (prefer the latter, and it sounds as if the 58’s are a good donor in that case if I can find another)

[1946zephyr]

I would do a full restoration on the 57. Those were actually the best years (55 – 57) for the 10hp. The 5 bolt lower unit held up a lot better, than any other lower unit, on a 10hp. The 58 is a smaller lower unit and the motors weigh a tiny bit less, but those lower units don’t handle "neglect" very well and water intrusion will quickly roast them out. The 54 qd has the same quality lower unit as the 5 bolt, but it is only a 4 bolt and I believe certain parts may not be quite as tough as the 5 bolt. That 5 bolt lower unit was used all the way up to 1973, on motors up to 25hp, so under a 10hp powerhead it wil hold up that much better.

And yes, 51 – 54 are interchangeable
55 – 57 are interchangeable

[shoestringmariner]

Wonderful, thanks.
I really like the paint schemes on both the 57 and 58, with the red and white, and vice versa. I will be doing both eventually and hopefully the 54 also because I’d like to have some greenies too

[outbdnut2]

QDs had a couple of piston rod upgrades in the 1950s to make them more robust, but I doubt that affects powerhead interchangeability.
Dave

[wedgie]

Best place to start when determining interchangeability of powerheads is to compare base gaskets. Same base gasket ,it should be ok ! That doesn’t mean the cowl mount bosses, starter bracket mounts etc wont be different though

[Steve D]

I was thinking the same thing Wedgie when it comes to the 53 to 54 years. Same base gaskets but different in the other respects as you mentioned.

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