Test Results

[brian]

After all the testing, tweaking, and fiddling around with these three motors here are the results of running them on the same boat rated for 16 hp, load, lake and similar weather conditions. Scott Atwater literature claims 30 mph on the 16 hp. That seems a bit optimistic.

1955 Firestone 16hp
19 cubic inches
4200 rpm indicated
9 x 9 prop
23 mph on 14′ aluminum boat

1952 Evinrude 4441 14hp
19 cubic inches
4000 rpm indicated
9 x 10 prop
21 mph on 14′ aluminum boat

1974 Mariner W15hp
15 cubic inches
5500 rpm indicated
9 x 9 prop
23 mph on 14′ aluminum boat

https://www.youtube.com/channel/UCzXzvw … qBA/videos

[fleetwin]

I’m surprised that Evinrude did so well!

[brian]

That Evinrude is one gutsy motor. Definitely my favorite of the three. Does everything asked of it from idle to top speed. My video of the high speed run messed up during rendering. I hope to get back out and film it.

[wbeaton]

Cool. I love real world results. Test and tube days are my favourite.

Wayne
Upper Canada Chapter

uccaomci.com

[opposedtwin]

So, it looks like more horse power and less pitch = more speed. At least among these three.

[brian]

It took the Mariner an extra 1300 – 1500 rpm to keep up with other two. It was working real hard to get there. The Evinrude was impressive at top speed only turning 4000 rpm and didn’t sound like it was working too hard. It would be interesting to try a 9 x 9 on the Evinrude. The manual says it runs 4000 to 5000 rpm. An extra grand would certainly show the Firestone who’s boss.

[squierka39]

I can agree with your sceptidism on tne Scott Atwater/Firestone. I have 1956 16hp Scott and a 1956 Evinrude 15hp Fastwin. On my Duranautic 13 ft aluminum boat the Scott goes about 22mph and the Evinrude is close to 25mph.
Good data, thanks for sharing.

[brian]

I need to do a search as to why the 19 cubic inch Evinrude is only rated at 14hp. The rpm range would certainly support a higher rating and it doesn’t feel like it is at it peak running at 4000 rpm. Garry probably has the answer 🙂

[garry-in-michigan]

The 4441 Fastwin was a souped up Elto 12 and a stop gap to the 20 cubic inch class while they worked on a more modern replacement – the 15012 Super Fastwin of 1953, It is a big improvement. , , 😀

[brian]

Thanks Garry. The 4441 has some serious compression when pulling the starter. The other two not so much. While it might take a little more effort to get to the powerhead, it certainly is robust and feels solid.

[Author]

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