Does size really matter??!!?!?

sergioy

Petty Officer 1st Class
Joined
Apr 14, 2003
Messages
376
Thsi is kind of a goofy question for most of you, but since I don't know for sure I am going to ask. I have '63 16' Mark Twain with a '63 75 hp V4 motor. It runs fine but it takes for ever to plane out. I have just had the prop rebuilt. Now just yeateday, I purchased an '88 40 hp Evinrude. The lower unit was completely rebuilt, carbs rebuilt, spark plug wire replaced, water pump replaced. All in all it runs like a champ. So here comes the goofy part. Could I get as much power out of the newer rude than I could the johnny??? :rolleyes: <br />I know we are looking at a 35 hp difference but I know how older motors tend to loose power as they get older. And I don't believe the johnny has had anything major done to it in the last five to ten years. Your advise would be greatly appreciated. :(
 

12Footer

Fleet Admiral
Joined
Mar 25, 2001
Messages
8,217
Re: Does size really matter??!!?!?

There will be some creep towards equalibrium, but not as much as 35HP. Your question is not a silly one.<br />As motors age, they do loose some performance,HP due to lower compression than they had new. Seals wear,as do bearings. <br />Also, take into your equation, that modern motors (1984-to date), are more likely rated entirely diffrently than the older ones.<br />The older meathod of rating HP was at the driveshaft.<br />The way we rate them today is HP at the prop.<br />The difference is roughly 10% of rated HP.<br />So a 1965 Chrysler 55HP was in today's rating, more like 45HP.<br />But the gap is too great. You're still getting around 60HP at the prop from the old girl (by my estimation).<br />No match for a little 40HP.
 

sergioy

Petty Officer 1st Class
Joined
Apr 14, 2003
Messages
376
Re: Does size really matter??!!?!?

Thanks for your input 12footer. :)
 

sparkroost

Petty Officer 1st Class
Joined
Mar 23, 2003
Messages
312
Re: Does size really matter??!!?!?

I asked my wife and she says yes.
 

BAD_Habit

Cadet
Joined
Feb 21, 2004
Messages
11
Re: Does size really matter??!!?!?

:D :D <br /><br />Confirmed what his wife said ;) <br /><br />J/k
 
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