Twin 40's vs Twin 50's

C-Quest · Posted: Mon Jan 24, 2005 12:38 pm Post subject: Twin 40's vs Twin 50's

Seems to me that twin 40's are the most popular twin setup for the CD22's. Why don't more people go with the twin 50's?

I would think the twin 40's are cheaper to purchase and the fuel economy should be better.

Maybe the extra 20hp of twin 50's isn't needed in most cases.

I would think if you have twins for redundancy sake that getting back on a single 50 would be better than a single 40.

Comments?

Byrdman · Posted: Mon Jan 24, 2005 12:42 pm Post subject:

You might want to check the torque/rpm ranges to see if they are that much different between the two motors... and compare to how YOU intend to travel/cruise.. I defer to those with 22s.

Captains Cat · Posted: Mon Jan 24, 2005 3:17 pm Post subject:

C-Qwest:

The 40 and 50 are identical (according to specs) in most areas.

Same Displacement,
Same Weight (50 is 2# heavier in the long shaft version)
Same RPM ranges (5000-6000),

They develop their rated HP at different RPMs though.

The 40 develops 40hp at 5500,

The 50 develops 50hp at 5750.

Would seem to be a matter of tuning.

I don't have that problem, I have twin 45's (they quit making those in 1995) and they do well. Only have 300hours on them.

I'd guess you'd get a little more oomph and a few less oompg (clever no?? Laughing

) out of the 50s over the 40's. Your call..

Charlie

Byrdman · Posted: Mon Jan 24, 2005 5:51 pm Post subject:

Charlie is target on...but I was actually referring to the low rpm torque/hp range...but without seeing the chart on both engines...that too may not matter and could be changed with a prop adjustment.. Flip of the coin so far...?

C-Quest · Posted: Mon Jan 24, 2005 9:14 pm Post subject:

If you have to run the 50 at a higher rpm, where's the advantage?

Is there really a performance difference as far as the boat is concerned?

Do the twin 50 boats get there any quicker than the twin 40's?

Captains Cat · Posted: Tue Jan 25, 2005 1:10 am Post subject:

I don't think there's a measurable difference. Let's have a race!! Twisted Evil

The 50's look neater than the 40's , is it really worth it? Question

If so, buy the 40's and replace the decals. Laughing

Matter of fact, if you find a source for the decals for any of them, let me know, mine are very worn on my 45's. Smile

Chuck S · Posted: Tue Jan 25, 2005 6:40 am Post subject:

Other than the peak torque and peak HP points there are no "curves" available for these two engines. I've written Honda to get this data and they refer me to "my dealer" who, of course, doesn't have the data either!

The 40 develops it's maximum torque at a lower rpm than the 50's maximum torque -- but we don't know what torque the 50 is putting out at the 40's max point. Since a torque curve is relatively flat it's reasonable to assume the 50 puts out more torque across the entire rpm range.

Horsepower is merely a mathematical equation derived from torque and rpm.

Horsepower = Torque x RPM / 5252

At 5252 rpm torque and horsepower are exactly equal.

Torque rules! Wink

-- Chuck