Model Boat Mayhem - Forum

Dry Dock / Shipyard: Builds & Questions => Pleasure boats, Sports, Race, Power and Leisure Boats: => Topic started by: snoopy on February 10, 2007, 04:07:06 PM

Title: Engine Advice
Post by: snoopy on February 10, 2007, 04:07:06 PM
I have 2 OS 46 la. I want to change them to 4 strokes of same power or slightly higher.  How do I go about converting or measuring a 46 to equal a 4 stroke ?

i.e is it equal to a 30, 40 or 90 4 stroke ?

many thanks
Title: Re: Engine Advice
Post by: BobF on February 10, 2007, 04:15:36 PM
Hi snoopy,

The best way would not be by capacity, but by power output.
You should establish the output of what you have and then find a four stroke that compairs.

When I was looking into four strokes last year, I did notice that the power was lower than most two strokes. This subject is a bit of a mine field. If you have to have a larger motor to equal power, then it will have to be larger still to make up for the heavier weight etc etc.

Bob
Title: Re: Engine Advice
Post by: snoopy on February 10, 2007, 04:23:02 PM
Thanks Bob I will try and find out what the output is.

many thanks
Title: Re: Engine Advice
Post by: BobF on February 10, 2007, 04:50:53 PM
1.2ps at 15000 rpm
Title: Re: Engine Advice
Post by: glennb2006 on February 11, 2007, 01:09:51 AM
The problem then is for a boat how do you cool the motor (s)? See 4 strokes started by Tobyker to see where it all ends up Snoopy.

We have not yet found a water cooled four stroke. ( Assuming that you plan to fit it to a boat - this is a model boat forum so assume that is your intent.)

Glenn