Horsepower Question

[ljc1957]

I just picked up a 1967 45 hp Chrysler outboard for parts. I have a 1966 West Bend 50hp outboard and these two engines are identical in every way except for the carbs and the cowling. Both are single barrel carbs but they are different. Would that explain the 5hp difference? I'm assuming that the heads are identical, at least they are from the outside.

 

[Frank Acampora]

Re: Horsepower Question

The 50 most likely has a slightly longer crankshaft stroke than the 45. (as I remember, the 50 and 55 had 2.80 stroke just like the big engines while the 45 was about 2.2. Don't quote me on that though) The 50 MAY have a 1/4 inch spacer behind the exhaust cover to increase the volume of the exhaust chest. Exhaust porting may be slightly different. The horsepower may be developed at a different RPM--higher for the 50. All very small differences that collectively add up yet most can not be seen. The carbs are different, primarily vented differently to accomodate the increased airflow expected from the larger displacement. Put the 50 carb on the 45 and you will get----45 HP.

 

[ljc1957]

Re: Horsepower Question

Frank, the 45 hp turns over and I'm going to do a compression check just to see where it's at. If the powerhead seems to be ok and, if it was necessary, would the 45 hp bolt right up to the 50 hp? Thanks