280 leg and AQ140A alternative

I have a 1987 22ft Double eagle with twin AQ140A and 280 legs. I bought the boat knowing it had engine issues and would like to know what else will fit these legs, which have low hours but have sat 5-6 years. I am thinking small 4 cyl. Chev or a single V8.
Thanks

Re: 280 leg and AQ140A alternative

Welcome to iboats!

The outdrives are geared internally for a 4 cylinder engine. So mating one with a V8 would take regearing or a different lower gear box.

The AQ140 was discontinued years before 1987, so can you confirm that is the correct engine model. The 140s used twin, side draft carbs. is that what you've got? If you're unsure, post a pic.

4 cyl Chev motors where never used with the 280 outdrive so mating those together would not be practical. Volvo was only using volvo 4 cyl engines back then.

Re: 280 leg and AQ140A alternative

My mistake, its a 1977 AQ140. I can see nothing but trouble here so Plan B was to put a pod on the boat and go the outboard route. Will I need to match the total inboard HP (2x140) with equal outboard HP, either with one large one or two smaller ones like 150's?
Thanks

Re: 280 leg and AQ140A alternative

yes, i think pushing a 22'er would require close to 300 hp. Twins are a good idea if your venturing off shore. I don't want to think of what twin 150 ob's would cost.

you may be able to find another boat with twin i/o's to swap out for less money...just thinking out loud.

I guess it depends on how creative you want to be.

Good Luck!

Re: 280 leg and AQ140A alternative

captmello; I am still a bit confused about 4 cyl to 8 and gear ratios. Wouldn't a 4 cyl have the same rpm as an 8 and therfore why does the gear need to be changed?

Re: 280 leg and AQ140A alternative

I'm no expert, but what it comes down to, is spinning a prop. even though the gear ratios and HP vary, they are using the same propellers. So, in order for the smaller engines to spin the prop, and reach the correct RPM range for the engine, it needs to have a different gear ratio.

4 cylinder volvos, like you have now, use a 2.15:1 gear ratio. Meaning, for every 2.15 turns of the engine, the outdrive turns once.

V8 Volvo outdrives of that era, like mine, had a 1.61:1 ratio. 1.61 engine revolutions for each outdrive revolution.

Both engines/outdrives can use the same prop, but the V8 ratio outdrive spins it faster at the same rpm because of the different ratio. 4 cyl engines are not powerful enough to use the same ratio.

Hope that helps, maybe someone else could explain better...