Just converted my RWC 87 250 SD 454/Alpha, to a volvo crank driven raw water pump with an 1 1/4" thru hull raw water pickup, so I no longer need the alpha cooling. Do I still need to keep an impeller in the sterndrive to cool the outdrive ? Or can I install drive shower to cool it, in place of the impeller. Are there other ways that will cool the outdrive without an impeller

I believe you have to keep the impeller in there. I wonder if you put a nose cone on it if that water forsed up the nose cone at speed would cool it off enough?

Jon

Take the hose that comes from the drive (the cooling water line) and turn it back out thru the transom using a thru hull fitting, just above your drive. Instant drive shower!! I've seen this done many times, especially on Bravo's with thru tansom intakes, while underway, you get great flow for a drive shower. With the Alpha, you will even get flow while at idle.

So apparently, the impeller must be used and replaced every year just like before. As this is the first year for the new crank pump, I was going to connect the existing transon (Alpha) cooling hose to an existing thru hull and just pump it "in and out". This way,,, I have it as a back up in case the Volvo crank pump fails for any reason "should I need it".

I'm waiting for other boaters to flag me down to tell me I'm taking on a lot of water "bilge is at full flow"

Thanks Scott

Do it Waterfoul's way and you don't have to change the impeller every year. It should last 5 years or more and you can tell if it's bad, just look over the transom.

I bought an alpha that had a nosecone on it and it didn't have an impeller in the drive, but I put one in anyway. I really don't think it's necessary, how much cooling is that three eighths line going to do compared to the entire leg in the water?

cuda, your probably right its not necessary. But I'm confused, what three eights line and what foot in the water. I must have missed something.

The little tube that carries the water and the foot is the lower outdrive in the water.