I know many of you have been over this a few times a 454 and alpha don`t mix well but I have not had any problems. I guess that means I baby her. I have a question about the cooling,the alpha water pump is in the drive, that`s fine when your up on plane the temps are cool 150*. If I have to go thru a long idle zone the temp will rise to 180-200* once out of idle zone temp falls like a rock right back to normal. I have checked the impeller thats fine and new temp sender.
What I would like to do is add a raw water pump and plumb it to the existing water line coming out of the drive at the transom. My theory is that the raw water pump will suck the water right from the drive like it would from a bravo, and still keep the drive cool.
Also is 200* for a short time that bad for a BBC.

Thanks for any input good or bad

mark

can i sell you a bravo 1 with a shiny brand new skeg guard

i put a pump on my eng. and put a tru hull sea water pick up i left the pump in the drive to cool it. it worked great

good question i would like to know also.

I would suggest that your proposed new raw water pump will have more than a bit of a problem trying to suck water through your current Alpha impeller / pump. I kind of doubt you'll gain much. If your OEM pump is working properly, you shouldn't be over heating anyway.

Thanks for the replies guys, I am not apposed too putting a water pick up on just something I was considering. At idle speed and wake zone that pump just can`t keep up. Hoping to here from some alpha guys if they have any problems like this.

Should I go with a transom pick up or a thru hull.

My Alphas don't do that. I'd be more inclined to think you have a problem elsewhere.

I would put another impeller in it. When up on plane water is forced into the drive. I had an alpha and it did the same thing

Merc used to make a belt driven sea pump kit for big block Alpha's. Back in the day we would retain the Alpha pump but divert to a dump directly on top of the drive for cooling. Solved all problems.

If your impeller is good, then you have issues elsewhere.

Check for debris in your oil cooler, and check the spring loaded backpressure valves at the water neck.

AND make sure you have a marine thermostat, not a car one (marine ones have an air bleed hole, which you can add to a car one). Without an air bleed hole, you can end up with too much air around the thermostat, which keeps the bimetal from heating up and opening it.