alpha 1 gen 1 waterpump

[coastalcruiser]

Hello, I have a rebuilt ford 302 mercruiser FWC engine with the alpha drive.
The boat is on a trailer and used in salt water
for a year now havent been able to get her on a plane just gets hot.
heat exchaner. manifolds. thermostat .hoses .flushed block this month water pump in leg new last year i can go slow all day never gets over 150 f.
took the raw waterhose off the heat exchanger and attached a hose, the water runs out below the hose in the bellhousing, could that be a waterpocket gasket? if so should i get a belt driven Raw water pump?
I can test the engine by putting a garden hose and running the engine while tied up someone said but...maybe this leg is just sucking air once the boat gets on a plane.
now sure what to do...or how to fix this

 

[Haut Medoc]

Re: alpha 1 gen 1 waterpump

Do you lose coolant?.....
I have the same engine/set-up in a '73 Sea Ray 220SRV.......
I had a similar problem & it was the heat exchanger had gone bad on the closed side for what ever reason......​

I went through everything twice, replaced, checked impeller, replaced risers, checked engine circulating pump , thermostat & was at wit's end......
If the risers are good, with no scale blocking the dumps, I would take the heat exchanger & have it boiled, rodded out at a radiator shop or think about a new one......
You can visually inspect the water pocket cover, but unless it is distorted from heat, I really doubt if it is your problem....
You can plumb in a smallsection of clear hose between the water feed from the stern to the exchanger to verify water flow & any unusual amounts of air.....
One other possibility is a blown head gasket, & you can get a test kit for the coolant to identify exhaust gasses.....
I'll wager you need a new exchanger....​

 

[coastalcruiser]

Re: alpha 1 gen 1 waterpump

had the heat exchanger boiled out, same with the risers and manifolds, they are like new

 

[coastalcruiser]

Re: alpha 1 gen 1 waterpump

no i dont think I lose coolant, and has pressure, I read the head gaskets are not great on this motor Most people say just get a used 5.7 package and that might be the best way to go.
i'm sure there is a leak in the leg somewhere, water should not be comming out of the leg so i'm having a look today at the raw water pump in the leg etc

 

[coastalcruiser]

Re: alpha 1 gen 1 waterpump

mechanic came by to take a look, he said there was good flow out of the drive, looked into the fill cap of the heat exchanger, there were lots of bubbles he says that's head gasket. $1000 to fix

 

[Haut Medoc]

Re: alpha 1 gen 1 waterpump

mechanic came by to take a look, he said there was good flow out of the drive, looked into the fill cap of the heat exchanger, there were lots of bubbles he says that's head gasket. $1000 to fix

I'd really consider a DIY on this one.....
If you are mechanically inclined.....

 

[coastalcruiser]

Re: alpha 1 gen 1 waterpump

when I got my boat it had no engine, I reglassed it myself ( have photos)and installed the motor-sterndrive, hooked it all up piece by piece. I would say it would be easy, except for getting the pieces apart I broke 3 bolts removing the manifolds...had to drill them out.