ha 1 outdrive with a 5.7L EFI closed cooling.

[Palone]

recently acquired a 89 Sea Ray 220cc that had a newer 5.7L EFI cc engine put in it. They took the Alpha 1 outdrive water pump hose inside the transom and plumbed it to the raw water pump of the engine. Mercruiser says that engine needs a thru hull water inlet. I agree. I understand that in this situation you need to plumb the outdrive hose over board or cut it on the outside and plug off the transom inlet fitting. What I would like to do is plumb the outdrive water hose to a tee on the thru hull for the raw water pump. This will give the OD water from it's pump somewhere to go and also allow me to run the engine at home . (by turning off the thru hull valve I would only have to supply water to the drive. Anyone see a down side to this?????

 

[achris]

The drive water pump can't supply enough water to an engine driven pump... When you close the thru-hull pickup and run it on the garden hose, the engine driven pump will burn itself up.

Chris.....

 

[Palone]

Chris, I have run it this way (drive water hose connected to raw water pump) on the garden hose (at idle) and the raw water pump and the exhaust elbows stayed cool. The previous owner said running in the lake the operating temp was 195.
I intend to put in a thru hull, but wanted to only have to supply one water source when running it at home (to change oil etc..). I would think keeping it a idle on the garden hose would be sufficient. I'm trying to avoid having to connect water to the drive AND the thru hull at the same time to run it at home.

 

[harringtondav]

More learning than contributing for me here, but I believe a flush 'cup' is available to supply hose water to the hull intake and onto the engine driven seawater pump. That is how Bravos do it, right? If so, I'd think removing the Alpha's impeller, and blocking off the transom hose should work. achris . Am I close on this one?

 

[thumpar]

More learning than contributing for me here, but I believe a flush 'cup' is available to supply hose water to the hull intake and onto the engine driven seawater pump. That is how Bravos do it, right? If so, I'd think removing the Alpha's impeller, and blocking off the transom hose should work. achris . Am I close on this one?

The impeller is left in the drive and hose cut to provide cooling to the drive. Most Bravos still suck water through the drive. Mine does.

 

[harringtondav]

The impeller is left in the drive and hose cut to provide cooling to the drive. Most Bravos still suck water through the drive. Mine does.

Cool. Thanks for the learning. Does the impeller flow discharge thru a hull side port, or where?

 

[achris]

Cool. Thanks for the learning. Does the impeller flow discharge thru a hull side port, or where?

Bravos don't have an impeller in the drive, and can be confgured for through hull or through drive pickup. Which is why the 'cup' works. .. Water is provided at the pickup point (drive or hull) and the engine mounted pump draws it from there. Used water is discharged through the drive, just like an Alpha. ..

Chris. ...

 

[Palone]

How does the drive water pump help to cool the drive? It does not circulate water thru and around the drive. It sends it directly from the drive pump thru the transom hose to the engine. The drive would be cooled by the fact it is submerged in the water. ?????? right????

 

[achris]

The Alpha drives have water passages internally that do cool the drive as the water flows to the engine. It's required because once the boat is 'on the plane' the upper housing is completely out of the water, and with a fairly high amount of power being transmitted, that housing gets hot. Remove the drive impeller and that housing will cook. That's why it's left in and the hose is cut just before it goes into the transom, to retain water flow through the drive.

Chris. ..