Stainless Cross-over

[onesubdrvr]

Someone (I believe Ted), posted a question about Stainless marine x-overs. I looked at a couple and have a question,....

The crossover eliminates the water re-circ pump on the engine, thus freeing up some horsepower,...how much? I'd guess 5 - 10? Anyway, is this saying that the water pump in the lower unit supplies enough cooling water without the recirc pump on the engine?

Just a question, thanks
Wayne

[Mr X]

Yes, it was me.
Usually these are used on Bravo applications, thus a raw water pump is already on the engine and still provides a ton of water pressure.
I have heard of Alpha (small block) crossovers
being used as long as long idle periods are avoided.

[gcarter]

When I bought the Minx it had a crossover, I'm glad it did because I reused it with my electric circ pump.
I removed the drive pump, added a transom pickup and a crank driven pump.
When I was talking to San Juan Engineering about a closed cooling system,
The engineer I spoke to said Alphas pump impellor blades are too long and in warm water like here in Florida, they can nearly stop pumping. In cold water it works fine.

[onesubdrvr]

I've got 'cha,....

So you really need a crank driven pump anyway, but like you said, in a Bravo application, you could pick up a little HP. I've always heard Alpha's have a tough problem with cooling here (Florida), but what about OMC / Volvo's (new and old) / etc?

Thanks
Wayne

[MOP]

Wayne the circ pump is usless on "raw" water cooled engines the drive or engine mounted pump supplies plenty to keep it cool. On closed cooling you must have a circ pump either engine driven or like George an electric pump, the cross over is a nice up grade when the circ pumps goes bye bye or sooner! The water flow does not change the same amount still goes through the system.

Phil

[Cuda]

I wouldn't worry too much about Alpha's not supplying enough water without a crossover. There are litterally millions of them out there equiped just this way. I have heard of many people having too much water pressure on a Bravo set up when they went to crossovers. My 302 has crossovers, and I've never had a problem with them. The 302 has seawater pumps, and offshore intakes.

Doesn't your boat have a Volvo? I'm unfamilliar with how they get water.

[onesubdrvr]

I wouldn't worry too much about Alpha's not supplying enough water without a crossover. There are litterally millions of them out there equiped just this way. I have heard of many people having too much water pressure on a Bravo set up when they went to crossovers. My 302 has crossovers, and I've never had a problem with them. The 302 has seawater pumps, and offshore intakes.
Doesn't your boat have a Volvo? I'm unfamilliar with how they get water.
Yup, new boat has a Volvo 270 drive, SBC. Not exactly sure of the water system until it gets here,.....

Wayne

[Islander]

I have a Stainless Marine crossover on my small block/alpha/18 and have never had a temp problem, even idling for extended periods in Miami summers.

[mattyboy]

Wayne ,
on the old 250 270 there is no pickup pump in the drive it is gravity feed thru the drive, or another source,to either a crank driven pump with a crossover, or a beltdriven raw water pump then to a circ pump not sure on the 280 290

on the 20 cig 350/volvo 270 we converted the chris craft chevy 350 from old cast iron logs with a raw water and circ pump to stainless marine risers and a cross over thus getting rid of around 250 lbs of stuff

[onesubdrvr]

Wayne ,
on the old 250 270 there is no pickup pump in the drive it is gravity feed thru the drive, or another source,to either a crank driven pump with a crossover, or a beltdriven raw water pump then to a circ pump not sure on the 280 290
on the 20 cig 350/volvo 270 we converted the chris craft chevy 350 from old cast iron logs with a raw water and circ pump to stainless marine risers and a cross over thus getting rid of around 250 lbs of stuff
Matty,

That's cool, kinda what I was thinking, especially after our "chat" the other night,.... That is a considerable amount of weight!! Something I'll be looking into more closely for sure!

Wayne