Minimum Water Temperature

[Tcheairs]

Installed a new Magnaflow cam drive water pump on my V Drive 454 in a vintage Rayson. The pump is a great improvement over the old Neovane V755 which kept eating impellers for some unknown reason. I normally operate in the 2,000 to 3,000 rpm range and I am only able to get 135-140 degree water temp in 85 degree lake/river waters. Even at idle the water temp does not rise over 140. I've verified the temperatures with an infrared gun. There is no way to install a thermostat that I can see as the intake manifold outlet to the block is chambered (Glenwood) and will not accept a thermostat. The motor is mostly stock low compression and probably in the 350hp range.

What would be an optimum operating temperature for proper combustion? I'm thinking at least 160 to 180 degrees? The inlet hose to the pump intake is 5/8" and the outlets to the exhaust logs are also 5/8" nipples, so the water flow through the system is plenty. I guess I'm faced with restricting the inlet water flow. Ideas? Is 140 degrees (or less) OK?

 

[Sleek Chode]

Installed a new Magnaflow cam drive water pump on my V Drive 454 in a vintage Rayson. The pump is a great improvement over the old Neovane V755 which kept eating impellers for some unknown reason. I normally operate in the 2,000 to 3,000 rpm range and I am only able to get 135-140 degree water temp in 85 degree lake/river waters. Even at idle the water temp does not rise over 140. I've verified the temperatures with an infrared gun. There is no way to install a thermostat that I can see as the intake manifold outlet to the block is chambered (Glenwood) and will not accept a thermostat. The motor is mostly stock low compression and probably in the 350hp range.

What would be an optimum operating temperature for proper combustion? I'm thinking at least 160 to 180 degrees? The inlet hose to the pump intake is 5/8" and the outlets to the exhaust logs are also 5/8" nipples, so the water flow through the system is plenty. I guess I'm faced with restricting the inlet water flow. Ideas? Is 140 degrees (or less) OK?

I had the same problem with my boat, the best thing you can do is convert over to the thermostat housing. I added the link below. Your boat should run about 160 to 180, when I ran the magna flow water pump I was lucky to see 100°. It will be very efficient and this thermostat housing will work awesome. You will have to do some new plumbing and your water jacket plates may need to be re-drilled and tapped to except the bigger water Hose fittings. If you need pictures for routing, please DM me and I will send you what the front of the block should look like. Good luck on your pursuit.

Polished Stainless Thermostat Kit For Chevy - CP Performance

Polished Stainless Thermostat Kit For Chevy

www.cpperformance.com

 

[Tcheairs]

Wow....I'm sure it works, but it sure is ugly. I also might have a clearance issue with my cowling. But I am a little confused about the plumbing. Right now my raw water is going from the pump to the front of the exhaust logs and through to cool them, then out the back of the logs directly to the divider thermostat cover which splits the flow into the block. From the block out to the exhaust elbows and into the through transom exhaust outlets.. Can you tell me the plumbing routing for the housing you are using? Of course I can call the distributor, but I'd appreciate your input if you have time...I'm just wondering if choking down the intake volume would do the trick. I only use the boat in warm (hot) weather and don't need additional heat from cold water..Comments? Thanks for the prompt reply...

 

[Sleek Chode]

Wow....I'm sure it works, but it sure is ugly. I also might have a clearance issue with my cowling. But I am a little confused about the plumbing. Right now my raw water is going from the pump to the front of the exhaust logs and through to cool them, then out the back of the logs directly to the divider thermostat cover which splits the flow into the block. From the block out to the exhaust elbows and into the through transom exhaust outlets.. Can you tell me the plumbing routing for the housing you are using? Of course I can call the distributor, but I'd appreciate your input if you have time...I'm just wondering if choking down the intake volume would do the trick. I only use the boat in warm (hot) weather and don't need additional heat from cold water..Comments? Thanks for the prompt reply...

Polished Stainless Thermostat Kit For Chevy - CP Performance

Polished Stainless Thermostat Kit For Chevy

www.cpperformance.com

 

[Sleek Chode]

Polished Stainless Thermostat Kit For Chevy - CP Performance

Polished Stainless Thermostat Kit For Chevy

www.cpperformance.com

It actually looks really nice when it’s connected up correctly on the front of your engine. My raw water goes through the pump and directly to my transmission cooling first, then I come out of the transmission and then go Into my logs. I really like the way it works on my boat, you may not. Just call CPP and ask them on a technical side.

 

[Sleek Chode]

Wow....I'm sure it works, but it sure is ugly. I also might have a clearance issue with my cowling. But I am a little confused about the plumbing. Right now my raw water is going from the pump to the front of the exhaust logs and through to cool them, then out the back of the logs directly to the divider thermostat cover which splits the flow into the block. From the block out to the exhaust elbows and into the through transom exhaust outlets.. Can you tell me the plumbing routing for the housing you are using? Of course I can call the distributor, but I'd appreciate your input if you have time...I'm just wondering if choking down the intake volume would do the trick. I only use the boat in warm (hot) weather and don't need additional heat from cold water..Comments? Thanks for the prompt reply...

Here is my setup....

 

[mash on it]

Installed a new Magnaflow cam drive water pump on my V Drive 454 in a vintage Rayson. The pump is a great improvement over the old Neovane V755 which kept eating impellers for some unknown reason. I normally operate in the 2,000 to 3,000 rpm range and I am only able to get 135-140 degree water temp in 85 degree lake/river waters. Even at idle the water temp does not rise over 140. I've verified the temperatures with an infrared gun. There is no way to install a thermostat that I can see as the intake manifold outlet to the block is chambered (Glenwood) and will not accept a thermostat. The motor is mostly stock low compression and probably in the 350hp range.

What would be an optimum operating temperature for proper combustion? I'm thinking at least 160 to 180 degrees? The inlet hose to the pump intake is 5/8" and the outlets to the exhaust logs are also 5/8" nipples, so the water flow through the system is plenty. I guess I'm faced with restricting the inlet water flow. Ideas? Is 140 degrees (or less) OK?

It sounds like you have a single pass system.

Tin. Tout.
Temperature in, at ~ 85° (known)
Temperature out, at ~140 (known)

That's 55 degrees. In a single pass. That's pretty efficient.

Look up how efficient a car radiator is. ~ 50° think about that.

Above 160, hard water deposits start sticking to the inside of the block. Not on my junk.

180°? Trying to pass smog? It's been proven, time after time, cooler engines make MORE horsepower.

140° is fine.

That's all I got.

Dan'l

 

[Tcheairs]

Thanks Dan'l. I think I will stick with what I've got for awhile. Might try dumbing down to 1/2" outlets from the pump but sure don't want to cavitate the impeller.

 

[Tcheairs]

Here's my Ole Purple Rayson...owned since 1969