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DRR Pro
Picture of Alaskaracer
posted Hide Post
quote:
Originally posted by Rick!:
It was just a little poke at ya. Smile Smile I know you got MFI, just lettin' ya know you could get better methanol mileage with EFI.


I dunno about the mileage......665" has a healthy appetite....even on gas it liked to drink......


Mark Goulette
Owner/Driver of the Livin' The Dream Racing dragster
www.livinthedreamracing.com
"Speed kills but it's better than going slow!"
Authorized Amsoil Retailer
 
Posts: 1465 | Location: Back home in Alaska! | Registered: February 13, 2011Reply With QuoteReport This Post
DRR Sportsman
posted Hide Post
quote:
Originally posted by Coloradoracer:
A restrictor does not increase flow. It does exactly what it says it will do, restrict flow...the faster you can flow the water through the engine, the better it will cool. A water pump will only cavitate if the suction side supply cannot keep up with the flow demand from the pump. The block itself is the restriction, take a look at the head gaskets...the holes on certain passages are not fully open. This is not by accident....T-stats and restrictors came about to keep heat in the block, not to remove it......that's why you have a heater in your daily.....


Sorry it took me awhile to get back to you. Maybe if you read what I said again you’ll understand, but I’ll say it again just in case.

Years ago somebody did some testing and figured out their water pump was cavitating.

That’s the summary statement that I’m providing from an article I read. You seem to say that’s impossible. Not that cavitation is impossible in general but that the block is too restrictive on the outlet of the pump....


That’s a pretty big jump for me.

Do you know the average flow size through the block, have some idea what the total pressure drop is everywhere in the system, and also the pumpnflow capcity curve of a typical water pump.

I don’t but I would need to know all those things before I would blatantly disregard the published article that I read.

I’ll try again aim with a slightly more generic statement that I don’t think you can refute.

If a pumpnsysrem is experiencing cavitation, you can potentially fix that simply by placing an orifice on the pump outlet. There is potentially a restrictive size that just barely moves the system out of cavitation which will almost certainly increase flow vs the cavitating system
 
Posts: 928 | Location: my own little world | Registered: July 20, 2005Reply With QuoteReport This Post
DRR Pro
Picture of Alaskaracer
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I need to clarify something as well. A lot of people think cavitation is air in the water (oil). It's not. Cavitation is starvation, lack of fluid. It creates vacuum bubbles in the fluid. Aeration is air bubbles in the fluid. They are created from an air leak on the suction side. If the water pump is trying to move the fluid too fast, it can pull a vacuum, creating the bubbles, which are referred to as cavitation. The head gasket itself creates a restriction before the water pump, due to the smaller water holes in the gasket than in the block, which is enough to prevent this. Any additional restriction serves only to slow the coolant flow, and nothing more. They do not help in cooling. The issue here is many water pumps aren't real efficient at moving water, and with an electric pump, if you turn it too fast, it can create that condition. Cashflow (Vern) had that issue on his car. The one thing to remember, is if you place another restrictor in the system, it will restrict not only coolant return to the radiator, but coolant supply to the water pump! Believe it or not, the less restrictive the cooling system is, the better the pump can move the coolant.....when you restrict the flow, as long as the flow from the restriction is greater than the intake of the water pump, it won't cavitate. But make the restriction small enough that that it does, and you'll have cavitation until you remove the restriction......adding restriction does not "fix" cavitation.....but it can cause it....Vern's stuff was moving the water faster from the pump than to the pump....so he stepped it down from 16v to 12 and it solved the problem...


Mark Goulette
Owner/Driver of the Livin' The Dream Racing dragster
www.livinthedreamracing.com
"Speed kills but it's better than going slow!"
Authorized Amsoil Retailer
 
Posts: 1465 | Location: Back home in Alaska! | Registered: February 13, 2011Reply With QuoteReport This Post
DRR Sportsman
posted Hide Post
quote:
Originally posted by Coloradoracer:
I need to clarify something as well. A lot of people think cavitation is air in the water (oil). It's not. Cavitation is starvation, lack of fluid. It creates vacuum bubbles in the fluid. Aeration is air bubbles in the fluid. They are created from an air leak on the suction side. If the water pump is trying to move the fluid too fast, it can pull a vacuum, creating the bubbles, which are referred to as cavitation. The head gasket itself creates a restriction before the water pump, due to the smaller water holes in the gasket than in the block, which is enough to prevent this. Any additional restriction serves only to slow the coolant flow, and nothing more. They do not help in cooling. The issue here is many water pumps aren't real efficient at moving water, and with an electric pump, if you turn it too fast, it can create that condition. Cashflow (Vern) had that issue on his car. The one thing to remember, is if you place another restrictor in the system, it will restrict not only coolant return to the radiator, but coolant supply to the water pump! Believe it or not, the less restrictive the cooling system is, the better the pump can move the coolant.....when you restrict the flow, as long as the flow from the restriction is greater than the intake of the water pump, it won't cavitate. But make the restriction small enough that that it does, and you'll have cavitation until you remove the restriction......adding restriction does not "fix" cavitation.....but it can cause it....Vern's stuff was moving the water faster from the pump than to the pump....so he stepped it down from 16v to 12 and it solved the problem...


Well, you got most of it right so I guess I’ll just drop it. I doubt anybody else is paying much attention.
 
Posts: 928 | Location: my own little world | Registered: July 20, 2005Reply With QuoteReport This Post
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