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flattie
03-06-2002, 06:57 PM
I'm replacing the rubber hoses going from the water pump to the block with braided lines and fittings. I was wondering if -8 is big enough for water flow?
Flattie

Infomaniac
03-06-2002, 07:03 PM
-8 Should be big enough

BadBoyzSkiRacer
03-07-2002, 04:20 AM
NO..... use - 10 line for engine water. how much hp do u have . which way do you have the water routed. is it running thru the bottom of the block as well as thru the upper water intake ports above the timing case... Steve 712 ph 622 ft pds ..bbc

V-Drive Tom
03-07-2002, 07:54 AM
Flattie, yes -8 is big enough You should have a valve in the out water line to keep the water in the engine a little longer. Never restrict the water to the pump. BadBoy is trying to impress and confuse you with all his BadBoy KNOWLEDGE...

schiada96
03-07-2002, 08:39 AM
I feel a -10 is the right line. Most of the timing covers now have a 1/2 npt thread in them that works with a -10 with no step in the an fitting. If you cover is a 3/8 npt your not going to gain any flow by going to a -10 without drilling the pipe fitting. I like a lot of water in, if you need heat in the engine block it on the way out. Just my opinion. Plus that small of a line just looks wimpy.

Fired Up
03-08-2002, 11:33 PM
I've seen different style pickups that attach to the cav plate. Some are rounded others are pointed. Is there a difference in the volume of water they scavenge?

HUFFPOWER
03-09-2002, 03:15 AM
i run -16 from pick-up on cav plate to waterpump,-12 from pick-up on cav to oil cooler to tranny cooler.

DetroitJim
03-09-2002, 09:03 AM
The cavitation plate water pickups with a hole in the front face were originally meant to be used in a force feed design. At 90 plus mph, it will feed the engine with no water pump at all. Mine kept getting weeds wrapped around it so I cut it off short with a angled bottom. It still works great. Also, in my opinion with a Magnaflow pump you had better not throttle it back on either the in or out. I was controlling temps by restricting the outlet, and the pump could blow right past a copper head gasket and spray water out the side. My next setup will be to divert water overboard right at the pump outlet until the temps are right and put a pressure gage on it. As far as hose size, with cold lake water coming in it has never made any difference for me.
DJ

Infomaniac
03-09-2002, 09:24 AM
Fired Up My pick up is on the bottom of the hull. It is only about an inch long and has an opening facing fwd. It will feed my engine unassisted right after the boat gets on plane. It shoots water out the back 6 feet at top speed. It even gets past the copper gaskets. I had to cut all the ears off the pump impeller before it would make any heat at all. (Blown Alcohol) Had to leave the pump on because of the roller cam. Now I start it up and let it idle until it shows 160 degrees or so. It keeps good temp while driving around. I plan to take the pump off this year and add a bypass regulator

DetroitJim
03-10-2002, 06:55 PM
Hey Infomaniac, if I go to a roller cam, you say the Magnaflow will work okay as a thrust device? My Merlin block has no bosses to add a cam thrust plate.

Fired Up
03-14-2002, 07:53 PM
I was going to use the pick-ups on the cav. plate and plumb directly to the block without a pump. Then plumb it out through the top of the intake to the back of the boat. I've seen several boats set up like this at the races. It seems very clean and easy since the most it will be running is about 30 seconds to a minute.

Infomaniac
03-14-2002, 08:09 PM
Originally posted by DetroitJim:
Hey Infomaniac, if I go to a roller cam, you say the Magnaflow will work okay as a thrust device? My Merlin block has no bosses to add a cam thrust plate.
It worked good for me on my Gen V Bowtie. Fuel pumps work good there, why not a water pump? If the pump was not there, all I would have is a button against the timing cover.
I turn it 7,700 RPM