gpm of water to run a mercruiser on hose
#41
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Most dynos I have been on have had a cooling tower or tank too with temp regulator on it, some water is added to help remove the heat, some is re-circulated. When you start running wet exhaust though your water requirements go way up. Crocketts dyno had the best setup out of all of them I been on, water cooled headers but they exhausted dry to avoid the water mess. I am going to dyno my boat engines WITH the exhaust that I would be running in the boats, the car dyno header thing creates its own tuning differences, extreme heat, false numbers etc!
Last edited by articfriends; 10-07-2015 at 09:47 PM.
#42
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That middle CL tank is sweet, 300 gallons and has a very little footprint, I will definately be looking for something like that locally, thanks for the idea , we are already tight on space so a tall , skinny tank is a GREAT idea!
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35 gpm with 7 spi ram pressure is what your going to get out of a brand new Merc pump thats on the 525efi, 600 & 700sci engines. Any more ram pressure will not help, it only adds drag to any given setup. Now run that same pump for around 20 hours and that number drops because of the burn marks in the housing. Here is a link explaining the burn marks. Artic if you need numbers on other pumps call me I can dig up my old test sheets https://youtu.be/HWGcvwHZSE8
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Oh one thing I forgot to clarify is that the 35 GPM is going to the engines I listed above. That number will go up to about 38 with an open cooled setup. And those numbers are with CMI headers, not the big tube headers either. No body should be running big tubes with a single stage water pump anyway. And "most" after market exhaust will run similar numbers. Back in the day, alot of people making pumps.. not mentioning any names... would advertise free flow numbers. Well thats crap, no body runs a pump that way. And their pumps were crap too.
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One more thing about pumps besides the burn marks. As the rubber impeller gets old and losses its set, the linear increase in gpm with rpm drops. Also after around 4000 rpm your GPM will not go up anymore depending on your pulley setup.
#46
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Large tanks are available on craigslist. Some are from fertilizer some are from concrete dye. I helped set up a dyno using 2 tanks and a large pump to transfer from tank to tank. If you have a bulk milk hauler in your area, he can bring water to fill the tanks. Just FYI.
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Yup. Also, the impeller isn't a PD pump, it's curve is going to drop substantially as discharge pressure climbs.
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When I dyno my stuff, we just feed the sea pump from the cooling tower and T the water fittings in the headers(where they meet the tails) together and return it to the cooling tower. Adjust the tower for the temp you want and you are done. Works perfectly. I am running the tails dry, but doesn't seem to hurt anything.
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He wants to tune with wet exhaust.
Speaking of that Arctic Friends, you will need to set up the dyno close to the garage wall so that your exhaust lengths stay the same as they'd be in most Bravo applications....if at all possible.
Exhaust lengths can changing tuning and power.
Speaking of that Arctic Friends, you will need to set up the dyno close to the garage wall so that your exhaust lengths stay the same as they'd be in most Bravo applications....if at all possible.
Exhaust lengths can changing tuning and power.
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here's a look at the dyno I have bin working on built the whole brake using superflow turbine and stators double stacked.[ATTACH=CONFIG]546314[/ATTACH][ATTACH=CONFIG]546315[/ATTACH][ATTACH=CONFIG]546316[/ATTACH] With a topfuel starter on the back.