alexideways Posted January 17, 2007 Share Posted January 17, 2007 Well, just like the title implies... Quote Link to comment Share on other sites More sharing options...
LineC Posted January 17, 2007 Share Posted January 17, 2007 Well, just like the title implies... One less accessory driven by the drive belt so it frees up horsepower. Sometimes more room for intercooler piping and fans. Quote Link to comment Share on other sites More sharing options...
rudypoochris Posted January 17, 2007 Share Posted January 17, 2007 I have heard only bad things about them. Anyone have a good story about them? Quote Link to comment Share on other sites More sharing options...
LLave Posted January 17, 2007 Share Posted January 17, 2007 I too have been wondering about how long an electric water pump will live on a street/track car Quote Link to comment Share on other sites More sharing options...
Pop N Wood Posted January 17, 2007 Share Posted January 17, 2007 One less accessory driven by the drive belt so it frees up horsepower. Sometimes more room for intercooler piping and fans. Only when it is not running. Otherwise it is loading down the alternator and putting the same load on the engine. Quote Link to comment Share on other sites More sharing options...
Bartman Posted January 18, 2007 Share Posted January 18, 2007 Only when it is not running. Otherwise it is loading down the alternator and putting the same load on the engine.I beg to differ, the load is not necessarily the same. Here's a link that talks about switching to an electric water pump on an LT1. http://www.wku.edu/~nathan.plemons/htmls/waterpump.html Although the write up is specific to the LT1, some of the same principles apply to any engine. There are differences in mechanical and electrical efficiencies and the slightly higher load on the alternator is generally going to be more efficient than the load of turning a mechanical water pump. In addition the electric water pump is going to turn at a nearly constant speed whereas a mechanical pump speed will vary with engine RPM. P.S. - I upgraded to an electric water pump on my engine. Quote Link to comment Share on other sites More sharing options...
alexideways Posted January 18, 2007 Author Share Posted January 18, 2007 Would it be useful to, let's say, flip the W/P pulley around, to trow it off line with the alt. belt and then run a small belt from the pulley to an electric motor??? Quote Link to comment Share on other sites More sharing options...
JMortensen Posted January 18, 2007 Share Posted January 18, 2007 Would it be useful to, let's say, flip the W/P pulley around, to trow it off line with the alt. belt and then run a small belt from the pulley to an electric motor??? Gian Bowles's EP 510 was run like that, but it had a Gilmer belt running around a "custom" pulley to a small electric motor. I think the idea was sound, but his was so hacked it made me want to puke when I thought of how badly he whipped my ass around the autox course. I don't think the water pump had much to do with the fact that the car was INSANELY FAST, but nevertheless, it was... My take on it is if you're looking for that last hp or if you have something funky like a radiator in the trunk or something, then consider the electric pump, but if you're just driving around town there isn't that much to be gained and L series water pumps are dirt cheap and super easy to install. Quote Link to comment Share on other sites More sharing options...
Challenger Posted January 18, 2007 Share Posted January 18, 2007 Only when it is not running. Otherwise it is loading down the alternator and putting the same load on the engine. Thats what Ive always thought. I dont know the really technical parts of how a alternator works with amps volts etc. But if you move it (water pump) to run off the alternator, your still putting the same amount of stress on a different part of the front of the motor that in the end still leads to loosing hp from the motor. If I bought one it would be purely cosmetic and for space issues like LINEC said. Quote Link to comment Share on other sites More sharing options...
Guest Mike Posted January 18, 2007 Share Posted January 18, 2007 An electric pump robs a bit less instantaneous power. The immediate power demand of the pump is transferred to the battery and when the demand lessens the alternator catches up to recharge the battery. That said, as I understand it, an electric fan makes more of a difference than an electric pump. So... I don't know if an electric pump is worth the added worry of failure. I'm going to try one... EDIT: ... and don't forget that you can install an alternator shut-off switch to eliminate alternator load for a quarter mile run. EDIT #2: Another benefit is the ability to keep coolant circulating and the fan running after the engine is shut off. Engines continue to heat up after shut down so this is a real plus. This is much better than having just the fan run. Quote Link to comment Share on other sites More sharing options...
(goldfish) Posted January 18, 2007 Share Posted January 18, 2007 Better control of coolant speeds, not having to worry pump cavitation during high rpm use. Quote Link to comment Share on other sites More sharing options...
Tony D Posted January 18, 2007 Share Posted January 18, 2007 Well, isn't a Buick currently using an OEM electric water pump? They have been using them in Europe for retrofit applications for years. I won't get into the "it makes reverse flow cooling of any engine easier" argument, that's a different can of worms altogether. Like Goldfish said, you can control the speed of the flow through the engine independent of engine speed, and linked more to temperature transfer. We use one like described above on the EP car. A hacked abortion of a Summit-Bought V8 conversion kit, along with a pulley almost as big as the fan on the alternator to drop it's speed as well. Alternator didn't like 9500 Engine Crankshaft RPMS...Neither did the OEM water pump. Quote Link to comment Share on other sites More sharing options...
nscason Posted January 18, 2007 Share Posted January 18, 2007 Ok i dont know about you guys but i bought my car almost 2 years ago and the damn fan clutch went out. I live in a desert and it was the beginning of summer. that ended up cracking the head. i got another fan clutch and it to went out a month later so i did the cheap thing and bought a solid flex fan. it is nosier and i didnt go with the electric pump only because i dont want to buy an electric fan. I do plan on going with the other set up some time when i get around to it. i think its well worth it especially when you have an aluminum radiator. to me that is a good sound cooling system that would work great in stopped traffic in a desert or on a race track. Quote Link to comment Share on other sites More sharing options...
Pop N Wood Posted January 18, 2007 Share Posted January 18, 2007 I beg to differ, the load is not necessarily the same. Here's a link that talks about switching to an electric water pump on an LT1. http://www.wku.edu/~nathan.plemons/htmls/waterpump.html Although the write up is specific to the LT1, some of the same principles apply to any engine. There are differences in mechanical and electrical efficiencies and the slightly higher load on the alternator is generally going to be more efficient than the load of turning a mechanical water pump. In addition the electric water pump is going to turn at a nearly constant speed whereas a mechanical pump speed will vary with engine RPM. P.S. - I upgraded to an electric water pump on my engine. People have raised some good points here that I didn't think of. If the mechanical WP is trying to move more water than it needs to, then yes, it will needlessly be consuming power. The cavitation issue is definitely real, and something I hadn't thought of. However the article above contains some inaccuracies, such as "the alternator is running anyway". More current draw = more load. One last thing to consider is the cooling load undoubtably varies with engine load. Thus having the WP flow rate vary with RPM may not be a bad thing. If the electric pump is constant speed, then the coolant flow will be the same regardles of RPM. This means the flow rate has to be set for the worst case heat load, which means the electric pump could very well be be drawing excess power when the heat load is low. Probably putting too much thought into this. Personally I would rather spend the $$ on better heads. Quote Link to comment Share on other sites More sharing options...
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