73-87chevytrucks.com
73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: Grover 1 on June 20, 2009, 05:23:27 am
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I'm thinking of going to an electric water pump for no real reason than eliminating belts and cleaning up a bit. Any pros or cons to doing this? Any brand better than than an other? Thanks!
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Don't. If you want to neaten up your drive belts get a serpentine conversion.
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You can check out my install here: http://forum.73-87chevytrucks.com/smforum/index.php?topic=12211.0
Your not going to be eliminating any belts, just re-routing them so they don't go around the water pump pulley...unless you do something pretty creative with the alternator/power steering. I haven't got to drive the truck much since the install. Raining just about every day here, daughter's grad, ect. ect. I have driven it around some, went to the track once & sat in a cruise line for about 20 min. last weekend, no overheating. I mainly did it for better cool downs between passes at the track (a few extra hp never hurts either :D). For a regular daily driver I wouldn't think it would be the best plan. Any questions, Just ask! Lorne
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Ville, I had read in an earlier post you didn't care for them. Also my other response voted thumbs down, I just curious why you don't care for them. I thought if I got rid of the belt driven fan and the pump I could gain a little extra power and clean it up. No money for serpentine belts system right now, needs too many other more pressing items.
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If you're drag racing and doing everything you can to squeeze every last drop of free'd up hp out of your truck I can see why you'd want to but for a dd or street vehicle I don't see it making any worthwhile difference. The reliability of the oe style pumps is there and the drag is minimal. Plus they're cheap! What $30 bucks? Like Lorne said, if it's for the purpose of neatening up your belts, you still have those other belts.
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OK, that makes sense. I could put the $200.00 into something else. How about electric cooling fans. What's your take on going that route. I'm kind of on a budget, but by the time I'm done with this I hope to have it pretty nice. It's a 78 S/W, Silverado, no rust, A/C, auto, 350/350, power windows/locks, tilt, cruise. I'll post some pictures later today.
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If you're drag racing and doing everything you can to squeeze every last drop of free'd up hp out of your truck I can see why you'd want to but for a dd or street vehicle I don't see it making any worthwhile difference. The reliability of the oe style pumps is there and the drag is minimal. Plus they're cheap! What $30 bucks? Like Lorne said, if it's for the purpose of neatening up your belts, you still have those other belts.
What do you think the actual drag (parasitic) difference is between them? Maybe like 5 HP?
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I always thought the reason behind electric water pumps was to keep an engine cool under extended idle/low rpm situations, not free up horsepower. Wouldn't any drag freed up by the electric water pump, then be transferred to the alternator?
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I dont know, maybe. I have heard though, that those high amp alternators are just more efficient than the lower ones. So maybe if you got one of those you could keep any gain. Dont know if it's true though.
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An electric cooling fan is a nice addition but you need to have a good shroud. I built a nice one for my 74
http://forum.73-87chevytrucks.com/smforum/index.php?topic=10647.0
The alternator will put a load on the engine also. Will it rob as much power from the crankshaft as the mechanical device is the question. If it's negligible then you need to ask yourself if it's worthwhile.
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I have often wonder this myself. It seems to me that the electric water pump is not going to save much power, if any. It takes a certain amount of power ( either mechanical or electrical) to do the work which is in this case, move the coolant. The engine requires a certain amount or flow to properly cool, the flow required is load. So, if it takes 5 hp to addequately flow enough coolant with a mechanical pump, then it seems an electric pump would be the same. I dont see this being the same with the fans because the stock fans have large blades and a clutch that limits the load on the engine in certain conditions, but when locked up due to temperature, is a heavy load. The electric fans ( especially like Villes) have more blades, different pitches on the blades, and are shrouded better, this allows more air flow with a less load because it is more efficient. Ive talked to several racers who like the electric water pump because they can allow the fans and the pump to run in the pits with the engine off and allow it to cool off. Some have even told me they turn it off during a pass, to free up power. This is what they said. Burnout and stage with the pump and fans on, when the tree lights for staging, they turn them off, make the pass, and turn it back on on the big end after tripping the lights. I dont know about this idea, but I guess in a 10 second run, it may not be too bad. I havent done it myself, so I cant verify that.
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Some have even told me they turn it off during a pass, to free up power. This is what they said. Burnout and stage with the pump and fans on, when the tree lights for staging, they turn them off, make the pass, and turn it back on on the big end after tripping the lights. I dont know about this idea, but I guess in a 10 second run, it may not be too bad. I havent done it myself, so I cant verify that.
Now there is an argument in favor of electric water pumps for dedicated drag racers. Also in the case of the electric fan, I do believe these add definite power and efficiency in street applications for the same reason. They are not on at all when airflow through the radiator is adequate. A clutch type fan can only decouple the fan from the engine so much but an electric fan, when it isn't on, is the equivalent of decoupling a mechanical fan 100%.
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If it's negligible then you need to ask yourself if it's worthwhile.
What i really want to know is, if you tally'd up all the negligible gains that a person could possibly squeeze out, would they then add up to being something worthwhile. I mean if you pulled out every last trick in the book, and maybe some that ain't in the book. To create the most efficient engine humanly possible. Maybe then your engine would last a very very long time, and you would get slightly better MPG than any one else with that particular engine. I know, I know, you guys think i should leave the MPG thing alone. But you see, there is quite a large difference between 13 mpg, and 18 mpg.
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But you see, there is quite a large difference between 13 mpg, and 18 mpg.
Yes, there is a big difference between 13mpg and 18mpg, a 38% increase to put a number on it. But there are other issues to consider. The cost of new parts, how much you drive the truck, picking parts that work together. I for one only put about 2000 miles a year on my truck and it would take a long time to recoup the cost.
2000mi X 1gal/13mi X $3/gal = $461
2000mi X 1gal/18mi X $3/gal = $333
that's a difference of $128/year or $10.67/mo.
For the sake of argument, even if an elect. water pump got you this gain, the part would probably wear out before it's "paid" for in my case.
In reality, it would be many components bought and installed, all of which have certain useful life. This makes the case in my book. Just keep it simple, replace what you need when you need and have fun.
Do your own analysis and act accordingly.
Sorry, it's just the engineer in me. :)
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Ok so by that standard, you would just kinda buy the efficient parts if you could afford them, or if they went on sale. And if the gains were too negligable, then you wouldn't but them at all. But if they were only a little negligable, then you would go ahead and buy them. So you would leave out the electric water pump, but you would go ahead and buy the longtube headers, instead of shortys.
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It all depends on YOUR criteria. My criteria is reliability, enjoyment, and cost. I tend towards mechanical solutions because of the proven reliability.
I just don't see my engine getting much more fuel efficient since teams of engineers worked tirelessly for 40 years and the best they could do for a 454 moving a 3 ton vehicle was 16mpg. So, I don't waste my time on that and just enjoy having a truck and not making payments.
Your quest is different than mine, so my way of solving problems and deciding what to buy may not fit your needs.
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I just don't see my engine getting much more fuel efficient since teams of engineers worked tirelessly for 40 years and the best they could do for a 454 moving a 3 ton vehicle was 16mpg.
I agree with what you're saying in terms of cost-to-benefit, but GM did anything but work "tirelessly" on either the SBC or BBC. They were given much attention during the 60's, but then R&D was pretty much haulted for better than 20 years. The current BBC designs do NOT represent 40+ years of R&D (more like 10, LOL). Good thing they had a winner from the start. ;)
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So really, they are 20 years behind. Maybe not that far behind other car co's, but behind what they could be. Although i will say a DOHC v8 is more efficient than a pushrod.
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Although i will say a DOHC v8 is more efficient than a pushrod.
The only clear advantage I can see with the OHC design is reduced valvetrain mass and subsequently increased rpm potential. There is nothing inherent in the OHC design that makes it more efficient that the OHV design. Now that said, 4 valve cylinder heads have the ability to satisfy the engines breathing requirements much better than 2 valve heads, but it comes at a cost of a less efficient combustion chamber design with dramatically less swirl (resulting in less mixture agitation after it passes the valve).
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Increased surface speeds also need to be factored in. Direct acting valves also hace no rocker ratio advantage and all of the lift needs to be built into the cam. If a rocker ratio is used then spark plug location has to be changed and can't be in the center of the combustion chamber. So there's + and - to each design.
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Yeah but i think overall, the OHC is the victor when it comes you get to the bottom line. That's why you won't find a 4 cylinder in the world that is being produced with pushrods anymore. At least not any that anyone would want. Even GM which was very slow to adopt the technology uses it in their cavaliers. Excuse me, cobalts. If you took a motor that was the exact same (as much as it could be, anyway) but one was a OHC or DOHC design, and one was a pushrod, the OHC engine would be more powerful and get better mileage. This is evidenced in those 10,000 RPM indy cars where they just simply can not use a pushrod system.