Topic: Aluminum water pump
in Forum: C3 Cooling and Heating Systems
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Lifetime MemberManteca, CA - USA
Joined: 11/20/2005
Posts: 3623
Vette(s): 1978,two tone,Metalic Rootbeer & gold
1975 L48 4 speed
I'm replacing the water pump on the '81 and questions began to arise. Do I want an aluminum pump instead. Some pump higher volumes of water, but are these really a practical upgrade ? Besides being more expensive, the manufacturers don't seem to want to warranty them past 30 days, kinda unnerving. I'd love to hear the voice of experience on the matter.
Jimmy B.
Just can't wait to get on the road again. 
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Lifetime MemberHOWELL, NJ - USA
Joined: 5/18/2004
Posts: 6812
Vette(s): 1979, Targa Blue (72 Color), Pace Car rear spoiler, L88 hood, Dark blue factory interior, 525HP 406, HD 700R4, 370 gears,Steeroids, composite rear spring, TT IIs wrapped in T/A Radials.
I've used the HD cast iron models for years with no failures.
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Lifetime MemberEquinunk, PA - USA
Joined: 10/31/2007
Posts: 2466
Vette(s): 1972 conv, 4-speed, 350, 200hp, numbers match, rally wheels, war bonnett yellow w/white top. good condition, nice driver.
If the GENERAL put them on it, they will work. CAST is best.
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Duncanville, TX - USA
Joined: 11/8/2003
Posts: 20214
Vette(s): #1-1974 L-48 4spd Cp Med Red Metallic/Black deluxe int w/AC/tilt/tele./p/w-p/b/
Am-Fm/map light National/Regional/Chapter NCRS "Top Flight"
#2-1985 Bright Red/Carmine Cp.L-98/auto
Member: NCRS, NCRS Texas, Corvette Legends of Texas
Most 'luminuminum pumps do have improved impellers that will flow more volume of coolant, which is not a bad thing. Is it worth the extra $$$? Not in my opinion, unless yer fightin a heat issue to start with. I'd stick with the plain jane pump, meself.....just get ya a can of AlumaBlast while yer at the parts house and paint it...no-one will ever know. 
Joel Adams
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Lifetime MemberManteca, CA - USA
Joined: 11/20/2005
Posts: 3623
Vette(s): 1978,two tone,Metalic Rootbeer & gold
1975 L48 4 speed
Thanks guys, I love this place. With too many cars, I've ordered a mess of parts on line, and when you make a mistake or change your mind (and I've done plenty of both) it's just not worth it sometimes to exchange items. I'll take this order in to town to my local Napa.
Jimmy B.
Just can't wait to get on the road again.
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I posted several months ago about a leaking weep hole problem I had with a parts store iron pump. Took it back to the parts store (about 5 years later) and they replaced it for free.
1976 Silver/Firethorn. L48, 4spd. Original 2 bolt, vortec heads, 9.4:1 CR, Speed Pro Cam: 224/224@0.050, 112 LSA, Eagle Steel Crank.
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Frederick, MD - USA
Joined: 9/8/2003
Posts: 3398
Vette(s): 1969 convertible L71 427/435 4-speed black interior
Given equal design, the only difference between a cast iron water pump and an aluminum one is less weight and possibly better heat transfer. The coolant doesn't care what material it's passing through.
Stewart Stage One cast iron pump will move more water and outlast stock or rebuilt pumps. The last one I installed was still working well after 10 years when the car was sold.
If concerned about original looks, the pump housing is an OEM unit machined inside to flow better.
http://www.summitracing.com/parts/EMP-13103/
If concerned about original looks, the pump housing is an OEM unit machined inside to flow better.
http://www.summitracing.com/parts/EMP-13103/
Lifetime MemberApache Junction, AZ - USA
Joined: 10/15/2006
Posts: 285
Vette(s): 1982,150K,Renegade CFI,Hooker Side Pipes,85 fuel pump,Bilsteins,HD suspension, Aluminum radiator, SharkBar/w 5-Point Restraints. 3:73 gears coming soon.
I've been using the Steward Stage 1 high-flow for several years with no problems. This was one of many things done to fight my high heat problem.
here's my story, bought a polished alum. WP on e-bay for 78.00 delivered,alum. impeller, 30% more volumn and a lifetime warr., for my rat rod, I'am feeling good about the deal so I go's to put the WP pulley on and its rubin on the heater hose and by pass boss I'am using stock chev pullies, what the &&^^%$# and I lift the hood on the vette cause I run Edel. on it, I noticed that the boss's have a flat spot in those area's to clear the pulleys, so's I figure I'll file the areas a bit to get some clearence I filed about 1/16 off and still not enough, so now with the spacer kits, and a new pulley I could have bought an Edel. 
, after filing on the pump there goes my warr. you really have eyeball the photos of the products you buy on line or made oversea's
, after filing on the pump there goes my warr. you really have eyeball the photos of the products you buy on line or made oversea'sin Forum: C3 Cooling and Heating Systems
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