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#1 |
Registered User
Join Date: Feb 2013
Location: GA
Posts: 1,313
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Water pump for an L31?
I am looking to buy a new water pump for the new L31 I have . Any ones to avoid? I just did a "5.7 350 water pump" search and found amazon has this one
https://www.amazon.com/ACDelco-252-7...8654463&sr=8-3 I guess the long style water pump will be what I buy since the plan is to reuse the same setup with the pulleys and brackets I had on the other 350. The few differences I am making on this build is I am adding the vintage air surefit to this setup, using rams horn intake and a new edelbrock intake for the same quadrajet. Pics of the older setup I had and a pic of the old pump |
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#2 |
Registered User
Join Date: May 2012
Location: horseheads,ny rust belt
Posts: 2,794
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Re: Water pump for an L31?
i just used the pump for the 90 k5 blazer with 5.7 and serp belt for my setup as i used the serp belt stuff also .
if v-belt just get one for say a 1985 350 . dont forget L31 vortec has no bypass hole port in the block so you need to do a bypass hose like a bbc uses . or you can get bubbling / girggling / coolant smell as it pushes up in to the over flow tank .
__________________
77-k30lb BIG truck build . 87-k30lb budget beater build . 85-k30lb the plow machine build . 85-c10sb summer fun toy . ----------------------------- HOLLEY SNIPER efi = worst case of p.i.t.a i ever had . EDELBROCK pro flo 4 = best deal going so far . love my setup works great. |
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#3 |
driving is in my blood
Join Date: Dec 1999
Location: Mesa AZ
Posts: 5,723
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Re: Water pump for an L31?
Use a normal long style water pump. Standard rotation for v belts and reverse for serp belts.
__________________
-78 c10 short/step: 388cid, M20, 5/5 drop, lots more. Playtoy and first vehicle. -98 c1500 x-cab: 5.7L, 17" rims, 5/6 drop, flowmaster, helper bags,NBS rear disk brakes. -02 Suburban 4x4: leveled front -CBR600F4i, CBR600RR, CBR1000RR, and standup skis DISCLAIMER: I cant spell for the life of me. |
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#4 | ||
Registered User
Join Date: Feb 2013
Location: GA
Posts: 1,313
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Re: Water pump for an L31?
Quote:
Quote:
https://www.rockauto.com/en/catalog/...ater+pump,2208 On the bypass hose I see what you were talking about with the bypass and saw this pic. But Im not sure how to do a bypass hose? ![]() |
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#5 |
Registered User
Join Date: Feb 2013
Location: GA
Posts: 1,313
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Re: Water pump for an L31?
I took a pic of that portion of my engine and I see this. Maybe Im confusing what you were saying about the bypass.
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#6 |
Registered User
Join Date: Feb 2013
Location: GA
Posts: 1,313
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Re: Water pump for an L31?
This?
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#7 |
Registered User
Join Date: May 2012
Location: horseheads,ny rust belt
Posts: 2,794
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Re: Water pump for an L31?
yes that hose .
and the port might be in the block to the water jacket area but the head surface to head hole is not there . this is why you need a bypass hose . the true vortec L31 installs from gm the water pump has a hose and the intake has the spot for it .
__________________
77-k30lb BIG truck build . 87-k30lb budget beater build . 85-k30lb the plow machine build . 85-c10sb summer fun toy . ----------------------------- HOLLEY SNIPER efi = worst case of p.i.t.a i ever had . EDELBROCK pro flo 4 = best deal going so far . love my setup works great. |
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#8 | |
driving is in my blood
Join Date: Dec 1999
Location: Mesa AZ
Posts: 5,723
|
Re: Water pump for an L31?
Quote:
__________________
-78 c10 short/step: 388cid, M20, 5/5 drop, lots more. Playtoy and first vehicle. -98 c1500 x-cab: 5.7L, 17" rims, 5/6 drop, flowmaster, helper bags,NBS rear disk brakes. -02 Suburban 4x4: leveled front -CBR600F4i, CBR600RR, CBR1000RR, and standup skis DISCLAIMER: I cant spell for the life of me. |
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#9 |
Registered User
Join Date: May 2016
Location: Henderson NC
Posts: 975
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Re: Water pump for an L31?
If you have just a heater and no ac the heater can serve as the bypass.
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#10 | ||
Registered User
Join Date: Feb 2013
Location: GA
Posts: 1,313
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Re: Water pump for an L31?
Quote:
Quote:
The Edelbrock intake manifold I bought is this one https://www.summitracing.com/parts/EDL-2116 The Vintage Air Surefit AC system will be added this time removing the heater from the firewall so it sounds like the water pump smaller port connected with a hose to the intake is what I need to do. |
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#11 | |
Registered User
Join Date: May 2012
Location: horseheads,ny rust belt
Posts: 2,794
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Re: Water pump for an L31?
Quote:
and the intake the O.P. posted from edelbrock has the bypass port in the front just under the t-stat . its a 3/8" pipe thread . i used a 3/8" pipe to 5/8" hose barb fitting from these guys in the intake . https://www.ebay.com/itm/5-8-HOSE-BA...72.m2749.l2649 then a molded 45* hose from the local napa / carquest rack to the water pump port on top almost dead in line with the intake port . hooked them up and ZERO problems ever since then . here is my thread on this problem and lots of people posted info and pics to back it up . and post #42 on 2nd page has my exact fix and hose part# . http://67-72chevytrucks.com/vboard/s...d.php?t=778518
__________________
77-k30lb BIG truck build . 87-k30lb budget beater build . 85-k30lb the plow machine build . 85-c10sb summer fun toy . ----------------------------- HOLLEY SNIPER efi = worst case of p.i.t.a i ever had . EDELBROCK pro flo 4 = best deal going so far . love my setup works great. |
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#12 |
Registered User
Join Date: Feb 2013
Location: GA
Posts: 1,313
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Re: Water pump for an L31?
Sweetk30, looks like the bypass parts were included in the intake kit. There is a straight type barb though not the 45 degree type and a plug which I guess is in case you arent using the bybass hose to the manifold.
Question on the water pump install, do you guys use rtv at all on the metal surface and then stick the gasket on it or gasket only? Ive seen a spec of 30 ft lbs of torque used for the bolts, sound right? |
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#13 |
Registered User
Join Date: May 2012
Location: horseheads,ny rust belt
Posts: 2,794
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Re: Water pump for an L31?
i do a super thin skim or use red & tacky thats it on both faces that get a gasket .
__________________
77-k30lb BIG truck build . 87-k30lb budget beater build . 85-k30lb the plow machine build . 85-c10sb summer fun toy . ----------------------------- HOLLEY SNIPER efi = worst case of p.i.t.a i ever had . EDELBROCK pro flo 4 = best deal going so far . love my setup works great. |
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#14 |
Registered User
Join Date: Feb 2013
Location: GA
Posts: 1,313
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Re: Water pump for an L31?
Looks like the 45 degree hose barb fitting is what I need just like you said. The instructions on this intake assume the user knows anything about them. No listing of what the holes are for in the manifold. Compared to my original 350 setup the only ones I recognize are the thermostat housing large port and the water pump I assume is the port I threaded the barb they supplied into. The other 2 I think were for heater hoses? I guess I need plugs then if thats the case since the vintage air system is self contained.
How do you mold the hose to get the angle right? |
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#15 |
Registered User
Join Date: May 2016
Location: Henderson NC
Posts: 975
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Re: Water pump for an L31?
As long as your heater core isn't clogged and you have it plumbed right it should work. All you need is a bypass from your intake below the thermostat to an intake on the water pump. It doesn't matter how far the water has to travel as long as it circulates.
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#16 | |
Registered User
Join Date: May 2012
Location: horseheads,ny rust belt
Posts: 2,794
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Re: Water pump for an L31?
Quote:
and i did NOT use a straight barb fitting . i used a 45* i had to order off ebay and a molded hose i got off the rack at the parts store .
__________________
77-k30lb BIG truck build . 87-k30lb budget beater build . 85-k30lb the plow machine build . 85-c10sb summer fun toy . ----------------------------- HOLLEY SNIPER efi = worst case of p.i.t.a i ever had . EDELBROCK pro flo 4 = best deal going so far . love my setup works great. |
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#17 |
Registered User
Join Date: Feb 2013
Location: GA
Posts: 1,313
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Re: Water pump for an L31?
Ive got the 45 barb you linked to on ebay ordered. The molded hose Ill need to go look for as well as the pumps fitting too which I think then is a 3/4 fitting to the pump and 5/8 barb like this?
https://www.amazon.com/Straight-Pipe.../dp/B06XSMD83X Last edited by msg; 10-07-2020 at 11:45 PM. |
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#18 |
Registered User
Join Date: May 2016
Location: Henderson NC
Posts: 975
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Re: Water pump for an L31?
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#19 |
Registered User
Join Date: May 2016
Location: Henderson NC
Posts: 975
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Re: Water pump for an L31?
I heard you could just drill a hole in the thermostat but that didn't work for me. I just ran a simple heater hose looped from the intake to the water pump until I got my new heater core installed.
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#20 |
Registered User
Join Date: Feb 2013
Location: GA
Posts: 1,313
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Re: Water pump for an L31?
Sweektk, did you run a 45 or a 90 type molded hose section? Im still waiting on the 45 fitting from ebay. Did you end up pointing the 45 fitting to point upward or sideways? I bought a 45 and thought it might work but Id have to see how the 45 fitting is best to angle of the manifold. If the 45 hose seems right I would try cutting the hose at the pump shorter ...about where the letter A and number 8 are on the hose. That might get is close.
Last edited by msg; 10-09-2020 at 01:20 PM. |
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#21 |
Registered User
Join Date: May 2012
Location: horseheads,ny rust belt
Posts: 2,794
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Re: Water pump for an L31?
45* in intake . straight in water pump . molded 90 hose .
shorten the hose as needed . maybe even take 1 or 2 barbs off the nipple you have in the water pump now . hope this pic helps .
__________________
77-k30lb BIG truck build . 87-k30lb budget beater build . 85-k30lb the plow machine build . 85-c10sb summer fun toy . ----------------------------- HOLLEY SNIPER efi = worst case of p.i.t.a i ever had . EDELBROCK pro flo 4 = best deal going so far . love my setup works great. |
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#22 |
Registered User
Join Date: Feb 2013
Location: GA
Posts: 1,313
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Re: Water pump for an L31?
It does help thanks, I got the 45 in today and ive already ordered this hose to pick up tomorrow
https://shop.advanceautoparts.com/p/...0001/5191343-P I wondered the same thing if I should cut off a few barbs. |
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#23 |
Registered User
Join Date: Feb 2013
Location: GA
Posts: 1,313
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Re: Water pump for an L31?
I did find the right hose and ended up cutting down a few barbs.
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#24 |
Registered User
Join Date: Apr 2005
Location: Austin, Texas
Posts: 300
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Re: Water pump for an L31?
Where did you get those fittings? Part numbers handy?
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My mother is a recent cancer survivor and this truck build is for her |
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#25 |
Registered User
Join Date: Apr 2005
Location: Austin, Texas
Posts: 300
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Re: Water pump for an L31?
And if you are using the non Vortec water pump, just a standard long pump, did you drill out the hole and thread a plug in it where it mounts to the block on the pass side?
__________________
My mother is a recent cancer survivor and this truck build is for her |
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