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You can modify the stock pump to plug the ports, or have them come out the top. There are several examples on this Forum. I plugged mine.
Old thread that I'm bringing back to life because I'm at this stage of my swap 😅
If you plug the inlet/outlet, do you need relocated them to come out somewhere else? Or can you simply delete the heater hose all together and not run heat into the passenger compartment?
I read somewhere that the thermostat on the LS water pump needs water to circulate through it, and that if the water stays stagnant it doesn't work correctly.
Do you know if there's any truth to that? If I can just plug up the inlet/outlet and not have to worry about tapping new holes, that'd save me a huge headache. I brought the pump to a local shop to have them do it, and the guy told me the walls of the pump were too thin to drill into and refused to do it. He simply took out the old fittings and plugged them. I figured I'd just drill myself, but if I don't have to, I'd prefer not to.
You need to loop the inlet and outlet. I had no issues drilling and tapping NPT fittings into the Camaro water pump. Yeah not a lot of threads but its NPT and the radiator cap is typically 15 PSI? Never had a leak.
You need to loop the inlet and outlet. I had no issues drilling and tapping NPT fittings into the Camaro water pump. Yeah not a lot of threads but its NPT and the radiator cap is typically 15 PSI? Never had a leak.
That's what I thought - mind if I ask where on the pump you actually drilled for the new fittings?
Yes, I have used it twice now on builds and it is the only thing I will use going forward. It included everything so the cost is a mute point because with the other kits by the time you buy or build everything you need you will have about the same money invested but alot less headache. Everything fits easily and you clear the heater hoses with plenty of space. Finishing up a 78 right now that I can take some pics of tomorrow. You will not regret going that route.
Old thread that I'm bringing back to life because I'm at this stage of my swap 😅
If you plug the inlet/outlet, do you need relocated them to come out somewhere else? Or can you simply delete the heater hose all together and not run heat into the passenger compartment?
I read somewhere that the thermostat on the LS water pump needs water to circulate through it, and that if the water stays stagnant it doesn't work correctly.
Do you know if there's any truth to that? If I can just plug up the inlet/outlet and not have to worry about tapping new holes, that'd save me a huge headache. I brought the pump to a local shop to have them do it, and the guy told me the walls of the pump were too thin to drill into and refused to do it. He simply took out the old fittings and plugged them. I figured I'd just drill myself, but if I don't have to, I'd prefer not to.
I read that the LS thermostat needs to see hot on the cold side in order to open. This can be done through the heater circuit, or it could be done by drilling a hole in the water pump to let hot water through. Since removing the two heater hose nipples, then drilling and tapping for NPT plugs, was a pretty permanent mod, I wasn't too concerned about ruining a $120- water pump.
But don't take my word for it. There are lots of videos on YouTube that give the same advice, with the same reasoning.
If I need heat in one of the cars, I'll make the mod after I check the A-Arm clearance. But since it seems that even the heater hose nipples themselves would cause issues, I removed and plugged them. Lots of heat from a MAPP gas torch and some vise grips got them out.
One more thing I like to do on my LS swaps. I use a -3 brake line for the steam line. I cut the nipple off the right side outlet of the steam line and drill and tap for 1/8" NPT.
Then using a 90 degree AN fitting and -3 SS brake line plumb that into a bung I have welded into the generic LS radiator.
Couple of pics.
Circling back on the Holley Mid Mount now that my LS3 is in the car. The Holley is expensive but has some clear advantages. It’s very compact, no clearance issues with the stock A-arms on both the water pump and PS. Alternator is a single wire 140a unit. Compact Sanden AC compressor with side connections. Steam port is on the back of the water pump for easy connection. Water pump has ports for both side and bottom heater hose connections. It’s also a late model GM cartridge pump so simple to replace in the future. The upper hose connection is extended to provide additional clearance for the pulley. Lastly the PS pump high pressure line has an extended fitting for easy connection from the side. It’s a well thought out system for LS swaps. If you need to purchase all new accessories the Holley Mid Mount is worth consideration.
Last edited by TorchZ51; Nov 19, 2024 at 11:53 PM.
J.Abbott
That wlll be good to see. Just curious so I looked on around on youtube but didn't find any C3s using the mid-mount.
Originally Posted by J.Abbott
Yes, I have used it twice now on builds and it is the only thing I will use going forward. It included everything so the cost is a mute point because with the other kits by the time you buy or build everything you need you will have about the same money invested but alot less headache. Everything fits easily and you clear the heater hoses with plenty of space. Finishing up a 78 right now that I can take some pics of tomorrow. You will not regret going that route.
Sorry these pics are big but I wanted you to see them in detail so you could see how much clearance there is. Don't mind the A/C lines they have to be fixed.
Found this interesting video that lists available part numbers (and prices) that can be used with the Holley mid mount.... would be well worth it to save like 900 bucks (as of date of video)..... it even lists the water pump number if somebody wants to find a cross reference for that.
parts list is at end of video.
I looked up that Holley water pump 97-200 on Summit website and it fits the following vehicle. So I looked on rockauto at a 2015 Corvette with a 6.2L/376 and you can get one for under 40 bucks.... interesting.
Make:
CHEVROLET Beginning Year:
2014 Ending Year:
2022 Engine Type:
V8 Engine Family:
Chevy small block Gen V Engine Size:
6.2L/376
Found this interesting video that lists available part numbers (and prices) that can be used with the Holley mid mount.... would be well worth it to save like 900 bucks (as of date of video)..... it even lists the water pump number if somebody wants to find a cross reference for that.
parts list is at end of video.
So a much more compact arrangement, seems to keep the -3 truck spacing accessories, and still lets me run a PWM controlled alternator, and doesn't cost $2K? Perfect!
I don't even have an LS ....I just find them so cool. I do have a PWM alternator to install ....but I've been a slug..... I might try to run it without the PWM to see if it can maintain the 13.7 vdc with all the loads going???? Or I'll just quit being lazy and wire in volts reducer and PWM controller .....
Oh yea that is awesome, they did not offer that when I purchased this one 2 years ago. The PS pump is just a GM pump and alt. You get the compressor when you do the Vintage air and the WP is cheap and the tensioner. The Holley kit is complete which makes it nice, but 2k is 2k. If you buy just the manifold they probably have that in stock. I had to wait on the kit for a couple of months.
For that price and the other available part numbers I don't see why any C3 dude would do anything else if going LS. Compact, tight, and don't have to deal with the annoying heater hoses being against the upper control arm alignment bolt.
Originally Posted by Bikespace
Here's the crucial Holley-only part, the "LS Cooling Manifold", in Raw, 97-163, or Black, 97-168 (Amazon links).
