BBC Water Pump By-Pass Hose

BBShark

BBShark

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I have an Edelbrock 8853 water pump. This is a reverse rotation serpentine drive pump made for 1988 and later BB trucks.

45d826d8287800.jpg

You can see from the picture that only one of the bosses has been drilled and tapped even though there are two bosses there. The boss that is tapped is for the bypass hose. The boss that is not tapped is for a heater hose. This is the way the GM pumps for this application are set up.

Lots of info on the internet about the actual need for the bypass hose. While searching I found a guy that used the bypass circuit as heater hoses. So, you get the heater and the bypass function. This would solve my problem.

See any holes in my theory?


BB BYPASS HOSE
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Respectfully, I'm not a big fan of plumbing it as anything other than strictly a bypass passage. I prefer that the coolant can only circulate within the engine during warm-ups, and not allowing additional external water volume to mix in (increasing the time it takes for the coolant to reach operating temperature). Also, I like the idea of the hot water from under the thermostat mixing with the "cold" water from the w/p inlet, reducing the amount of thermal shock or delta T across the engine. If the heater core is used as the bypass function, the function is lost during hot days when the heater flow valve is closed.

Just my thoughts and philosophy. I welcome correction if I am misunderstanding any of the plumbing/flow routing in BB engines.
 
I saw that the other day. The comment is 3 years old and Edelbrock has not done anything about it. I like this part:

I called Edelbrock tech support and they even said that they don't know why it doesn't come with 2 drilled and tapped ports for the 454

I don't want to disassemble this and re-machine this. I dont know how you could do it without disassembling the pump too.

Mike, the valve I am going to use does not block the flow it diverts it into the heater core. So in the summer it would be just a longer bypass hose and in the winter, the flow would be diverted through the heater core.

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BBShark said:
I saw that the other day. The comment is 3 years old and Edelbrock has not done anything about it. I like this part:

I called Edelbrock tech support and they even said that they don't know why it doesn't come with 2 drilled and tapped ports for the 454

I don't want to disassemble this and re-machine this. I dont know how you could do it without disassembling the pump too.

Mike, the valve I am going to use does not block the flow it diverts it into the heater core. So in the summer it would be just a longer bypass hose and in the winter, the flow would be diverted through the heater core.

44a77815914885.jpg
Click to expand...

That's the part I don't care for. I don't like the scenario where the engine is asked/forced to heat up additional hose water volume and heater-core water volume/mass during the warm up period..
 
Yes, disassembly required in my opinion. I see some guys talking about drilling holes in the thermostat and running one loop to the heater. But, engine is $$$.
 
Now you have me thinking, a dangerous thing. How much water is in the cooling system?
 
rtj said:
https://www.thirdgen.org/forums/cooling/550419-plumbing-heater-core-electric.html

Guys with electric water pumps have a similar problem. They take water off the manifold and dump into the return. I didn’t read it all but there are some ideas and pics at the link.
Click to expand...

There is an idea to plumb the heater hose into a "T" in the lower radiator hose and retain the little bypass hose. I could use the port on the manifold (pictured below on the left of the T stat) for the other hose. I have to make a connector pipe on the lower hose anyway (stock hose won't fit).

This is probably not optimal but cold weather driving is not really a concern.

45d8c8db034f1c.jpg
 
The information I have found so far tells me that the bypass is required. Mostly from tech info about industrial centrifugal pump applications where the pump is "deadheaded" (like a car engine when the t-stat is closed). In a car, the bypass allows the coolant to temperature to "even out" though the engine because there is (bypass) re circulation when the t-stat is closed.

The bypass also allows the pump to provide minimum flow under deadheaded conditions which reduces cavitation and pump failure (pump is churning water without flow). This is from an industrial site:

In order to ensure adequate cooling and lubrication of the pump, there must be sufficient volume flow through the pump. Inadequate cooling and lubrication leads to overheating, bearing wear, friction between the sealing faces, leaks at the shaft seal, all of which will lead to pump malfunctions or failures. This is why a bypass line needs to be installed if there is a risk that the pump cannot be operated at the necessary minimum flow rate.

The bypass line is to be drawn from the pump's vent port or the discharge pipe's vent port, either back to the suction side (if possible) or into a tank, in order to ensure sufficient cooling by the pumped medium. On return, it must be possible for the pumped medium to cool down before it is fed back into the pump in order to avoid overheating the pump. For this reason, the bypass line must never be connected directly to the pump's suction port. The bypass line has been configured correctly if the minimum flow rate requirements for the respective pump as specified in the operating instructions have been fulfilled. At full load, the volume flowing through the system and the bypass may not exceed the maximum flow rate delivered by the pump.
 
Follow up:

I ended up using a traditional by-pass hose. I considered machining the other port and talked to someone at Edelbrock. What I was told is that, since this is a reverse rotation pump, opening that port would probably not do anything. Depends on the impeller housing.

Now to find a 2" radiator hose coupling with a 5/8 T fitting for the heater hose return.
 
On a sbc there is no bi pass hose, I don,t see the need.
On our boats we don’t use it but we Don’t have a radiator. Water pump work good without it.
 
The 63-67 327 Corvette with HiPerformance has a bypass hose on the water pump right from the factory. But 327 is old school to new school LS...

63 340 & 360 HP
64 & 65 365 & 375 HP
65 ? 350 HP - CRS
66-67 350 HP
 
That’s what I’m going to do.finaly found a tee section for the lower hose

Hose Tee
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By-pass hose
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Last edited:
Well that was fun!

I just finished installing the lower hose. It wasn't fun at all. My lower hose is made out sections of hose from two different cars, a 1 3/4 tee fitting with a 5/8 tee for the heater hose and five band clamps. getting this fitted and on has taken a day and a half, lots of undercar contortion and some blood loss from scrapes and cuts.

I would take a picture but there is no vantage point that you can see anything :amazed:
 
I know this is old, but I have a question. Would it be a problem to run the bypass hose from the bypass hole in the water pump to a different hole in the intake? Say the heater hole to the left of the typical bypass hole in the intake. I am using AN fittings on everything and that short hose is a problem. It's a 70 ls6 454
 
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