Bbc coolant hose w/p to intake

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Customblue

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Is it necessary to connect the waterpump to the intake on a 7.4l block? Attached is the locations in question.

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Turbo4whl

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Both of my BBC's have that hose connection, 1971 402 and 1998 454. There was a molded hose from the factory, but you can use a piece of 3/4" heater hose. Need the two hose barb to pipe connectors.

Back in the day this was referred to as the by-pass hose.
 

Customblue

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Is the only purpose to bypass the thermostat before it warms up? I just transplanted that 489 in ol blue and she runs down the road at 180 but if I idle for more than five minutes she climbs to 200 on the dot. No hotter, would adding this line help keep her cool at stoplights? Thanks for the quick response!
 

bucket

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Everyone always runs the bypass hose, it must be needed for proper cooling?
 

AuroraGirl

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200 doesnt seem hot. Unless you mean thats only recently, and its gonna get hotter with summer.
 

Customblue

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Ive got less than 100 miles on the motor, I'm not sure what the norm is for my first big block. All I can say is she has way more power than the old 350 with less than 1/2 throttle
 

QBuff02

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The bypass hose keeps coolant circulating through the block before the t-stat opens, but it also allows for extra coolant to keep circulating while the engine is up to temp and running. I would say for certain applications it wouldn't be entirely necessary, but for any kind of street driving it would be a must. My BBC runs 195-200 and it doesn't matter of it's 40 degrees or 100 degrees out, I have the bypass hose on. I also say that Chevrolet Engineers put it on there for a reason.
 

Shorty81

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My BBC runs around 180 all the time. 3 core radiator. When I dropped it in it would heat up at idle. My clutch fan was wore out, so I bolted on a direct drive fan. I also ran a spacer to push the fan deeper into the shroud. And yes I hooked up the Little bypass hose. I'm extremely happy with set-up because all my other BBC in the past tended to run hot.
 

AuroraGirl

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A testament to coolant quality: my 1999 park avenue runs about 210 idling but 180 down the road..... if I get the coolant flushed it will be about 180 down the road and 195 in idle
 

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