Rebelrob

Hello,

Need some direction on some heater hose connections and the short hose that runs from the intake to the water-pump for BBC.

This is NOT my engine. I pulled it from the forum. It belongs to 71Coupe454. Very clean BTW...

1. What is the function of the small hose that runs from the intake to the water pump? I have seen a few with this connection capped up, but most do have the hose in place. Also what type of pipe connections is this hose connected too? I obviously cannot tell since the hose is connected See pic below. Does anybody have a pic of these? Or do I need to purchase ones similar that I have displayed below.

[IMG][/IMG]

2. What size heater hose from the intake and water pump? Not the lenght but the diameter.
The heater hose pipe connection from the Water pump is larger opening/diameter than the heater hose connection from the intake.
See pic below.
The corroded/rusted connection ON THE LEFT is the original connection
from the water pump.
The corroded rusted connection on the right is the original from the intake manifold. They were difficult to remove.
They both have different diameters. Do they take two different size hoses or does the screw clamps take care of that when you tighten it down?

[IMG][/IMG]

Here is another shot of the same original connections with new parts looking down. The intake manifold connection is sized smaller hole. Actually the original size hole is a bit smaller than the replacement part.

[IMG][/IMG]

Thanks,

midyearvette

the 5/8" nipple and hose go to the intake manifold and then to the small nipple on the heater core
the 3/4" nipple goes to the water pump above the lower hose and to the larger heater core nipple

BHRIG

Great engine!!!!

One observation, I would loose that GLASS fuel filter!!!

The tend to leak or break easily..

FIRE HAZARD

Rebelrob

Not my engine, its just a pic for a reference. But yes it is nice.

OK, I will make my edit here, since I was successful with the search tool.
The small hose that runs from the top of the water pump to the intake, looks around 5 inches or so is a Bypass hose. I remember reading about this but never had any pics for a reference.
I have read several conflicting opinions, and I am not wanting to stir this subject up. Seems that the SB water pumps have this built in and the BB water pumps do not and use the hose.
Bypass hose: The main purpose of the hose is to circulate a small amount of water during warm-up of the engine. If the bypass is removed the existing water in the block heats up very fast and can cause a shock to the engine when the thermostat opens with cooler water.
Sounds like its a good idea to install this hose vs plugging these ports up.
Thanks for the hose sizes above....

baxsom

Not sure of the size of the bypass but I do know that it is not normal heater hose. It is an actual part already preformed and ready to install. I have read a lot of people either drill holes in the T stat to let water circulate or take the t stat out all together and plug that hose up. It works fine in my BB. I found the hose in stock at the local Napa.

Rebelrob

thanks for the info baxsom, I ran across similar reads as well about the whole drilling the thermostat with holes. The hose is 4.5 inches. I plan to use it, I just wanted more info on the subject/ what its function is, etc. Now after reading, I think I am informed.


Can anyone recommend what type of fittings to use for the bypass hose? Will one of the types I have pictured above work or do I need the one with the small diameter hole?

Bob Heine

On my 72 BB, the 3/4" hose makes a detour through the radiator expansion tank. The side tank on the BB radiator doesn't have a filler, just a small 3/8" pipe that bleeds air from the top of the radiator into the expansion tank. If you're installing a big block, that expansion tank is pretty important because it's the only part of the cooling system that's higher than the engine water jacket.



Lots of folks put a shutoff valve in the hose going to the heater but that means there's virtually no circulation through the expansion tank or any coolant returned to the intake manifold. I think a H-pipe bypass would be a better solution than just shutting off the flow.

eastltd

Well, did you order the Mikalor clamps?

Rebelrob

Those sure are nice, much cleaner/classier looking than the original type. They are pricey though....

I asked above, but can you tell me what type of fittings you you used for your bypass hose? I mentioned above, they seem to come in different outlet sizes where the hole is small or opened up like I have pictured above. I do not want to buy one that is too restrictive for flow or too much flow.
Thx,

eastltd

Sorry Rob, I suffer from CRS.

Looking at them the are stainless, but I couldn't confirm the size without taking things apart.

Bob Heine

I measured mine and they are 3/4 inch. Unlike the ones for the heater hoses, these fittings have no hex, just a slot for tightening.



I don't remember off-hand where I bought the fittings but Volunteer has something that looks pretty close.
http://www.volvette.com/CL095.html

Rebelrob

Bingo........ thx BOB... that is the pic I was looking for. If you see my pic above, I have the same type that I pulled from the original water pump, its all rusty. What is with the slotted top on these?? I do not like these as you cannot get a wrench on them. The replacement I bought at least has hex pattern on and I can get a wrench on it. I had to take the old one off with a pipe wrench. So now I can see that they have a large opening which was my first assumption.
Both you and East have some envious engines. I like the silver brackets. That is a nice touch.
Thanks,