ls1_chevelle

iTrader: (9)

I was reading through several threads and there doesn't seem to be a positive answer towards where to bypass this hose... Most methods are backed with "Well my engine doesn't over heat".

I would like to tap into my waterpump seeing how it's cleaner, but others say to bypass it into the pressure side.

My rad is just a stock recored 72 rad.... I have a 15lb rad cap, and the little thinger for when it overheats and kicks out...(I don't have a seperate fill tank, should I and if so HOW should I?). I'd like to keep a 1 peice upper rad hose and not run a long line.

These are the main threads that I read.... Any thoughts or input guys?

https://ls1tech.com/forums/showthrea...ht=heater+hose

https://ls1tech.com/forums/showthrea...ight=TB+bypass

https://ls1tech.com/forums/showthrea...ight=TB+bypass

Edit: Heres what I ended up doing... This is now GM does it. Its just a peice of copper tubing with a copper tube soldered to make a "T".

-Matt

01PewterWS6

Im in the same boat you are, id like to know too...
Im using a carb intake, and wont need the line(I had thought about just blocking it off, BUT thanks for the links, seems thats not the way to go)

If I run it to the nipple on the radiator, then I wont be able to have an expansion tank(unless I get another barb welded on)

Hope someone has more insight...

67pete

I'm pretty sure it must go on the pressure side of the radiator(the overflow tank is on the non pressure side). Someone makes T's that go in the high side radiator hose for this return.......

5.3 racer

iTrader: (8)

you can't run it to your expansion tank, you'll fill it up. the "bleed" has a constant flow of coolant. some members have fabbed a union in their upper hose with a nipple to connect the hose to. if i were you i'd remove my radiator and take it to a radiator shop and have them solder a nipple into one of the radiator tanks. you could also at this time upgrade to an aluminum radiator. my northern radiator already had provisions in it for a small return line. it was less than $300 for a universal gm rad with tranny cooler.

ls1_chevelle

iTrader: (9)

I get pretty good deals on rad work so I just opted with getting my recored. This way if it leaks I can still pull into a huck town and get someone to fix it up for me.

I was thinking of buying a T to go in the pressure side(feeding) the heater core, this way it will pull the coolant from top to bottom, rather then fighting against it and trying to push it upstream. This is how GM does it from the factory....

Oh, Getting another barb soldered onto the rad looks tacky(unless you do it like Steve did with a braided line) but my engine sits back quite a bit so I have quite the space between my rad and engine. Equalling one ugly *** line.

I'll wait till we get a few more comments.

-Matt

MrDude_1

iTrader: (4)

no.
it must goto someplace in the system WITHOUT pressure.

coolant/air must be able to constantly flow out of the hose... stock does this by returning it to the radiator, or returning it in the heater core RETURN hose.. and thats the same passage as having it on the upper radiator hose...

ls1_chevelle

iTrader: (9)

So Andrew is wrong by saying this?
-Matt

69blackwidow

iTrader: (1)

i was looking at this today, why can`t you just plug it at the t and be done with it. i don`t think you need it. its just for cold temp warm up right ????? MIKE

John McGraw

67pete is correct. The line MUST run to a part of the pressurized system, preferably the return side of the radiator. If you run it to the expansion tank or any other unpressurized portion of the system, you will empty the cooling system out, and the system will never build pressure. It is not necessary to run it through the TB, but it is necessary to run it somehwere that will bleed the air and steam out of the top of the coolant passages. It just should be returned at a point where the pressure is lower so that natural circulation will keep the air and steam purged out. Plugging this line is not a good idea and will cause hot spots in the block where water will never get due to air pockets. While the purpose of the line is to purge air, it is also used to heat the TB. Most performance guys will bypass the portion of it that goes through the TB, but the line still has to vent the air!

Regards, John McGraw

Keith

Could you drill and tap a fitting into the return side of the water pump? Run a short line just to the water pump, instead of al the way to the rad?

ls1_chevelle

iTrader: (9)

I just got a peice built for the return line on my heater core. Both lines(going in and out) of the heater core are at 16psi. This is how GM does it from the factory. I'll just copy them!

-Matt

John McGraw

LS1_chevelle is correct, the GM trucks are done in this very manner.

01PewterWS6

On that note, can standard rubber lines take 16psi?
Or is it a better idea to run a pipe with minimal hose(only for connections)?

ls1_chevelle

iTrader: (9)

The stock hose for the TB(1/4"ID) doesn't see 16psi... The heater hoses do. GM runs the very same rubber line that exits the TB to the heater hose. Just go to your local parts store and buy some 1/4"ID rubber line.

-Matt

01PewterWS6

I was asking about the heater hose lines.(if stock rubber hoses can take the pressure)
Also, how would the tb line dump into a higher pressure hose?
(how would it get the air out, if the pressure isnt the same as the heater hose lines?)

ls1_chevelle

iTrader: (9)

The stock rubber lines(for example on my 72 Chevelle) will take 16psi easy. It works by suction.... The TB line dumps into the heater hose which is flowing at 16psi into (or out of) the water pump. This suction will pull the antifreeze from the TB down. If everything is sealed, there is no way possible for air to stay trapped at the top of the heads. Just like bleeding brake lines!

-Mattt

01PewterWS6

Cool, thanks for the explaination, makes sense, I just thought about it wrong.

67pete

For those interested here is a company that offers some T's .....

https://shell7.tdl.com/~jags/Pages/P...rass-Tees.html

the company JTR(Jaguars That Run) offers a variety, but it needs to run to a lower pressure area, such as the upper radiator hose, so that the air pressure that builds in the TB area can escape to a lower pressure spot.

MrDude_1

iTrader: (4)

hes saying the same thing i am.


in order for water to flow, it must go from a low pressure area to a high pressure area.

the reason this thread seems confusing is that we're all using different terminology.



if i get a chance at work today, i'll draw a pic and see if i can make it clearer.. but we're all saying the same thing.. lol.

ls1_chevelle

iTrader: (9)

You confused me with saying no.
it must goto someplace in the system WITHOUT pressure. in response to "I'm pretty sure it must go on the pressure side of the radiator(the overflow tank is on the non pressure side). Someone makes T's that go in the high side radiator hose for this return......."

-Matt