which ones are the bloody heater in/outlets on a sbc?

[marq]

Ok guys need some help here,which ones are the inlet and outlet heater pipes on a small block chev?can't seem to get a workshop manual at the moment because i'm tight and i know you helpful guys know..................Marq

[BELLM]

Might be wrong but seems like older ones had 5/8" hose going to the intake and 3/4" hose going to the water pump. Later all were 5/8". Don't think would matter if heater core takes same size hose on both sides. This really doesn't answer your question but hope it helps.

[CURIOUS RASH]

<font color="green">Yeah,

Mama's 59 has a 3/4 line into the top of the water pump (long) and a 5/8 line in the intake passenger front.

Now, the smaller line should be pressure and larger should be return.

The larger hose probably to aleviate pressure on the heater core. Although I would think the cooling value would aleviate it anyways.

But, It would seem the feed side would come from the pump and the return would go to the intake manifold where the return water would return to the radiator.

I guess it doesn't really matter.

Your heater inlet outlet should be two different sizes.

Big one runs to pump, little one to intake.

Good luck,

RASHY </font>

[skipperman]

The FEED line ( hot water supply to heater ) is from the intake manifold ...then...3/4 hose to heater...then 5/8 RETURN to the water pump. You can use 5/8 on both ....

jersey Skip

[marq]

Thanx guys another few bucks saved that i can spend on the truck

[DrJ]

Now you think you've got that figured out, how do you know the heater core isn't upside down? http://www.jalopyjournal.com/ubbthreads/images/graemlins/wink.gif
I don't think it really matters that much. if you don't have flow it won't get hot and pressure is going to be baxically whatever the radiator cap pressure is. As far as pump pressure goes, th heater core isn't inline to the engine coolant flow, it's parallel so if it doesn't want to handle an increase flow it doesn't have to because there's pleanty of block for it to go though instead. If the water pump is building pressure in the engine like it might at high RPM with a cold closed thermostat. tht pressure is going to affect either side of the heater core, unless the heater outlet goes straight back to the radiator. At least that's what I think...