I'm replacing the HG today on my track car. I'm also maintenencing a couple things. I have a question. For those of you who pulled the hoses to the heater core what did you plug the nipples with? I've used vacuum nipple plug thingys in the past but they just crack and leak after a short while. Is there a silicone variant that works better?

Also, what's the break-in procedure after a new head gasket? Is there one? Can I just heat cycle the motor 10 times while the car sits on jack stands and then re-torque the head studs? Then am I free to run 23psi? Or is there some sort of gradual method?

 

Bah, just take the core out...you know you want to

 

I don't mean the nipples on the core, I mean the nipples on the coolant tube that goes around the back of the block which feeds the core.

 

Ah, well i've seen silicone caps at the hardware store, but i can't remember if Billitt used those or did something else on my car. I'll have my dad take a look and send me pics.

 

Please do. I need to get the car back together tomorrow. Anyone else have any experience?

 

It's been awhile since I did it and don't have the car handy, but I think I just used a piece of the old hose to connect the two nipples together. Rather than capping them off, I wanted to keep the water flowing.

 

I found out that there actually is a rubber grommet nipple cover thingy that is made specifically for the cooling system by the brand "HELP". It is sold at your typical auto parts store like advance auto.

lol, connecting the two hoses would have been a bad deal since one of them is smaller than the other and since it would totally send my cooling system to crap by connecting the hot and cold sides... "shorting" the system.

 

I'm confused here, the Heater core does the same thing as a piece of hose would, connecting the two water heater nipples on the Motor together. Am I missing something here? Hot coolant from the Motor goes thru the Heater Core and heats the air that passes thru it and then the returns back to the Motor cooler than when it left the Motor because of the heat transfer to the relatively cooler air going thru the Heater Core. The different nipple sizes on the Motor is a different issue but I don't see where the " "shorting" the system" occurs.

Bob

 

Yeah, the difference is that when the heater core is in the circuit you have that fluid being cooled by the air that goes across it. When it goes through the core and out to the "cold coolant pipe" that is behind the engine it is considerably cooler than the fluid that went in from just behind the thermostat. If you just put a hose there you're directly piping super hot coolant from behind the thermostat right into the coolant piped that is supposed to contain only coolant that has been cooled from the radiator. Make sense?

The water pump will create a suction pressure in the coolant pipe (behind the motor) and will continually suck hot water from behind the thermostat and pump it into the coolant pipe. This will also decrease the efficiency of the water pump.