Question on blocking off the heater core on a C2

[Larry E.]

Just looking in the future for my 66 Base Engine Non-AC. AFAIK I still have the original Heater Core
in the car. I only use the car in warm/good weather. Is there any simple way of blocking the water
that goes to the heater core? Any way to do this that will still make the cooling system to look stock?
Perhaps to eliminate the core completely and replacing it with some type of "U" pipe/hose inside the box?
Everything is OK now but I know I'm living on "Borrowed Time" with the core. As I understand to change
it is a "BEAR". Thanks in Advance>>Larry

[Bill M.]

Re: Question on blocking off the heater core on a C2

Larry the only way I have ever bypassed a core was at the pump very obvious. I think it would be as much work to I Instal a u tube inside the box as it would be to replace the core. It is a PAI but take your time and it will be well worth it. Bill

[Joe R.]

Re: Question on blocking off the heater core on a C2

To save time and hassle why don't you just remove the heater hoses at the firewall going into the heater core and fill the ends with silicone carefully leaving enough room to plug the hoses back into the heater nipples. Later you can just replace the hoses if you want heat or spend the time to replace the heater core. If the existing heater core ever leaks it won't be much as most has drained when you remove the lower heater hose.

JR

[Larry E.]

Re: Question on blocking off the heater core on a C2

Larry the only way I have ever bypassed a core was at the pump very obvious. I think it would be as much work to I Instal a u tube inside the box as it would be to replace the core. It is a PAI but take your time and it will be well worth it. Bill

Bill>Thanks for the response. True what you say but if done right it would be "one and done". Never to address this problem again. Larry

[Larry E.]

Re: Question on blocking off the heater core on a C2

To save time and hassle why don't you just remove the heater hoses at the firewall going into the heater core and fill the ends with silicone carefully leaving enough room to plug the hoses back into the heater nipples. Later you can just replace the hoses if you want heat or spend the time to replace the heater core. If the existing heater core ever leaks it won't be much as most has drained when you remove the lower heater hose.

JR

JR>Thanks for the response. Nice idea for sure. May just try it;but not sure the silicone could hold off the water pressure for any length of time. Better idea would be if someone make stock looking outlet nipples for
the water pump and intake manifold with built in blocking plates embedded in them. Anybody ever seen or heard of this? Larry

[Bill M.]

Re: Question on blocking off the heater core on a C2

Larry if you decide to do it be sure you buy a heater box seal kit and maybe a few extra of the pressed steel nuts They tend to round out. When removing

[Rick H.]

Re: Question on blocking off the heater core on a C2

I am considering doing this on my `67. My concern isn't heater core leaks as I recently replaced my heater core. My motivation is to reduce interior heat. After researching, I think I'm going with the shutoff valve shown in post #6 in this Corvette Forum thread. Using a valve that screws into the intake manifold is more subtle than an inline hose valve IMO, especially if you remove the black actuator lever.

https://www.corvetteforum.com/forums/c1-and-c2-corvettes/4181314-heater-shut-off-valve-s.html

[Patrick B.]

Re: Question on blocking off the heater core on a C2

I think it would be easy to tap the openings in the water pump and manifold fittings for small pipe thread plugs that would be covered by the heater hoses and totally invisible. If the holes were not close to standard pipe plug sizes, regular thread set screws with some sealer could be used. This would be very easy to undo if you decided to replace the heater core later.

[Larry E.]

Re: Question on blocking off the heater core on a C2

I think it would be easy to tap the openings in the water pump and manifold fittings for small pipe thread plugs that would be covered by the heater hoses and totally invisible. If the holes were not close to standard pipe plug sizes, regular thread set screws with some sealer could be used. This would be very easy to undo if you decided to replace the heater core later.

Thanks Patrick for this idea; best plan I heard so far. Larry

[Mike E.]

Re: Question on blocking off the heater core on a C2

What about freeze plugs the exact ID of each hose, and placing them in the hoses so that when you slide the hoses on the heater nipples, the freeze plugs butt up against the nipples?

[Frank D.]

Re: Question on blocking off the heater core on a C2

Well - you said "simple" and "look stock" in the first post - possibly an oxymoron...

On my '61 I just used simple shutoff valves in the heater hoses (BOTH of them) 3/4" and 5/8"; O'Reilly and others have them and when tucked up under the fender they are not too obtrusive and I never got a comment on them...no idea if the same could be done on a C2 but it does have some "ugly". But as my Dad used to say, "you're hollerin' before you're hit".

I don't know how radical I would get on a solution to a problem that you're anticipating but might never occur during your ownership..

[Larry E.]

Re: Question on blocking off the heater core on a C2

I don't know how radical I would get on a solution to a problem that you're anticipating but might never occur during your ownership..[/QUOTE]

Frank>Very true BUT if you put a search on this subject it has been a big big headache for many. Your last statement above could also be a " oxymoron.." Larry P.S. I would not hesitate to put a new one(Core) in but there is not one made in the entire world that has longevity/quality with it. JMHO

[Larry E.]

Re: Question on blocking off the heater core on a C2

What about freeze plugs the exact ID of each hose, and placing them in the hoses so that when you slide the hoses on the heater nipples, the freeze plugs butt up against the nipples?

Mike>Thanks for the idea; somewhat similar to JR's above which brings me to>>Not sure if it could hold off the water pressure for any length of time. Larry

[Mike E.]

Re: Question on blocking off the heater core on a C2

It has for about 12 years on mine, and it is regularly driven.

Mike>Thanks for the idea; somewhat similar to JR's above which brings me to>>Not sure if it could hold off the water pressure for any length of time. Larry

[Joe L.]

Re: Question on blocking off the heater core on a C2

All-------


While it can be done the way described for many vehicles, I don't think it can be done that way for any 63-72 Corvette with an aluminum radiator. These cars all use an external supply tank. If the hoses are blocked the supply tank is effectively removed from the system.