Can I bypass the heater core?

[jwinkler]

I've got a problem with the routing of the block-to-heater-core hoses going over (and overheating) my ignition control module (a HyFire that's apparently very heat-sensitive). Since the module worked up until I opened the heater valve and let water through the hoses, I would like to simply remove the hoses until I can figure out how to re-route them so they don't affect the HyFire.

Is there any problem with simply plugging the thermostat-housing outlet, and water pump inlet so that no water flows into or out of the heater core?

Thanks,

JLW

[Jack21]

You can install plugs on your heater core water outlet and inlet without affecting engine operation.

You can try insulating the hot water lines near the ignition module with some insulating pipe wrap typically used on your home hot water heater.

Heater hose temperatures (150 - 180 deg) are not that hot from an ignition module standpoint. Got to be more going on here than we can see. Called factory Tech Support?

All elce fails, take out the Hi-Fire and install an MSD6A.

[jwinkler]

Thanks for the reply, Jack - now I've got another question.

I see that I can get a plug to go into the manifold hole - what should be used to plug the inlet from the water pump? My water pump is stock Ford, with a clamp-fit inlet connection. Would autozone know what I was talking about if I told them I needed to plug it?

Thanks,

JLW

PS - the MSD option has occurred to me - Mallory tech support had no idea why the unit might have failed until I mentioned I wondered if it could be heat, at which point the response was "oh yeah, you can't have it around the heater hoses". Like you said - the hoses realistically couldn't have made it much warmer than it was normally in the engine bay, and I would have to imagine the Cobra engine bay has more flow than most cars that have the Mallory unit mounted.

However, since you've got a CR, do you think I might have it in a hot spot? I put it on the right side where the battery is originally mounted (on the ledge near the firewall).

Thanks again,

JLW

[ron427]

NAPA has rubber caps for the water pump in both 5/8 and 3/4 inch. i bought one of each about 5-6 months ago.
Ron

[Jack21]

Hello JW,

The aforementioned plugs will work on the inlet, and outlet. In a pinch, a short length of hose and a bolt clamped on the other end will work.

Battery mounted in stock location. MSD6A mounted on the little shelf where the OEM alternator control box goes. (Using Delco 12SI which doesn't need external relay box)

These MSD's haven't changed much (if at all) since the 70's. Had one on a '72 GTO. But work they do. Probably 70% of the folks on this forum are running MSD ignitions because they're so reliable and trouble free. And for a 351W, the same can be said for MSD distributors. Their Pro-Billet is a Delco unit on a Ford stalk. (Their vacuum unit is non-adjustable and needs to be replaced with a Crane, or Moroso adjustable vacuum canister so you can adjust the vacuum advance down to 8 - 10 deg vacuum advance at cruise).

Bottom line is you need your heater/defroster. (And/or you need to keep a towel in the car to defog windshield when it rains or it's just damp.)

It's this little sh!t that makes the difference between a daaily driver, and a garage queen.