I apologize if this has already been discussed somewhere on the forums previously, but I attempted a search and found nothing on the topic.

My question to the group is concerning the ducts connected to the heat exchangers which direct warmed air up to the heater blower for the cabin. I recently rebuilt my motor and reinstalled in in the car, but I'm not sure I care to hook up all the little parts for the heating system.

My main concern is whether or not the engine required these parts to function properly. If these components really are just for the warming of air to be sent to the cabin, then it can wait. I'll worry about hooking it all up once everything else is done and the car is drivable.

Thanks for all your help and wisdom!

No need besides window defrosting can be kinda important. The motor will not care either way. Just make sure the heat exchangers are not dumping hot air on the fuel lines. That was a stock "feature" when they built them.

Thanks for the input.

I'm mainly trying to prioritize the "important stuff" so that I can get this thing back on the road. I'd rather spend an hour putting my calipers back together than fiddling with the heater ductwork.

As long as the air that flows out of that section doesn't impact the cooling of the motor, I'm fine with leaving it off for the short term.

Until you can fully install all of the components, cap the 2 ducts entering the cabin. The Aux fan is removed from the equation as the engine cooling fan speed increases. The 2 small ‘doors’ on the shroud are forced closed by the hot HE air. I took the fan off my car and capped the J tubes. A well sealed system will provide plenty of heat and defrost air. The HEs should be free of rot.

When I was planning my build, the heat exchangers were not in the build. Things changed and did use them. However I did pressure test them prior and being in the Northeast it is nice to have cabin heat. I do have another build without the thin gauge jackets and things run are just fine.