Over the weeknd I had the car up and I removed some of the heater pieces down under the engine. The PO had removed the blower motor but I had venting hot air up into the engine compartment.

I took out a couple of trapezoidal shaped plates that held the ducting attached to the exchangers.

So no the exchangers are there now with no ducting attached to them. I can see the bottom end of the heads, push rod tubes and valve covers.

Also now exposed on each side of the fan are square openings that have flappers and puff air.

can I drive like this? Do I need to close up those square vents somehow?

You probably could run that way, though you would be losing air that could be used for cooling the engine if they are left open. As the air would flow through the heat exchangers and out of the control flaps if the heat was turned off, the amount would probable be negligible, but every little bit of cooling helps IMHO.

My car has no heat, everything has been removed. The PO covered the lower fan housing outlets with sheet metal. I agree that covering them probably has minimal cooling effects but what the heck.

I think I would like to close them since more air is better and i think it may quiet it up a little bit.

Not sure how. JB Weld? or will that fry off. Welded? Is it magnesium?

As I preface most of my threads... I'm no expert. BUT, I do recall a thread about this very recently. Jake Raby did testing and found that if anything this might make the car run hotter! Be careful. I'd do some testing before doing anything permanent. I never had mine closed and never had heat and my car (1.7) runs real cool.

with my stock 1.7 TIV running D-JET I have headers, no heat, and open flaps at the bottom of the fan. For four years. Raced 12-14 AX races in that time. Oil temp never over 200F. Stop and go traffic in the CA summer, oil up to 210-220F.
No worries

mice

you NEED to run cool air thru the heater exchangers all the time the motor is running. the system as designed is supposed to always have air flow when the motor cooling impeller is turning, the electric fan (you say removed) is for additional air flow for added cockpit heat.

the air from the motor impeller is flowing thru the heater exchangers even when cockpit heat is off. When off ,the heated air is dumped out the heater valve (valve either dumps the heat under the car, or directs it to the cockpit.

with no air flow thru the heater exchangers, they will over heat and fail prematurely (ie leak). they may radiate more heat to the heads when no air is flowing thru them.

You need to reinstall the heater stuff if you keep the heater exchangers. If you dont have the electric heater booster fan, then you should block off the two holes that the duct hose passes thru on the side sheet metal, this will stop hot air from getting into the engine bay, AND still allow the motor impeller to cool the heater exchangers.

the flat plates that go under the pushrods can serve two purposes, one is to help the air flow out of the bottom of the motor, by better directing the air flow into the slip stream. they also can serve to protect the fragile pushrod tubes from damage from debries.

yes you are right in seeing the need to block off the hot air that was entering the engine bay, however you did not go about it the correct way, and this can damage the heater exchangers.

As for as the rectangular holes on the impeller housing, block them if you run no heater exchangers, but if you run heater exchangers hook the ducting back up, and instead simply block off the two duct holes in the side engine tins, that will prevent hot air from entering your engine bay, and will protect the heat exchangers, and allow you to have heat in the cockpit when needed.

i would reinstall the l&r warm air guides. they also provide some degree of protection to the push rod tube area and help secure the he's to engine case.

k