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Was having problem with overheating. Disconnected the radiator hoses and jury rigged a set up to flush the radiator and the block separately. Flushed each both ways. Took off water pump and inspected it....looks OK. Ran the car and it was better but still wanted to overheat. My suspicion is that the radiator may be the problem. My questions are:
1. Is there some chemical like CLR remover used in the bathroom that can be poured into the radiator and let sit and then flush out?
2. How big a deal is it to remove the radiator?

Thanks Bill

Oxalic acid solutions will assist in removing rust buildup, available at most any decent hardware store. It was the active component in the vintage duPont radiator cleaner. Use about 2 cups in 5 gallons of water. Go for an hour drive and let the solution get good and hot. You'll want to use a neutralizer afterwards, something like sodium carbonate. Consider doing a before and after flow rate test on your core.

Yes, it's a significant job to remove the radiator, it must come off with the shell and shutters as an assembly. Really heavy, wrap the headlights with cushioning and rotate them out of the way to prevent accidental damage, it's close quarters. Of course you'll have to remove the hood and the radiator support rods; consider the use of a block and tackle.

Didn't I suggest a while back that if your oil cooler had been blanked off, your problem may be with the internal baffle at the front end of the water jacket plate? I don't recall your ever clarifying that issue.

Yes you did suggest that the problem might be where the oil cooler was removed. I've been trying to step through different things before committing to taking the water jacket cover off. Like I say, the flushing I did modulated the problem but has not seemed to solve it. As far as putting a cleaner in and driving the car for an hour, I estimate it will start overheating in the first ten minutes so I don't think that's a viable option. I was looking for some acceptable solution to put in the radiator and then flush profusely perhaps with an, as you say, before and after flow rate test.

I wouldn't think a radiator cleaner would be very effective just sitting static in the radiator, but what do you have to loose other than some time and the cost of the oxalic acid. Preparing the oxalic acid solution with hot water would increase its effectiveness; give it a good long soak and consider perhaps using a heat lamp to keep it warm. And don't forget to flush and neutralize after you drain it.

Took the plate off where the oil cooler used to sit. There are two rectangular ports, presumably for entry and exit of water to the oil cooler. There is not any sort of baffle or deflector there. Still learning about the car. It looks like that side cover (the water jacket cover?) is essentially a channel that accepts coolant at the front and then the coolant goes out at the back of the engine into the cylinder bank cavity. Do i have that right?

Most inner water jacket plates that I have seen have holes between each cylinder, some have short nipples to direct the flow closer to the cylinders.
You might talk with O-D about replacing the 34 plate with a 33 that does not use the same oil cooler.

Bill, apparently I haven't done a very good job explaining the unique 1934 system to you, so let me try again. And remember 1934 was the first year for the full-flow oil filtration and the oil cooler, and the only year with the cooler fed its coolant water from the water jacket side plate.

For 1933 and prior years, and 1935 and later years, on this style engine the coolant enters the side jacket plate from the bottom of the radiator and flows down a channel within the plate created by an internal plate or cover. In that innter plate are openings so as the water progresses down the length of the plate it has exits for each cylinder to distribute the coolant to all cylinders more or less uniformly. There was a later 1934 style plate with nozzles for the water rather than simple openings (see the service letters for illustrations) but the net effect is the same.

BUT NOT FOR 1934.

You're right, when you removed the cover that blanked off the opening for the oil cooler you saw two rectangular openings, one for coolant entry and one for exit after it had circulated thru the core and cooled the oil. After the water enters the side jacket plate from the lower radiator hose, it is no longer free to pass unrestricted to the rearward cylinders, if so the cooler would be nonfunctional. Instead within the side jacket plate there is a small baffle that directs the water specifically into the oil cooler; after it exits the cooler it is free to resume it's path to the rearward cylinders. Unless whoever eliminated the cooler and blanked off the openings in the side plate then removed or bent out the the way the small baffle within the internals of the water jacket side plate that directs this diversion of flow, the coolant is no longer free to flow unrestricted to the rear cylinders. Yes, some will get there by being forced past the little baffle.

So you have some choices to undo what was previously done if in fact it was done incorrectly (something we don't know yet):
1. Find and reinstall the oil cooler. Lots of challenges with this choice.
2. Leave the cooler off and remove or flatten the internal baffle that is now trying to force the coolant into the cooler that is not there.
3. Install a water jacket plate from and earlier or later engine.

And just to add, to my knowledge we can't be sure this is the reason for your overheating, but it is a not uncommon problem on modified 1934 models and should be checked out. The reason for your overheating may still lie elsewhere.

Owen, I think you have done a great job of explaining and I really appreciate your patience. Sometimes though, it is hard to understand what is meant until I actually see it. So with the flat plate that is in the oil cooler position removed, I can see a limited portion of the channel inside the side jacket plate. I see to deflector or baffle anywhere near the two rectangular holes. There is a sort of 'nub' that may have held one but there appears to be no restriction at that spot. With my limited view I see no openings between the channel and the cylinder bank except at the front and I think at the rear. I can see those with much difficulty by inserting a boroscope down the channel.

Don't know if you resolved this yet but I'll play too. A rusted coolant baffle will disturb the circulation as engineered. The radiator flow rate is supposed to be like 50 gal per minute. So if you dump 5 gallons of water in and it flows out in 6 or 8 seconds? Radiator OK. Let's assume you have flow at all and set any water pump discussion aside.

So far we're at check for a rotted baffle plate and I'll assume you can put a finger thru that rectangle hole and see it in the other one? Let's hope so.

Now let's get to an often overlooked issue. Hows the ignition timing? Late ignition has been "salesman of the month" for radiator/cooling systems lots of times. If the timing in off 3 or 4 degrees its gonna run hot. Might idle ok, a little warm, but load it and it's ready to make coffee (!). Worth a look. I had an old pattern for the 34 baffle and used to whip up a new one out of thin stainless. I think there's 5 holes in it, and the idea is to even out the coolant flow on those long motors. To put us all at ease (although it's been a while) I think there was a separate baffle in the "pack" for the oil cooler. To explain, cooler, gasket, small baffle, gasket. I'll check my parts book and admittedly I'm peeking thru memory cobwebs. That's all for now...