1936 Overheating Problem

[Ketronj281989]

Overheating, one of the major issues my 1936 has been plagued with for what would seem like at least several "decades". I say decades as someone installed a plastic overflow tank back in the 1970s or 1980s before the cars was stored away for the next 30+ years. Upon previous owner take out of storage, the overflow tank was still on the car. Since my purchase and now possession of the car I plan to take everything back to a stock outfit as it was brand new off the line. I have since removed the plastic overflow tank and have started my trouble-shoot of the cooling system in this car.

Notes: After flushing the oil and cooling system I deemed the car safe for driveway idle and movement confined to the drive way area at the house. Regarding the cooling system I flushed two times, second time with a mild rust remover. Bits of rusty iron (size of crumbs) as well as brown murky coolant came out on 1st and 2nd flush after I drained the initial green Prestone the previous owner added 2 years ago. I used distilled water as a flush agent between and after each chemical flush. No acid in chemical flush. This engine has never been pulled and likely the water jackets inside the block have plenty of rust and contaminants present.

I figure it will take several flushes to remedy the rust issue (it will always be present to some degree since the engine has not been rebuilt). I will complete several more flushes in the near future to help with that issue. Stock original water pumps are on the car, never pulled or re-built, stock original radiator, never pulled or serviced, radiator hoses 30+ years old, fan belt 30+ years old, thermostats missing (they were in a box inside the trunk upon my purchase) Looks like they were pulled many years ago, likely back in the 1980's as an attempt to try and remedy the overheating issued that was had back then before I purchased the car.

The cooling system will need a tune-up.

WHY I KNOW I HAVE AN OVERHEATING PROBLEM: Two separate occasions under different outside temperature days I let the car idle in the driveway under no load. Day one the temperature was 80 degrees F (afternoon). Day two day the temperature was 58 degrees F (early morning). Constant factors: Coolant 1 inch above radiator tubes and car stopped-throttle at idle. I used distilled water as the coolant+water wetter. Fill up 1 inch above radiator tubes allowed space for expansion of coolant upon heat up. On both days after about 20 min of idle the car overflow tube on front of radiator let steam and water droplets out the bottom. Upon both occasions of steam and water droplets, my temperature hand gun showed 220 degree F on each head near water pump inlet (on cast iron head side) as well as 220 degree F on top end of radiator. Bottom end of radiator showed 190-200 degree F. Car dash temperature gauge level showed halfway mark between the bottom of the tube and first line on the dash gauge metal face. Temp gauge did not max out, fluid in tube moved to halfway mark (temp gauge appears to be factory original).

From research and intense study of Ford service books circa 1936 to 1940, I kind of realize what I will need to do to service the cooling system. I want to complete a process of elimination first before I decide to take off the radiator for a re-core or factory reproduction replacement exact to the original. Pulling the radiator will be a job for this winter when I plan to service several other items that sit behind the radiator (including dropping the oil pan for the first time).

Several questions:

How should I proceed with the water pumps? - Both on my car appear to be factory originals and look to have never been taken off or re-build, never. I have discovered Drakes as well as Third Gen sell rebuilt "improved impeller" water pumps that are identical to the original style and type. What are your recommendations? I want to keep this car as original as possible and realize I will have to do something with the water pumps. They could be part of the overheating issue.

What are your thoughts on radiator servicing? - Likely a major culprit regarding my overheating issue. The tubes and catacombs could be clogged. I could have the radiator "re-cored" or purchase a brand new perfect reproduction to stock original. Would it be wise to start fresh regarding the radiator in order to eliminate trouble-shooting guesswork after other cooling parts are addressed?

Fan belt, how do I know the proper tension? The shop manual states perfect adjustment is obtained once the belt can be moved in and out 1 inch. What is meant by this? This is my first Pre-war car purchase and experience. Is there a "best" belt to purchase. I noticed Drake and Third Gen both offer belts.

Appreciate any help!

Jon