Hi... today I took off the top hose nipple (on the block, in front of the head)..... and took out the thermostat, (which looks to be the original ?) shinning a light down in there... I see this little knob about 3/4" tall that has an opening on the block side...... See photo #1 & #2 What is it There For...??? It's Function...?? I also pulled off the water pump.... the rotor & fins look good to me, (but what do I know.?).... the shaft has no play and rotates easily... I think I will just clean it up and put on a new gasket, lube it up and reinstall..... BUT..... there is no baffle behind it... I found a piece of brass or bronze metal laying in there (photo #3).... and looking in, I see what must be the front cylinder wall... and the water jacket opening is larger on the right (driver's side), and about half that size on the left (#4 & #5 photo)....... I am going to put that thermostat in hot water and see if it opens.... Please post a few photos showing me what the baffle is supposed to look like and how it is positioned in the opening, behind the water pump.... Thank you Guys for sharing this information with we, who are new to this.... Sunny
I am out of my depth with the knob and the baffle. Some years use a baffle and some don't, but you are in the right place. Someone will know. I cant remember what happens to those thermostats when they fail, but I think the bellows gets big and they go open. Boiling it will tell. I'll bet it's good.
Thermostat tested good opened at 160... ...opens wide... closes tight... Now I need to know about the Baffle.... This is a 1934 Master 207 engine... any info and photos would be greatly appreciated.....
You might want to try to find a picture of a good water impeller for that engine. Based on the pictures there sure seems to be a lot of erosion on the blades.
It also appears that the block has its share of corrosion buildup. The discouraging point is that the rear of the head and block tend to accumulate more rust and debris. Do whatever you can to flush the block and head.
If the thermostat is opening reliably at 160 it should be usable. Remember that a thermostat controls the minimum operating temperature of an engine, not the maximum.
The brass piece you have looks to be the remains of the brass baffle that should have been there. I suspect it rattled around in there long enough that it wore down the impeller lobes on your water pump. They should be a fair amount taller, and sharper. Buy a baffle plate from the Filling Station. It is a brass plate about 3 inches across that is driven into the area open in your block. Take the opportunity to run a wire in to that area to break any large rust particles loose to be flushed out with a hose. I have heard of people connecting a welding wire to a drill and spinning it into the block. If you have the head off that can make for a more thorough job of rust removal.
The little "knob" you show in photo #1 and #2 is a brass (or copper, I don't remember which) insert that was pressed into the bottom face of the head. It's purpose was to direct coolant flow coming up from the block into the head directly on the exhaust valve seat area of the head. This helped keep the exhaust valve seats (and thus the exhaust valves also) cooler so they would last longer. Here is a link to an old Chev movie from 1936 showing what you are looking at:
Watch the part starting at the 8:38 mark and running through to 9:19. Enjoy!
Has anyone here used Evaporust... as a means of dissolving rust in the block & head.... then flushing.... and/or running it in the entire cooling system until all the rust in the engine is dissolved.... and water running clear..... I hear it is a good product, and is non-toxic as well..... I will try to find a photo of good impellers on a water pump... so that I can compare them with mine.... Thanks for all the helpful advice & information... Sunny
Note that the water circulation in 1936 was not the same as previous years. The 1936 has no baffle behind the water pump and full length cylinder cooling.
