Changing water flow in block

AL in NY

AL in NY

Well-known member
With all the threads talking about how much hotter cylinders 3 and 4 run in a Model A engine, which also leads to most head gasket failures in this area, has anyone ever tried putting in a piece of metal just inside the water return inlet on the side of the block to divert most of the incoming water to the back of the engine? I realize there is a small cast piece that is suppose to do just that. My thoughts were to try and divert all the incoming water to the back of the engine. What do the experts say?
 
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Yes. I block off the water passages at the front with pieces of thin beer can, over the head gasket. Leave one small bleed hole open, and it works like a charm.
 
On the subject, as a newbie, I take laser temperature shots of my engine after every drive. I notice the base of the spark plugs are about the same +1 or 2 F. for #3 and #4 as compared to #1 and #2. I wonder though if a better measure would be the drive side cylinder walls... Or would this not really be good way of measuring the heat differences of the engine?
 
If you are taking a temp. reading off of the spark plugs, If spark plug adapters are used the temps will be higher because the plugs can't transfer the heat to the water jacket the same.
 
When the side water inlet is removed, you can see a baffle at the rear of the hole. I've read that if a hole is drilled in this baffle that flow will increase. It seems that it would probably help. I hesitate to recommend drilling because I don't want to be responsible if it doesn't work or causes other problems .
 
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Purdy, the baffle is in the front just on the backside of cylinder #2. The inlet water can go straight in between cylinders 2 and 3 with the stock baffle trying to divert some of the water to the rear of the engine. My thought was to block that straight in flow and divert most water to the back of the engine along the left hand side of cylinders 3 and 4. Just wanted to know if anyone had tried that before and what their results were.
 
Wouldn't running a restrictor in the upper hose do the same thing? (or a thermostat) This would add pressure to the flow and force some of the incoming water to run to the back of the engine where the pressure is less.

Frank
 
Coolant will always flow from the highest pressure to the lowest pressure in the shortest path possible. In the case of the Model "A" and Model "B" engines, coolant will take the shortest path from the water inlet on the side of the blocks to the water pumps. Redirecting the flow stream using a deflector at the water inlet as FoMoCo did will not work.

There are two ways to get positive coolant flow to Cylinder No. 4: Move the water inlet to the water jacket aside Cylinder No. 4; Run a pipe to the water jacket aside or behind Cylinder No.4.
 
Jim Brierley said:
if it ain't broke, don't fix it!
Click to expand...

Hey Jim,
Ha,ha...that brings a smile, !

Yeah, 'don't FIX it', but MODIFY it, eh ..whoohoo :D
What ever happen to the idea that someone brought up ,about tapping the rear of the block/head area to deliver cooler water to that area via piping. I guess the idea was to provide 'extra' cooling to rear of head/block area :confused:

BTW...There has been lots of threads/talk about how it is hard and/or cannot be easily done ...to remove 80+ years of corrosion from the rear of the A/B block. My opinion is that if you ensure that that area is **** and span clean when redoing/rebuilding a block, that cooling problems will be taking care of thereby. Offer of proof is that I run a NOS B block that has never overflowed and I have to use a thermostat to bring water up to a good operating temperature...ergo, no rust no overheating #3 and #4.
 
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Here's how I do it.
No heat problems even when running flat out at 100 mph.
 

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There are two ways to get positive coolant flow to Cylinder No. 4: Move the water inlet to the water jacket aside Cylinder No. 4; Run a pipe to the water jacket aside or behind Cylinder No.4.
I have a motor that has that done
 
What Pete shows is the best way to do it, and several of the old engine were built this way. Having a similar water manifold for the outlet would also be great, and the best way to ensure even coolant to each cylinder.

Even though Pete has the ultimate, with a good radiator and CLEAN block, the stock Model A will do fine.
 
Pete said:
Here's how I do it.
No heat problems even when running flat out at 100 mph.
Click to expand...

Hey Pete,
Yeah, that looks like a different approach for cool water delivery, for sure !
What sort of tool do you use to cut the block, for inlet holes ? Nice work. Is that a Price head and what cr ?
 
hardtimes said:
Hey Pete,
Yeah, that looks like a different approach for cool water delivery, for sure !
What sort of tool do you use to cut the block, for inlet holes ? Nice work. Is that a Price head and what cr ?
Click to expand...

End mill.
Yes that is a Dan Price head.
Same procedure for model A block.
 

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