HELP!! Edmunds Head on '55 Plymouth Flathead

[StreamlineDeco47]

Hey everyone,

Got a little dilemma, here. Recently got my hand on an Edmunds Aluminum head for my '55 Flathead. All the bolt holes line up. The only difference is, as opposed to the stock cast head, the 'hump' in the front for the water pump is absent. As you can see in the first photograph, this is how much lip is left once the head is aligned. The little bypass port is exposed. The second picture is just to show the area clearer. Does one plug the bypass? If so, any recommendations on what type of sealant to use to plug this? I've been going crazy trying to figure this out. Any tips would be helpful and appreciated. Thanks!

[Merle Coggins]

That head is for an external bypass setup. Recently a member on the truck side had a similar issue. His engine shop plugged the coolant port in the block and he used the external bypass thermostat and housing.

 

Merle

[StreamlineDeco47]

That head is for an external bypass setup. Recently a member on the truck side had a similar issue. His engine shop plugged the coolant port in the block and he used the external bypass thermostat and housing.

 

Merle

Thanks for the response Merle! So, I need to have the external setup for my thermostat? Do most shops do plugs on blocks like this? 

 

=Adrian=

[StreamlineDeco47]

After doing some research, I realize I will also need to get a water pump without the bypass port to the water passage in the block. All I would need then is a new thermostat housing with the external bypass and just plug up the hole in the block. Correct me if I'm wrong anyone?? 

[_shel_ny]

After doing some research, I realize I will also need to get a water pump without the bypass port to the water passage in the block. All I would need then is a new thermostat housing with the external bypass and just plug up the hole in the block. Correct me if I'm wrong anyone?? 

If your water pump is good you can just swap the back plate to the other style. Maybe someone has a plate.

[StreamlineDeco47]

Thanks shel_ny. Do you think a different backing pate would block off any water from seeping through? The passage being there would'nt interfere with anything?

[_shel_ny]

That I do not know for sure, but the water pump gets a gasket, and the water from the distribution tube hole does not leak out, so it seems that it would not leak. You are talking '55 engine that would indicate pressurized system, but don't know what you are putting it in, so pressurized may or may not make a difference.

 

 

 

EDIT: your water pump would also need to have the spot to mount the bypass elbow with the connection to the external bypass thermostat housing, so a new pump may be needed anyway.

Edited November 14, 2014 by shel_ny

[StreamlineDeco47]

Thanks for the response! My water pump has the top spot to mount the bypass elbow to route to the thermostat housing elbow on top of the cylinder head. I found some backing plates without the extra hole for the bypass on the block. We will see how that works once I receive it.

[Merle Coggins]

I wouldn't worry about changing the water pump plate. If the port in the block is plugged then there will be no connection to anything anyway, so essentially the water pump port will be blocked.

You'll just need the external bypass thermostat housing and connection elbow for the top of the water pump.

[StreamlineDeco47]

Sorry for the late response Merle Coggins. I already found a replacement backing plate without the hole for the bypass. I plan on plugging the block port, as well. Thanks! I will fill you guys in on how it works out. I'm sure someone else will (or has) run into this issue.

[countrytravler]

What was the end result?