Staright 8 water dist

[martanke]

I'm rebuilding the straight 8 Chrysler Royal marine engine in my boat, using a 1950 industrial IND-12 block as base. It's pretty much identical to the C49 block.

 

I'm a litlle confused about the hole placements in my new water distribution tube. Laying it on top of the engine I had expected the holes to align with the exhaust valves. But as seen in the attached pictures they don't. The hole spacing is the same as the exhaust valve spacing but they seem to be offset. If I line up the holes perfectly with the valves the tube won't fit inside. Is this the way it's supposed to be or should I open the holes to improve coolant flow towards the valves?

 

Thanks

[Sniper]

I suspect the offset is there because if it was directly aimed at the valve center line it would be obstructed by the valve pocket casting.  I suspect the offset is to allow the coolant to flow around the valve pocket casting , carrying off the heat and then unto the water outlet and ultimately the radiator.

[Sam Buchanan]

That will be one cool sounding boat!  

 

The little Suzuki on my little ZIP runabout would run and hide.......   ?

 

[martanke]

That's a beautiful boat though!

[Ivan_B]

If you look at the same pipe for the in-line 6 engine, you will notice exactly the same configuration of the openings. I suspect that the openings are not aimed directly onto the exhaust valves, but are rather evenly spaced-out throughout the block to provide more even coolant circulation to the working engine in general.

 

Later: actually, the above assumption might be incorrect, since the engine diagrams seem to show the openings directly where the valves are ?

 

 

Edited January 23, 2024 by Ivan_B

[Dodgeb4ya]

Tomorrow I can post a picture of an original factory water tube if you like?

[martanke]

21 hours ago, Sniper said:

I suspect the offset is there because if it was directly aimed at the valve center line it would be obstructed by the valve pocket casting.  I suspect the offset is to allow the coolant to flow around the valve pocket casting , carrying off the heat and then unto the water outlet and ultimately the radiator.

Maybe that is it.

[martanke]

1 hour ago, Dodgeb4ya said:

Tomorrow I can post a picture of an original factory water tube if you like?

Yes please do!

[Tired iron]

I used to own a seamule pusher tug with a pair of straight eight Royals in it. Great motors. I sent you a pm cause i've got lots of extra parts.

[Dodgeb4ya]

Here is a picture of a tube out of a 1946-50 eight with mrasurements to the center line of each cooling slot...the arrows point to each exact measurement center line.

[martanke]

2 hours ago, Dodgeb4ya said:

Here is a picture of a tube out of a 1946-50 eight with mrasurements to the center line of each cooling slot...the arrows point to each exact measurement center line.

 

Thanks! I will compare with my tube over the weekend.

[martanke]

The slots in my tube line up well with the measurements of the original one. So all good!