Customs Cadillac 346 exhaust

Does anyone know why GM routed the exhaust on top of the engine?
Was it to warm up the intake and carb?
Thanks!

 

Yes; having the exhaust exit out the top made the path from valve to manifold short and got the heat out of the block unlike Ford with it's exhaust passages running through the water jackets.

 

Interesting.

 

Fascinating.
Who else did it this way I wonder?
And why did GM stop doing it on the OHV 331?

Also...wouldnt this make the carb and fuel hot in summer?
Todays ethanol gas in this engine might be a nightmare.
Anyone know?

 

Because they could!

Also, having the water pump on one side, sending the water to the other side of the engine the way it does, probably contributes to how warm the 346 likes to run when it's working hard.

 

Are there cooling remedies?
An electric fan of course.
But is modern Ethanol gas a problem?
(An electric fuel pump and a return gas line will help)
20-50 oil for the friction? (CLC advice)
Thick carb gasket?

 

Put it in a light hot rod, with an open engine bay....

 

I'd like to see one with headers.

 

https://www.jalopyjournal.com/forum/threads/cadillac-346-flathead-headers.273395/

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I think once OHV blocks had an exhaust port for each cylinder, the heat issues were much less of a problem.
Cadillac flathead engines seemed to like the cold with that exhaust manifold located up high and close by to the carb, but in hot States it was recorded as a problem.
I've found engines with lagged portions to hide the heat...

Google;
YouTube - Cadflat Video Series - Engine Running Sound