Reverse cooling, any thoughts?

[Budweiser]

I was just thinking, why not reverse cool the engine in my boat. I've read about the terrific benefits reverse cooling offers in late model cars... I'm sure one of you guys can fill me in.

[fc-pilot]

With the temp of the lake or river water that we are putting into the engine it is almost a moot point. For a boat like yours it may not be a bad idea to have a little more heat in the chamber of the head. That is just my thought anyway.
Paul

[gbelt]

Also those engines that are reverse cooled are designed that way with specific cooling passage requirements, take a look at an late model LT1 SBC and compare it to a regular 350, you'll see larger passages in the head.

[Boostedballs]

I have a late model LT1 in my Chevy Monza.
I think the reverse flow is great if you have a close cooling system but with lake water, I wouldn't try it because I would think you would get air pockets that would not escape. Air can bubble up in a normal setup and escape the thermostat housing rather easily. I think the air would be pushed down constantly until you get enough flow to force them out the block. Air is constantly put into the system when you get air at the pickup. I would think that at idle, you would not be able to purge the air out of a freshly-started engine until you really get the water flowing.
That's just my guess

[River Rat 005]

I think without a closed system you would have a hard time keeping the block filled. You're filling it from the top and draining it from near the bottom.

[Boostedballs]

I think without a closed system you would have a hard time keeping the block filled. You're filling it from the top and draining it from near the bottom.
it'll be like trying to fill a bucket full of rocks with a hole in the bottom. Not much water in the top rocks.
You need to fill the bucket from the bottom up to make sure all the rocks get wet.
No, I'm not smoking dope; I'm still at work;)

[Budweiser]

I have a late model LT1 in my Chevy Monza.
I think the reverse flow is great if you have a close cooling system but with lake water, I wouldn't try it because I would think you would get air pockets that would not escape. Air can bubble up in a normal setup and escape the thermostat housing rather easily. I think the air would be pushed down constantly until you get enough flow to force them out the block. Air is constantly put into the system when you get air at the pickup. I would think that at idle, you would not be able to purge the air out of a freshly-started engine until you really get the water flowing.
That's just my guess
Ah hah, this makes complete sense. It would explain why "Dragboats" try at it would be OK at speed but overheat at lower RPM's. Enough said, sounds like a headache to me.
Oh well, what common practice to challenge next?

[steelcomp]

I run my water in through the drain holes in the block, and out the thermo. housing.

[Budweiser]

OK, not reverse cooling, but sounds like it would offer more uniform cooling without causing air entrapment problems. Did you modify the diameter of the drain hole before making it the H2O inlet or not?

[steelcomp]

OK, not reverse cooling, but sounds like it would offer more uniform cooling without causing air entrapment problems. Did you modify the diameter of the drain hole before making it the H2O inlet or not?Yes, drill and tap for 3/8 npt and if you're using AN fittings, use -8 x 3/8 mip fitting. I never had any issues. More even cooling and also keeps sand and other unwanted material in the block more in suspension. It works well on BB Chev because the water drains are close to the center of the block. On BBF engines it's not quite that way.

[Boostedballs]

Yes, drill and tap for 3/8 npt and if you're using AN fittings, use -8 x 3/8 mip fitting. I never had any issues. More even cooling and also keeps sand and other unwanted material in the block more in suspension. It works well on BB Chev because the water drains are close to the center of the block. On BBF engines it's not quite that way.
Awesome! I will do this to my 496 i'm building! Should tidy up the engine compartment a bit and save a few bucks on hose too!