Thread:

Has anyone tried this??

I know a few people who have done it that way,

Originally Posted by Widetrack

...a jet boater...was telling me to run my infeed water lines into the block drains on the bottom of the block! Has anyone tried this? He said there were some advantages to running this setup!

Automotive passenger car engines use a closed cooling system where heated water is always entering the engine. As a result, the water temperature throughout the cylinder block is reasonably uniform.

But most high performance jet boats force lake-cold water right smack into the front two cylinders of the engine block. Depending on how optimally you've managed to maintain the operating temp of your engine, it is not too uncommon, upon disassembly, to see accelerated wear in the front to cylinders because they don't have the chance to get to full operating temperture as do the rear six cylinders in the block.

One way that some people have tried to "even out" this operating temperature differential is by plumbing the water inlet at the middle of the block, specifically the block cooling system drain holes.

I'd say that if you are going to attempt this, then do not try it with the tiny NPT-threaded drain back holes that are currently in place for draining the block. They should be enlarged and retapped to a larger thread size so that the newly installed fitting has enough ID to allow water to flow.

Will this even out the temperature differential? I don't know, as I've never researched it. But bear in mind that your V8 engine's head gaskets have holes in them allow the water to pass from the block to the cylinder heads, and these holes get larger as the you inspect the head gasket from the front of engine to the rear. In other words, the gaskets are engineered so that as water enters from the normal locaton (waterpump holes), it will be influenced to flow toward the rear of the block rather than just turn straight up to pass right through the head at the front and then out the intake manifold/thermostat housing (thereby causing the rear of the engine to have stagnant water and run hot). The cooling system is desinged so that water flows front-to-rear. Of course, this does not help the "overcooling" situation at the front two cylinders, but the other question is: how is this system affected when you plumb at the middle fo the block? Think about it...hmmmmmmmmmm.

LO

Originally Posted by SWAMP-ROOSTER

I drive a 93 1 ton dually with stock tbi 454,at 80,000 miles the thermostat hung up so I removed it.I was told after removing it that the motor was designed to operate at 180 - 200.I never put it back in,(happy the motor was not on the threshold of over heating living in the hot ass gulf region). It stays at 110-130 unless I'm in traffic or towing.I have 258,000 miles with no trouble,no smoke,no blow by that i can see.It makes me wonder about the correct temp a motor will survive the longest at.

It will survive longer at 200* F than it will at 130* F. Probably make a little more power, too. The internal combustion engine is a "heat" engine and for a number of reasons works better with a certain amount of internal heat.

LO

I'm not tryin to thread jack. But while the subject is brought up. What about running it bass-akwards?? heads down??

Wide ,Old school V -drive boats were sometimes plumbed that way and it probably worked for them (seen a few) these "basically automotive" motors were designed to have coolant/water flow '"up" from the water pump inlet area thru the block and heads and out the out intake "T-stat" hsg Kreg Ive seen a few plumbed backa$$wards that always ran hot just my Heat rises ! 02 Tom