[CatalinaMike]

What would happen if the water pump sleeves were not installed? Engine didn't overheat

[Vid]

I’m amazed that it didn’t overheat because I imagine the flow through the cooling system would be reduced significantly. At least that’s my speculation.


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[chuckies76ta]

With the thermostat closed on startup, the only coolant flowing into the block comes from the cross-over bypass, and the heater core. That would supply probably enough coolant into the block to not cause any issues. at idle maybe. With thermostat open there would be more supply of coolant to enter the block.
What happens with the sleeves removed coolant will be allowed to escape entering the block and would return directly back to the pump. It would be mixed with the bypass, heater hose return and return from radiator. You still will be moving coolant into the block, just at a reduced amount. how much I don't know. It really would depend on how tight the divider plate rest up against the timing cover hole that feed the block.
Having said all that I'm thinking everything would still work OK. That's why your engine didn't over heat. There is probably a 1/8" to 1/4" Gap between divider plate and the timing cover coolant holes without the sleeves.

[77 TRASHCAN]

The coolant will be moving, some, but not forcefully through the engine, as intended.

Just curious where your temp sender is located.

The amount of coolant in Pontiac blocks is on the huge side, compared to what I've seen of later V8 engines, mostly LS stuff.

You will need the sleeves and square rubber donuts that go in them!!!

[25stevem]

As rpm goes up and coolant temp along with that there will come a point without those sleeves and round gaskets where the bleed off of pump pressure will mean that coolant will not be able to move into the block and flow as needed due to cooling system pressure acting against it.

In other words the tipping point for the blockage of flow ( this is a bit of a guess) will be when the pump is putting out 12 psi and the system is running at 12 psi with the normal 16 psi rad cap being used.

[Formulas]

those sleeves and seals seperate the suction from the pressure side of the divider plate , So overall meaningful flow through the block is reduced as some coolant will just rotate around the plate.

if you dont need the lost block flow then you wont overheat

its of course best to have them in

.

[ZeGermanHam]

My brother had a 461ci built for his GTO that he drove for a long time before he discovered the builder had not installed the water pump sleeves. It always ran on the hot side. If the weather was cool and you were moving, it could maintain a somewhat acceptable water temp. But if it was warm out and/or you got caught in traffic, it the temp needle would start climbing and it was very hard to get it cooled off again.

My brother decided to replace the water pump to see if that would help the situation, and when he removed the old pump that's when he discovered there were no sleeves installed by the engine builder. My brother also installed a new radiator and clutch fan at this time, and now the car never overheats. But since he changed a number of things at the same time, we don't know what the primary cause of overheating was. We both suspect it was the missing sleeves.

This is all just to say that the engine will be driveable without the sleeves, but in my brother's experience, it will have a tendency to run hot.

[geeteeohguy]

Neither of my GTO's have water pump sleeves. Both are first-gen cars with 8 bolt pumps. So I guess it helps to know what year engine you have.