Thermostat balls, why are they there?

[SCORPIO]

Merc 5.7L on '89 300 DA. I'm haveing a temp problem at idle, see my thread on the Classics forum. I'm wondering what purpose the spring balls in the thermostat housing serve? Could they be removed? What would that do? What do the balls actually do? Anybody know?

 

[fc3]

Back pressure. Without them, too much water would by-pass the engine.

No, you can't remove them. Mercruiser has guys sweating bullets to shave every penny of cost from their engines. Those balls, the rod, springs and nuts probably raise their costs by a whole 50 cents. If they were truly extraneous, the engineer who spec'ed those unnecessary parts would have been led outside, stood up against the wall, blindfolded and shot by the bean counters.

 

[mistercomputerman]

They probably wouldn't actually shoot him, but, only because bullets cost money and they are, after all, bean counters. They might beat him to death with their pocket protectors or something though.

 

[SCORPIO]

Back pressure. Without them, too much water would by-pass the engine.

No, you can't remove them. Mercruiser has guys sweating bullets to shave every penny of cost from their engines. Those balls, the rod, springs and nuts probably raise their costs by a whole 50 cents. If they were truly extraneous, the engineer who spec'ed those unnecessary parts would have been led outside, stood up against the wall, blindfolded and shot by the bean counters.

Thats the best explaination I've heard yet. Confirms what I thought the balls did. Now if I could just find out why I'm having a low speed temp problem, I'd be a happy boater.

 

[fc3]

They probably wouldn't actually shoot him, but, only because bullets cost money and they are, after all, bean counters. They might beat him to death with their pocket protectors or something though.

Don't the ChiComs bill the family for the cost of the bullet when they execute someone? Merc probably could do the same by taking the cost from his last check.

Thats the best explaination I've heard yet. Confirms what I thought the balls did. Now if I could just find out why I'm having a low speed temp problem, I'd be a happy boater.

The Alpha has a low volume, high pressure raw water pump. It doesn't take much to cause a problem. Any restriction will push the system over the edge. I'd look for an obstruction in either the drive or the exhaust system. Also check that the intake in the drive and the passage from the intake to the pump is clear. Check that the seal in the top of the pump body is good as well as the body and impeller itself. There's also a seal in the top of the drive in a plastic piece. The water tube is pressed into that tube. Check the seal, the plastic housing, and the gasket between the plastic housing and upper drive housing. Then check the raw water tube between the drive and the transom plate.

These are all commonly under-maintained parts that you or you mechanic might have overlooked.

Best regards,
Frank