possible block cracked?

[catfishcarl99]

so I went to start and successfully did start my motor I have been working on. I put a hose on the water inlet since I don't have an impeller yet. it came through the pee tube I added to the top of head but when I started the motor for 30-40 seconds the water was running back down through the holes by the water inlet tube. almost nothing from the exaust port or spitter holes on rear of motor leg. this coming from the block or another issue? ugh.

 

[catfishcarl99]

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[catfishcarl99]

there is two holes by water tube circled. is this normal until thermostat opens? im praying its not block. engine sounded fine. ran it a few times for 30-40 seconds. started right up.

 

[catfishcarl99]

ok after some digging I found that the rubber water tube seal can be the problem. I assume there is no easy way of changing this aside from removing engine?

 

[racerone]

All the water that is pumped into the engine has to come out again.-----Some comes out and into the exhaust housing.

 

[catfishcarl99]

but its coming out of the inlet tube area. not exhaust area at all. from what I have read the rubber seal can rot and leak. the water flow is coming right back out were the inlet tube goes up into the motor leg. the slot up in the leg where tube runs in front of exhaust outlet.

 

[catfishcarl99]

the seal im talking about. the waters running right back down the inlet tube from two weap holes.

 

[catfishcarl99]

found this on a search. a pic from frank A. this is the leg plate and the seal retainer.

 

[jerryjerry05]

That seal could be a problem??
But the pump sends way more water through the system than the motor can use.

Yes the only way to fix that seal is t remove the block.
If you look at Franks pic, you'll see 2 very tiny screws holding the seal and tube in place.

You might get lucky and get one free but the other will probably break

What I've done is take and clean up the spot and then apply 2-3 thin layers of silicone
on the seal.
Build up the surface and it will seal the area when the blocks replaced.

 

[Nordin]

Catfisher as jerryjerry says the seal can be the issue and you can build it up if you can not change it.

But first run the engine more the 30-40 sec. and let the thermostat start to open, then you have to check that the thermostat work.

These Chryslers has a waterpressure relief valve that suppose to open and let some cooling water to passes out the leg if the waterpressure gets to high before the thermostat opens.
This valve use to operate allmost at idling.

I do not think the block is cracked.
If the is a crack it use to be in the water jackets around the cylinders and if there is the engine would run on 2 cylinders.

 

[catfishcarl99]

and there she be. bolts came out easily. no issues. the seal on the other hand. not good. replacement NOS $10.50 on ebay. ordered.

 

[catfishcarl99]

nordin would that be the bypass valve on the water chest side of the engine below exhaust chest cover? the one that releases pressure?

 

[Nordin]

Yes it is, be careful when unscrew the bolts. If you not need to unscrew do not do it.
They snap really easy.
I think you can access the valve when you have pull the power head from the middleg.

If the engine has been in salt water the relief valve can be stuck because of dirt from the salt and other stuff.

 

[catfishcarl99]

will do. I looked one a week ago up cause im replacing most all gaskets from the carbs reed plate reed valves exhaust chest recirc plate ect. the bypass valve was cheap on ebay. so far all bolts came loose easily. I don't believe its seen saltwater. bought here in Illinois.

 

[jerryjerry05]

That seal doesn't look bad.

What motor /year are we working on?
I see a 50 in your signature? but the seal/tube is from a 75+

The pressure relief is on the bottom corner of the exhaust plate.
2 tiny screws and a diamond shaped cover.

My 88/85 hp clogged after years of use in salt water. Made NO difference in the
way it ran or cooled.
One good grounding or running in mud/sand can clog it.

They stopped putting them in in late 89/90

 

[catfishcarl99]

yes I acquired 2 1976 Chrysler 75 hp distributer motors both model # 757 hb a couple months back. restoring one spare parting the other. it was seized. the one I have running wasn't. seal was hard and cracking.

 

[catfishcarl99]

got new seal today. replaced and sealed and replaced leg be ready for another test soon. the bottom drain hose on the intake that runs to the carb intake housing had watery looking drain in it. I reused the old head gasket for testing. new one is on order.

 

[jerryjerry05]

That fitting on the block??
Carb cleaner, little red tube, spray in the fitting making sure it's clear.

 

[catfishcarl99]

ya I had the reed valves off and reedplate when I replaced piston rings. I thourghly cleaned and painted this engine. all the fuel lines and recirc lines are brand new. I blew out all the fittings and removed recirc plate cleaned it as well as the bypass valve.

 

[catfishcarl99]

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