Water has gotten into crankcase and Oil

[sastanley]

+1 on the MMI flange pump

Man, I love my MMI pump I got a few years ago..which reminds me I probably should change the impeller.

[thatch]

Bingo

With all of the information you have given us, I personally feel that the break in the hot section is at the root of the problem. The pumping dynamic between the exhaust pressure and the waterlift would be greatly compromised with that break. It doesn't take much of a stretch of the imagination to to see "un-pumped" water building up at that point and flowing back into the #4 cylinder and being blown past the rings and into the pan. While you're at the task of oil changes, I have to ask the question "what access point are you using to extract the oil?". The factory designed removal point is through the 3/4" pipe plug hole under the carb. It is at the lowest point in the "V" on the bottom of the pan where any water would eventually settle. I would also recommend using your current water pump, just to verify that the hot section break was the problem.
Tom

[JOHN COOKSON]

Another +1 On The MMI Pump

Man, I love my MMI pump I got a few years ago..which reminds me I probably should change the impeller.

When I replaced my tired Oberdorfer with the MMI pump my RWC cooled engine dropped from 155 degrees to 130 degrees at cruise RPM.
The Moyer pump is just plain a better pump.

TRUE GRIT

[RobH2]

When I replaced my tired Oberdorfer with the MMI pump my RWC cooled engine dropped from 155 degrees to 130 degrees at cruise RPM.
The Moyer pump is just plain a better pump.

TRUE GRIT

Two things:

1. Exhaust update: I rebuilt the exhaust black iron pipe today. I haven't installed it yet but when I got to the boat I noticed I had left my pump/gauge attached. I can confidently say I don't have a water jacket leak as the engine still had 5lbs of pressure left in it from two days ago.

2. This is interesting about the MMI pump. However, I seem to recall reading somewhere that the engine really should be running between 150° and 180° to prevent scale buildup inside the water jacket. Was that bad info? Is it better for the engine to run cooler? I ask mainly because my engine never gets over 150°, even in the summer. I even close off the bypass valve for the thermostat to force it to what I thought was the right temp, above 150° and can never get there.

[ndutton]

Closing the bypass valve has the effect of the engine running cooler.

[RobH2]

I misspoke. Yep, I realize that. No matter how I set the valve, I rarely hit 150°. I'm unclear now as to what temp is the best to be running at. But that's for a different thread.

Let me report back soon about my oil issue and get that solved.

[Sam]

I can shed a little light on the temp subject - pre 1969 A4, early models [mine], have a 140 F degree Dole thermostat setup. Reason was to eliminate or minimize salt leaching out of water at higher temps forming deposits. The A4 runs fine at 140 but at 20 -30 higher temps it should run a little better. Best running temps depend on where you use your boat.

[RobH2]

Ok, so I'm ignorant on the temps. I thought it need to be closer to 180 to prevent salt leaching out. I appear to have been mistaken. I'm in the Patapsco River which leads into the Chesapeake Bay. The salinity in the Patapsco is between 5 and 10 ppt. So, what temp should I target?

Second and more importantly for the short-term:
I'm installing my newly built exhaust pipe tomorrow. It currently has a hose connecting the lift and the water injection fitting that has a wire inside. It took me two hours to get it on originally as I have no space to work and it's all one-handed. Can I use a hose that has NO wire in that 3" location?

[thatch]

For that short run, an un-reinforced hose will work just fine. Have you considered lowering the hot section onto the water-lift first and then installing the flange bolts? Many of us prefer using studs and nuts in the manifold to save wear and tear on those valuable threads and which may also ease the reassembly.
Tom

[RobH2]

Tom, those are great suggestions. I didn't mention, one of the bolts (of course the harder one to get to) into my manifold wrung off and I had a really hard time getting it out. I will definitely use studs and bolts.

Also, you make a good point. I'll attach the hose first and then bring it to the manifold. Now that you say it, it seems like a "no-brainer" but sometimes you just need for someone else to say it.

I will use wire reinforced since the repair is not intended for the "short-term". If you had said, "sure, won't matter" then I wouldn't have. But since there is some concern, I'll go "wire".

Good suggestions. I hope this fixes my issue. We'll know by the weekend.

[sastanley]

Rob, you could also use silicone hose which is designed for that application. Lots of power boater engines use them between the manifold and exhaust to allow the engine to move independently..

I bet they are a bit more $$ than old wire exhaust hose though.

[Wisakedjack]

Rob, I had the issue with engine running cold. I did not have a thermostat and just used bypass valve. I've installed Indigo thermostat last year that recirculates cold water back into the engine. With that setup my engine consistently in 130-140F range. I am very happy about this new setup.

[RobH2]

Rob, I had the issue with engine running cold. I did not have a thermostat and just used bypass valve. I've installed Indigo thermostat last year that recirculates cold water back into the engine. With that setup my engine consistently in 130-140F range. I am very happy about this new setup.

This is interesting to hear. What kind of water are you in? I always run in the same range as you.

I'm in slightly salty water in the upper Chesapeake Bay. There has been some talk that water temperature has some effect with salty water but no one has been specific about it so far. I'm still trying to figure out if I should be having a higher or lower average temperature when in slightly salty water.

[Wisakedjack]

My boat is in New Jersey (Raritan Bay) so the water should be pretty similar.

[RobH2]

Update:

I'm still getting water incursion. Things I've done:

1. Rebuilt the exhaust
2. Pressure treated water jacket twice. 2nd test held 5 lbs for nearly 3 days.

I've now run (wasted 8 gallons of oil) trying to diagnose. So I've pulled the water pump. I've ordered seals and a new shaft. The water must be getting injected at the pump, at least I hope. There "is" wear on my shaft but I don't think enough to leak but I'm replacing it just to role it out. That's a cheap place of mind, right?

I've attached a few photos of the pump. Updates soon.