Something interesting..

[Chemdawg]

So I have a 1987 Arrow Glass Carisma 175 with 3.0L Mercruiser Sterndrive, and alpha 1 drive. This boat was rather a basket case when I got it, so I have been fixing all the problems as I go along here.

I got the motor running like a champ, and got all the fuel issues worked out. So yesterday I decided to take it out on the water, and see how it would do. Ran great, and the only problem I found was a small oil drip by the oil pressure sending unit.

Here is what I have. On the drivers side of the block there was a brass fitting that went into the side of the block with the oil pressure sending unit screwed into that. What I did was removed the sending unit, put a 1" nipple into the brass insert, and added a T. The Pressure sending unit is on the end, and there is a oil pressure switch for the electric fuel pump that comes out of the T part. The oil leak was coming from a crack that occurred in the threads of the nipple that I put into the brass insert.

Heres my question. Because this whole setup is about 4 inches long coming from the side of the block, was the weight and vibration from the motor a bit too much for that small nipple, and that caused it to crack? Or maybe it was just a bad nipple? I don't want to install another nipple just to have this happen again.

Ideas?

Thanks. Pat

 

[LawHungLow]

I had that happen on a car. I added a brass nipple and T fitting for an extra oil line to a turbo. Mine broke completely off and I feel like it was the weight on the end of the nipple. You could maybe use a steel nipple if you can find one.

 

[alldodge]

So I have a 1987 Arrow Glass Carisma 175 with 3.0L Mercruiser Sterndrive, and alpha 1 drive. This boat was rather a basket case when I got it, so I have been fixing all the problems as I go along here.

I got the motor running like a champ, and got all the fuel issues worked out. So yesterday I decided to take it out on the water, and see how it would do. Ran great, and the only problem I found was a small oil drip by the oil pressure sending unit.

Here is what I have. On the drivers side of the block there was a brass fitting that went into the side of the block with the oil pressure sending unit screwed into that. What I did was removed the sending unit, put a 1" nipple into the brass insert, and added a T. The Pressure sending unit is on the end, and there is a oil pressure switch for the electric fuel pump that comes out of the T part. The oil leak was coming from a crack that occurred in the threads of the nipple that I put into the brass insert.

Heres my question. Because this whole setup is about 4 inches long coming from the side of the block, was the weight and vibration from the motor a bit too much for that small nipple, and that caused it to crack? Or maybe it was just a bad nipple? I don't want to install another nipple just to have this happen again.

Ideas?

Thanks. Pat

That's kind of long, but cannot say if it was the length or the fitting which caused the failure. Materials these days used to manufacture are from the cheapest methods known. I would chance it, and if it does show up again, suggest either adding flex tubing in line between first fitting and senders. Distance should be much of at issue with 1/4 tubing