Stuffing box

[chusansail]

Stuffing box on lehman 120 constantly running very hot engine has had alignment checked many times repacked gland still runs very hot.

 

[Comodave]

Does it have water injection? Photo of the stuffing box or model would help.

 

[Mambo42]

I would indeed check the water injection, perhaps that line is blocked. When the gland is wet there should be no way that it runs hot. I had a stuffing box on both engines in the past and even with the engine off (just wind milling when the other one was running) the stuffing box would not get hot.

 

[Comodave]

I don’t remember what the specifics are for temperature but I believe it is 10 degrees over the sea water temperature.

 

[chusansail]

Does it have water injection? Photo of the stuffing box or model would help.

The water inj is fine. Had the engine aligned. Still runs very hot. One point there is a little ding on the prop would that cause a problem

 

[Bmarler]

Have you tried increasing the drip rate a bit?

 

[DavidM]

What kind of packing do you have in your stuffing box. Flax packing, the old type needs several drops of water a minute of leakage to keep it cool. Modern Gore packing can get by without any leakage once it is bedded.

Flax packing generally results in the gland running 10 degrees warmer than seawater, Gore less.

David

 

[Bmarler]

What type of packing are you using?

 

[Bmarler]

What kind of packing do you have in your stuffing box. Flax packing, the old type needs several drops of water a minute of leakage to keep it cool. Modern Gore packing can get by without any leakage once it is bedded.

Flax packing generally results in the gland running 10 degrees warmer than seawater, Gore less.

David

Exactly what I was wondering.

 

[chusansail]

What kind of packing do you have in your stuffing box. Flax packing, the old type needs several drops of water a minute of leakage to keep it cool. Modern Gore packing can get by without any leakage once it is bedded.

Flax packing generally results in the gland running 10 degrees warmer than seawater, Gore less.

David

Gore but I still left a drip until it seats

 

[chusansail]

Have you tried increasing the drip rate a bit?

Yes

 

[Bmarler]

Is the shaft tough to turn by hand in neutral? Packing the right size? Too many rings? Any chance it was over tightened on installation? Possible the shaft is running against the box hose?
I have read that the stuffing box can run 30-40 degrees over water temp during break in.

 

[Comodave]

Could be, maybe, the shaft isn’t aligned properly with the cutlass bearing. Can you turn it by hand?

 

[chusansail]

Could be, maybe, the shaft isn’t aligned properly with the cutlass bearing. Can you turn it by hand?

Yes

 

[boomerang]

You said the water injection is ok. I guess you removed the hose at the barb to check the flow to the gland. Do you know that water is coming out of the shaft tube at the other end?

 

[chusansail]

You said the water injection is ok. I guess you removed the hose at the barb to check the flow to the gland. Do you know that water is coming out of the shaft tube at the other end?

Yes it's fine. My question now could the little damage the prop cause vibrations

 

[Comodave]

Yes it's fine. My question now could the little damage the prop cause vibrations

Yes it can cause vibrations but I don’t think it would cause the stuffing box to overheat.

 

[chusansail]

Yes it can cause vibrations but I don’t think it would cause the stuffing box to overheat.

Run out of options unless the shaft is bent I hope there is a simpler answer

 

[Comodave]

Only way to know for sure is to have the prop rebuilt and see what happens.

 

[BruceK]

Run out of options unless the shaft is bent I hope there is a simpler answer

One stuffing box on my last boat would chew out packing material fast while the other lasted problem free. I never checked temps to compare, but eventual investigation revealed a bent shaft.

 

[chusansail]

One stuffing box on my last boat would chew out packing material fast while the other lasted problem free. I never checked temps to compare, but eventual investigation revealed a bent shaft.

Packing doesn't get chewed but the other engine is fine so I suspect it's probably a shaft problem

 

[lwarden]

I don't see how this could be a shaft issue. If it were bad enough to cause rubbing on inside of the stuffing box you would see it when it's running.
Has the stuffing box been checked to be concentric with the shaft? Just something to remember that if the shaft turns freely at the dock it may not when the engine is loaded up on it's mounts. This could result in some binding/rubbing I suppose, but not something I've encountered myself.
If you have a laser thermometer try shooting different areas of the stuffing box to see if you can located the highest temperature part and post the results.