Stuffing Box/Stuffing Tube Configuration

[David Bryant]

Just curious if it is best to use Teflon tube lining inside brass stuffing tube? Or is conventional brass stuffing tube by itself best? This would be for .250in diameter flex-cable drive.

Thanks

 

[dr gary turner]

No Teflon tube

 

[Charles Perdue]

Teflon will work if installed correctly. The correct teflon tubing to use is about .010 OVERSIZED tubing. The teflon tubing outside diameter is larger than the inside diameter of the stuffing tube. It must be stretched and pulled through the stuffing tube when installing, then when it is released it will expand against the ID of the stuffing tube and stay firmly in place. Slightly roughing up the OD of the teflon tubing before installing with a course grit sand paper adds extra grip here.

One other thing that needs to be considered is the free length of the cable, if the upper end is fixed in the engine collet. Do not allow the prop shaft to push so hard against the cable as to cause it to rub hard against the outside of the arc of the cable where the cable goes through curved teflon inside of the stuffing tube. In other words, do not leave excessive clearance between the drive dog and the thrust bearing on the strut. Ideally, the thrust of the propeller should be shared between the strut thrust bearing and the engine bearings. If a square drive cable is used then this will not have to be considered.

I am sure that some on here will not agree with me but when installed correctly this will work. This system has been used very successfully for many years and with record holding boats.

Charles

 

[dr gary turner]

My Teflon tube is my oiler. The synthetic oil creates an emulsion with the water and it totally encases the shaft. NO SKIP AREAS. The shaft feels like it is on ball bearings.

 

[David Bryant]

Appreciate the input.

Dave

 

[John Beardslee]

I'm with Doc on this, over the years of working with prop customers, many were using the teflon liner and for one reason or another the liners were getting hot and stealing hp from the engine and the boats wouldn't pull the props that other set up with no teflon liners did. I have never run a teflon liner, and never will. It'd like to know how many people at Hobart ran a teflon liner? Sorry Charles, I think in a perfect world with maybe polishing the flex cable and having just the right bend it might work great but for most in the hobby it just not a good choise.

Thanks, John

 

[Charles Perdue]

Differences of opinions do not make you enemies but it can make you competitors.....and competitors makes for good racing.

Written by a very smart man

 

[John Beardslee]

Yup, hope I'm on your friend and competitor side! Love the competition side!!! Missed it for a lot of years and didn't realize it!!!! Hope to see you at one of these events again one of these days!!! The south is warm and great in the winter - Nitro Championships would be great to see you at!!!!

Thanks, John

 

[Charles Perdue]

OH yes, no problem. Most of my comments on here must be taken with a sense of humor. I had rather tease someone than to eat when I am hungry....

It would be nice to have an "OLD TIMERS" race. To participate you must be over 65 and be able to power your boats with 1/2 nitro and 1/2 bullsh**