Stinger or strut?

[Old School]

After doing a little googling, it seems that struts were popular for mono hulls until about six years ago then stingers became the drive to use. Does either have its advantages or disadvantages? I like the Speedmaster stinger with its vertical adjustment mount slots, however, I have read criticism that the vertical adjustment screw does not have enough mechanical advantage to securely retain a setting.

[rol243]

For playing around go for a Stinger Drive but for racing go for the reliable Strut Drive.

[Old School]

I have no intention of being competitive so looks like a stinger.

[fweasel]

Vertical adjustment is only useful if you have that same amount of vertical play in your driveline. Trim angle is another adjustment entirely.

[Fluid]

...I like the Speedmaster stinger with its vertical adjustment mount slots, however, I have read criticism that the vertical adjustment screw does not have enough mechanical advantage to securely retain a setting.

Stingers have been popular in gas boats for years, only becoming more popular in serious FE boats when RTR boats started using them and cheaper versions were available. Not sure where the OP read that stingers don’t hold adjustment, this simply isn’t so as hundreds of gas racers have proven (this assumes a quality stinger like SpeedMaster, not cheap Chinese junk).

If you know the strut depth your hull and setup requires then then I prefer the stinger - neater and more compact than a strut. But it’s limited vertical adjustment can be a handicap when setting up a less known hull or when trying to settle the boat in rougher water. Then, the classic strut has the advantage with its easier to make and larger range of adjustments.



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[Old School]

Many thanks gentlemen.

[Old School]

I am attracted towards the Speedmaster stinger with the cross drilled rotating brass bearing, however, it seems that the Europeans are reporting rapid wear and are resorting back to lead/teflon bushings. Perhaps this is based on competition running and not hobby/sport running (lower RPM). The cross drilled brass bearing is easily replaced if this is the source of wear or is the wear actually in the tube the bearing rotates in? Is this replaceable, please.

Also with the Speedmaster stinger is a flood tube the more desirable method to enable vertical adjustment of the stinger strut tube? On the mono hull I have chosen with large pad area, the hull is renowned for chine walking and a raised position (not trim angle) stinger is desirable to hopefully counteract this. I could simply mount the stinger slightly higher and test, then adjust as needs be.

[Luck as a Constant]

speedmaster stinger are great. no problems. just gotta get the mounting position rite.
struts are more adjustable, but unless you do a flood chamber, i don't see how you really get any adjustment out of it.
ide imagine someone at some point will do a stinger with a flood chamber.that would be awesome

[Old School]

I suppose other than a flood tube/chamber then one would need a vertical elongated hole in the transom and reseal the opening after an adjustment has been made. The flood tube does allow instant adjustment without waiting for sealant to cure. For sport running I assume that once a sweet spot is found then no further adjustment is required.

[Luck as a Constant]

thats why you get advise about the hull. for example, i can tell you on a titan 29, you want the bottom of the strut about 3-4 mm above the ride pads rear edge.

[rol243]

vertical adjustment of the strut or stinger can be controlled by prop selection ie; too high more diameter prop. i have never needed to adjust the vertical height of a strut in any mono hull i have owned , only needed with tunnel and rigger hull trim.

[Old School]

I assumed that raising the stinger vertically would allow more of the rear pad on the hull undersurface to contact the water, improving the handling at the expense of speed. Does a larger diameter prop settle the hull lower in the water as logically I would have thought that it would lift the hull, increasing the tendency to chine walk? So much to learn.

This is what I found after a quick search. Not sure that it makes much sense to me as regards the effect on the hull raising the stinger height.
Quote:
"Raising Strut/Stinger Height
An increase in the height of the outrive will move the prop away from the water. The prop will run more shallow. This may increase output drive RPM from a reduction of load.
A decrease in height of the outdrive will run the prop deeper in the water. A deeper prop will increase the load on the motor."


For a strut on a hydro apparently altering the strut height has a more marked effect -
Quote:
"Raising Strut Height
An increase in height of the strut(prop line closer to hull bottom) on a hydro style hull will lower the rear of the hull in to the water. A strut that is too high may allow the hull to run too deep.
A decrease in the height of the strut (prop line further from hull bottom) will force the hull higher out of the water. This will decrease hull drag. Over doing this will cause the rear of the hull to hop along.


Edit: Quote "Lowering the strut will raise the boat out of the water, raising will lower it,but if you raise it just a tad from dead level then the prop will loosen up a bit this is where the confusion starts some think because the prop unloads this way the boat must run faster but it doesn't because the hull itself is running deeper thus more drag so slower if you raise it too much the transom is dragged down."

[rol243]

yes the idea of tuning a mono hull is to get the hull out of the water so drag is reduced to a minimum, you don,t want the rear to drag in the water like a cat scraping its arse on the ground , you want it to air out. this is also why i mentioned about the higher up the strut on transom the larger diameter prop can be used to compensate for blade loss , caution must be taken into consideration if your going up prop diameter you don,t want to also go up in prop pitch as motor loading will occur and performance will be lost.

[Old School]

Makes sense. Many thanks