Outboard prop depth

[Mike lasorsa]

What’s everyone running for prop depth on 3.5 tunnels? I find the only thing that works consistent with my boats is keeping the motor as far in the water as possible.

 

[Grimracer]

depending on the hull and prop.. I run in the area of .040" bottom of the prop hub above to as much as .25inches.

 

[Mike lasorsa]

depending on the hull and prop.. I run in the area of .040" bottom of the prop hub above to as much as .25inches.

How far is that in correlation with the bottom of the sponson?

 

[Grimracer]

that number IS the distance from the bottom of the prop hub to the sponsons..

 

[Grimracer]

I have not run a prop EVEN or below the sponsons in many many years!

 

[Mike lasorsa]

that number IS the distance from the bottom of the prop hub to the sponsons..

Ahhh got it yea that’s about where mine are As well and I run the 438 or 437/3 prop on all of them

 

[Kris Flynn]

What do you mean by "the only thing that works consistent with my boats"? What is that in reference to? Tune of motor? Removing porposing? Cornering load on motor?

I run heights similar to Mike...but just curious on your line of thought.

 

[Tony currie]

Does anyone out there produce a scale or semi scale looking tunnel hull?

 

[LohringMiller]

These are the instructions we sent for the XTR-21. It should apply to most similar tunnels.

Lohring Miller

 

[David Krienke]

These are the instructions we sent for the XTR-21. It should apply to most similar tunnels.

Lohring Miller

there is 3 pictures showing the prop setup on that manual and is confusing. The top two pictures would make you think it is really deep in the water . I would say the bottom picture near the tuning section is the correct way to have the height?

 

[henkie]

Does anyone out there produce a scale or semi scale looking tunnel hull?

Waterland scaleboats on facebook

 

[dave roach]

Carl Van Houten makes a 450 and a 470 1/4 scale tunnlel boat kit.

Dave Roach

 

[Tony currie]

Thanks for the info guys.

 

[Kris Flynn]

Does anyone out there produce a scale or semi scale looking tunnel hull?

Definitely speak to Marc Huider at Waterland Scale Boats, his are top notch scale like glass hulls.

 

[Kris Flynn]

there is 3 pictures showing the prop setup on that manual and is confusing. The top two pictures would make you think it is really deep in the water . I would say the bottom picture near the tuning section is the correct way to have the height?

Alot of earlier designed boats needed the prop really deep to make them work.

All newer designs from the past few years do not need them so deep or below sponsons, almost all of them you can run the prop centreline above the sponson bottoms a certain amount.