3.5 Tunnel Test Video

[David Moyle]

Hi all,

I thought it would be interesting to share some footage of a recent test session I had with my tunnel.

Hull: My own design Breakthrough tunnel - laser cut birch ply over Klegecell foam construction. Approx 28.5in long.

Powerhead: GO 7 port from Leyde Racing. .008" head clearance, 180deg exhaust timing, not sure of the transfer timing.

Pipe: SPP

Carb: Zoom

Plug: K&B 1L

Lower: OS

Prop: Grimracer 40x53, sharpened and balanced

Fuel: My own mix, 60% nitro, 15% Klotz KL-100

Flex shaft: Kris Flynn

The pipe is a bit too peaky and that test pond was just a bit too small. The GO still had some rpm to be had but I kept running out of room. It is a fun drive!



Enjoy,

Dave

 

[RodneyPierce]

Dave, boat looks very very stable!!! Very nice riding tunnel!! And man o man is that GO turning some RPM Looks really good.

 

[julianconde]

that's pretty dam good there Dave that thing had some good RPM WOW great video. I have to agree the pond was small but it ran very good.

Julian

 

[David Moyle]

Thanks for the comments guys! Here's another video of the tunnel in action.

 

[kesso2118]

Dave,

I like this video because with more of a side view it shows the running attitude of the hull, it looks great !

A bit like this one B)

 

[David Moyle]

I love that shot Kesso! (Thanks again Murph for the great photography).

Here's one more short video for good measure.



I still have a few tweaks to make on the hull, then a couple more test sessions and hopefully then I can call the design 'good to go'.

 

[julianconde]

David i think that boats looks really well attitude when its on the straits looks very good i like it buddy great job.

julian

 

[David Moyle]

Just one more bit of video I found

http://www.youtube.com/watch?v=P_4-KTxh8tk&feature=player_detailpage

 

[RodneyPierce]

David, that thing screams man!!!

 

[RodneyPierce]

Also, have you ran it in rough water much? How does it handle, with running nose high like that? Had any blow over's? Ran my sniper II last weekend in I would say a solid 15 mph wind, and it was surprisingly stable!! just curious about this hull, as it really looks SWEET!!

 

[camaroboy383]

David, that thing screams man!!!

surely does.... goes real good

 

[David Moyle]

Also, have you ran it in rough water much? How does it handle, with running nose high like that? Had any blow over's? Ran my sniper II last weekend in I would say a solid 15 mph wind, and it was surprisingly stable!! just curious about this hull, as it really looks SWEET!!

As with any 21 tunnel, get enough chop in the water and it's not a fun ride. Up to a certain point, it's quite good in the rough, and the nose running high actually helps it to miss the worst of the waves. That's if I'm game enough to keep the power on in the rougher water, something I'm only just learning to do! As far as wind and blowovers, it's really quite stable for a 21 tunnel. The only time that I've blown this boat over is when I didn't realise the engine was set to full positive trim, after bringing it in a bit quickly to shore one time, and the trim got knocked back. Otherwise, it's really stable at speed. Your Sniper II sounds like it's a winner in the rough!

 

[RodneyPierce]

Im the same way, trying to find that smart, but fast throttle finger setting in the windy rough stuff. I have blown mine off my fair share of times. I like to run em loose though. nose high, just like yours is running! Love that boat brother. Keep me posted.

 

[Kevin Krogness]

That thing scoots!!!!!!!!

 

[Carl Van Houten]

David,

I enjoyed reviewing your breakthroughcad site. You are building your prototypes like I do. I have all my designs on Cad and crosssection them just as you have. It is the only way to go in my book.

The Switzer is one of my favorite old tunnel boats. I have a lots of pictures of them. It is good to see that you are building your own design. This hobby needs that. The thing that I like about building from cad plans is the control you have when making modifications.

Keep us posted.

-Carl,

 

[David Moyle]

Thanks for the comments Carl, I'm glad you enjoyed having a look at my site. It's well overdue for an update, I really need to get on to that!

 

[Carl Van Houten]

Good luck to you David. As I have stated in another thread, I am finishing my last model this winter. I will not be building anymore boats after this one. If you stick with it, you will enjoy designing for a long time. I have met a lot of really good friends through modeling.

-Carl,

 

[LarryConrad]

Dave, your boat looks great. That little go engine is a screamer! Which SPP pipe are you running on it?

 

[David Moyle]

Hi Larry, thanks very much! It's a buzz to drive. The GO and the SPP really work together well. I'm honestly not sure whether it's the NR or TD pipe, I bought it second hand years ago. I have cut the muffled section off it, didn't seem to make much difference to the noise and it's a bit more streamlined without it.

 

[David Moyle]

Good luck to you David. As I have stated in another thread, I am finishing my last model this winter. I will not be building anymore boats after this one. If you stick with it, you will enjoy designing for a long time. I have met a lot of really good friends through modeling.

-Carl,

Thanks Carl. Will be great to see some pictures of your new hull when it's ready and on the water! I sent you a PM the other day, not sure if you've been able to take a look at that or not.

Designing is great fun, but sure tests your patience at times.