Gas tunnel outboards

[Ronald van Essen]

Im building a scaled up wood version 1/4 scale tunnel, I would be interested in a lower unit. I would prefer cable drive, light weight and functionality over a scale look. something similar to the already produced Lawless and the Aussie lower unit...

~James

I will bring this lower to the tunnel races:

https://www.intlwaters.com/gallery/displayimage...10113&pos=0

I hope there are more lower units there to compare them.

Ronald.

 

[MarkScott]

Here's my lower that will be at the race:

 

[topfuel443]

Mark, will it be attached to a boat? Will it be run?

Looking forward to watching this gas clas...

~James

 

[MarkScott]

The lower is currently mounted on the Predator. SPP pipe is mounted on the motor via a header Fred created. Waiting for IV bag, fuel line and a few other goodies needed to finish the boat. Going away from the pull start, will be using a starter cone.

And I do hope it will run as the boat is entered in the Gas class....

 

[MarkScott]

Mark, will it be attached to a boat? ~James

Had to get to work so the pics could be made smaller. Don't have MS Photo editor on the home puter anymore.

 

[Jerry Wyss]

Hey, You Got a Big Black Mamba Snake On Yer Boat!

Marrrrk ,, I can't believe YOU didn't build your own tunnel hull whats the world coming to?

 

[waltr]

Hey, You Got a Big Black Mamba Snake On Yer Boat!
Marrrrk ,, I can't believe YOU didn't build your own tunnel hull whats the world coming to?

Hey Jerry,

Look,he's runin a bunch of HTBs too.

Mark,

I can't see from your pics,I had to raise up and strengthen the transom in Aeromarine. Did you end up doing the same?

 

[Tim_Duggan]

Don't forget a carb snorkel, Mark! The spray from the transom will go straight into the carb otherwise!

 

[MarkScott]

Hey, You Got a Big Black Mamba Snake On Yer Boat!
Marrrrk ,, I can't believe YOU didn't build your own tunnel hull whats the world coming to?

I know, I know, the world is coming to the end.. Excuses excuses made me buy some boats for the OB Tunnel champs. Give me some time and I'll make a new batch of boats..

Hey Jerry,Look,he's runin a bunch of HTBs too.

Mark,

I can't see from your pics,I had to raise up and strengthen the transom in Aeromarine. Did you end up doing the same?

Ouch, you didn't have to notice that :blink:

As for the transom build up, not yet. Didn't know if it would be needed. Seems plenty strong, just a bit short on the height requirements.

Don't forget a carb snorkel, Mark! The spray from the transom will go straight into the carb otherwise!

I bought a 1/2" 90 angle that will be built into the carb venturi as in a previous posting.

It's coming along, just a bit slower than I had hoped..

 

[waltr]

"As for the transom build up, not yet. Didn't know if it would be needed. Seems plenty strong, just a bit short on the height requirements."

Mark,

I'll post a few pics later of the transom build up I did.

It's fairly simple and really strong.

 

[waltr]

Mark,

I put a few pics in my gallery with the transom build up.

https://www.intlwaters.com/gallery/displayimage...m=809&pos=0

 

[topfuel443]

Looks good Mark!

Cant wait to see it in person...

~James

 

[MarkScott]

Walt,

Thanks for the pics. I have some work to do :unsure:

James,

Looking good, now I need to work on it! LOL... See ya in a couple of weeks!

 

[PCMBOATS]

I don't know but I couldn't wait for Lawless or MHZ to come thru with anything resembling an OUTBOARD motor?? I did it myself!! I have the Ossi Tunnel and in a few weeks when it is pretty I will be getteing her on the water!! Anybody interested in my Leg/Lower unit feel free to contact me at [email protected] I'm always happy to say what the real story is!!

Later!!

Pat

 

[AFIRacing]

What kind of speeds are ya'll coming up with? Need to know what the benchmark is. Going to test and tune mine this weekend.

Steve H.

 

[Mike Byer]

What kind of speeds are ya'll coming up with? Need to know what the benchmark is. Going to test and tune mine this weekend.
Steve H.

Speeds are not quite what I thought they would be, but not too bad to start, 52-54 on gps using a 6717/3 at 4.2". Does the pond for the race have 330ft. straights? Take plenty of lead for the nose with you.

Mike B

 

[waltr]

I recieved mail from down under that said someone ran 64mph with a mod 230 Zenoah and one of Gregs lowers.

I thought that was pretty darn respectable.

I'm in the process of building 2 boats myself.One stock with a can muffler and one full mod.

Carlos built a J&G conversion on a full mod 260 and it also has a SPP exhaust.

One boat is a new Aeromaine and the other is a new Woodstuff.We'll see how it goes.

 

[Mike Byer]

I recieved mail from down under that said someone ran 64mph with a mod 230 Zenoah and one of Gregs lowers.I thought that was pretty darn respectable.

I'm in the process of building 2 boats myself.One stock with a can muffler and one full mod.

Carlos built a J&G conversion on a full mod 260 and it also has a SPP exhaust.

One boat is a new Aeromaine and the other is a new Woodstuff.We'll see how it goes.

Numbers is numbers, must have been very slick water, no wind and a little down hill, power is not a problem, the handling is the biggest problem with the Aeromarine boat. The Woodstuff boat looks like it should do a lot better.

mb

 

[Tim_Duggan]

I recieved mail from down under that said someone ran 64mph with a mod 230 Zenoah and one of Gregs lowers.I thought that was pretty darn respectable.

I'm in the process of building 2 boats myself.One stock with a can muffler and one full mod.

Carlos built a J&G conversion on a full mod 260 and it also has a SPP exhaust.

One boat is a new Aeromaine and the other is a new Woodstuff.We'll see how it goes.

Numbers is numbers, must have been very slick water, no wind and a little down hill, power is not a problem, the handling is the biggest problem with the Aeromarine boat. The Woodstuff boat looks like it should do a lot better.

mb

With all due respect, ( & you said yourself that power is not the speed limiter and that it's handling) the boat in Oz is not an Aeromarine hull.

Speed wise the boat in question was regularly running 95kph on GPS early on in it's development months ago. Thats a hair under 60mph, so I wouldn't find it totally unreasonable to gain 4 mph with more development.

I'm sure you guys will gain that much, if not more, with more time on the water.

 

[KGilbert]

Where can I find these Woodstuff boats?