Saving Old Seagulls

The Great Annual Waikato River Seagull Race

Boasts to be the Longest Seagull Outboard Race in the World
Every Easter from the Karapiro dam to Port Waikato 88 miles (76Nm) over two days.
The main emphasis is on finishing & having lots of fun.

http://www.seagulloutboard.com/1_10_Waikato-River.html

videos & photos here

http://www.seagulloutboard.com/index.php?p=1_14

Also, the entire NZ calendar of events at

http://www.regattaevents.co.nz

I'm a little surprised you Pom's haven't gotten into it like us Kiwi's. UK being the home of British Seagull & all. Must be a colonial thing.

Rex

This race in nz sounds very interesting to me being a very newcomer to seagull ownership. I am wondering if there is anything like it in aus. being a resident of mid north coast n.s.w. 300 odd klm's north of sydney.
Any news most welcome and cheers to a great site.

Ahhh... near Taree. There is a steam boat fraternity in those parts. Welcome! Nope, nothing in OZ.

Perhaps the Round Hayling Island Marathon could be "Probably the best race in the world"

Sponsored by Carlesberg, not Heineken.

H-A

H-A

Could well be

Having the Hayling Island start & finish in the same place is a very good logistical move, especially for visitors

Our longest event is the 'Clutha River' at 325km. It takes 4x days & it takes alot of logistical planning

Here's some newspaper articles;
http://www.odt.co.nz/the-regions/south- ... -comes-end
http://www.odt.co.nz/your-town/wanaka/4 ... record-run

Rex

lawrenceb55

That's a great part of the country to live

Maybe you chaps could put an event together. You only need 3 or 4 mates & a river/waterway somewhere. Motor-camps make great start/finish places

Rex

200 miles, with camping sounds great.

All I need is a lottery win and I will be there

H-A

Waikato race last year was fantastic, when you thought it was boring you ended up on a sand bar, when it was beautiful you broke down, when people where watching you ran out of gas. Enjoyed it so much I have built a new boat and bought a few more engines. Doing the whole length of the waikato is possible. A few dams and rapids to negotiate, maybe an easier river to set a record on. And lots of great sites to camp on the dam lakes.

You've gone very quiet on your new boat, I'm guessing it flys & your laying low, so the competition does not copy your hull.

Don't talk to me about the bloody Waikato, I've hit almost every sandbar, always got as far as Hamilton before the "breaking Seagull components" Gremlin strikes, except the time he got me in Karapiro the night before the start.

So my campain medals are,

Piston at Karapiro
Snapped 5R leg at Hamilton
Ignition at Tuakau
Almost sank just after Tuakau
Crankshaft 75 meters before finish at Hoods Landing.
Oh I forgot a Sport crankshaft at Huntley.

Still painting hull. Bright red. Trying to get a smooth finish with a brush and roller. Going to spray next boat. starting to lay up next boat today. Sea trails on first boat next week.

Tinker

We did a run a few years back from Aratiatia down to Ohakuri. Very scenic & an easy waterway. Doing the entire Waikato sounds like the greatest adventure of all time 425km. Would almost make Indiana Jones look lame. That's never been done before. We could tie in the final leg to be the easter Waikato race. Might warrant a reconnaissance mission. Either way I'd be keen

You've made good progress on the boat. I see alot of work has gone into the fairing, so the finish will be good.

I'm working on a reliable rescue boat for Waikato. Air cooled shallow drive outboards. We need good support boats to keep the race going.

Still working on a modified engine. Squish-banding is proving difficuilt. Scrapped several versions so far. My mathematical model predicts 6hp~8hp depending on BMEP value, so, that's encouraging.

Rex

BMEP = 75.4 x TORQUE (lb-ft) / DISPLACEMENT (ci)

I would think that squish band would be an easier thing to sort than the cylinder porting.

Dont you need a flat or domed piston to have a working squish band ? I thought that the rules required the piston to be standard.

H-A

H-A

Aaah somebody's thinking

Your formula has BMEP proportionate to torque & inversely proportionate to displacement. Without checking the constant value (75.4), I concur.

This fits the proven formula
HP=PLAN/K
given
HP=(C) Nrot x Torq
&
Disp=L x A

Must use a genuine seagull piston (& conrod & crank & other bits). However, piston can be modified. Incl re-shaped crown, drilled, welded, other. Therein lies the challenge. I think of it as a comprehensive test of engineering skills, & what can be done. Not into trophies & records here.

The seagull is a wonderful basis. Cheap, available, limiting oem design.

If we start using non-seagull parts, then, any muggin could achieve 20hp~30hp with 'off-the-shelf' bike parts.

Rex

How far can you go with the piston?

Is it possible to re-profile the piston crown using a tig welder.

Can you weld high silicon ali, without destroying its low expansion properties.

H-A

H-A

Therein lies our problem. Still working out this squish-banding biz

I'm not keen about piston welding for 3x reasons;
* distortion
* changes to the expansion character
* the weld HAZ 'heat affected zone' will impart a columnar crystal grain structure & porosity. Could have fatigue issues down the road. Reciprocating mass increases

Current Ideas;
* There are alloy 'soldering/brazing' rods available. Brazon & Dura-fix & others. These are on my 'experimental' list
* Having said all that, Practical testing has shown cylinder head weld building & contouring to be successful. Albeit a bit limiting. I don't think British Seagull bothered to heat treat their heads to impart hardness, as modern alloy heads are.
* Have thought about machining the crown off, &, threading a new one on. But, heat transfer & expansion issues.
* The idea of using metal spray building has come up, but there's fixing issues
* could reduce the crown, then, fit a cap, then ceramic coat the cap to address the heat transfer.
* other

I haven't found the 'Holy Grail' answer of how to squish-band yet. But I'm sure it's possible. I need to keep thinking. Ideas welcome.

Rex