[JOHN HANSON]

I mentioned this double Triumph in the Vintage Fuel Drag Bikes thread almost 8 years ago. Don't know where the time has gone but I rolled it out a year ago to clean up and take to a show that was canceled due to Covid. That's when I decided then it was time to do it justice and spend the time to do it up right.
We have a small website that was started a few years ago for local vintage bikers so I started a thread there on the restoration. Hopefully it will be finished and running this year.

http://olymoto.org/viewtopic.php?f=2&t=589&sid=ae573ad91bf7ad2448860ba0dbc1b5f3

 

[Thunderbird]

Re: Triumph Double Restoration

great read John. I've used the Murray wheelie shot as an avatar on another site for years so a real buzz to get details of the motor.

 

[JOHN HANSON]

I put off rebuilding the motors to last. Several one-off parts are missing or damaged so it's taking more time to build. Both motors have been blown so lots of weld repairs. Some done well and some not. I'm lucky to have a shop and can rebuild most of it, just takes time.

 

[Ratso]

Thanks for this thread, sir, and for directing me to olymoto.org. Beyond containing the build details of your double, that site looks to have a lot of highly interesting this&that for future perusals. I bookmarked it right quick.

I lack everything necessary to pursue your bringing-back-the-dead project -- theoretical knowledge, practical experience, personal history, skills, equipment, money, motivation, etc. etc. But it sure is a pleasure to follow your progress.

 

[thefrenchowl]

What a rebuilt!!!

Thanks for the link, John...

I'm planning a cut down iron head Sportster with Jawa speedway 2 speed gear box, so plenty of pointers on how to proceed...

Patrick

 

[JOHN HANSON]

Patrick, glad you enjoyed my web page. I followed your interesting KR build on the Land racing forum. Quite a project to supercharge a bike like that. I made it out there in 2009, 13, 14 and 16 and really enjoyed going but health now makes it impossible to go. Sadly my Vincent project which was almost finished will never be there.

 

[Thunderbird]

did someone say Vincent!.

now look, i like my Triumphs but a Vincent land speed machine that's gotta be worthy of another thread.

 

[thefrenchowl]

Hi John,

Thanks for the praise!!! We went 122.775 mph in 2013 with an international crew (2 x USA, 1 x Australia, 1 x GB and meself, French!!!)

That was higher than the record in MPS so a qualifier... but in impound they told us we were really APS where the record was open... By the time we did the change of class and another run, the rear head had a moment and that was it!!!

I'm rebuilding the bike at the moment, with revised street Sportster frame so that'll be deffo an MPS, Don't know if I can raise money for another trip but if I go, I'd rather beat an existing record rather than set an open one...

I've never tried nitro in me life, but looking at your Triumph, the term Double Trouble seems appropriate looking at all the blow ups/repairs over the years...

I'm not too familiar with the Hilborn injector... What is triggering the unit when an inlet valve opens? Or is it on all the time???

All the very best from Patrick

PS: my latest foray at Bonneville, with a french Jonghi bike, in 2019...

 

[JOHN HANSON]

Patrick, If I recall correctly you had a bit of a burn from the blower pop-off valve leaking on your KR?
Did you meet some Swedes there with the Jawa powered bike? That was Hilborn fuel injected.
Their 2013 record was 130+ for a short time. I traded some things to them for their next project so I now have the bike.

 

[thefrenchowl]

Yeah, the burn was in 2011, my 1st year on the salt for my 60th!!!

I met a Suede guy, Lars (Octane on the land racing forum). He has a supercharged Indian... His american mate, Nortonist here, has a Weslake powered red sidecar.

I do not recall the Jawa powered bike!!!

Patrick

 

[Thunderbird]

Re; Double Trouble. apart from originality is there any reason the front head could not be rotated 180 Deg. Negligible benefit, introduces more problems, space/flow restrictions?.

 

[joe49]

Thunderbird, are you wondering what exactly would the exhaust look like. My brother reversed his head on his. Pipes were not exactly compact. Would be a interference problem on a double. Then unless air flow of front injector, was restricted, the front engine would get a ram air effect. The ram air effect was one of the things my brother was after when he built his in the 80's, along with the 800cc cylinder, big cam, roller lifters, Mikuni's, taper bored ports, and I think 11 to 1 pistons.

 

[JOHN HANSON]

Re; Double Trouble. apart from originality is there any reason the front head could not be rotated 180 Deg. Negligible benefit, introduces more problems, space/flow restrictions?.

There were a number of early Triumph drag bikes that rotated the head trying to get a ram air effect.
I don't recall any of them ever winning a championship. Bud Hare may have come the closest in the early 50s.

 

[Thunderbird]

was thinking more about a cooler/fatter intake charge for the front motor but maybe that would be offset by twisty turny routing for exhaust gasses. hadn't considered that with a twin motor setup this would mean a loping effect on the firing between front and rear motors.

just the idea of all the carp being thrown up by the front wheel would put me off the idea.

 

[JOHN HANSON]

Top fuel quarter mile engines usually run for only a few seconds, not enough time to heat fuel or intake air. Blown engines do benefit from the bug catcher ram air effects. Land speed engines certainly benefit from cool fuel and ram air too.

 

[JOHN HANSON]

The plan is to finish the Double then get back on the Vincent land speed project. It's 1650cc.
The serious parts inside the engine are finished but I still need to make valves.
It had a rough life as a fuel drag bike and it's taken a lot of weld repair and machine work to get this far.

 

[Thunderbird]

will the Vincent be up for Special Construction- Vintage Fuel, same class as Alp's 666 Beast?.

 

[JOHN HANSON]

Alp's bike is APS-VF/ 1000 so different class. My Vincent would be APS-VG or VF / 1650cc.

 

[Ratso]

Have you discussed/described the injectors elsewhere, and if so would you please point me toward that discussion? Those things confuse me. Thanks.

 

[JOHN HANSON]

There isn't much out there on mechanical fuel injection for motorcycles.
Hilborn had a good tech section on their website for years but it was removed soon after Holley took over. Midget and TQ racers still use some mechanical injection. This site explains the basics here:
http://web.archive.org/web/20131005...resource.com/Engine_Tuning___Maintenance.html

Kinsler, Waterman, Ron's and others have websites as well that show how their setups operate.