Manky Monkey Motors

Technical Section => Bike Tech => Topic started by: Tony oily bike on January 05, 2016, 12:33:47 PM



Title: Blown Triumph sprint bike built by dslam - from scratch
Post by: Tony oily bike on January 05, 2016, 12:33:47 PM
Following on from a different thread
http://www.mankymonkeymotors.co.uk/forum/index.php?topic=15282.msg214551#msg214551

This is a thread about dslams blown Triumph

My mate Andy (dslam) doesn’t like to blow his own Trumpet (geddit??), so following his post about the blown (supercharged) Triumph sprint bike that he’s built from scratch, I’ve put this separate post together, along with some photos of the build.

We went to watch our first Sprint meeting around 20 years ago (although I’d been to the drags as early as ’71), and within a year we were competing on a shared bike. The rest as they say………..

Andy started the build in mid 2013, as is the “Big Brother” to a 500cc normally aspirated Triumph that Andy has ridden for many years.

I’ve assisted at times in the build as tea-maker, cake-supplier, observer, constructive-criticiser, photo snapper, “hold this for a moment” assistant and occasional parts donator.

The basics of the bike:
Home built frame based on the 500’s frame, mated to a set of shortened lightweight forks with re-laced half-width (brake) front wheel, and modified and re-laced rear wheel assembly.

Engine & transmission – 650 pre-unit Triumph, taken to 750cc with reversed head, supercharged by an Aisin 500, running methanol fed by an early SU with remote float bowl (from a pre war MG if I remember correctly). Ignition is tuneable electronic. Gearbox is Norton lay-down running a modern NEB speedway clutch.

All the engineering and build work was carried out by Andy apart from the powder-coating and (correction, Andy painted it)  manufacture of the fuel tanks. The engine has now had some heat cycles, the gearing of the blower revised, and an issue with the inlet hose rectified, so the motor will shortly be taken down again and the initial rebuild double checked prior to being used on the strip.

Enjoy the piccies

Some tubes, some old forks, an engine and the start of the build. Engine plates are wooden mock ups.


Title: Re: Blown Triumph sprint bike by dslam - from scratch
Post by: Tony oily bike on January 05, 2016, 12:39:22 PM
The frame taking shape. Joints are brazed.


Title: Re: Blown Triumph sprint bike by dslam - from scratch
Post by: Tony oily bike on January 05, 2016, 12:40:32 PM
Rear wheel 'in place' for frame line up


Title: Re: Blown Triumph sprint bike by dslam - from scratch
Post by: Tony oily bike on January 05, 2016, 12:41:49 PM
Frame completed except for a couple of small mounting lugs


Title: Re: Blown Triumph sprint bike by dslam - from scratch
Post by: Tony oily bike on January 05, 2016, 12:44:07 PM
Engine plates now made of dural and mounted in place. Note the blower at this stage is from a Mercedes, however this was changed later in favour of a smaller Aisin. Front forks and rear wheel now attached.


Title: Re: Blown Triumph sprint bike by dslam- from scratch
Post by: Tony oily bike on January 05, 2016, 12:45:55 PM
The drive-side of things. Plenum chamber partially constructed.


Title: Re: Blown Triumph sprint bike by dslam - from scratch
Post by: Tony oily bike on January 05, 2016, 12:48:32 PM
Another view of the LHS (still with old blower)


Title: Re: Blown Triumph sprint bike by dslam - from scratch
Post by: Tony oily bike on January 05, 2016, 12:49:11 PM
More detail of the frame


Title: Re: Blown Triumph sprint bike by dslam - from scratch
Post by: Tony oily bike on January 05, 2016, 12:50:07 PM
Wheeled outdoors for the first time to get a perspective view


Title: Re: Blown Triumph sprint bike by dslam - from scratch
Post by: Tony oily bike on January 05, 2016, 12:51:16 PM
The lightweight NEB speedway clutch (nice piece of kit!).

The blower is now the small Aisin 500


Title: Re: Blown Triumph sprint bike build by dslam - from scratch
Post by: Tony oily bike on January 05, 2016, 12:53:24 PM
Drive for the Aisin.

A toothed belt was chosen, and pulley wheels modified to suit


Title: Re: Blown Triumph sprint bike built by dslam - from scratch
Post by: Tony oily bike on January 05, 2016, 12:55:35 PM
Frame back from the powder coaters after had sprayed it.

Forks shortened.


Title: Re: Blown Triumph sprint bike built by dslam - from scratch
Post by: Tony oily bike on January 05, 2016, 12:57:25 PM
Rebuilt wheels fitted.

Sourcing a front tyre with a suitable speed rating and profile was still on-going at this point.

Rear tyre is a new M&H 4" slick, as used 'in the day'


Title: Re: Blown Triumph sprint bike built by dslam - from scratch
Post by: Tony oily bike on January 05, 2016, 01:07:29 PM
A bit of a jump, but here Andy's bike is around 80/90% done.

Timing, final drive, rear brake, gear change mechanism all to be sorted, front tyre to be sourced, and the route of the feed to the blower also needed to be revised


Title: Re: Blown Triumph sprint bike built by dslam - from scratch
Post by: Tony oily bike on January 05, 2016, 01:08:55 PM
The other side


Title: Re: Blown Triumph sprint bike built by dslam - from scratch
Post by: Tony oily bike on January 05, 2016, 01:09:35 PM
Rear wheel detail


Title: Re: Blown Triumph sprint bike built by dslam - from scratch
Post by: Tony oily bike on January 05, 2016, 01:10:32 PM
Back on the bench


Title: Re: Blown Triumph sprint bike built by dslam - from scratch
Post by: Tony oily bike on January 05, 2016, 01:11:45 PM
Revised intake route.

Fuel lines to be fitted.


Title: Re: Blown Triumph sprint bike built by dslam - from scratch
Post by: Tony oily bike on January 05, 2016, 01:13:31 PM
The Norton gearbox.

the gear-change lever, Andy made this from a lump of ally.


Title: Re: Blown Triumph sprint bike built by dslam - from scratch
Post by: Tony oily bike on January 05, 2016, 01:17:40 PM
More detail of the blower's intake.

When Andy ran this up for the first time, an issue arose with respect to the inlet hose, which he says has now been resolved.


Title: Re: Blown Triumph sprint bike built by dslam - from scratch
Post by: Tony oily bike on January 05, 2016, 01:19:34 PM
Another view of the supercharger


Title: Re: Blown Triumph sprint bike built by dslam - from scratch
Post by: the coppersmith on January 05, 2016, 05:40:19 PM
Fascinating, I will of course be looking out for it at Brighton. Great bit of work. Puts the Great in Great Britain


Title: Re: Blown Triumph sprint bike built by dslam - from scratch
Post by: minimutly on January 05, 2016, 06:01:07 PM
I would junk the tea strainer and fit a K&N.
I can't think of anything else I could improve....


Title: Re: Blown Triumph sprint bike built by dslam - from scratch
Post by: Mendalot on January 05, 2016, 06:42:30 PM
Excellent build, great to see old time brazing being employed.   How do you calculate the fuel mixture with a blower?


Title: Re: Blown Triumph sprint bike built by dslam - from scratch
Post by: Dslam on January 05, 2016, 07:56:11 PM
Thanks Tony, it would have taken me ages to put that lot up.

The tea strainer is fitted for shape rather than filtration although it will stop a stone but little else. At speed with a blower and the angle of the carb you run the risk of cavitation with a closed end K&N type filter. The curved shape of the trumpet allows for a smoother, less restricted/turbulent airflow. It is possible that the blower would suck a K&N out of shape too. In addition, I prefer the look. Function and form all in one hit. Thanks for the comment though.

Rule of thumb is between 6 to 8 to 1 air/fuel mixture (seems that there are differing opinions on this and like most engines requirements vary due to losses through the inlet tract) as apposed to 14-1 Air/petrol. The reality is drill a 1/4" main jet and shorten the needle then see what happens.
I was really lucky in that the motor was run some years ago by a good mate and he advised where to start. With Methanol you have about a 30% window and can run quite rich. As the blower is pumping air/fuel mixture rather than air you need volume of fuel. The carb can deliver up to 1000cc of fuel per second with the blower delivering up to 16psi, dependant on revs. Fuel efficient she ain't! Should be ample for my needs. The blower is a 'rootes' type and suffers some losses across the rotor tips but as it sucks fuel/air this reduces the losses, aids vaporisation and cools the charge. The Aisin was used as a shorrocks C75's are so expensive to buy. I can buy 5 Aisin's for the price of one Shorrock.

A small correction with the 'powder coat' statement. The frame was painted by me in Cadbury's purple. A light primer coat and a light top coat. If the frame cracks anywhere you can see it whereas powder can hide it until it has grown or moved.
I will put some more piccies up when it is finished. Some changes to the blower drive and inlet manifold between carb and blower have been done.


Title: Re: Blown Triumph sprint bike built by dslam - from scratch
Post by: scannerzer on January 05, 2016, 08:40:18 PM
tis a work of art gentlemen ...well done


Title: Re: Blown Triumph sprint bike built by dslam - from scratch
Post by: Tony oily bike on January 05, 2016, 10:52:10 PM
Thanks Tony, it would have taken me ages to put that lot up.

A small correction with the 'powder coat' statement. The frame was painted by me in Cadbury's purple. A light primer coat and a light top coat. If the frame cracks anywhere you can see it whereas powder can hide it until it has grown or moved.

Opps, now I remember, bit of a 'senior' moment.  ::)


Title: Re: Blown Triumph sprint bike built by dslam - from scratch
Post by: Manky Monkey on January 06, 2016, 09:40:41 AM
Beautifully done. My brother, Mr Brock, builds drag cars, so I appreciate how much thought & work go into even the smallest parts. Tis indeed a thing of beauty.


Title: Re: Blown Triumph sprint bike built by dslam - from scratch
Post by: Tony oily bike on January 06, 2016, 05:32:22 PM
Went and visited Mr dslam today, and here are some pics he gave me.

The inlet from the carb to the blower was black braided hose (2" dia) - This has now been replaced with the nice shiny stuff you see here. Cut/shut/welded by Andy from two standard 90 degree components.

I'll let Andy explain the whys & wherefores


Title: Re: Blown Triumph sprint bike built by dslam - from scratch
Post by: Tony oily bike on January 06, 2016, 05:33:26 PM
And this time viewed from the other side


Title: Re: Blown Triumph sprint bike built by dslam - from scratch
Post by: Tony oily bike on January 06, 2016, 05:34:38 PM
Kinda says it all  8)


Title: Re: Blown Triumph sprint bike built by dslam - from scratch
Post by: Tony oily bike on January 06, 2016, 05:37:28 PM
The "finished" article, and its not just for show, this bike will be properly used!!

Pretty ain't it!


46 just happens to the racing number issued, and pure coincidence that Valentino shares it with Andy  :D


Title: Re: Blown Triumph sprint bike built by dslam - from scratch
Post by: Tony oily bike on January 06, 2016, 05:39:28 PM
From the other side


Title: Re: Blown Triumph sprint bike built by dslam - from scratch
Post by: Dslam on January 06, 2016, 05:44:14 PM
Thanks Tony.
The black hose from the carb to the blower was replaced due to a schoolboy error.
When started the bike ran fine, blipped the throttle all OK. When the throttle was shut the hose collapsed completely flat! Doh!!!
The engine was turning the blower but the butterfly being closed cause a sudden vacuum in which overcame the ability of the hose to stay hose shaped.
Now replaced with shiny stuff that will stay hose shaped ;D


Title: Re: Blown Triumph sprint bike built by dslam - from scratch
Post by: BikerGran on January 06, 2016, 11:00:45 PM
That is, indeed, very pretty!

And when something is pretty AND functional - well it can't get any better, can it?

 :) :)


Title: Re: Blown Triumph sprint bike built by dslam - from scratch
Post by: hunter on January 07, 2016, 12:18:40 PM
Very nice Dave.
I may have to take a trip to Brighton this year.


Title: Re: Blown Triumph sprint bike built by dslam - from scratch
Post by: Olds on January 08, 2016, 07:08:29 AM
Lovely bike and great workmanship.


Title: Re: Blown Triumph sprint bike built by dslam - from scratch
Post by: morrag on January 08, 2016, 09:38:02 AM
Well, it looks quick standing still! so....very pretty..Morrag


Title: Re: Blown Triumph sprint bike built by dslam - from scratch
Post by: Dslam on January 20, 2016, 08:50:47 PM
Thanks for the positive comments, much appreciated.
I am waiting for the weather to warm up a bit so I can start it and make sure it does what it is supposed to.
When the time comes I will video it running put a link to it here.


Title: Re: Blown Triumph sprint bike built by dslam - from scratch
Post by: Mendalot on January 24, 2016, 10:38:10 AM
Looking forward to the video ;)


Title: Re: Blown Triumph sprint bike built by dslam - from scratch
Post by: Tony oily bike on February 13, 2017, 11:58:27 AM
Well it been around a year since the last posts on Dslam’s blown Triumph drag/sprint bike, so its time for some updates.

The original build design & construction had blower-drive from the crank pulley to the Aisin supercharger but toothed belt.
This has been re-engineered to have the more traditional “double V belt configuration”  (and of course, this stuff isn’t all available off-the-shelf so machining had to take place to get the ratios and alignment etc all sorted).

Although the position of the SU carb and its remote float bowl, along with induction pipe/manifold to the blower was engineeringly all AOK, the possibility of damage should the bike be knocked or fall over gave cause for concern.
Following much Al welding to form a new induction pipe/manifold, the carb and float bowl now reside in a more protective location.

The only remaining tasks (apart from the shakedown runs and final set-up) are to manufacture a new fork-brace, and carry out modifications to, or fabricate a complete new, exhaust to allow a temporary silencer to fitted so the machine will pass the strict noise regs of the Brighton Speed Trials.
The issue being with a blown motor (and running methanol) is that any back pressure is detrimental.

Photo shows the new double V belt drive, but un-revised carb position


Title: Re: Blown Triumph sprint bike built by dslam - from scratch
Post by: Tony oily bike on February 13, 2017, 11:59:43 AM
The original position of the SU carb and remote float bowl


Title: Re: Blown Triumph sprint bike built by dslam - from scratch
Post by: Tony oily bike on February 13, 2017, 12:01:30 PM
The revised carb position (float bowl on bench at time of photo but ready to be bolted up) along with newly-manufactured (in Dslam's shed of course!) intake to blower


Title: Re: Blown Triumph sprint bike built by dslam - from scratch
Post by: Tony oily bike on February 13, 2017, 12:05:15 PM
and from the other side


Title: Re: Blown Triumph sprint bike built by dslam - from scratch
Post by: Manky Monkey on February 13, 2017, 12:10:43 PM
That truly is a thing of beauty.


Title: Re: Blown Triumph sprint bike built by dslam - from scratch
Post by: stinkey on February 13, 2017, 01:06:01 PM
Bloody horrible thing ?  ;) should be in a window down New Bond Street..work of ART..


Title: Re: Blown Triumph sprint bike built by dslam - from scratch
Post by: the coppersmith on February 13, 2017, 02:12:11 PM
Oh, I like that ! Will seek you out at Brighton and maybe I can have a pokey oily finger thing  :D


Title: Re: Blown Triumph sprint bike built by dslam - from scratch
Post by: Dslam on February 13, 2017, 08:41:33 PM
Cheers Tony. Didn't expect you to do all this, I simply don't have the patience to load all that stuff on, I'd rather be in the shed.
This bike has been a while in the making. Mostly due to my soft nature helping others out which took about 9 months out of the schedule.
It will be out on track this year to shake it (and me) down and get the setup right. Then its time to up the anti and pin the throttle.
I will attempt to keep you all posted as to the progress.
New fork brace made and fitted. Last item is the chain guard then its ready to go.
Assuming I can get it quiet enough it will be at Brighton so if you're about come and say hello and feel free to poke the oily finger. Ooo Matron!!


Title: Re: Blown Triumph sprint bike built by dslam - from scratch
Post by: Dslam on July 19, 2019, 05:52:41 PM
Well. A bit of time has passed. A number of shakedown runs and some head scratching, a few carb mods like jetting and weight on the SU piston as the blower has a tendency of sucking the carb piston straight up making the throttle somewhat uncontrollable. A bit of all or nothing.
I ran the bike at Weston Zoyland and at Mallory and some good headway has been made. When it 'gathers its skirts' it a proper rocket ship and handles well. I left an 80foot darkie at Mallory which bodes well (no vulgar remarks please!). Some more carb mods before Brighton and we shall see how we go.
Softly softly catchee manky ;D
It sounds amazing and has the ability to scare. Bring it on.
Thinking of a name change to 'Parabellum' Latin for prepare for war and common usage for a 9mm bullet. Mildly accurate I think.
I'll put some pictures up after Brighton if all goes to plan.


Title: Re: Blown Triumph sprint bike built by dslam - from scratch
Post by: Manky Monkey on July 19, 2019, 06:43:13 PM
Love the name :)
You should meet my brother, the slingshot dragster pilot. You'd get on well with him!


Title: Re: Blown Triumph sprint bike built by dslam - from scratch
Post by: Tony oily bike on September 02, 2019, 06:20:16 AM
Well. A bit of time has passed. A number of shakedown runs and some head scratching, a few carb mods like jetting and weight on the SU piston as the blower has a tendency of sucking the carb piston straight up making the throttle somewhat uncontrollable. A bit of all or nothing.
I ran the bike at Weston Zoyland and at Mallory and some good headway has been made. When it 'gathers its skirts' it a proper rocket ship and handles well. I left an 80foot darkie at Mallory which bodes well (no vulgar remarks please!). Some more carb mods before Brighton and we shall see how we go.
Softly softly catchee manky ;D
It sounds amazing and has the ability to scare. Bring it on.
Thinking of a name change to 'Parabellum' Latin for prepare for war and common usage for a 9mm bullet. Mildly accurate I think.
I'll put some pictures up after Brighton if all goes to plan.

Brighton Speed Trials - Saturday 7th September 2019

http://www.mankymonkeymotors.co.uk/forum/index.php?topic=16973.0


Title: Re: Blown Triumph sprint bike built by dslam - from scratch
Post by: Tony oily bike on October 29, 2019, 09:27:05 AM
Brighton Speed Trials 2019 – Having just helped Mr Slam / Andy start the bike on my rollers, he’s ready to proceed towards the start line. The large silencer is a requirement to meet the Brighton noise limits (other events are un-silenced).


Title: Re: Blown Triumph sprint bike built by dslam - from scratch
Post by: Tony oily bike on October 29, 2019, 09:27:47 AM
Brighton Speed Trials 2019 – Heading towards the start line.


Title: Re: Blown Triumph sprint bike built by dslam - from scratch
Post by: Tony oily bike on October 29, 2019, 09:28:19 AM
Brighton Speed Trials 2019 – Chocked, ready for the off along the famous Madeira Drive. This year, the start line duties for the bikes were performed by members of the VMCC Sprint Section (Paul & Steve in this case).



Title: Re: Blown Triumph sprint bike built by dslam - from scratch
Post by: Tony oily bike on October 29, 2019, 09:28:59 AM
Late October - Post Brighton and the engine has been stripped down and inspected by Mr Slam, a must-do when running a supercharged engine for a season on methanol.
With the engine re-build having just been completed, and the home-made frame (following inspection) freshly powder coated in a new purple with a hint of flake, its assembly time and the bike is wheeled into the sunlight, resplendent in its new colour and “Parabellum” stickers on the fuel tanks.


Title: Re: Blown Triumph sprint bike built by dslam - from scratch
Post by: Tony oily bike on October 29, 2019, 09:29:32 AM
The new purple looking rather cool in the late October sun


Title: Re: Blown Triumph sprint bike built by dslam - from scratch
Post by: Tony oily bike on October 29, 2019, 09:33:45 AM
New "Parabellum" tank badges.


Title: Re: Blown Triumph sprint bike built by dslam - from scratch
Post by: the coppersmith on October 29, 2019, 11:43:08 AM
simply put: very impressive. A tad envious too  ;)


Title: Re: Blown Triumph sprint bike built by dslam - from scratch
Post by: BikerGran on October 31, 2019, 10:23:41 PM
Mmmmmm purple!


Title: Re: Blown Triumph sprint bike built by dslam - from scratch
Post by: morrag on November 18, 2019, 07:49:18 PM
I may have mentioned it before 8), but it would grace any ones Drawing room! on possibly a rotating plinth, when it's working life is done, of course!! ;D..Morrag


Title: Re: Blown Triumph sprint bike built by dslam - from scratch
Post by: Dslam on November 19, 2019, 03:59:14 PM
Thanks for the positive responses. If my gaff was big enough each room would have a bike in it.
When I met Deb I had a 1926 Raleigh 250 in the dining room. She was not happy about that so by way of compromise I built a heated garage at the end of the garden where all my mistresses now reside!
The blown Triumph is nearly there. When she 'gathers her skirts' she goes like stink but is as flat as a roof tilers nail bag off the line. Some cam timing changes have been made to shunt the power back down the rev range then it will be tinkering with fuelling to get it just so. Its a never ending story  but one I am happy and proud to be part of. This stuff doesn't happen without the help, encouragement and sponsorship of some good friends. You all know who you are!!
Roll on 2020  ;D


Title: Re: Blown Triumph sprint bike built by dslam - from scratch
Post by: Manky Monkey on November 19, 2019, 06:39:33 PM
Must try & get to one of your sprint meets in the Spring Andy.


Title: Re: Blown Triumph sprint bike built by dslam - from scratch
Post by: Dslam on November 20, 2019, 06:47:39 AM
I will let you know when and where mate.


Title: Re: Blown Triumph sprint bike built by dslam - from scratch
Post by: Manky Monkey on November 20, 2019, 09:21:17 PM
Thanks :)