V-Twin Panthers

 

Return to Index page: V-TWIN OBSESSION

Previous page: V-TWIN NEWS PAGE 28

5 Jun 2025

ALL PANTHER UPDATES ON ONE PAGE:

In November 1914, Phelon and Moore confirmed rumours they had been working on a vee-twin machine. It was a six horepower 750cc ninety-degree sidevalve vee twin. After develoment during the war years, it underwent further development and the second version had a 770cc engine. There were at least four prototypes (some sources say "half a dozen prototypes") and photographs of four of these survive. Unfortunately all the prototypes have now disappeared.

The 770 model (AK 3652) from The Motor Cycle, 1914

...................................................... ...............panther770b

The "fourth" 1916 model (HM7)

panther770

THE PANTLEY: Several years ago, Long John (Jan Koopmans), a Panther owner in the Netherlands, wanted to hear a Panther vee-twin, so he grafted a pair of Panther M120 top ends onto a Harley Davidson 1200 bottom end. The barrels have plates welded so they can be bolted to the cases. There were rumours in the Panther Owners Club that he had actually started it up... but the project languished, unfinished in his garage....

panther-1_zpsee6a04ce panther2

96242110_10221932001384713_1447673243136688128_o 96417223_10221932014385038_3830484540195864576_o 96362339_10221932009744922_3535454655288967168_o

Meanwhile, another Panther owner, Geoff Stray (webmaster of A V-Twin Obsession), started a project to build a V-Twin Panther that would feature an engine looking like it could have been built as a Phelon and Moore prototype, except this time, a 1200cc or 1300cc overhead valve v-twin (depending on which model - (the 600cc M100 or 650cc M120) was used as the basis of the build. It took two years to collect enough parts, and then the engine started to take shape. The crankcases were modified to accept a barrel mounting from another set of cases and the alloy mounting parts were welded in. At the Bristol Show in Feb 2016, the engine was on display but the crankshaft and other internal parts were not fitted. This made it much lighter to transport.

IMG-20160207-00150

At the Bristol Show in Feb 2017, the engine was sitting in a specially-made Dresda Manx frame ... here it is with my M100 Panther on the Panther Owners Club stand.

IMG_4714 IMG_4716

At the Bristol Show in Feb 2018, the engine had progressed - crank balanced, oil pump drive working, Rover pistons; Jaguar Gudgeon pins. Can you recognise the oil pump?

IMG-20180203-00474 26870737_564852833863573_924519224024498176_n-1

27540159_10155859409591885_8637857507420459023_n

STRAY-PANTHER at the Bristol Show in 2019: Since the 2018 Bristol Classic Bike Show, it has had the Norton gearbox exchanged for Ariel Square Four box and clutch (due to longer mainshaft); new wheel-rims and spokes; polished hubs; lightweight valves and springs (Dresda); Modified Norton Dominator fuel tank; Matchless silencers with temporary flexible exhausts; mudguards; front brake fittings; polished yokes; clutch lever and throttle; Norton Commando filter and Citroen oil filter; temporary paint. Photographed at the Bristol Classic Bike Show, Feb 23-24 2019 by Rob Green and Jerry Fox.

52698914_2190541571275152_3626125327622733824_n

Scorpioid pressure release valve installed:

61409257_10156972329016885_4359738598279348224_n

Exhausts constructed by Alldens Exhausts.

70916216_2345814129005046_6061906035436683264_o 70869833_2345814069005052_8731765789482287104_o

The Stray Panther at the Bristol Classic Bike Show, February 2020, "Highly Commended"

83322038_10157659787021885_6121975542527819776_n

83785195_10157659788641885_2970189443912171520_o 83822024_10157659788051885_3486728839726366720_n

Engine stripped and completely overhauled, honed, adjusted, compression plates added and many other alterations by Panther Legend, Will Hawkes.

89886401_1592531627568763_2910678892454871040_o

AUGUST 2020: Finally, the Stray Panther runs! Here it is at the Beast of Dartmoor Private Panther Party - its first outing:

118351602_10158321124466885_7373968438585688630_n

118282458_10158321132946885_1795522973380684204_n 118310027_10158321135256885_1753023770251416748_n 117764986_1813693272103192_8858650329585498644_n

...

At the Burrow Hill Cider Barn meet:

119564728_10158000870848995_7798543997288268191_o 119232033_10164148841705453_3797486762915574334_o

119902020_1579648132239690_3342641203350093082_n

289577309_10159730157481885_2814639100103217519_n 340636200_162934583039301_375872686819727119_n

340655478_1629054160876660_3229431981618073003_n

DOUBLE PAGE SPREAD in CLASSIC BIKE MAGAZINE, April 2024: (for a full article, see REAL CLASSIC Magazine, January 2021) also SLOPER Magazine, DEC 2020 and JAN 2021

434162590_10161023123106885_8346211753736678967_n Screen Shot 2025-07-05 at 17.50.51

THE STRAY CAT ROARS: Various sounds of the Stray Cat (Stray Panther) v-twin Panther recorded by various people on various devices:

WHEN THE STRAY-CAT WAS COMPLETED, THE BOOK WAS PUBLISHED telling the story....go to this link for details: V-TWIN PANTHER BOOK

panthervee cover2

THE PANTLEY (Harley with Panther heads) Following the debut of the STRAY CAT, Long John finally completed his Panther Vee:

Screen Shot 2023-05-16 at 11.58.12 Screen Shot 2023-05-16 at 11.59.21

 

When the Stray Panther was aired and taken to Panther rallies, four Panther owners announced their intention to build V-Twin Panthers. Mark Sanderson is the first to complete his bike, and what a masterpiece it is! It took only two and a half years to bring it the idea to full fruition - a working motorcycle!

Mark Sanderson's post on the Panther Motorcycles Facebook group, announcing the first startup:

"The first start up of V twin engine. No nasty rattles or leaks, oil pumping to both heads and big ends through Harley crank. Bit of fine tuning to do on charging system and tick over. So far, so good." Everything was designed, made, machined, milled and welded by him!

Mark Sanderson's 1200cc v-twin Panther: "Sneak preview of the V Twin. Just needs wiring up and road testing." This is the second OHV (overhad valve) v-twin Panther to be built. (The first one was Geoff Stray's 1300cc "Stray Cat".)

481165890_2071573549978700_3405120689078488425_n-1 504114408_2154351465034241_3237579042374044337_n-1

Walk around the bike.

She runs!

MORE V-TWIN PANTHERS COMING...

This unfinished Panther V-Twin project was amongst a pile of Panther spares received by Neil Turner in a deal with another Panther enthusiast. The modified crankcases will soon be forming the base for a Will Hawkes project. The engine will be a 90-degree Vee-Twin (or "Ell-twin") of about 700cc capacity, using the top ends of two 350cc Panthers (and possibly featuring the Harley 750cc con-rods that I swopped with Will).

IMG_4043 IMG_4042

After getting hold of a wide line feather bed rolling frame with v5 at an auto jumble, Graham Bryan did a quick mock-up to see how much room he had to play with... (not alot)

Graham used some old welded-up crankcases from Grahame Sherbourne for his V-Twin Panther project. Here we can see the rear part of the crankcase has been removed, ready for the insertion of the barrel mounting from the other set of cases.

Next, we see that Graham has made a mandrel for getting the rear cylinder lined up.... then the transplant is inserted.

Screen Shot 2025-07-05 at 15.11.27 copy Screen Shot 2025-07-05 at 15.00.00 copy Screen Shot 2025-07-05 at 14.49.24 copy Screen Shot 2025-07-05 at 14.50.57

DARREN GOODYEAR'S SECRET PROJECT... started many years ago, this project continues to progress in a secret Yorkshire location. Yet another approach to the Panther v-twin dream: Two single-port Panther M100 top ends lie atop a set of crankcases in which one set of cases have been swivelled backwards, attached to the front half of another engine!

darrenengine

Previous page: V-TWIN NEWS PAGE 28

Return to Index page: V-TWIN OBSESSION