BritBike Forum logo
BritBike SponsorBritBike SponsorBritBike SponsorBritBike SponsorBritBike Sponsor SteadfastCyclesBritBike SponsorBritBike SponsorBritBike SponsorBritBike SponsorHepolite PistonsBritBike SponsorBritBike Sponsor
Upgrade to: Gold Membership | Premium Membership | Vendor Membership | Site Sponsor Membership
Words from our sponsors..
Vintage Motorcycle Auctioneers!
Vintage Motorcycle Auctioneers

CLICK HERE to see VIDEO
How the Electric Roller Starter works.

ORDER on eBay. CLICK HERE!
Buy your Electric Roller Starter here
ShoutChat Box
Comment Guidelines: Do post respectful and insightful comments.
Buy BritBike staff a coffee
Buy BritBike's staff a coffeeStill here since 1996 serving BritBike enthusiasts..
Search eBay for motorcycle parts in following countries
Australia, Canada, France, Holland, Italy, United Kingdom, USA
Random Gallery photo
Member Spotlight
T120C
T120C
Central Virginia
Posts: 824
Joined: August 2001
Show All Member Profiles 
Newest Members
BradM, Andrew C., muzza123, Siwy, Troy Walls
11012 Registered Users
Top Posters(30 Days)
franko 134
koan58 69
DavidP 50
Popular Topics(Views)
1,148,432 mail-order LSR
a word from..
Forum Statistics
Forums35
Topics68,913
Posts690,774
Members11,012
Most Online14,755
May 5th, 2019
Who's Online Now
58 registered members (Al Eckstadt), 1,081 guests, and 924 spiders.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate Thread
Triumph timing gears lightening? #792084 12/05/19 2:13 am
Joined: Dec 2013
Posts: 7
T
tritr6 Offline OP
BritBike Forum member
OP Offline
BritBike Forum member
T
Joined: Dec 2013
Posts: 7
What is the latest recommendation on drilling timing gears

Support Your #1 BritBike Forum!

Check out British motorcycles for sale:
British Motorcycles on e-Bay UK
British motorcycles on e-Bay North America
CLICK HERE to see VIDEO
How the Electric Roller Starter works.


ORDER on eBay. CLICK HERE!

Buy your Electric Roller Starter here
Re: Triumph timing gears lightening? [Re: tritr6] #792106 12/05/19 4:04 pm
Joined: Mar 2005
Posts: 10,326
J
John Healy Online Content
BritBike Forum member
Online Content
BritBike Forum member
J
Joined: Mar 2005
Posts: 10,326
Great way to kill a couple of cold winter evenings. It really impresses your buddies. As to possible gain, or loss it can be debated "until the cows come home."
The current theory you get better results using heavier cam wheels with the twins and singles. The mass helps dampen the oscillations as the valve spring
snaps the cam wheel rotation backward and forward. Triumph went to full width cam wheels on the 750. and if anything, we saw slight improvement in performance.

Any one have a Spintron?

You will get more out of spending your money on improving the flow around the valve seat.


Re: Triumph timing gears lightening? [Re: tritr6] #792118 12/05/19 8:09 pm
Joined: Aug 2015
Posts: 1,493
A
Andy Higham Offline
BritBike Forum member
Offline
BritBike Forum member
A
Joined: Aug 2015
Posts: 1,493
Removing weight from reciprocating parts will have much more effect


BSA B31 500 "Stargazer"
Greeves 200 "Blue Meanie"
Greeves 350
Greeves 360
Suzuki GSX1100 EFE "Sorcerers Apprentice"
GM500 sprint/LSR bike "Deofol"
Jawa 500 "Llareggub"
Aprilia RSV Mille "Lo Stregone"
'35 & '36 OK Supreme
Kawasaki ZZR1400 "Kuro no senshi"
Re: Triumph timing gears lightening? [Re: Andy Higham] #792120 12/05/19 8:35 pm
Joined: Aug 2001
Posts: 8,081
triton thrasher Online Content
BritBike Forum member
Online Content
BritBike Forum member
Joined: Aug 2001
Posts: 8,081
Originally Posted by Andy Higham
Removing weight from reciprocating parts will have much more effect


Are you sure it will have any effect that you will notice when you’re riding the bike?


Amateur Loctite enthusiast.
Re: Triumph timing gears lightening? [Re: tritr6] #792123 12/05/19 9:39 pm
Joined: Mar 2005
Posts: 10,326
J
John Healy Online Content
BritBike Forum member
Online Content
BritBike Forum member
J
Joined: Mar 2005
Posts: 10,326
Quote
Removing weight from reciprocating parts will have much more effect


That's an interesting subject that engineers using the spintron system have explored.
Changing the resonant frequency of a part, or group of parts that act in unison, often
delivers interesting results. They are not always intuitive.


Re: Triumph timing gears lightening? [Re: tritr6] #792131 12/05/19 10:57 pm
Joined: Dec 2013
Posts: 4,878
kevin roberts Offline
DOPE
Offline
DOPE
Joined: Dec 2013
Posts: 4,878
bought these at the swap meet at the OVBSA meet in steubenville. can't remember whether i put pictures of them up before.

[Linked Image from i.imgur.com]

these have been milled thinner as well being drilled

[Linked Image from i.imgur.com]


every day you do not take a chance is a day of your life that you will never get back.
Re: Triumph timing gears lightening? [Re: tritr6] #792166 12/06/19 10:31 am
Joined: Jan 2005
Posts: 1,644
Dick Harris Offline
BritBike Forum member
Offline
BritBike Forum member
Joined: Jan 2005
Posts: 1,644
As usual, John hit the nail on the head.. Dick

Re: Triumph timing gears lightening? [Re: tritr6] #792169 12/06/19 11:44 am
Joined: Oct 2012
Posts: 4,810
Hillbilly bike Offline
BritBike Forum member
Offline
BritBike Forum member
Joined: Oct 2012
Posts: 4,810
You want drilled gears ? How about a WW2 Bristol sleeve valve radial engine aircraft engine..

[Linked Image from live.staticflickr.com]


79 T140D, 96 900M Ducati ....On a bike you can out run the demons..
Re: Triumph timing gears lightening? [Re: tritr6] #792213 12/06/19 9:32 pm
Joined: Dec 2013
Posts: 4,878
kevin roberts Offline
DOPE
Offline
DOPE
Joined: Dec 2013
Posts: 4,878
jeez

did those radials use a distributor cam or massive waste sparks?


every day you do not take a chance is a day of your life that you will never get back.
Re: Triumph timing gears lightening? [Re: kevin roberts] #792218 12/06/19 10:52 pm
Joined: Sep 2013
Posts: 2,285
Q
quinten Offline
BritBike Forum member
Offline
BritBike Forum member
Q
Joined: Sep 2013
Posts: 2,285
Originally Posted by kevin roberts
jeez

did those radials use a distributor cam or massive waste sparks?

[Linked Image from gracesguide.co.uk]
[Linked Image from gracesguide.co.uk]

Re: Triumph timing gears lightening? [Re: tritr6] #792219 12/06/19 11:27 pm
Joined: Dec 2013
Posts: 4,878
kevin roberts Offline
DOPE
Offline
DOPE
Joined: Dec 2013
Posts: 4,878
that's a magdyno, isn't it? the generator is part on the bottom?

i don't see a spark distribution system in there, although i think i see one set of ignition points on the left end of the lower shaft.

why would the spinning armature have spark towers on it?

strange instrument.


every day you do not take a chance is a day of your life that you will never get back.
Re: Triumph timing gears lightening? [Re: tritr6] #792228 12/07/19 12:56 am
Joined: Jan 2014
Posts: 569
N
NickL Offline
BritBike Forum member
Offline
BritBike Forum member
N
Joined: Jan 2014
Posts: 569
It's just a mag Kevin, no dynamo.

The 500 cam pinions are thinner/lighter but the idler is too small to use.
I wouldn't bother, they rattle enough with the full width normally.
When racing i saw enough 'lightened' bits break and wear at extreme rates
to wonder about the advantages..................
But, as John said, it's a way to spend cold winter evenings.

The Centaurus was a lovely bit of kit for a radial thing. Sleeve valves, a complex way
to go about things eh?

Re: Triumph timing gears lightening? [Re: NickL] #792266 12/07/19 3:27 pm
Joined: Oct 2012
Posts: 4,810
Hillbilly bike Offline
BritBike Forum member
Offline
BritBike Forum member
Joined: Oct 2012
Posts: 4,810
Originally Posted by NickL


The Centaurus was a lovely bit of kit for a radial thing. Sleeve valves, a complex way
to go about things eh?


Yes, The Brits seemed to love very complicated piston engines considering some materials were harder come by.The Napier engines were even more complicated...The Americans, with no limit to materials, built their engines using a lot less parts mostly because of mass production by unskilled workers and maintenance done 1000's of miles from the factories.

Napier Sabre sleeve valve

[Linked Image from aviationshoppe.com]


The somewhat less complex Pratt & Whitney R2800 Double Wasp....

[Linked Image from williammaloney.com]


79 T140D, 96 900M Ducati ....On a bike you can out run the demons..
Re: Triumph timing gears lightening? [Re: tritr6] #792312 12/08/19 12:14 am
Joined: Jan 2014
Posts: 569
N
NickL Offline
BritBike Forum member
Offline
BritBike Forum member
N
Joined: Jan 2014
Posts: 569
Both the Sabre and the Centaurus were developments of earlier engines (Dagger+Hercules)
When their early development was going on the best way of running detonation free on low octane
fuel was to use a flat cylinder head. Sleeve valve engines had flat heads and no valves to overheat.
It was much later on that higher octane fuel became available. They had embarked on a mission by then.
Also as an aero engine, the emphasis at that time was for low frontal area so the H section was
quite sensible. BRM made a formula 1 racing car with a 16 cyl H engine in the early 60's too.

On the face of it the sleeve valve arrangement is complicated but the PW does have it's own
internal complexity too, varying the timing around the radial engine etc.

Britain at that time having a huge empire also had the situation of engines being repaired and serviced many
thousands of miles from the factories and had been doing it for years before 1939. Unskilled workers
were also used in their thousands in british factories during and before the war. It's a bit of a myth that all
the workers at Rolls Royce Aero wore white coats and carried slide rules. Two or three new factories opened
to produce the merlin during the war at various locations, largely staffed by initially 'unskilled' workers.
Same thing with aircraft production or in fact any form of production, huge demand required lots of labour.
America was not unique in this approach, it was just bigger, had more resource and was not under attack.

If you talk to some mechanics who worked on any two row radial they will all tell you what a pain they were to work on.

Re: Triumph timing gears lightening? [Re: tritr6] #792329 12/08/19 7:24 am
Joined: Apr 2005
Posts: 2,605
Mark Parker Offline
BritBike Forum member
Offline
BritBike Forum member
Joined: Apr 2005
Posts: 2,605
So is the cam on the P&W driven at half crankshaft speed and using one set off lobes to feed all cylinders it each row?


mark
Re: Triumph timing gears lightening? [Re: Mark Parker] #792333 12/08/19 12:28 pm
Joined: Oct 2012
Posts: 4,810
Hillbilly bike Offline
BritBike Forum member
Offline
BritBike Forum member
Joined: Oct 2012
Posts: 4,810
Originally Posted by Mark Parker
So is the cam on the P&W driven at half crankshaft speed and using one set off lobes to feed all cylinders it each row?



I believe it's driven at 1/6 crank speed,,It's a large ring with external lobes (6?), one ring for each row, 9 cylinders in each row...It is aguably the best all around large radial of the War. over 125,000 were made and unlike most other WW2 engines, it was used in passanger and cargo planes until the jets took over in the 1950's..


79 T140D, 96 900M Ducati ....On a bike you can out run the demons..
Re: Triumph timing gears lightening? [Re: tritr6] #792340 12/08/19 1:27 pm
Joined: Dec 2013
Posts: 4,878
kevin roberts Offline
DOPE
Offline
DOPE
Joined: Dec 2013
Posts: 4,878
what are the relative advantagez and disadvantagez of radials over inline enginez in aircraft?

when i lived in california the crop dusters used both.


every day you do not take a chance is a day of your life that you will never get back.
Re: Triumph timing gears lightening? [Re: tritr6] #792341 12/08/19 1:39 pm
Joined: Mar 2019
Posts: 212
Hugh Jorgen Online Content
BritBike Forum member
Online Content
BritBike Forum member
Joined: Mar 2019
Posts: 212
My guess regarding fighter aircraft would be the reduced frontal profile of an inline, both for aerodynamics and presentation of a smaller target.


1970 T120R
1970 Commando
Re: Triumph timing gears lightening? [Re: tritr6] #792349 12/08/19 2:17 pm
Joined: Dec 2013
Posts: 4,878
kevin roberts Offline
DOPE
Offline
DOPE
Joined: Dec 2013
Posts: 4,878
well, the cropdusters certainly flew very slowly, no matter what the engine was.

torque is what tbey worked with.

they would drop stuff on you for fun, if they knew you.


every day you do not take a chance is a day of your life that you will never get back.
Re: Triumph timing gears lightening? [Re: tritr6] #792351 12/08/19 2:25 pm
Joined: Oct 2012
Posts: 4,810
Hillbilly bike Offline
BritBike Forum member
Offline
BritBike Forum member
Joined: Oct 2012
Posts: 4,810
Crop dusters generally use air cooled inline or radial engines...Inline aircooled engines can be Ranger inverted inlines or V's. Some use flat opposed 4 or 6 cylinder air cooled Lycomings..For duster use it's more likely a design choice by the airframe manufacturer ....
For warplanes, the radials used in the FW190 and US fighters such as the Corsair and P-47 gave up little to no top speed in exhange for the ability to absorb more combat damage ...One bullet can puncure the radiator or maze of coolant lines and the engine will seize soon afterward..


79 T140D, 96 900M Ducati ....On a bike you can out run the demons..
Re: Triumph timing gears lightening? [Re: tritr6] #792395 12/08/19 9:15 pm
Joined: Dec 2013
Posts: 4,878
kevin roberts Offline
DOPE
Offline
DOPE
Joined: Dec 2013
Posts: 4,878


well, i didn't always get along with the dusters, being a beekeeper with some 800 hives scattered around their workspace, but i can appreciate what they do.


every day you do not take a chance is a day of your life that you will never get back.
Re: Triumph timing gears lightening? [Re: tritr6] #792421 12/09/19 1:11 am
Joined: Jan 2014
Posts: 569
N
NickL Offline
BritBike Forum member
Offline
BritBike Forum member
N
Joined: Jan 2014
Posts: 569

Last edited by NickL; 12/09/19 2:15 am.

Moderated by  Allan Gill 

Home | Sponsors | Newsletter | Regalia | Calendar | Bike Project | BritBike Museum | Spiders Cartoons | DVD- Manuals & Parts books
Upgrade to: Gold Membership | Premium Membership | Vendor Membership | Site Sponsor Membership
Powered by UBB.threads™ PHP Forum Software 7.7.3