BritBike Forum logo
BritBike SponsorBritBike SponsorBritBike SponsorBritBike SponsorBritBike SponsorBritBike SponsorBritBike SponsorBritBike SponsorThe Bonneville ShopBritBike Sponsor
Upgrade to: Premium Membership | Premium Life Membership | Vendor Membership | Site Sponsor Membership
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
MotorEddy
MotorEddy
Lancashire, UK
Posts: 39
Joined: August 2011
Show All Member Profiles 
Newest Members
Alex Lynch, B Mac, Lenz-a-lot, UncleYeti, harold2019
10774 Registered Users
Top Posters(30 Days)
franko 128
NickL 66
MarcB 53
Popular Topics(Views)
947,603 mail-order LSR
Forum Statistics
Forums34
Topics67,493
Posts675,613
Members10,774
Most Online14,755
May 5th, 2019
Who's Online Now
77 registered members (Alex Lynch), 437 guests, and 854 spiders.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate Thread
triumph 5T build questions #773505 05/12/19 9:28 pm
Joined: Apr 2019
Posts: 5
W
Waechter Machinery Offline OP
BritBike Forum member
OP Offline
BritBike Forum member
W
Joined: Apr 2019
Posts: 5
Hey There! New to the board and located in Colorado. I just acquired a 5T and a 6T project. I have a Trophy hardtail frame and currently have the 1948 5T mounted in it. I have a few questions regarding the engines to help decide what direction to go. First off, both engines are rather complete but the other than the frame, there is nothing else, thus doing a bit of a gow job. Had an old triumph rear wheel and 18" spool hub hanging around and My buddy Ed is hooking me up with a super short vintage springer for it. I guess my questions are:

What are some relatively cheap hop up options?
Which engine would be the wisest to build?(I would prefer to stick with the 48)
Are there any shops In my general area who are knowledgeable in pre units?
Who sells a good dry clutch and belt to run open for the long primary?
Where can I send my magneto to for a rebuild?


Any other tips or tricks would be greatly appreciated!

Last edited by Waechter Machinery; 05/13/19 5:07 pm. Reason: Silly mistakes
Support Your #1 BritBike Forum!

Check out British motorcycles for sale:
British Motorcycles on e-Bay UK
British motorcycles on e-Bay North America
Re: triumph t5 build questions [Re: Waechter Machinery] #773516 05/12/19 11:10 pm
Joined: Aug 2001
Posts: 6,056
Jon W. Whitley Offline
BritBike Forum member
Offline
BritBike Forum member
Joined: Aug 2001
Posts: 6,056
I'm sure you meant to type 5T and 6T ? There is no such Triumph model known as a T5 or T6...it is either 5T or 6T.


Jon W.


1957 6T Thunderbird 650
1968 T100R Daytona 500
1971 TR6R Tiger 650
1970 BSA A65F 650
1955 Tiger 100 - Project

Re: triumph t5 build questions [Re: Waechter Machinery] #773611 05/13/19 9:56 pm
Joined: Oct 2006
Posts: 3,119
I
Irish Swede Online Content
BritBike Forum member
Online Content
BritBike Forum member
I
Joined: Oct 2006
Posts: 3,119
These were low-power bikes.
Anything to make them MORE powerful will cost you.

Re: triumph t5 build questions [Re: Waechter Machinery] #773617 05/13/19 10:24 pm
Joined: Apr 2019
Posts: 5
W
Waechter Machinery Offline OP
BritBike Forum member
OP Offline
BritBike Forum member
W
Joined: Apr 2019
Posts: 5
I don't necessarily mean CHEAP, I just mean can some parts from later models be used with better results, interesting machining/porting, tried and trued power gains, like big bore(if even possible). I know these weren't rocket ships to begin with and well aware nothing is cheap, just looking for advice and direction.

Re: triumph t5 build questions [Re: Waechter Machinery] #773625 05/13/19 11:48 pm
Joined: Jun 2007
Posts: 6,387
HawaiianTiger Offline
BritBike Forum member
Offline
BritBike Forum member
Joined: Jun 2007
Posts: 6,387
I plan to drop a 750 kit on my old Thunderbird. Tired of just putting around in the back.
I have the unit head and rocker boxes in storage. I plan to disguise them so a first glance you won't notice it's not pre unit top end parts.
I think I will trade my Bonnie head for a TR6 head, too. I like the simplicity of the single carb and the better low lend response, too. Then there's the expense...
It's really the easiest and cheapest way into high performance for these bikes. You can buy a set of cams and what labor there is in installing them will be much more than just dropping on a 750 kit.

cheers,
Bill


Bikes
1974 Commando
1985 Honda Nighthawk 650
1957 Thunderbird/T110 "Black Tiger"
Antique Fans: Loads of Emersons (Two six wingers) plus gyros and orbiters.
Re: triumph t5 build questions [Re: Waechter Machinery] #773661 05/14/19 7:15 am
Joined: Sep 2008
Posts: 1,101
S
Stein Roger Offline
BritBike Forum member
Offline
BritBike Forum member
S
Joined: Sep 2008
Posts: 1,101
If these are pre 55 engines you'd be ill advised to tune them for more power. They had smaller crank journals and a smaller timing side main than later engines.
It's possible to install a later crank in them, with a special main bearing, but I'd sooner source a later engine as a basis.
55-on engines can be tuned and I've put E3134 cams in a 6T with late 9:1 pistons (easier to source), that gives around 8:1 CR or so with these cylinder heads. Went pretty well.
I did gas flow the ports some, they're pretty convoluted around the guide area.

A 750 kit with a TR6 head as Bill suggests is a winner! The small port head gives the engine a fantastic throttle response, especially with a T110 exhaust cam and a Bonnie inlet cam.
The small (1 1/6") ports can flow more than the valve at full lift anyway, so you lose nothing but gain a bunch. A wonderful combination!
I wish more people would try it, in stead most people go for the Hot Rod philosophy, big cam, big carb, big port, big valve. And lose big power...


Re: triumph t5 build questions [Re: Waechter Machinery] #773665 05/14/19 7:55 am
Joined: Jun 2007
Posts: 6,387
HawaiianTiger Offline
BritBike Forum member
Offline
BritBike Forum member
Joined: Jun 2007
Posts: 6,387
I already have a later crank in my big bearing cases. My engine is actually from a '57 Thunderbird. The crank is already balanced to 85% but with lower compression and power, it doesn't seem to be a match.
I am hoping and expecting the motor to be as smooth or smoother with the 750 as long as I try hard to duplicate the weight and balance with the new pistons.
Here's a pic of the motor when I was building it about 10 years ago.
[Linked Image]55T-Bird86
I have heard it here that the 750 pistons are very close to the 650's in weight. I installed 3134 profile 69-70 cams in there when I built it. It should run fine. I have a distributor in there as well and I can customize the advance curve if I want to go that far.
I'm not looking to do wheelies or burn-outs, but I'd like to up the gearing a little for highway cruising. 750 long rods pull higher gearing with ease.

I may also get to tune the '67 750 Street tracker I worked on 3 years ago or so. That one went from Portland, Oregon across the Rockies and eventually climbed Pike's Peak without problems. But it's down on power now. I suspect a valve job will restore it's power. Also, the same man owns a 55 T110 long rod 750 chopper I built about 20 years ago. That bike was the fastest Triumph here.....then I put a 750 kit on it. It is a monster.....it needs some TLC. I will post both of these if I get a chance to massage them.

My experiences with hotrodded small bearing motors has not been good. I worked on a '52 Bird. It was pretty fast, had megaphones(LOUD) but holed a piston with those. It happens. Then the right side bearing went and I replaced it with the heavy duty racing one. That was fine until the motor eventually grenaded spilling parts all over the Piilani Highway.....oh what fun.

Cheers,
Bill

Last edited by HawaiianTiger; 05/14/19 8:14 am.

Bikes
1974 Commando
1985 Honda Nighthawk 650
1957 Thunderbird/T110 "Black Tiger"
Antique Fans: Loads of Emersons (Two six wingers) plus gyros and orbiters.
Re: triumph t5 build questions [Re: Waechter Machinery] #773676 05/14/19 12:38 pm
Joined: Oct 2006
Posts: 3,119
I
Irish Swede Online Content
BritBike Forum member
Online Content
BritBike Forum member
I
Joined: Oct 2006
Posts: 3,119
Bill, what are you using for that red inside-the-cases sealer?

Re: triumph t5 build questions [Re: Waechter Machinery] #773678 05/14/19 12:49 pm
Joined: Sep 2008
Posts: 1,101
S
Stein Roger Offline
BritBike Forum member
Offline
BritBike Forum member
S
Joined: Sep 2008
Posts: 1,101
I've only worked with Morgo kits, plus my ARE alloy kit, the original pistons were the same on these two, the weight not much more than a 650 piston.
I used to have the numbers somewhere, gone now, but I will weigh some pistons later. The 650 pistons vary a bit though, some really light, some heavy.
As many will know, the T140 pistons are much heavier. I have a Triton with a P/U engine and a T140E top end in the shop at the moment, haven't ridden it yet but they who have says it's a shaker...

Re: triumph t5 build questions [Re: Waechter Machinery] #773717 05/14/19 6:53 pm
Joined: Jun 2007
Posts: 6,387
HawaiianTiger Offline
BritBike Forum member
Offline
BritBike Forum member
Joined: Jun 2007
Posts: 6,387
I had a '67 Bonnie with a Routt 750. What a boneshaker! With alloy wheels and a Ceriani front end, it was impossible to keep the front wheel on the ground at full throttle in the first two gears.
When a bike is that much fun, you tend not to notice the vibrations much.
But ten minutes on the freeway and you can't feel your hands anymore.
And that kit came with some radical slipper pistons. They at least looked lighter, but they weren't.
That's a Chevvy Red powder coat inside the motor. I did a dozen engines like that starting with Glyptal, which is a royal pain to use and expensive as well.
Makes for CLEAN oil changes.
Cheers,
Bill

Last edited by HawaiianTiger; 05/14/19 7:05 pm.

Bikes
1974 Commando
1985 Honda Nighthawk 650
1957 Thunderbird/T110 "Black Tiger"
Antique Fans: Loads of Emersons (Two six wingers) plus gyros and orbiters.
Re: triumph t5 build questions [Re: Waechter Machinery] #773722 05/14/19 7:44 pm
Joined: Jun 2007
Posts: 6,387
HawaiianTiger Offline
BritBike Forum member
Offline
BritBike Forum member
Joined: Jun 2007
Posts: 6,387
I wanted to add one more thought. When I installed the 750 kit on my friend's '55 T110, no modifications to the cases were necessary. However, when reading up on these kits, some folks have had to machine the mouth to accept the big bore cylinder's flange. So, ask questions first before you buy something. I sourced mine from JRC who I believe was involved in the manufacture of his kits.
Cheers,
Bill

Last edited by HawaiianTiger; 05/14/19 9:45 pm.

Bikes
1974 Commando
1985 Honda Nighthawk 650
1957 Thunderbird/T110 "Black Tiger"
Antique Fans: Loads of Emersons (Two six wingers) plus gyros and orbiters.
Re: triumph t5 build questions [Re: Waechter Machinery] #773734 05/14/19 9:19 pm
Joined: Oct 2006
Posts: 3,119
I
Irish Swede Online Content
BritBike Forum member
Online Content
BritBike Forum member
I
Joined: Oct 2006
Posts: 3,119
GLYPTAL!

That's the name I couldn't remember.

Re: triumph t5 build questions [Re: Waechter Machinery] #773736 05/14/19 9:49 pm
Joined: Jun 2007
Posts: 6,387
HawaiianTiger Offline
BritBike Forum member
Offline
BritBike Forum member
Joined: Jun 2007
Posts: 6,387
Glyptal is normally used as a dielectric paint. For example, Lucas K2FC mags have Glyptal coated pick-ups. I'm sure you are aware of that since you've been judging these bikes.
Cheers,
Bill


Bikes
1974 Commando
1985 Honda Nighthawk 650
1957 Thunderbird/T110 "Black Tiger"
Antique Fans: Loads of Emersons (Two six wingers) plus gyros and orbiters.
Re: triumph t5 build questions [Re: HawaiianTiger] #773810 05/15/19 4:20 pm
Joined: Sep 2008
Posts: 1,101
S
Stein Roger Offline
BritBike Forum member
Offline
BritBike Forum member
S
Joined: Sep 2008
Posts: 1,101
Originally Posted by HawaiianTiger
I had a '67 Bonnie with a Routt 750. What a boneshaker! With alloy wheels and a Ceriani front end, it was impossible to keep the front wheel on the ground at full throttle in the first two gears.
When a bike is that much fun, you tend not to notice the vibrations much.
But ten minutes on the freeway and you can't feel your hands anymore.
And that kit came with some radical slipper pistons. They at least looked lighter, but they weren't.
That's a Chevvy Red powder coat inside the motor. I did a dozen engines like that starting with Glyptal, which is a royal pain to use and expensive as well.
Makes for CLEAN oil changes.
Cheers,
Bill

I have a pair of Routt/TRW pistons (bought from Hillbilly Bike) that weighs 271 gram, typical 650 pistons weigh around 240-245 g but I've seen them as low as 230.
A 7.9:1 T140 piston weighs a whopping 279 g. No wonder they shake. The shorter rod adds to the shakes, even if it's a little lighter.

Re: triumph t5 build questions [Re: Waechter Machinery] #773819 05/15/19 6:36 pm
Joined: Jun 2007
Posts: 6,387
HawaiianTiger Offline
BritBike Forum member
Offline
BritBike Forum member
Joined: Jun 2007
Posts: 6,387
One of the Norton guys installs shorter rods and taller pistons (perhaps it's the other way around?)in 750 Atlas motors and claims that they are smooth as butter thereafter. If you know the Atlas, that's a bold statement.
I wonder if anyone has experimented with these ideas on Triumph motors.
Some of these bikes could use some help in that department that isn't cured by dynamic balancing or re-gearing.

Cheers,
Bill
PS I've just about got my friend convinced to build a "Featherlastic" custom bike. I have itchy palms.
B.


Bikes
1974 Commando
1985 Honda Nighthawk 650
1957 Thunderbird/T110 "Black Tiger"
Antique Fans: Loads of Emersons (Two six wingers) plus gyros and orbiters.
Re: triumph t5 build questions [Re: Waechter Machinery] #773888 05/16/19 5:36 am
Joined: Sep 2008
Posts: 1,101
S
Stein Roger Offline
BritBike Forum member
Offline
BritBike Forum member
S
Joined: Sep 2008
Posts: 1,101
That would be Jim Schmidt https://jsmotorsport.com/js-motorsport-technical-pistons-and-rods/ who makes longer and lighter rods for Norton, along with lighter forged pistons. The rod to stroke ration determines the piston's rate of acceleration and deceleration at TDC and BDC, which has an impact on vibration levels. The weight of the reciprocating parts plays a big role too, of course. Tom Gunn discussed this in an article in Vintage Bike Magazine some time ago. He was concerned that the rod/stroke ratio along with the heavier pistons were detrimental to T140 longevity.
The rod (6") to stroke ratio on a T140 is 1.86, the Norton with it's shorter rod (5.875")and longer stroke comes out at 1,68. JSM rods (6.4") with standard stroke is 1.83, closer to the T140 ratio.
Triumph 650 (6.5") is 2.01. These numbers are important on a parallell twin and a single as they affect the unbalanced forces involved.
It has an effect on cylinder filling too, a lower rod/stroke ratio will be more efficient at lower revs and vice versa, but the differences aren't great.

In an attempt to (vaguely) backtrack to the OP's questions, you can use a 750 kit on a pre-unit engine, but go for one that use the long rods. I wouldn't use a T140 top end and rods myself, and my experience with the T140 kitted Triton I rode yesterday underlines this. My hands went numb within minutes from the vibrations.

Re: triumph t5 build questions [Re: Waechter Machinery] #773933 05/16/19 6:43 pm
Joined: Jun 2007
Posts: 6,387
HawaiianTiger Offline
BritBike Forum member
Offline
BritBike Forum member
Joined: Jun 2007
Posts: 6,387
Well, someone HAS been thinking along these lines. So when will the SteinKit for Triumph T140 become available?
I know, like you have time for that kind of thing...
There has been some topic drift here, but the good kind....
Spyder Integrated Technologies
Lucas, BTH, & Miller Magneto & Dynamo Restoration
SMITHS Chronometric Restoration
[email protected]
There, that answers one of the OP's questions.



Cheers,
Bill

Last edited by HawaiianTiger; 05/16/19 6:45 pm.

Bikes
1974 Commando
1985 Honda Nighthawk 650
1957 Thunderbird/T110 "Black Tiger"
Antique Fans: Loads of Emersons (Two six wingers) plus gyros and orbiters.

Moderated by  John Healy 

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