Thanks Guys, its turned out a lot better than I could have hoped for so I'm really pleased
Went back into the workshop today and worked on my "Eddie Dow type" Damper rods, I was never impressed with the factory fitment for dampening and eventually decided to use the Eddie Dow type damper rods that I bought from Autocycle. When I bought them they came with the thinner domed cap nuts as used on the pre units and had a Acorn nut on top. I wasnt impressed with the look but ran with them anyway and they worked really well. You soon find how altering the dampening on the front can improve the ride at the rear too (and vise versa) Although I think a little tweaking might improve it further (like opening up the bleed holes by a drill size) and improve the transition between the spring compression and dampening, or rather soften it) However it works really well.
Well.. Until one of the Acorn nuts flew off when I was blasting down the bypass, and the rod dropped down. So modifications were made for them to be fitted into the proper 1968' onwards style fork nuts.
I firstly made measurements of the rod as standard, then marked up the overall length from under the nut head.
Cut the excess off and reduced the rod diameter to 5/16 in the lathe.
Both rods now will insert into the stanchions same length as the un-altered ones (total length of rod now 420mm for those interested) and I can't wait to see how they perform (especially after a bit of locktite and 5/16 CEI nut has been applied to lock against the cap nut )
I wanted to get the bike back to its clubmans trim asap, I love the riding position and the look and well I have the tank to match it now too...
So Saturday morning the bike looked like this....
I was close to getting the jetting spot on, but managed to find (have 2 sets now) an original pair of Dunstall silencers, I found this style on Mauro's A65 when I was in Italy and really liked them, they are the non reverse cone type but have the trade mark 7 circles in the outlet. These have been re-chromed before and had the Dunstall stamping polished out of them, but the chrome is a little flakey in places even now. The other pair I have are pretty beaten and battered and some nerk has cut the inlet (1" 5/8) and crushed it down to be 1.5"
I have the silencer pushed pretty far up the pipe now, I think it looks better on these Pre-OIF's (Thanks to PRT for the photo of his with the mega's) It might also alter the HP curve. However... With Factory style rear-sets I will have to use a siamese (OR TT pipes, but I doubt TT pipes will look right with the big tank!)
So now I am looking for an Original RHS down pipe, the pattern ones dont have the same lines as the originals, and as I am going to copy my original factory siamese I'd like to get it as close as possible, and make a single downpipe into a siamese type (but shorter than original )
How it stands currently
Unlike the pattern silencers the original Dunstalls have a second hanger bracket welded to the silencer So I will end up fitting a rod from the rear frame loop down to pick that up too. I also have some nice short reach Ace bars which may also make an apearance
Well, the next stage to this saga made a president this weekend and work was underway!
I bought a set of downpipes off eBay which looked to have a thick wall tube, most of whats available is thinner than stock and my only reason I think why they golden so quickly. Unfortunately they wouldn't have fitted without modification even if I wanted them too . However, I had already had them stripped of their new shiny chrome and ready for chopping apart.
I had my original factory 2-1 to make as close to copy as I could. So a lot of reference photos, lots of chopping and lots of welding was carried out. I pretty much wasted the Saturday as I really wanted to heat the pipe to add/correct the bends. However the Oxy-Propane setup wasn't usable and I had a much better idea! Cutting the pipe in certain places meant I could spread it bit by bit (bigger the bend the more the cuts) and re-weld. when sanded back it was virtually invisible to change.
So this is what the original looked like from the side:
Followed by mine, it still required work after the hanger mount at this point:
At this point whilst the appearance from the front looked near identical, the pipe came much closer to the frame at the taped end. so a correction was added to kick the pipe outwards after the lug, and then back in again so that the silencer didn't stick outwards but kept tucked in with the frame (being cone shaped it would look out of place very quickly
Original from the front:
Original showing split, and weld technique:
Most of the visible weld would have been polished before chroming, but I think that look is great, naturally I blended the welds on mine where there shouldn't be any!
My build from the front:
The Siamese bend being made up, unfortunately I haven't a piece of pre bent pipe which I could have attached as an all in one piece, so chop out the bad and put in a bit of good
It looks a little angular there between the join but some sanding later and it starts to come good.
Complete frontal shot to check visual balance:
Bracing tube goes in! fitted as one piece to ensure correct alignment, then cut in two then shortened:
The old girl after a quick run, at this point I hadn't added a proper slide in section between the two pipes (used a pinch clamp for this) Still need to make a decent/rugged silencer bracket and add silencer clamp. Its using a step up adapter at the moment, but I will enlarge the pipe to take up the space and make a more satisfactory appearance
I'm looking at getting it ceramic coated in "Volcano Black" which is like a satin black. but meantime I might just spray them black and see what I think of the appearance as I may have them chromed again.
Running results: So far so good, seems to have a lot more bite and torque than the standard setup, but will require some re-jetting. Re-jet because its a mega, and the extra grunt because the silencer is in a better placed position (from memory the tuned length is 26 inch from the valve. I haven't measured this setup, but it seems to work well with the cam.
That's a great look Allan. I love the tank! Sometimes I dream about putting the Hornet back to a Hornet. Not quite yet though.
PS It's hard to beat the Siamese for anything but top end power. I have pretty much tried 'em all
Thanks Tom, Im finding its making good low-mid torque like this, not had the chance to get it on the open road yet and I need to get it jetted up, but it pulled from standstill in 4th (36:70, 18:42), so it could get geared up a tooth yet. But in first it needs some clutch slipping to keep the front end down. It really seems to work well with the X12 cam.
Top end on this bike would be nice to see but I have my doubts that it would ever see a "top speed" more than once or twice, but for a road bike the tractability and mid-range willl be where I need it. I may start making up a TT pipe with cross over and mega's off this bike as I will be using it on the racer when its done. I did even consider making another siamese but 1.75" in the hope to soften the midrange but give more to the top end... Now I've done one, it will be easier to do other versions from the lessons I've learned.
I've sprayed it black BBQ paint for now and i'll see how it looks like that before deciding on ceramic coating or chrome. If chrome I will have it ceramic coated on the inside.
The paint finish isn't great but it will give me a good idea what it will look like when done properly.
Paul, Gavin, thankyou for your comments. The downpipe (shorter side) measures about 26" from the valve to where the mega starts, the longer section is 33" When I ran the bike briefly the right side seemed to get hotter on the first bend. This could be becasue I hadnt sealed the system properly or the shortness of the pipe? It will go back on properly sealed and ill monitor the temperatures with a IR heat monitor. Theres a neat 2 in one lambda sensor (wide band) on eBay, so it will show both pipe readings at the same time. Im tempted by this but dont really want bungs stuck in the pipes after the sensor has been removed, Unless I make another pipe.. This is always possible with the use of an original Right hand down pipe, and will make the look a lot neater.
The 40" would be hard to achieve unless I used a short mega, as this is already pretty loud, i'll leave out the short mega for the moment.
Joined: Aug 2014 Posts: 1,325Triless
BritBike Forum member
BritBike Forum member
Joined: Aug 2014
I have a book, "A Bit on the Side " written by Jan Havard, about Steve Webster. Interesting, in a bland sort of way. Now, Nick, with your inimitable humour, and interesting command of vocabulary, you are capable of writing an incredible tome of fascinating anecdotes and invaluable technical interests! Now, you probably have your reasons for not doing so, but I reckon you just want to be an insidious little ogre ! And thats the only pocket urinating caper you are going to get ! Many would be interested in your story, horrible little Pom !
Some photo's now of how it will end up looking for this season, although its still my tourer (till I find myself a nice B31/B33) So it may feature some Craven Panniers if I don't keep getting outbid . Still undecided between chrome or black exhaust but..... Also not fitted the exhaust roses, didn't think they would look quite right somehow.
Thanks guys, I think the black pipes show up how much chrome these bikes actually have standard and gives it a lower looking stance. Good chance the BBQ paint will have flakes off on its first outing, but I will get black ceramic... going to bend another Kick start lever today (closer to the fulcrum point so it isn't acting as a rest for my knee)
Kick starter bent, the previous version against the better positioned version.
The chroming can wait till back end of the year, the two chromers I trust are quoting 8-12 week turnaround times, the pivoting arm also was a bone of contention, when used on a straight lever it would often flick back and catch the side panel taking a bit of paint off on occasion. Welded up the original ball locating hole, reprofiled and using the drill centre bit off the lathe, I set the pillar drill up on an angle and re-drilled the hole. Much more positive stop and doesn't over extend on the return so completely misses the pannel.
Taken the bike for a proper run yesterday, main intention to working the jetting out and it has changed, at the lower end at least. From memory I have 2.5 slides fitted which is what I needed with stock silencer. I can tell when opening throttle that it isn't too far out so a #3 slide will be tried, or keep going leaner until it hesitates on pick up. Needle jet position feels like it needs richening up, maybe a bigger jet but a position change will be tried for now. Top end... well normally I can run the bike and get it in 3rd or 4th gear, hold it at full throttle till it starts running out of puff and close the choke at that point....
Err yeah, not the case. It winds right round to 8k in second, nothing new there and don't need to hold it there so I change up. 3rd gear it's still pulling strong (not going to give speeds here) so I thought I'll drop it into top and it just start running out of puff so I can start trying the choke ( if I can close the choke with no effect then it's too lean) drops it into top and opened the throttle and it continued accelerating...
So I looked at the petrol tank, and thought... that cost too much money to throw it down the road and realised that I must be an idiot so I slowed down somewhat, I can't not say that my throwing it down the Dutch motorway when the front brake locked up 18 month ago didn't give me cause to think twice, especially when braking as it did. But to get the jetting right on this I'll need to book some dyno time. Was just very surprised how well the head mods, cam and exhaust compliment each other, more by chance than anything else although a bit of research on pipe lengths etc. But if nothing else.... I sure know what they called the silencers Dunstall power!
I'm not sure what "dunk time" means (dyno?), but it sounds like the jetting is plenty close enough to just relax and enjoy the ride. The bike is looking great. First off, try not to hurt yourself; second, try not to send that tank down the road.
I've been reading your stuff on here long enough to know that most of your joy is from trying this, that, and the other thing on your bike. Just remember that even Gavin pauses the work long enough to ride his bike during the good weather.
'64 TR6R Plus some Twins from other countries (U.S., Germany, Japan)