DDK - Die Deutschen Klassiker

As my system uses the original carb manifolds, I used the pivot and quadrant to pull on a simple slide ( box section inside a biggest box) I crudely welded the ball for the rod, and two separate cable clamps to the slide. The two cable adjusters allow me to take the slack out of each cable separately. It’s crude, not pretty and it’s been there doing a great job for 10+ years.

Thx
You've got me perusing Fleabay now

Any issues with the 'slide' sticking or any need for extra return springs ?

There’s a return spring on the quadrant on the end of the manifold. Just a helper spring really, a flat spring robbed from inside a domestic door handle !! Necessity being the mother of invention etc…
No, never had a problem with it sticking (yet).
I always thought I could come up with something a little nicer using an Igus Slide/linear bearing , but for now if it isn’t broke, don’t fix it !!

Hi Peter
Great project writeup as usual. always enjoy your efforts
MikeS

Thx
I tweaked my VE map some more & now have 30% less than Phill/Lee all over. Still runs slightly rich when cruising, but MOT passed (maybe with a little creativity on emissions - Dyno not available until 25th).

A pair of Triumph Sprint RS cables (longer than others I believe) have arrived this morning, and I’ve been thinking about how I’m going to link them to the rod from the accelerator. I have a cunning plan - watch this space.

So, a cunning plan .

It was Phill’s fault that I went Triumph ITB , and he recommended the MaxxECU as well (he must be carrying a lot of guilt !), but Tim (Impmad2000) is to blame for the move to cable operated throttle.

There is the potential for a difference left to right in lengths from butterfly axle to the throttle operating linkage rod end and also in the distance from the swivel pivot point to the other end of the rod ended operating linkage rods (I measured a difference of 0.25mm in 72mm centre distance here). These could add up to differences in the rate of throttle opening left to right.

Additionally, in my ‘I don’t need that’ removing to clean but not putting back the original Triumph cable brackets, I didn’t realise that I also lost the throttle stop, so determining when 100% throttle opening became somewhat subjective and I could go past fully open and start closing again.

My thinking (always a bad sign when I start thinking, its beyond my pay grade, so that’s why I have SWMBO) was that with the original Triumph cable quadrants refitted, I would have a hard stop at full throttle. With cables, adjustment to ensure equal opening would be easier, relative to all the different elements of the rod linkages. So that’s where we’re headed.

I needed cables (original Triumph), and I opted for the Sprint RS versions as they’re about 100mm longer than others. I needed to dig out the cable brackets, blast and paint them. This was the easy bit.



The other end will need a mechanism to join the cables to the accelerator rod (at the original quadrant) and to pull the cables (enough). This is not the order I did things, but hopefully makes it a little easier to follow.

To attach the cables to the accelerator rod, I concocted the idea of a tee bar, attached to the rod via the original rod end. I started with an M12 bolt, cutting the head and the thread off, essentially leaving a piece of round bar.


This was cleaned up in the lathe (with a slight pause to fix the lathe – the cross slide bearing pulled out, so I used some thread loc k to ‘stick’ it in place, but that caused an over-night delay (which is one of the reason why I ended up jumping between different elements of this engineering masterpiece – well I can dream, but my standards are low).

I roughly marked the centre of the bar, drilled to 5mm and inserted an M5 bolt.


Putting this back in the lathe allowed me to spin the rod, while using a tool to mark equal distances each side.


While I was at the lathe, I also tapped the rod M5


I tried to use my drill press (quicker than setting up the mill), but the small vice I wanted to hold the rod wouldn’t hold it steady, so I tried drilling using an X-block.


This too, allowed the rod to spin a bit, so the eagle eyed will notice that the two small diameter holes are not properly in line. We’ll call this a prototype.

I then bolted on the rod end


I added bolts into each end – these will trap the throttle cables. Unfortunately, when trying to tap a little deeper, I managed to snap the tap. Not ideal. There was insufficient tap poking out to get pliers onto (I tried), and it was too tight to drift around (tried that as well), so with nothing to loose, I put it in the lathe. By turning down the diameter, I left only the tap end poking out, sufficient to get the pliers on and unscrew the tap. Phew.


I then cleaned up the end (re-faced) and then had to take off an equal length on the other end. So now I have a slightly shorter tee-bar, but it will work and I added the bolts into the ends and refitted the rod end.




This should pull the cables nicely, but the cable outers need to be restrained, so more bracketry needed. I intended to fabricate something from an offcut of 2mm plate, but while looking for something else (always the way), I found some construction brackets. Hmm. With an initial trim, we have



Before this I had tapped two through holes in the quadrant / bracket / thingymagig


I also replaced one of the bushings, as a small petrol spillage earlier in the installation had not ended well for the plastic. Luckily, when I replaced them, I had kept the nearly new ones I removed.



So, all mocked up, I give you my best Heath Robinson


and after a little more trimming




With it all bolted back into the car, along with the cables, it was time to work out routing and lengths


I marked up the required lengths (the outer sheaths are now 65 and 75cms shorter, so I didn’t need to worry about getting the longer RS cables afterall !)


All trimmed up and installed
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Plans now are to plug in the computer and to reset 100% throttle, adjust cable lengths to give full throttle at the same time and see if the car will run well enough to drive it around and fully warm it up. I can then adjust tick-over and check for left to right balance (using the Syncrometer this time).

Looking great there. I’m loving the levels of invention. Hopefully that will keep both banks synchronised nicely

The car is far from tuned, has no acceleration enhancement & I’m driving it gently. Or so I thought - I use a tracker for security and it shows ‘aggressive acceleration’ at several points during my pre-MOT warm up drive.

I could believe that the car is good (it picks up so much better than with CIS and doesn’t feel slow), but the lambda readings do vary by 10% side to side at various times. Whilst this could of course be sensor related, I suspect it is mainly related to different throttle opening rates. How many cars are driving around with significant bank to bank differences ?

I’m thankful that I was encouraged to go with twin WBO2 lambda sensors

Best things I fitted were twin lambdas and afr readers … and it gives something for your passenger to watch

… and something else to worry about when they're not the same

So, tuning……. I have been playing and driving. Struggling to get comparable lambda readings on each bank while driving, I spent some time trying to get the throttle response balanced better. After much playing, I did get comparable lambda readings at a constant throttle (& apparently still needing a further 10% reduction in fueling), which is good. However, with any acceleration the lambdas digress materially.
Back in the garage, and while watching the throttle openings (kneeling behind the car and playing with the throttle), I realised that the accelerator linkage was twisting during throttle opening, but did settle when held constant. Time for further refinements to the linkage connecting to the cables.

I purchased a clevis fork and just in case, a pair of rod end bearings. I drilled out the rod end from the original actuation lever


and added the clevis fork and my cable attachment


Unfortunately, at full actuation, the clevis fork was not long enough to fully pivot


So, time for yet another plan B – rod end bearings, spaced out with copper sealing washers. I would have preferred some slippy plasticy material, but this was the least bad option from what I had lying around in the garage. I also needed a new flat plate to join them and couple the cables. More use of the left-overs from the cable bracket, previously a construction bracket.


So good news was lots of articulation. Less good news was that even though I bought 2 rod end bearings from the same place in the same order, when I came to use them, it was clear that they were slightly different lengths. I tried grinding a little off the end of one, which was better, but for whatever reason, they twisted in use, so ….



onto plan B, mark 2 - make my own (longer) clevis fork.
The eagle eyed will notice the use of yet more left-over pieces of the bracket. I Clamped 3 pieces together (the middle one was merely a spacer for now), drilled my 6mm pivot hole, and then welded them to my original cable clamping piece.


Not the neatest, so we’ll call this another prototype, but it works



Time to rebalance the ITBs. Great consistency of lambda at 2000/2500 rpm, but at tick-over things were jumping all over the place on the left bank, gradually going very lean. More thinking needed.

Only one thing will cause lean like that (apart from lack of fuel, lack of spark, etc), and that is an air leak, so time to take up smoking. I inserted my lance (oh er missus) into the vacuum take-off pipes, one at a time.
The good news was no obvious leakage around the manifolds, but interestingly, quite a lot of leakage at the spindles, especially between cylinders 2 & 3.


Not too obvious maybe, but by the time I had the smoke in, grabbed the camera, tried to focus on the spindles, not the vacuum pipes, we got this


I then tried adding the smoke from above


Still smoking from the spindles, but not as much. So, with a quick spannering, we get


And this



And with a shake of a lamb’s tail, we’re back to this….



After balancing at tick-over and higher, we have lambda readings within 10% of each other and spraying brake cleaner does not change the readings, so that’s another issue sorted. I initially had very lean left bank readings, but remembering to plug injector 1 in certainly improved things there. In the end, I even had to add back some fuel !

With (hopefully) all of the mechanical issuettes sorted, it is now worth going to the Dyno for a tune. Remaining options or potential causes of the remaining differences could include
- the two sets of ITBs are from different age Triumphs. The bores are the same (I think), so as they use the same injectors, this is less likely. I could replace the right hand side with a ‘same age set’, but not before dyno day (unless I postpone)
- the WBO2 sensor is calibrated slightly differently or one has become more clogged with the rich running. The letter should sort itself, maybe on the drive to Brands Hatch, the former not. I do have a spare sensor, although that is just as likely to give slightly different readings, so I’m leaving this avenue of investigation until after the dyno. Whether the dyno has probes to replace my sensors – maybe I should temporarily refit the 2 in, 2 out silencer, then we can probe each bank separately . I’m not able to access the garage until Monday and the dyno is booked for Tuesday, so there is still time.

It’s all impressive stuff

Before dyno report, there’s a little update for between last time and today …..

I decided to replace the right bank TBs to match the left bank. I was not at home when the postie tried to deliver, so had to wait until Monday (the day before dyno). Anyway, a good job I decided to risk my dyno day and replace them – although the inlet / filter end of the TBs were the same left to right, the right side TBs were older (knew that, but still Triumph 955i allegedly) and the outlets (Manifold end) were smaller !. Anyway, swapped over – now the TBs have the same part numbers, and even the same stamping on the butterflies.

One issue was the mounting ring for the trumpets. They are a press fit onto the top of the TB, only I managed to break one. In desperation I used the ‘jubilee clip’ from the old engine bay fan to hold the two halves together, clamped onto the TB top, and crossed my fingers. A new one has been ordered.

After resetting throttle cables, rebalancing TBs and test driving – oh dear, definitely seems to be a cylinder not present. So 8pm the day before dyno sees me back in the garage, starting with the side I had been playing with, but it turned out to be cylinder 2 and a dirty plug. Plug removed, cleaned, replaced and all now present and correct. Even that didn’t go smoothly, as the rubber insert from the plug spanner decided it was nice and warm on the spark plug. I tried for a while (faffed about) with long nose pliers, before facing reality and removing the plug again, pressing the rubber more firmly into the spanner and refitting the plug. All good now. I am still having to use the inspection camera to ensure that the coil pack is sitting properly on the plugs.

I filled the froot with all the tools that might conceivably be needed, plus some that wouldn’t, and a load of spare parts (TBs, gasket material, terminals, etc, etc.).

That brings us to today, and at just after sparrows’ fart (well just before 8am, but everyone needs some engineered drama in their blog), off I set to rendezvous with Alex (The Garage Bitch) at Cobham services (the Hogs Back and Wisley junctions are both still nightmares), along the M25 and finally to HT Racing at Brands Hatch.


And after tying down, we’re ready for Aaron to work his magic


I even got a noisy bit, though here the revs weren’t at full chat (always concerning when a stranger is wellying your pride and joy !)



So what have we learnt ?
1 – I still need to refine my cable pull – the cables are not both pointing exactly at the clevis, leading to a slight difference in initial pull. This is most noticeable now if I floor the throttle at low revs (say 1400 revs in top), with a tiny stumble before all hell breaking loose.
2 – there is a 24% difference in fuelling needed bank to bank at low revs ????? I will smoke check for air leaks, but what else might cause this ? Cam timing ? The ECU is dealing with whatever it is marvellously though. I just might be leaving a little HP on the table if they 2 banks are not the same.
3 – dyno showed 236.4 HP (don’t forget the 0.4) @ 5872 revs with 220.8 lb/ft torque @ 4856 revs.
4 – drives like a scalded cat
5 – mpg. Best ever with CIS was 24.4mpg cruising across France, with a normal range of 19-23mpg. Immediately after fitting ITBs it was 11.4 driving to the dyno, 14.2 on the dyno and a mahoosive 26.7 driving home. Well pleased with that I am.
Oh, and I didn't need anything from the froot, except for my ear defenders

Slightly less pleased that my gearbox seems to be having an argument with the bearings associated with 4th gear on the way home – works fine but quite noisy now. Still, the gearbox is the only thing that I didn’t lay my hands on during the resto, a man always needs a project and it wouldn’t be my fault if a LSD accidentally fell in during the rebuild.

Just realised that the Garage Bitch is photo-bombing the first photo

Coooooooeeeeeeeeee