'79 CIS TO EFI

[impmad2000]

All sounds very pleasing. At least you have a good state of tune to be going on with. When I took mine to CLM on its 1st run out, it was terrible, but then. We were trying to tune it as we drove down !! I got Bob Watson to tune it in the end and never touched it since. I also only run one wideband and so have no idea about cross bank mismatch! I do just love the way ITBs just pick up, rev through the range and howl at the top end.
You are running 3.2 yeah? Did you get any indication that the bore of the ITBs was becoming a limitation ? Mine is only 2.2, so was never a concern on mine.

[PeterK]

Yes. It’s a short stroke 3.2
Nothing makes me suspect too much throttling at the top end, the dyno curves look ‘normal’ or expected shape and Aaron commented about it being ‘sweet’, nothing about limits reached.
They're probably close to the limit for top end hp but better for torque.

The induction howl is glorious but different, so initially I kept worrying about the strange / different engine sound

[The Garage Bitch]

My lingering memory of the day (apart from the bacon buttie in the time-warp cafe at lunchtime) was feeling the vibes in my chest standing next to the car when Aaron was, to coin a phrase, giving it the beans.

[jb]

What a great write up and brilliant result.

[impmad2000]

It is awesome to be stood beside your own car at full welly, watching the heat exchangers glowing cherry red !
Nice to know the Triumph ITBs are ok on a 3.2 as it’s something I always believed.

[Bruce M]

Well done.

On the subject of linkages, that was the most challenging part for me.

Initially i used a cable based design and the throttle pedal progression was excellent but i had trouble with balancing.

My design took the throttle cable to the right ITB and then a slave cable across to the left. Thats when I learned about the mechanical engineering of bowden control cables. Matching the opening rate was difficult and I ended up needing to shim the master pulley diameter(increasing the rate of pull).

When you use an adjustable conduit to set the starting point of the cable travel, as the tension increases on the inner cable (stranded or rope depending on the winding method, with different properties) the inner cable stretches a small amount and the outer conduit compresses by even more.

I ended up swapping to a generic (CSP) carb linkage and modifying it. But the pedal feel is better with cable pulleys.

I think the split cable design is probably the best but the initial length & compression on the conduits each side needs to be well matched or you’ll get some difference in opening rate. The master / slave approach wasn’t a great idea, although there are commercial products that use that design.

[PeterK]

It’s been a while, so here’s where we’re upto now ….

The good - Efi – rebalanced TBs (almost spot on before, but a little tweak needed) and car now running even better, with very little difference bank to bank.

The not-so-good – decided that the gearbox has had its day (for now), so engine and box out and gearbox now with Angus for strip and advise. I have a second box lined up if needed, although it’s a ’76. Still electronic speedo, all gears are the same, but the clutch arrangement is different. Mike (2310bhp) has been a star in sending loads of photos. Hard to be 100%, but it looks like I could remove the later bolt-on parts from my ’79 box, grind off a web on the ’76 box, then fix the Omega helper spring system from the ’79. Not sure whether I can simply just use an earlier cable and make no changes to the ’76 box at this time. Anyone know more / better ?

Unfortunately, while removing the engine and box on my own, I didn’t notice the oil pipe (engine to stat) being caught up, so it became a little customised. As they were looking a little crusty, and with thanks to Matthew (Typoe911), I now have shiny new flexibles (I’ve also replaced the stat to oil tank). Naturally, the oil stat decided that it was too in love with the pipes and despite a lot of heat and kind (and less kind) words, didn’t want to part company. I had to take the stat with two pipes still attached to the vice and get the BFH involved.
One of the hard pipes to the front cooler (those with memories of my resto might recall that I have to make new thread savers for the pipes from the cooler) or rather the thread saver itself, started turning before I could get the nut to move. In the end, I needed mega heat and a monkey wrench holding the thread saver before the big nut gave in. The threads had a lot of galled aluminium, so I replaced it with one I cut off the old flexible pipe. To rejoin the hard pipe I used a 22mm copper plumbing connector (as I did on the other hard line during the resto).
The rear-facing threads of the engine to stat pipe weren’t happy. Of course that was the pipe that I most needed to remove, and when the nut finally admitted defeat, it took the threads on the stat with it.
I now have a new secondhand stat. Probably a good thing, as there was a slight weepage from one of the previous pipe connections, and more importantly, the car took a while to get warm, but then never got much out of the warming-up zone. I suspect that maybe the stat was not fully closing, so always giving full cooling.

Moving on, and while waiting to hear how bad my gearbox might be and the engine is on the stand ….


I have removed the throttle cable mounting plate, and replaced it with a mark 2 version.


Key changes are that I have lined the cable holes up to suit the latest iteration of the tee-bar pulling arm, such that the cables are pulled equally and straight. I made the holes larger in diameter than needed, then added penny washers on either side of the plate, so that I have some fine-tuning adjustment. I also slotted the top of the plate, down to the cable holes – I can now remove the cables from the bracket without needing to take them free from the pull tee-bar.

Anyway, now looking a lot better, although I will have to wait until the engine is back in and running before final adjustment and I can confirm that all is good enough now.




I am not around for the next 5 weeks, so a good time for the gearbox to be on its holidays. Whether I get any time this week, or maybe straight after I am back in the game, also while the engine is out and on the stand, I plan to check valve clearances, etc.


Probably less appropriate here, but does the world need a new thread with pictures of an engine removal ?

[Darren65]

Shame about the box but hats off to you Peter for getting there with the engine. Well done