Reconnaissance LTV Nachtrit 2018

Yesterday I finally got the SU carburettors on the DHC set up correctly, using the emission tester from a friends workshop. Turned out that it was running pretty rich at almost 7% CO, but that was easily rectified by turning the adjustment nuts 3 flats up. Which gave a reading of just above 3%. Synchronising them brought the CO level to 3,5%. With an idle speed of circa 1000 rpm. Result! Sadly the homeward journey turned into a shower dodging contest. So it was kept short ...

But today the weather forecast was much better, so I used the reconnaissance for the 30th edition of our Nachtrit, which will be held on Saturday the 27th of October, as an excuse to take the DHC for a drive in the country. And it turned out to be a rather enjoyable day, clocking up well over 300 kilometres all together. A few pictures of some of the areas we will be visiting this time;

And the car behaved quite nicely. Most noticeable is that since fitting the slightly richer needles, the engines temperature is running slightly lower than before. So that looks good. And another trip planned for this Sunday!

FHC resto nr. 70; More small jobs

In between solving the DHC's carburettor's problems, and with no motivation at all to finish the heater, I carried out some more smaller jobs on the FHC. First of these was collecting the refurbished parts for the headlight mechanism for reassembly:

Putting them back together was a rather straightforward job. Though I was surprised it took me a fair amount of time, mainly caused by the fact that all the threaded holes needing careful cleaning with a tap. This was to remove the powder coating that got in there despite all threads being plugged during coating. But after spending a few relaxing hours outside, and enjoying the fine late summer weather, the headlight mechanism platforms and headlight bowls were back together:

Next came the rear quarter grills, together with various small parts to fit them and for the head lights. Again back to the shed to search through my spare parts. First to select the best pair of rear quarter grills:

Followed by a search through my many boxes with various small parts. Not too bad a job when you can combine it with some nice weather!

These were all taken home for a much needed clean up. Rather time consuming but also very relaxing and rewarding to do. With everything cleaned it was time to fit the rear quarters grills, but not before fitting 2 pairs of newly fabricated air extractor flaps to the B-post together with two small plastic spacers to help keep the rear of the grills in position:

Followed by the grills themselves. This is turned out to be a bit of a fiddle with the small plastic T-bolts and nuts. At least I didn't lose any of the small (M4) nuts, to secure the grills with, in the depths of the car's interior!

And to finish off on a very rainy day, I fitted the drain plugs to the rear underside of the front wings:

New carburettors - final take (5.1)

It had to be something simple! This morning I visited a friend's workshop, for some kind of second opinion on the carburettors. And after coffee and vlaai we started with a few checks. His verdict was that the throttle disc of the front carburettor wasn't aligned properly. Which also meant that fine tuning had to wait till this was rectified. After some more coffee and vlaai I headed home to do some household shopping, after which I made myself comfortable to remove the carburettors again to check the alignment of the throttle disc of the front carburettor. Well there was nothing wrong with the throttle disc. It was nicely centred and moved freely. But by the time I found that out I already had found the culprit for the problems, this small piece of tissue paper:

Rather embarrassing really! While fitting the carburettors for the umpteenth time I almost forgot to remove one of the gags of tissue paper I had stuffed in the two manifold ports to prevent dust from entering. But with the front carburettor loosely in place I noticed my error. So I just pulled the carburettor back a bit and pulled the gag of tissue paper out. And I didn't notice that a small piece tore of and remained behind on the two lower mounting studs, where it got wedged between the carburettor flange and the manifold mount. And here, soaked in fuel and preventing an airtight seal, it could provide extra air and fuel. But it could also prevent the throttle disc from closing properly. Resulting in the problems mentioned in the previous two posts on this subject. I knew it had to be something embarrassingly simple!

With the carburettors again in place it turned out very simple to set the idle speed at around 950 rpm. I won't set it any lower as the idle will become rather lumpy. This being caused by the by now ancient Triumph Tune TT10204 Fast Road (280° duration) cam shaft that is fitted to the car's engine. Hopefully I'll be able to fine tune the carburettors within the next couple of days and see how the car runs now!

At least I am now again rather experienced in removing and adjusting SU carburettors and have gathered a lot of knowledge on SU working pressures, needle valve closing pressures, fuel pumps and so on. And I have learned not to use tissue paper to keep dirt out, but to use cloth rags in the future. But also to take my time to carry out  certain jobs, and not rush them!

New carburettors - take five

How time flies! It is already well over a month ago, that I decided I needed a few spacers to go between the fuel pump and the engine block. The idea was that fitting the spacers would reduce the throw of the fuel pumps arm. This way I hoped the fuel pressure would be lowered enough to get the car running well enough to drive her to friend's garage. And there I would be able to check the fuel pressure from the fitted mechanical fuel pump. It turned out I was on the wrong track! Fitting various spacers (ranging from 1,5 up to 6 mm) didn't change the engine's running at all. Luckily they were not very expensive to make ...

Though a round trip to pick up the fuel pressure gauge from a friend would have been slightly more cost effective. Which I eventually did as I couldn't get a decent idle from the engine. So I had to take the fuel pressure gauge to the car, just to rule things out! With the pressure gauge plumbed into the fuel supply system I found out that the fuel pressure was actually pretty low at just 0,07 Bar (or 1,0 psi). So not a chance that the carburettors were over fuelling because of the fuel pressure being too high!

I already had checked the free movement of the floats and the proper functioning of the needle valves. And these had turned out to be fine. As there still was some fuel sitting around the jets, it did look like a float problem. As the carburettors are fully rebuilt I presumed that the floats were set correctly. But I decided it would be well worth another check. The front float turned out nicely within the prescribed range. Though the rear one wasn't. With the float cover held upside down, the float wasn't resting on the float needle but on the float lid itself, though it just closed of the needle valve. But not fully compressing the needle valve's spring! Luckily I found a thin spacer for the needle valve seat in one of my spare carburettors. This brought the gap between the top of the float and the lid within the prescribed range. And after that I was able to start adjusting the idle speed. That's when I found another small problem. The throttle lever pins to be precise:

I had placed them to far apart on the spindle, resulting in them locking inside the throttle levers. Again a small gain! With these two jobs completed I was able to bring down the idle speed from 2000 rpm to under 1500 rpm, result at last! And just in case I swapped the original carburettor needles (BDL) back to see if this would change anything, it didn't.

With the carburettors now performing fairly well and the car driveable, it was time to enjoy today's fine autumn weather:

This was to blow away any cobwebs from the engine in preparation for a visit to a  friend's workshop which is planned for this Saturday. Here I have the opportunity to use his calibrated emissions tester for fine tuning the carburettors. And a second pair of eyes to check for anything else I might have overlooked. Yes I still have a strong suspicion I have overlooked something simple and obvious!

As for the car, she behaved rather well, but doesn't pull as strongly as with the slightly richer needles (BCE), I fitted before. So these will be swapped before Saturday! And the idle speed remains around 1500 rpm, with a slight irregularity from time to time. Also to be continued ...

FHC resto nr. 69; Heater rebuild part 7

This should have been the final chapter of the heater rebuild! Sadly I had to take a few steps backwards. First I had to remove the back plate for the bulkhead seal from the heater unit. Not because anything was wrong with it, but because I decided it could do with some detail changes.

With the original set-up the steel tubes supply some of the rigidity to the plate to help press the seal more firmly against the bulk head. But while measuring an old seal for remanufacturing purposes, I noticed that even with the original set-up the seal wouldn't seat  properly against the bulk head!  Time for a redesign of the plates mounting, especially as the coolant tubes don't support the plate anymore, because they just pass through the original holes without any physical connection. And the plastic tabs on the heater body, to which the back plate is riveted, look rather flimsy too. This prompted me to add a second mounting bracket to the plate. It not only adds stability to the plate, it also helps with compressing the seal better!

With this part ready I used the back plate as a template to generate a DXF-file, which in turn was used by Rubberhuis Maastricht to fabricate the (cell foam rubber) seal, using modern CNC equipment. They also used this equipment to fabricated the condensation drain seal, which is fitted between the bottom of the heater's fan housing and the transmission tunnel:

Next it was time to remanufacture a new seal to go between the heaters fresh air intake and the bulk head. For this I also used cell foam rubber, a self adhesive rectangular profile of 20 x 15 mm. And with four carefully measured 90° V's cut from the seal, it could be fitted to its designated location:

With all seals ready and fitted where possible, it was time for the heater's final assembly; refitting the back plate and fitting the coolant hoses between the heater's matrix and the pipes passing through the bulkhead. At least that's what I had hoped for. Sadly even with the fairly slim heater hose I had acquired, it  was still impossible to negotiate the bends needed to fit the hose between heater matrix and bulk head passage. Especially the radius for the top hose turned out to be impossible tight for a proper fit.

Time for another step back and plan B, consisting of a stainless heater pipe assembly for the original heater layout, purchased through one of the rather reputable TR7 suppliers in the UK:

Which was duly cut down approximately in the middle of the pipes, shortening the necessary hose length considerably. But most importantly this got rid of the tight bend for the top hose, at least it should have ... The picture above does give a clue to what's the main problem. The two pipes are identical and much too far apart in the centre section. As a result of this even with the top pipe hard against the ventilator motor there still is an almost 10 mm gap between the rivet holes in the base plate and the ones on the heater's casing, not good! Luckily I still had the old pipes lying around for comparison:

Clearly visible is the difference in shape between the aftermarket stainless pipes and the original ones. And this frontal shot of the assembly clearly shows the rather poor quality of the work done by whoever fabricated it:

So instead of fitting the heater to the car I will have to adapt/prepare the original pipes and use them instead. To be continued, but hopefully not for too long!

FHC resto nr. 68; Some small jobs

As the work on the DHC's carburettors and this car's heater has hit a small snag, I decided to address some smaller jobs to keep myself busy and keep motivation going. The first one was to store one small part that otherwise would probably get lost somewhere in the shed. So I decided to fit it to the car. This way there's no way I can lose it! It was the infamous steering shaft bush, in this case in the poly bush variety. As I could work from inside the engine bay, fitting it was even easier than when I had to replace the one from 't Kreng a few years ago. I only needed the handle from a hammer to give it a final push to seat it properly:

Next job was fitting the fuel tank's gauge unit. Sounds straightforward, but it took me almost half an hour to get it into position. This was caused by the tank sealant I used, blocking part of one of the recesses for the two alignment tabs of the unit. But after carefully cleaning the recess with a pen knife and with the help of a small hammer the unit finally yielded, and seated properly:

And I trial fitted the fuel filler neck together with its bezel and filler cap. Just to find out that the fuel filler neck is from a very early car indeed, as the mounting holes in the filler necks mounting plate were less than ø 5 mm, while the nuts welded to the filler panel have M6 threads. And that isn't surprising as the filler neck is from ACG96L and the rear deck from ACG10448L. At least this was easily sorted with a ø 6,5 mm drill to enlarge the holes in the filler neck's mounting plate. But the main reason for fitting it was to determine the length of the filler hose that will be needed for this set up. And it gave a good impression how the rear deck will look once it is finished:

But most importantly I spent some time in the shed trying to get a feel of all the parts stacked there and where everything is put away. And hoping to find a fuel filler hose to use on the car or as a template. So far none found, but still a few boxes to go ...