Augusta progress

[Mikenoangelo]

After a hint from Karl I began to worry whether the new clutch spring, which follows the spec of a slightly stronger spring made for Augustas a couple of years ago, might be too strong for the cast clutch withdrawal claw (or whatever it is called) which has been known to shear by the retaining nut So I spent some time checking the spring rate of the previously fitted and new springs. I measured the load needed to compress the spring using bathroom scales and my pillar drill, noting the height of the spring with each additional 20 kg load. It turned out that both springs when loaded to 120kg were compressed  by 30-32mm. The compression in mm per kg of force applied was very uniform over the range I tested. However I realised that the new spring, being a bit longer to start with would, when compressed from 87 to 30mm, probably apply more load on the clutch as engagement compresses the spring very close to solid and more so in the longer spring.  As I could not apply more than 120 kg I made up a bar to turn the clutch actuating lever with the same 5 to 1 mechanical advantage as the pedal and used a large spring balance to measure the force need to disengage the clutch, this being detected with a weight attached to the gearbox output spider. The original spring required about 10.5kg and the new one about 11.5 kg to disengage the clutch which is very close to the calculated increase in the spring design - phew!

As a further security I also crack tested the clutch actuating claw with a dye penetration detection fluid which is applied to the test sample and penetrates any cracks, to reveal these later when chalk is applied. Nothing showed up so I felt confident in using the stronger spring and could put the whole thing together again. The thrust bearing runs smoothly and the nut which retains the bearing showed no sign of brutal spannering.

As you can imagine each time I needed to test a spring in or out of the transmission I had to remove the gearbox, unload the spring and then put it back. I got quite good at the task!

Mike

[JohnMillham]

Many years ago I fitted extra springs to my clutch, copying the design of Mike Wheeler. I spent some while with Bill May with various springs and my bathroom scales under my milling machine, rather like your set-up.

[Raahauge]

 Bit more info, I bought a new spring when they were available a year or two ago before I had dismantled my car. When it came to it I reused the old spring  (not necessarily original) as it was marginally stronger. My notes show that when compressing the two in a stack the new one compressed by 29mm to 26 for the old one. Cannot find a note but my recollection is that the OD and wire section were the same but the new one had an extra quarter turn.

[Mikenoangelo]

John - I knew Bill May for more than 60 years from the mid 50's when a group of us did vintage holidays together - one year buying a Trojan in the Highlands and towing it back to Yorkshire with a Humber 12/25. A jolly good engineer and a good bloke. Coincidentally another participant was the late Tommy Longbottom, later known to the LMC when he owned an Augusta.

Mike - I also found that the new spring seemed marginally easier to compress in the middle range of compression which is almost linear which was why I did the test of pedal force. I suspect that at the extreme of compression when the spring is nearly solid the force/compression relationship goes non linear and the new "stronger" spring arrives at this point sooner than the old spring so applies more load to clutch and pedal. It is not much different though.

For those who have not removed the clutch and gearbox here are a couple of tips. Firstly before trying to pull the gearbox away from the engine the clutch engagement fork must be disengaged from the claw fitting which operates the clutch. In the normal position the clutch lever is tight up to the gearbox side.


At the other side of box the fiddly wire circlip must be removed from the end of the clutch cross shaft.

Then the clutch lever is pulled out about 10mm away from the gearbox which separates it from the claw so that the box can be removed. The box slides off quite easily if this is done so beware if you feel a need for crowbars!

The clutch spring is compressed by the cover plate, held down by three 5mm bolts, about 50mm long. These amazingly take the full 200kg pressure of the clutch spring. To remove the cover plate and unload the spring I made this fitting which takes the strain off the small bolts as they are undone. Slacking the bolts and the nuts on the fitting evenly by 6 turns at a time allows the cover plate to come away evenly without binding on the bolt threads. I found that there is still a small load on the bolts even when they are almost fully unscrewed so the fitting is useful to line it all up to start the bolts in the threads.


Mike
 


 

[Kari]

Thanks Mike we see another means of compressing the spring of the clutch. What we are not seeing is how the driven plate is centred for easy installation of the gear box. I am sure Mike will enlighten us. I am using a shaft which centres the driven plate onto the ball bearing in the fly wheel. At the other end of the shaft, there is a female 8 mm tread, by screwing in a long bolt, the shaft can be withdrawn after the spring is compressed.
For compression of the spring I use a modified puller. 6 mm rods guide the cover plate until the attaching bolts can be fitted. However I believe at the factory they have been using just 55 to 60 mm long bolts to screw the cover plate home, drawings confirm that.

Regards  Karl 

[Mikenoangelo]

The first time I fitted the spring the gearbox was dismantled so I could use the main input shaft to centre the clutch plate. Next time when the box was back together I expected a problem but in fact found that before the spring was fitted I could adjust the centering of the clutch plate (which is lightly nipped by the pressure plate and the three legged spring spider) simply by aligning it by eye with the pressure plate and pushing it by hand. This was evidently accurate enough to fit the gearbox and of course as soon as the clutch is disengaged and re-engaged the clutch plate aligns itself exactly. Unless your fingers are a lot stronger than mine the clutch lever on the bell housing cannot be moved by hand and needs an extension bar as I did when testing the likely pedal load.

I now need to make a new flange and downpipe for the exhaust as the original flange was very much eroded by corrosion and leaking exhaust. All a bit tricky as although the 60 degree angle bend at the lower end of the downpipe is easy, the corresponding bend where the downpipe connects to the cylinder head is rotated about 25 degrees towards the centre line of the car relative to the rest of the downpipe. I can't imagine just giving the old downpipe to an exhaust fabricator to copy will work out and because of the virus I can't get a welder to come and do the job in my garage, so decided to make a joint toward the bottom of the down pipe before it bends to horizontal so I can adjust it prior to taking it to my local welder. I found a very good supplier of exhaust parts, ordered two 60 degree bends on Thursday afternoon which arrived today Saturday so as soon as I get the engine back in place I can trim the pipe, make a new flange and get it to the welder next week. The only snag is that nobody seems to have the kit to make mandrel bends in 38mm (1.5 inch) with a curve radius of 3 times the pipe diameter as is the original so I had to settle for a slightly sharper 2 diameter curve. It would have been OK if I'd wanted a 3 or 4 inch pipe, but the Augusta is no hotrod.

I have bought a bolted sleeve joint to connect the down pipe to the rest of the exhaust where it goes through the cruciform frame of the car. With that the exhaust can be removed without having to cut is as I had to this time. There was a short section of thicker pipe connecting the pipes but it was too tight to remove. The new downpipe is in stainless which is a good plan re corrosion but looks wrong, unless grit blasted when it just looks like mild steel but doesn't rust. I would not use stainless for the rest of the exhaust or the silencer because its sound damping properties are less than mild steel so the noise can be annoying.

Mike

[Raahauge]

I had to make a new flange (and face the head) to stand any chance of it being reliable. I also made a jig to weld the flange at the correct angle to the pipe.
You are most welcome to borrow it if you wish. I am in North Glos but DPD could deliver for, I guess, £20 ish.
Mike R

[Mikenoangelo]

Thanks for your offer Mike. I hope to get the engine back in tomorrow and will make up my mind then and come back to you.

Mike

[Kari]

The discussion about exhaust pipes and the connection to the cylinder head brings up the matter of exhaust gasket material.
On my car, the condition of the flange and face at the cylinder head is less than perfect. I have tried several materials until I came across a gasket material from the German company Frenzelit. Among the products is a material "Frenzelit novaMICA THERMEX". It can stand temperatures up to 1000° C and can adjust to small differences at the mating surfaces. But, without proper tools it's difficult to cut. I made 2 steel templates of the original gasket shape to clamp the material in between and was able to cut it to shape. Just!

www.frenzelit.com

regards  Karl

[Mikenoangelo]

Engine refitted today. Crane to lift it, trolley jack under the back of the gearbox and slide it in. Luckily the angle that the engine and gearbox adopt when suspended from the engine bearers is close to that needed to wriggle it back under the bulkhead.  With everything set up it took just 45 minutes to put it in working on my own but there are few points to note so I'll post more comments and pictures tomorrow.

Mike

[DavidLaver]

Mike - out of interest - where did you go for the exhaust components?

Am loving this series, even something as simple as numbering the photos is an inspiration.

[Mikenoangelo]

David thanks for that - I do think sharing experience is worth while. The exhaust part supplier was https://exhaustpartsuk.com/shop// A very helpful outfit.

Refitting engine and gearbox - a few tips.

You probably found this on removing the unit but worth while remembering that the lever on the gearbox which actuates the freewheel can be removed to give more clearance, particularly needed  if removing the gearbox while leaving the engine in place.

Before the big lift, one headlight should be unbolted from the mudguard to give clearance for the engine bearers to pass and the distributor and its drive removed from the cylinder head. The bolts which connect the engine bearers to the leaf spring mounts should be pushed down so that they are flush with the upper rubber blocks

To refit the engine and gearbox a hoist or crane is needed from which the unit is slung by the two engine bearers. It will balance at a good angle to slide into the car. If you have a crane like mine it can be rolled towards the front of the car and the gearbox pushed down under the bulkhead. With a fixed hoist the car has to be rolled forward. A trolley jack placed longitudinally under the car can be used to raise the back of the gearbox as needed, and will roll back with the gearbox. Before pushing the gearbox under the bulkhead, put a wodge of rag  on top of the box so that it can slide freely without scraping on the underside of the footboard/bulkhead - don’t forget (as I did!) to take the rag out before the tail of the gearbox is jacked up into place!

It takes time to slide the unit in place as the sump and crankshaft pulley get very close to the front cross member and the studs for the exhaust manifold get close to the cover over the starter contacts on the bulkhead. Lower the engine in very small stages while pushing it over the cross member, each time watching the clearance at these two points until the engine bearers are over their mounting bolts and the sump is behind the cross member.  At this point the jack under the gearbox can be raised (while lowering the engine) until the tube through which the rear gear box mounting bolt goes lines up with the holes in the transmission tunnel and the engine bearers sit on the mounting springs. Before putting the rear bolt in, push the two engine bearer bolts up through the rubber bushes, easily done with the aid of a ratchet spanner, with extension inserted through the holes in the underskirt to screw the bolt up through the rubber. Next fit the rear cross bolt at the back of the gearbox. I found that a pair of washers had been welded inside the transmission tunnel to reinforce these holes and this made the gap fractionally too narrow - corrected by a prod with a screwdriver.  Lancia's precision really helps here as each part lines up and fits perfectly as long as nothing has been bodged.

Mike




 

[Kari]

Mike,
A very good description of the job! I like your last sentence.

Regards Karl

[Mikenoangelo]

I’ve been working on the exhaust which appears to consist of the original silencer with replacement pipes. I may be able to salvage the silencer which seems very solid but will replace the pipes and insert a bolted flange joint just after the point where the down pipe passes through the cross member to make it easier to detach the down pipe from the cylinder head. All this is for the Winter though as I’m getting rather impatient to try the car and find out whether all this fettling has improved it and particularly got rid of the vibrations.

I thought the flange connecting the down pipe to the manifold was a write-off due to corrosion but decided that I could re-face it on the milling machine and at least temporarily re-use it and fit the old exhaust system back to test the car.

Facing the flange is quite tricky as it is hard to attach it to the bed of the milling machine at the correct angle. My first attempt using a large milling cutter as in the picture failed to hit the proper angle although I faced it to line up with the non eroded parts of the face. It turns out that the alignment is extremely critical if the downpipe is to avoid rattling against the hole in the cross member so I had to take a little more off, about 1.5 mm at one side tapering to zero across the flange. I could work this out by bolting the flange loosely to the manifold then aligning the down pipe through the cross member and measuring the gap between flange and manifold around the rim of the flange. I also swapped to a fly cutter instead of the milling cutter which (using a round carbide tip) makes a cleaner finish and also make is far easier to align the job to the chosen angle.

The silencer does look original with its rounded ends, the tags to attach the springs from which it hangs and the insulated shield on the top which presumably discourages noise from penetrating the floor. There is also small fishtail at the end of the exhaust, also original although quite rusty.

I’ve reconnected the clutch pedal and as I expected from my testing, the pressure is not noticeably changed by the stronger spring. In fact a lot of the force from foot to pedal is taken up by the pedal return spring which is really strong - certainly a sloppy driver would never damage the clutch by resting his foot on the pedal.


Mike

[Mikenoangelo]

After an exhausting day yesterday lying under the car to re-attach the exhaust and the propshaft and a few final bits to the engine I filled the rad with water, the sump and gearbox with oil and waited for drips - none came overnight so today I had no excuse for not starting the engine. Oh boy - it started first push on the button, and ran! I let it warm up and gave the cylinder head nuts a final tweak to 60 lbs ft - surprising how tight that feels when using a short 250mm torque wrench. I was very nervous that I was over-doing it and spent some time checking the torque wrench against my ancient but accurate spring balance - it seems about right, if anything slightly over-reading. After refitting the radiator cowl the only excuse left for not trying the car was rain and lots of it. Tomorrow is another day.

Can anyone tell me more about the small steel lug at the top front of the radiator cowl (picture 103)?  It fits closely above the T shaped bracket which holds the top of the radiator shutter to the chrome grill with bolts through the square holes behind the radiator badge (Photo104).  I would like to know what fits into the large hole in the lug - possibly a rubber buffer as there are some black stains just where it would lie against the inside of the grill above the badge. As with many Augustas the thermostatic mechanism for the shutters is missing so I’ll have to decide whether to use an Appia pressure capsule or to make a manual cable actuated arrangement.

Mike