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Sunday, January 1, 2012

Moto Guzzi '74 Police Eldorado

GET ME TO THE CHURCH ON TIME!

I am getting married on 15th April 2012. My bride to be was also built in '74. This bike has to be finished on time.


The frame has been scuffed back, flatted off and finished with satin black powdercoat. Mechanically the bike will be as good as or better than new, whilst retaining its 'patina'.

I didn't think to take any before pix. I started stripping/inspecting the bike in October '11. It was a bit of a mess. Flaking chrome bores, badly corroded carbies and a cracked cylinder head top the list. This Guzzi had been apart before, and messed with by a ham fisted previous owner. At least it is complete.


The standard Eldorado 850 motor has no oil filter other than a screen over the oil pick-up. They also have chrome plated alloy cylinders. This early chrome plating, well past its use by date, has a habit of detaching itself from the bores, traveling through the lubrication system and 'lunching' the oil pump, main and big end bearings. This was the case with my bike. The crank journals were scored, but not badly. The oil pump had also suffered. I elected to have the crank ground 1st undersize and use new mains and big ends. That does not leave a lot but the rest of the motor appears to be good. Later big block Moto Guzzi engines have an oil filter in the oil pan. I like the idea of filtering my oil so I have elected to use a oil filter sump from a later Tonti framed bike. This modification makes use of a later front main bearing with a revised oil passage position and mounting hole.


The four modifications that need to be made to the early crankcase to use the later sump and front main bearing are:
1) 8mm drilling to supply oil to later front main bearing
2) Block off early main bearing mounting hole
3) Drill and tap mounting hole for later front main bearing
4) 10mm drilling for oil pick-up from oil pan

The 'Boomerang' in the picture below is the block off plate for the original oil pickup mounting point. The black line beside it gives you an indication of how long the new 8mm drilling has to be. Scarey.


I took the crank case to my usual machinist, but it would not fit under the mill head without changing the mill bed. I umm'd an ahh'd for several weeks before I set it up in the drill press ...

Set up was 'by eye' after leveling and squaring up the press. I used a blank VW Cro Mo push rod in the chuck to eyeball the drilling. Armed with a new 8mm drill 160mm long I just got it done! I had lots of reservations but it worked and I am very happy with the result. The drilling is within 0.25mm of being perfect. Got to be happy with that!


Forks stripped and given a preliminary clean. All in good condition for 38 year old forks. It all looks pretty original and straight. The staunchions have some corrosion up top where covered by the shrouds but the rest of the chrome is great. The cartridge dampers work after a fashion but I have ordered new ones. I have also ordered a set of uprated springs. They will go together with new seals of course.

It is now 2 weeks before the wedding. Parts orders have gone astray. Some have arrived but some crucial parts have disappeared in transit. In the midst of this we have moved house.

This bike will not be together to get me to the church.

The rebuild will continue without 'the' deadline.

It took a little longer than I thought to get settled in the new place. I also have a new job! YAY

This box was sent to the old address, I found it 6 weeks later


Some of the other parts that went astray in the USA have surfaced, one of them a sump from a later 'Guzzi with internal in sump oil filter. This one started life in a Lemans 2.



On the left a later sump from a Lemans 2.


Note the 4 extra holes for  fasteners on the newer (LH) sump.


The 4 threaded holes in the early crank case that line up with the 4 holes in the later sump are 8 X 1.25 mm from the factory. They usually retain a pipe that conveys oil to the rear main bearing and which includes the oil pressure relief valve. This job is performed by the sump in the later engine. The original holes in my crankcase have been damaged by a previous owner, I suspect something imperial has been used. I should have paid more attention during dis-assembly. I would prefer to use the later factory 6 X 1 mm through bolts to secure the middle of the later sump to my early crank case. I found a solution by TIME-SERT. They make what is called a 'BIG-SERT' for holes that have been thread repaired before. I will post pix of the process once the kit arrives.


The BIG-SERT kit arrived. The process involves drilling the thread holes (2nd from top), tapping the hole (3rd from top), recessing the top of the hole (top), then inserting the BIG-SERT with the insertion tool (bottom). A pretty simple process really.


Holes drilled, tapped and recessed.


 BIG-SERT being inserted.


 BIG-SERT in place.


Whilst waiting for the BIG-SERT kit to arrive from the USof A, I inspected the rear drive (bevel box). This was the last thing I needed to look at. Externally it looked great. It had a little bit of lash, but I expected it to be OK. This was not to be the case. I pulled the pinion carrier from the box, it was not good.

  
I drained the box, the oil was brown and full of grit. I delved further.


The drive side of the crown is ground away. Lots of rude words muttered under breath. Dark thoughts. Enough for today.

After a good nights sleep I cast the net amongst the guzzi community and was able to score an excellent used rear drive in the US of A. It is only money after-all!


My camshaft and lifters had also seen better days. I sent them down to Barry Jones of IME (Melb) for a mid range camshaft grind and lifter re-facing. He sugessted I would get the most out of the cam if I ran it with a 2 deg advance in the cam timing. To do this I set up a 20mm OD socket on the bed of the drill press. The old degree wheel that has been hanging around for years came in handy.


I made sure the bed was perpendicular to the drill. I set up on the existing hole so the drill went into the hole neatly. Rotated the sprocket 178 deg clockwise and drilled the revised hole.

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