Mclaren Brush 55KW Generating Set
Unloaded from trailer after 30 years storage
Unloaded from trailer after 30 years storage
Unloaded from trailer after 30 years storage
July 2020
After not seeing daylight for decades it's time to tackle this project.
After a few tentative lifts and finding the point of balance, getting the load fully back to the heel of the forks, some rags on the tines to prevent slipping, a careful lift and only reversing as far as to clear the trailer, lowering to the floor completed this basic procedure.
Now the work starts.
Getting the Compressor started
Unloaded from trailer after 30 years storage
Unloaded from trailer after 30 years storage
The more restorations anyone does , the more they appreciate that addressing the mechanical issues and acquiring any missing parts must come before the cosmetic side of the project.
The Petter W2 combined engine and high pressure compressor is at the heart of getting the Mclaren to run.
These starter units are designed to give an air receiver pressure of 300PSI , which cannot be achieved from your average workshop compressor.
There were 2 obvious problems, no compression and a strange arrangement with the magneto involving an external coil and a pair of 12 volt battery leads.
Removing the head showed the valves to be stuck and after freeing off and a quick lapping in with grinding paste the compression was excellent.
The magneto was a different story. On investigation it had no coil, but with spares we had on the shelf and a bit of TLC, the mag produced an excellent spark.
The mag timing proved a little tricky, but once you know what to do it seems so simple.
the Petter A literature states TDC is with the Crankshaft keyway at the top, but the diagrams show with a 2 cylinder version the keyway is at the bottom.
A tip from an internet video shows a very handy trick to solve the issue of 20 degree timing for the the spark and setting up with an impulse mag.
Simply set the engine at TDC or slightly before, at which point the engine will have fired and carefully revolve the magneto by hand until it has clicked, when it will have sparked and insert it back into the engine.
A new long reach spark plug and we are up and running.
Many thanks to all concerned.
Attempting to start the Mclaren
Unloaded from trailer after 30 years storage
Attempting to start the Mclaren
Not having much success!
At last, success. Runs OK
At last, success. Runs OK
Attempting to start the Mclaren
Once the fuel is fully bled through, the air start in cylinders one and two does the trick.
Restoration Complete
At last, success. Runs OK
Restoration Complete
After dismantling, blasting, painting and reassembly with a few minor adjustments we have a fully functioning 3 phase generator.
Moved to display area November 2020
Ingersoll Rand Compressor - type 20 - size 72 CFM
History
Parts Required and Availability
Dismantling and Fault Finding.
The start of another interesting restoration project.
Dry stored by us for a number of years, but not before being subjected to the affect of the British weather by previous owners, corroding most of the sheet metal parts.
An initial inspection showed the unit to generally be complete, but with some noticeable exeptions, whilst the wheels turned freely, the engine/ compressor was a different matter, seized solid. The carburettor was in place but there was no sign of a magneto, just a bracket to mount it on.
Fortunately the brass specification plates were intact showing the engine to be a Waukesha model XA dated 1926 with
other plates which will add to the appeal of the finished project.
Dismantling and Fault Finding.
Parts Required and Availability
Dismantling and Fault Finding.
Investigating what was seized, the engine was the obvious place to start. If that problem couldn’t be resolved at a sensible cost the project was destined for the scrap bin.
The first bit of good news was that the compressor unit was free.
The engine itself was the problem. The second bit of good news was that it was the pistons that were wedged in the bores, the crankshaft and big ends appeared OK. The big end caps were shimmed and would therefore adjust to an acceptable tolerance.
It’s always a challenge to get the pistons out of these older engines as the big end is larger than the bore and the gudgeon pln is never visible above the block.
The pistons have to come downhill past the crankshaft which needs to turn to permit this manoeuvre. The more pistons that are seized the more difficult to dismantle
Machines of this age have Plenty brasswork and this compressor is no exception. All carefully removed for cleaning ready for reassembly.
Parts Required and Availability
Parts Required and Availability
Parts Required and Availability
First on the list was piston rings, 2 compression and 1 scraper ring per piston.
The pistons were 15 thou oversize and we managed to obtain replacements from Cox and Turner of Yeovil. The compression rings were 1/2 depth, needing 2 rings per groove.
The valves were beyond lapping, but attention on the Black and Decker valve refacer gave us an acceptable surface.
A Simms magneto from our “stores” was a perfect match for rotation, centre height and fixing bolts. The points had been removed by a previous owner but our stores came to the rescue once again.
A Simms vernier coupling was purchased and machined to fit.
We needed plastigauge to check big end clearances, eventually compromising on 3-4 thou shell clearance - better not to be too tight.
Balata flat belting for the fan belt from E bay.
UNC/UNF nuts and bolts and for authenticity new Castle Nuts for many of the fixings
The radiator has 4 core sections the bottom tank of the cores are brass and perished , but a quality soldering job should sort that problem
Testing the Engine after Rebuild
Testing the Engine after Rebuild
Parts Required and Availability
After ascertaining the firing order to be 1, 2, 4, 3. and marking TDC on the flywheel as a timing mark, a quick test run of the engine proved successful.
The Magneto is working well and with excellent oil pressure it is time to move onto blasting and painting
Blasting and Painting
Testing the Engine after Rebuild
Blasting and Painting
After a Coronavirus delay of several weeks we can tackle the the next phase.
Further stripping down into component parts:- engine, compressor unit, radiator frame, air tank, fuel tank, chassis and all the ancillary items was the first step to improving the appearance of the unit.
Blasting, priming and filling followed by a 2 pack paint job started to make all the hard work so far look worthwhile.
Will it make air?
Testing the Engine after Rebuild
Blasting and Painting
The answer is yes, just a couple of issues.
Engine timing, magneto refitted incorrectly after painting and sorting a few water leaks.
She runs well, good oil pressure and makes air - a satisfying feeling and a big thank you to everyone who contributed.
Final Test Run
Final Test Run
Final Test Run
Just a few snagging items to sort but otherwise a success.
Job Complete
Final Test Run
Final Test Run
All the finishing touches now complete.
Compressor moved to the display area July 2020.