Thursday, 18 February 2021

Blackburne Engine Complete

 The 13 November 2020 report described the progress Martin Greenland was making on rebuilding the Blackburne 4HP donkey engine. It’s good to report that we have a tick in the box for the donkey engine and the team is looking forward to the time that the spark meets the petrol.


There is no drawing of the engine mounting, but the starting engine drawing does provide guidance on the height
 and there is a detail for the cast iron mount.


As an aside the starting engine drawing also includes a detail for the sump drain from the MDB4. If anyone has a Winns medium pattern No1700 ½” gas screwed plug cock in their shed we’ll be very pleased to hear from you, this is not a project for compromises. Combining the words ‘screwed’, ‘plug’ and ‘cock’ in a Google search isn’t great and while I now know a little bit about Charles Winn & Co of Granville Street, Birmingham, my education has been increased in other ways too.


 

In the terms of the story of early Diesel traction having the petrol engine is an important part of the tale. Without irony 15/- Change states …’one of the greatest drawbacks of the ordinary petrol engine… is the difficulty of starting them in cold weather’ before also observing the starting a Diesel in cold weather is very difficult and that the solution is to fit a petrol engine to start the Diesel engine. If the ever optimistic brochure is correct then on a cold morning this little beauty will be spluttering away for 2 ½ to 3 minutes before the Diesel starts. This is the overture, preparing the audience for what is to come!


Wednesday, 27 January 2021

MDB4 Progress January 2021

Winter is usually a good time for Kerr Stuart progress, with the distraction of train playing reduced.  After some tussles to find a bit of space at Boston Lodge, Rick cracks on and makes progress while other members of the team sit back and relax in the reflected glory of his progress. 

This winter is different from others, but with the steady drip, drip of stalagmite formation, progress continues to be made. In the 25/10/18 blog the dispatch of the crankshaft to Farndon Engineering was reported, closing with the line Imagine the excitement when the new one comes back and we start worrying about the broken piston, the missing fuel pump and injectors…  

Brace yourselves; it’s back. Obviously still fretting about the other bits on the list, but two of the biggest challenges facing the engine restoration have now been ticked off with the repair of both the crankcase and the crankshaft.



Before we formally accept the delivery of this significant component, we are hoping that one of the works machinists will be able to give it a dimensional check. Assuming that it is fine, then this will free up some work to be carried out by the staff at Boston Lodge. 

After a rummage round in the store of components, the crankshaft bearings and housings have been locatedfor a quick trial fit up to understand what we have, and what needs doing.




Hopefully the next job will remove the last of the crankshaft failure damage. The bearings need to be re-whitemetalled and then bored out to fit the new shaft. The rather nasty score marks in the photo below show the point of crankshaft failure. 




Moving from the bottom to the top of the engine, the 16/2/20 blog reported on the dispatch to the foundry of the rocker covers. These have now been cast and are with Chris ‘Rimmer’ Barry, who has offered to machine them up as a homework project.   




Still some way to go and clearly difficult to be bullish regarding progress, but we also have the cylinder heads away with T&L Engineering and also have new cylinder liners on order, so we are getting close to the point when we stop taking things apart, and start putting them back together.  

When that will be of course is anybody’s guess. 


Monday, 16 November 2020

Making a Name For Yourselves

 

Back in February we were all excited by the dispatch of our first batch of patterns to the foundry. These included both the rocker covers and also the manufacturer's plates to attach to the engine & radiator.



Reference has been made before to the curious misspelling of McLaren on the radiator plate, which is of course irritatingly close to the driver's eye line. As a project being run by pedantic people the jury is still out as to whether this is annoying (as it is wrong) or if it is satisfying (as it is wrong but right). Perhaps it is just there as a conversation piece?



The McLaren–Benz plate is from the right hand side of the engine block and can be just glimpsed in this view of the donkey engine:


Not convinced? This is a view of the 4MDB in the Armley Mills winch from a similar angle:


If you would like your own conversation piece, we have a small stock of both plates available at £150.00. All profit to the project, contact us via the Facebook page. They have been cast in iron, but if you want to fasten it to a partition wall we might be able to do you one in aluminium. 

Not really after a big chunk of iron work for the chimney breast? We still have stocks of our other ‘merch’, books, T shirts & badges available from https://www.frheritage.org.uk/sales/



Friday, 13 November 2020

Starting again

For obvious reasons 2020 has been a slow news year. In a rather different world last December, buoyed up by the additional funding provided by the Ffestiniog Railway Society, we dispatched the magneto from the 4HP Blackburne donkey engine for overhaul, hoping that this would be the catalyst for a side project overhauling the starter motor. The Blackburne engine sits on a cast iron frame in the cab which Rick machined up (blog entry 14 December 2019). We were hoping that our petrol engine man, Martin Greenland might be spurred on by the magneto overhaul and find time to look at the rest of the engine. Fortunately in late February the relevant box of bits left Boston Lodge and made it to Martin's workshop just before lockdown started.

Job number one was that the drive side main bearing was very loose in the crankcase. To effect a repair Martin machined up a thin steel collar to be inserted into the crankcase, which allows the roller bearing once again to be an interference fit in the casing:


What do you do if you need to insert a steel collar in a crankcase with an interference fit at home during lockdown?  Place your collar in the freezer to shrink it; place your crankcase in the oven to expand it; stick both on kitchen table and work bloody fast!


Bingo!


The bearing is secured by three 0BA countersunk screws. Even in lockdown you can buy these, but the heads on modern ones are 3/8” in diameter and it turns out that back in the twenties the head diameter was ½”, so another opportunity to while away the hours. The view below shows the fitted bearing, complete with Martins bespoke made set screws:


This is the inlet tract all cleaned up and ready for reassembly:


The cylinder head with the carburettor fitted:


The engine sits in a fabricated cradle, very similar to the one which supports the vacuum pump. There is one important difference; a bracket is needed to carry the magneto:


This is the donkey engine sub-assembly nearing completion, showing the new sprockets and chain drive to the refurbished magneto with the carburettor above. The chain guard cover (yet to be fitted) proudly carries the Blackburne makers name. It’s a pity, but this is the back side of the engine (inside the cab sheet), so all you will get in the cab is the flywheel and chain drive to the main engine:


So, the starter motor wasn’t quite the side show that had been anticipated, it is centre stage for 2020. Having this technically complex piece of work nearing completion is a great achievement.  

Sunday, 16 February 2020

Pipe Up at the Back

The vacuum brake gear was fitted to KS4415 in February 1929. They produced six drawings to show how to make this modification, and the August 18 blog describes how some of this information has been used to make the vacuum pump. Even the pipe clips and timber packers are detailed on an individual basis.

This is the process followed for one of the clips:

Extract from drawing 33737:



First, formed up on a jig:




Drilled using a radial arm drill:




Painted:



Timber packer made:



And finally fitted to the hind buffer beam:


Off to the Foundry

Preparing drawings and planning for patterns is all well and good and requires both time and skill, but we need to draw a line in the sand somewhere, or at least make a mark in the sand and start pouring molten metal. The first three patterns have now been dispatched to the foundry.
These are -

For the rocker covers:




For the radiator header ‘nameplate’ (which is to be cast off this original):



And for a McLaren-Benz plate to fit to the engine block. The photo below shows the pattern in production, based on a rubbing taken from the Armley Mills MDB4:



The finished product:


We need four rocker covers and one off of each of the plates. If your man-cave needs retro-Diesel memorabilia then get in touch, we’re having a couple of spares cast.




More on Fuel Pumps & Governor



A bit more on the fuel pump & governor & the timing gear train which drives them.

The image below is of the timing gear cover, with the fuel pump wheel in situ:



The drive from the back of this wheel to the governor is a simple fork. The bracket which carried the fuel pump/ governor body has also been fitted in this photo so we can check some dimensions:



This is the drawing Will High is preparing of the casting which will sit on these brackets:


Some of the information used in the drawing has been taken from the MDB2 fuel pump body (below) and we have also measured up some components on the pump on the MDB4 owned by Armley Mills:




Progress on drawing up the cam followers for the fuel pumps.

McLaren call these ‘Kicker for Fuel Pump Plunger’ and they are components 569 & 570 in the ‘I-Spy fuel pumps’ diagram in the last blog. We of course need four, the two in the photo being from the MDB2:




This drawing shows a cam and kicker together with the fuel pump plunger in place in the casting. The kickers on the MDB4 pump we are replicating are carried on a radius arm (allowing the travel of the kicker & pump to be increased) rather than the slide arrangement in the MDB2 shown in the photos in the previous blog entry:




Finally a view of the timing train, MDB4 (left) & MDB2 (right):