Monday, 25 August 2008
My new Blog will be about the tours of the waterways on NB Ocelot. Reporting on the events, incidents and people I meet along the way.
I will, of course, continue to report on progress of the National. But there are a few things that need doing to Ocelot before the winter.
Saturday, 19 July 2008
Now, it's not time to get to excited as its all got to come apart again, but it does give an impression of the finished article.
I also now know of a few studs that need to be replaced and a couple of nuts that are missing. Additionally it has helped me find a few places (on the machines surfaces of the castings) that need to be painted before final assembly as they will be virtually impossible to get too once assembled.
A useful exercise and it does raise the level of hope!
Saturday, 5 July 2008
Well…. I made a decision about the mounting method and have gone for a modern product call ‘TICO S’. A "High performance machinery mounting pad", according to the manufacturers.
It comes in various guises, but I bought a strip of the stuff 100mm wide (4" in old money) by the standard 12.5mm deep. I also bought some of their TICO S washers.
The engine is to be mounted on the TICO strip and the bolts have TICO washers at the top of the engine. This has effectively cushioned the engine between the TICO material and should absorb a lot of the vibration but still hold it firmly to the engine bed.
Well… Whilst carrying out this exercise I noticed an error in the engine bed manufacturing process.
I welded the cross members between the longitudinal members at the engine mounting points. This would give the frame the most strength/rigidity at the mounting points. Fine at the front (this will be effectively covered by the flywheel overhang). A problem at the rear though.
The National has a sump that is separate to the crankcase. The clearance from the bottom of the crankcase to the top of the rear cross member is 4.1/4". What’s the depth of the sump?… 5.1/4" ……. Bugger!
I’ve now got to ‘notch’ out at least 1" from the top of the rear cross member. A bit of an exercise if the engine bed had been built of wood, but its not. It’s built from 6mm structural steel!
It’s been a while since I’ve used a gas axe. Man the fire extinguishers!
Still, at least I’m dealing with these problems in the comfort(?) of the garage. Imagine trying to do it having just lowered the engine in through the roof of your boat on to an engine bed that had just been welded to the bottom plate of your Narrowboat!
It's quiet a boring heading I know, but I have finally attacked the flywheel.
Originally the engine had an industrial flywheel (as can be seen on the blog header). This would have been a problem as it did not have any teeth for an electric starter (the engine being hand start only). However, a suitable toothed marine flywheel that matched the crankshaft mounting was supplied with the engine.
So, as per usual, the task in hand was to remove all of the paint back to bare metal.
How much paint can a flywheel have on it! There were layers of the stuff!
There's a lot more surface area to a flywheel than you think. Several tins of paint stripper and many hours with a wire brush and the thing was cleaned up.
One thing it did reveal on the inner boss was the stamping 49909. Could this have been the engine number of the 'donor' engine? If it is; thank you 49909, because your flywheel is now going to be well and truly bolted to the front of 56214. And long may it remain there (mainly because its to blood heavy to get off!).
Of course, once you get all of the old paint off and get the metalwork cleaned up, you've got to put the new stuff on. The result is:
A nice big black shiny flywheel!
Oh........ and another thing. The previous entry was with regard to the water pump. Well, here's a picci of the finished item assembled in full. I think it looks great against the black of the engine (the picci doesn't do it justice and it looks better in the flesh)
Thursday, 19 June 2008
A set of skew gears turns the drive through 90 degrees and operates a brass plunger via an eccentric cam.
All very simple but, hopefully, very effective.
Obviously the first thing to do was to break it down in to its component parts so that every thing can be inspected and cleaned up.In fairness, it was all in pretty good nick, so it then followed on with the usual (you know the score).
At the end of the task, another semi component is ready and wait for the great assembly processI love the cam lubrication process. Remove cover by undoing brass wing nut, open the spring loaded reservoir cap and fill reservoir with oil. A wick feed then drips the oil down on the the 'big-end' of the plunger and trough via an oil way to the 'little-end' of the plunger.
Another little pre-start up job.
Next up, I intend to attack the flywheel. It shouldn't be to much trouble apart from the many layers of paint and the sheer weight of the thing and the associated problems that that brings with it.
Monday, 26 May 2008
The large section at the top housed a set of spring loaded centrifugal weights and the shaft drives the oil pump at the bottom.
Obviously the first job was to strip it down in to its component parts. Then the usual cleaning up, etc, etc. Eventually it turns in to this:
Ensuring the oil pump had the correct thickness of cover plate joint took a while. To thin and the gears were tight against the cover plate. To thick and there would be to much clearance between the cover plate and the gears which would result in a noisy and inefficient pump. The task was done by trial and error with multiple 0.5mm joints (all hand cut) until the correct thickness was achieved.
New joints where made for all of the other mating faces and, after a bit of fiddling around the final result:
Another bit ready to fit come the time of the great re-assembly.
Sunday, 25 May 2008
I had a bit of a sort out of the photo's and have put them in to 10 basic categories.
Ignore the Photo Bucket cr#p and feel free to have a look.
Please let me know if any of the links don't work.
Engine porn at its best!
Edited to add:
A gentle slap on the hand from Sarah (see comments). There are a couple of acknowledgements I should really add.
The photos of the 'National Works' are courtesy of Sarah (NB Warrior). See: http://d3national.blogspot.com/2007/12/national-works-aston-under-lyne.html
The 'Engine Pre strip down' and 'Initial strip down' are courtesy of Lionel Knight: http://d3national.blogspot.com/2007/12/well-i-think-i-may-have-added-some.html
I think the rest are mine.
Wednesday, 21 May 2008
Monday, 12 May 2008
Tuesday, 6 May 2008
Anyway, The sunshine saw me wheeling out the engine, putting together the 2 tonne engine hoist and lift up the flywheel to offer it up to the crank. Did it fit? Like a glove! The shoulder on the crank matched the recess of the flywheel, as did the bolt holes and diameters.
I then took various photograph and measurements so that I could look at working out how to mount the starter motor bracket (once it was fabricated - which is another job!).
Looking at the above photo you would expect the paint to be in fairly poor condition. Over about 30% of the area it was, the remaining 70% it was stuck like poo to a blanket. I spent a whole day stripping several layers of paint off the flywheel ready for the usual wirebrushing etc, etc. Again a job complicated by having to move a 2 cwt lump of metal around.
Sunday, 27 April 2008
I’m going to mount the engine: flywheel at the forward end and the gearbox at the rear. If I took the propshaft of off the flywheel end, I had a 4" stub of crankshaft at the non-flywheel end to mount any drive pulleys for alternator(s), water pumps etc. Where as the flywheel has numerous holes to through mount an extension shaft to run anything.
Flange of off the 4" stub, flexible coupling, then into the gearbox. The gearbox mounted in its own frame just behind the engine and all bolted to the same engine bed.
I’ve also decided to wait for the new PRM 260 with a 1:1 ratio as well. Its currently being tested (still no timeframes for ‘launch to the market’) but it will be ideal for my requirements. 21" standard prop and 1 ½" shaft/stern gear.
Now that the decision is made, my thoughts turned to an engine bed.
My plan is to set up whole engine up on an engine bed as part of the rebuild process. Everything would then be bolted down and aligned etc before the whole thing was supplied to the boat builder. All that would then be required would be to weld the engine bed to the base plate.
The engine is sitting on a 2 tonne trolley during the rebuild and it has an excellent flat surface. I wanted to make a template so that I could confirm all of the dimensions, hole centres and crank alignment dimensions.
First thing was to get every thing of off the trolley and give it a good clean. Next I stuck sheets of A3 paper all over it and then carefully placed the engine back on it. It was then a case of marking around the engine feet and the mounting holes.
The next thing was marking the ends of the crankshaft to get the centreline. I did this by carefully ‘plumb-lining’ from the ends of the crank.
Lift everything off, and hey presto, one engine bed template.
Knowing the gearbox dimensions and allowing some space for the coupling in between, I have estimated the engine bed to be approximately 5’ long. In practice it may be a bit shorter, but its easy to cut a bit off!
The engine bed will now be constructed out of 3 x 6 ‘C’ section (75mm x 150mm in new money). A quick call to my local steel stockist confirmed 13’ of channel would be a shade over £100.
Monday, 14 April 2008
Saturday, 12 April 2008
NB Warrior kindly donated their old liners and pistons to see if they were better than mine. Now it was time to see which ones where the best.
There is no real alternative but to use good old fashioned measuring. And the measuring device – an internal micrometer of course.
Along came the evening when I had the house to myself. The liners duly found themselves on the kitchen table (hence the house to myself) all in a nice neat row.
Now I know, there’s only 5. The left hand three being mine the right hand two being ex’ Warrior (one never made it http://nbwarrior.blogspot.com/2008/03/even-goldfish-can-count-to-three.html)
The first measurement was the very top and very bottom of a liner. This confirms the original (non worn) diameter. Measurements are taken at 90 deg’ at each point to check to see how oval the bore is.
The reference measurements on my original liners was 4.125" (4.1/8th"). All three were spot-on.
Next was measuring the ‘worn area’. I was pleasantly surprised to find each liner gave the same readings of wear:
Longitudinally: 4.128 (3 thou wear). Transverse: 4.130 (5 thou wear) at the top of the stroke and slowly tapering out down to the original diameter as you went down the stroke. A max of 5 thou wear and 2 thou oval. Not a bad result.
Next up was the two (of three) liners from Warrior. The first difference was the original diameter. 4.135" top and bottom. They were both 10 thou oversize. The remaining measurements confirmed that the overall wear was of a similar pattern to mine but 1 thou less on each measurement.
The original factory spec was 4.1/8th" bore and 6" stroke. It would appear the Warriors liners, although slightly less worn than mine, have had a 10 thou re-bore in a previous part of their life.
Which ones to use – well, mine of course. I’ll have a chat with the machine shop, but I think a 5 thou hone from the original diameter to remove the oval bore and "the jobs a good un".
An examination of the pistons found them all to be of a similar condition. Mine have got the oil rings well and truly jammed in and are yet to be eased out. Both sets of pistons have slightly scuffed skirts, but nothing much to worry about. The ring groves are still tight and true. Overall, either set could be recycled with no problems.
All its going to take now is a trip over to Warrior to re-unite them with their 'bits'. Any excuse to see another National will do!
A useful exercise - and thanks to Jim & Sarah for the offer of their old liners and pistons.
Thursday, 27 March 2008
Wednesday, 26 March 2008
It's not that I haven’t been doing anything either. I’ve been doing bits here and there, plus a bit of socialising. I can’t spend all my time in the garage being "Billy –no mates".
The main thing of note is ‘pistons and liners’.
I want to try to keep the engine as original as possible (I may have mentioned this before - yawn). Anyway – to cut a long story short, Jim and Sarah of NB Warrior fame very kindly offered me Warrior’s old pistons and liners if theirs were better than mine (they had all of theirs replaced with new shiny alloy ones when RN re-built their engine).
Plans were made and we decided to attend a CWF Banter at Napton (last Monday). Pistons would be compared and exchanged there. As it happen, I went to the boat gathering at Stoke Bruerne on the Sunday, so did Jim & Sarah, and the exchange took place in the Museum car park.
A few other bits finished off now are the rocker covers and the cylinder head air intakes.
They where a real pain to clean up and paint, but they look nice now.
Hopefully I’ll hear back from PRM soon about the gearbox and coupling arrangements, I can then get the crank etc sent off for machining. It’s sat in the garage at the moment ready to go.