Its been a while since the last blog....

 

we start where we left off....me and my fellow 26 workers beavering away all over the depths of winter...changing windscreen seals....cutting out rot....repainting yellow ends....all for the start of the ever promising 2020 season . 

 

Two visits already planned, 1 to Somerset and Dorset, and one to the severn valley....even my fellow diesel dept members thought we wouldn't make it...but we did...we finished all our body work and repairs to internal systems, and were ready....one last job needed to be done and that was an oil change....

 

the oil sum on a 6lda holds 130gallons of your finest straight 30 engine oil, the frequency of oil changes generally depends on the condition of the engine and turbo charger, 26043 on average has an oil change every 2 to 3 years, and this is commonly due to fuel contamination, which is caused by a lot of cold starts...something which all preserved locos suffer from, which thins the oil. 26043 has the additional issue of a high soot value in the oil but we will touch on this later....so what does an oil change look like

 

 

It looks like this...2 oil drums on brand new oil....best part of £1k not cheap....this year 26043 has had the addition benefit of a full filter change, £500....but this is the first filter change its had since it had been withdrawn. Inspecting the filter turned up good news...the only thing in there was paint flecks...and lots of it....but NO METAL which corresponded with what I read on the oil sample results. (the insides of Sulzer engines are painted) no it doesn't make sense to me either!

 

 

the engine side cover off allowing access to the crankshaft main bearings and big end bearings, and allowing for general inspection of the engine to the right is piston 6, this is what's known as "B Side" (non air compressor side)

 

Now seasoned BR depot staff reading this will say...to change the oil all you do is get the engine hot....connect the hose to the oil drain and open the ratchet and just wait....easy....no I know full well if open that valve after 25-30 years its not going to seal....and just like 26010....it will just drip and drip and make a mess everywhere. So...what I do is pop the engine access door off  (3 man lift) and stick a barrel pump down to the depths of the sump to suck the oil out....its a tried and tested method.....it just takes a while

 

Its here....things started to go down hill

 

 

a pear into the depths of 043a engine, the oil sump (currently full of oil) reflecting the flash off my camera, note the surface rust on the crankshaft counter weights...this isn't unusual as condensation over the winter forms internally (as the engine has a large vent) and this ends up with inevitable surface rust. Nothing unusual here

 

 

Piston number 4, the piston and rod assembly for all sulzers is about 4 feet tall, its held on the crankshaft using an end cap (not unlike a car) with 4 bolts...the toothed wheels prevent one bolt undoing another. the piston has a 28" stroke hence the name 6lda28 again on the left we see standard rust....its the right hand side counterweight which shows something is amis, we see a fresh streak of rust indicating a flow of water has occurred recently....its at this point I asked one of my colleagues to run the triple pump to bring the water system up to pressure, and while the cover was off I could see if any was escaping from the water jacket above and into the crank case, after a short period of running the pump I could see a bead of water form at the bottom of the cylinder liner....after wiping away the water it then returned...its at this point I knew the cylinder liner seals had failed on at least piston 4....and after close inspection I could see they had also failed on cylinder liner 1.

 

So this then wrote the season off....the engine would require a full strip down and rebuild.....

 

So what's first...

 

first there's the rocker gear and fuel pumps....sadly because of the sheer amount of fiddly work we didn't get pictures of this...but its a fairly straightforward process. 

 

Then...

 

the heads

 

a 6 LDA like all sulzers and EE loco's have individual cylinder heads....unlike your car which has one head for the engine (or bank if its a V) 

 

 

the heads are held in with 6 nuts on studs, its common for these studs to snap and require drilling out of the engine block...thankfully we avoided this....but the nuts are sighted up to 650nm and, you have absolutely no chance with a spanner so a torque multiplier is needed, and a strong man....up steps fireman sam (his real name is fireman Jon but fireman sam is more humourous) with fireman sam pulling funny faces and me providing a little finger of morale support all 6 heads were undone ins about 3 hours....at which point fireman sam departed for a 12 hour night shift at his Bristol fire station!

 

the heads weigh roughly 1/4 ton and are a minimum four man lift...you first need to remove the handy fibreglass cover so you can lift them out the engine bay with an overhead gantry.

 

 

3. of the. 6 heads after steam cleaning, they were covered in a 1/4" of grime and will be full stripped down and inspected before re-use each head is a minimum 4 man lift! you can see the twin valves and the studding which holds the rocker gear, the angled port to the right is the exhaust, and the port to the left is the inlet.

 

next... the pistons...

 

 

a piston being lifted out the roof with a gantry, each piston has a threaded hole for an eyebolt in the crown

 

 

All six pistons weighting to be lifted into the racks

 

 

All 6 pistons (well 5 you can see) awaiting clean up and piston ring inspection piston 3 had a broken piston ring and this will be replaced.

 

 

The pistons with the bearings and end caps in situ, its vital that these are kept together the end caps are not interchangeable, the bearings are in excellent condition with only minor scoring, but very very little wear.

 

finally...the liners...and liners are the biggest pain to remove, they have been in place for over 35 years and are reluctant to give that up, they are pressed into position and held in with the liner seals, a base plate and two 1.5" diameter bars are passed down the liner and installed at the bottom, at the top the a top plate sits over two head studs and the two bars pass through it, and then two 1.5" whiteworth nuts are installed, which clamps the liner against the studs....then with two ratchets and two people you wind the liner out using the two nuts, but doing the nuts up the bars pull the liners up...its slow and painful process until the liner jumps up (which is when the seals have been released)

 

 

the base of the liners showing the 3 liners seals which are nothing more than overgrown. O rings...yes an £18.50 o ring has caused this failure! you can see above where the water circulates  round cooling the liner, the lower portion protrudes into the crankcase.

 

 

the liner bores...these are in fair condition, a few scores and a little corrosion evident where the locomotive sat for long periods after withdrawal, lack of spare liners means these will have to be re-used. after a light honing.

 

 

finally a view into the now dry cylinder jacket looking down the bore at the liner sealing surface down to the crankshaft.

 

at this point lockdown hit and min waiting to go back to carry on.

 

thanks for reading.