Internal Fire Museum of Power

i was just thinking about some of the jobs from hell i have had on restoring old engines over the years. I wondered if any of you have any experiences you would like to relate... ie a simple job that turned into a nightmare or something that just wont fit no matter what.

sometimes i just get so fed up with being unable to make progress on something i "park" it at the end of the workshop and ignore it until inspiration is restored (even months later !!).

the most annoying thing i do (but infrequently...thank god !!) is to loose stuff.

i remember buying some old parts from a terminal lister CE quite a few years ago and now that i need them Iam darned if I can find them. In the time I have spent looking, I could have fully restored something else. Its enough to drive you nuts !! I know I bought them, I know exactly what they are and they can only bein one of three places.


I am often heard muttering "it must be in here somewhere" !!!

welding cast iron is the worst technical challenge i seem to face but I am getting better at it with age. bizarrely i find stick welding mild steel easy which many people dont (cant get on with mig welders !!).

assembling an engine only to find i have left out something important (oil pump on a Petter AV2..recently !!)

god knows how i managed that one !!

anyway, it will be nice to know if its just me or if we all drop a golden clanger form time to time !!

The thing that really bugs me is sorting out the issues caused by misguided folk fitting non-whitemetal bearings to a Petter M. I don't care what grade of phosphor bronze or how much lead its got, it's too *$*%*&*&* hard for Petters soft cranks! Furthermore a Petter M sucks in dust and P-B entirely lacks the embedding qualities of whitemetal. No Petter M ever left the factory with a P-B bearing.
Every one I get like that has badly scored journals which need a regrind. If well made the P-B bearings can be bored out, treated as shells, and re-lined with whitemetal.
and a reminder for anyone having a ring-oiled crank reground - don't forget to lightly peen the bore of, or make new, oil-throwers to fit the reduced journal. Leaving the originals to spin just grooves the crank.

rant over
Roland

I have done my share of strange repairs in the navy, but one particular one springs to mind regarding cast iron welding.
Yeas ago we were in some US port. Can't remember exactly, but it must have been Houston or New Orleans. Upon arrival, the US coast guard gave us a check up and found that the engine of one of the life boats wouldn't run. Now since that was the only deficiency they could find, they decided in their great whisdom that we couldn't leeve port until it was fixed. It was a rather large vessel and by no means the only life boat, but there you have it.
Now these are cheapish little diesel engines that suffer greatly from neglect and being out in the open in salty air all the time.
Same with this engine. Since it had no compression I removed the head and I found that sea water had eaten a large hole in the exhaust valve seat. Sea water must have entered the exhaust in bad weather and this tends to turn cast iron into a sort of soft clay like matter. The valve seats are ground directly in the cast iron head and can't be replaced. With spares a thousand miles away I had no choice but trying to repair the damage. I found some nickle electrodes and against all odds I decided to try and weld up the damage.
A complex shape like a head will almost certainly crack if you weld it just like that, but after all it only had to run for ten minutes to satisfy the coast guard and if it didn't crack too badly, it would probably run without cooling water for a couple of minutes.
To minimise the risk of cracking, I build a small furnace from exhaust pipe insulation material and heated the head with a torch. When it was quite hot, I quickly welded the damaged area with the nickle and repacked the head with the insulation, so it would cool down as slow and evenly as possible.
When it had cooled down I cut a small slot in the old valve disc and brazed a widia bit from the auxiliary engine valve seat grinder in place. With that and an electric drill I cut a new valve seat in place and fitted a new valve that we had in stock.
To my own surprise the engine ran, ran quite well and when I checked 5 years later with a collegue, the engine still ran.

Hubert

Hurumph - try telling someone that in 'the other place' ("white metal is also more forgiving of hard contaminants which tend to embed deeply rather than scoring the shaft. No coincidence that in the evolution of car engines, the replacement of white metal with longer lived, harder, bearing materials went hand in hand with proper oil filtration!") and you are just being awkward!

NHH

Indeed if it had white metal.... replace it with white metal... hence I have a lump spare incase I get the urge to buy a Petter M again

Cheers Steve

Hi Everyone,
When I was in H M S Adamant, depot ship to the second submarine squadron, based at Devonport, I can state that whenever the crankcases of the P and O class submarines were opened for bearing replacement, the routine on rebuilding the engine was to fit white metal lined shells, and the crankcase was flushed with a flushing rig for some hours. The boat then went to sea for a normal patrol. On return the white metal bearings were removed, and checked for contamination. If none was found they were then replaced by lead indium lined shells, which then remained in place till the next refit/breakdown. The big end bolts were tightend using a stretch gauge.
Regards,
Harry

I was on a cargo vessel in the Caribbean and it had 3 Deutz 600 hp generator sets. Now these engines were without turbines and originally designed for either a submarine or a locomotive; I can't remember. (I was told that they were prototypes and they got them at a discount when the vessel was built).
Now because of that, they were compact design and a nightmare to work on. These engines had the nasty habit of seizing every week or so and in 6 months time, we exchanged more than 20 units.
Deutz had been unable to sort it and I guess they must have bought off the guarantee a many years ago. In any case, we got used to it and after some time, when watching television at night, we wouldn't even go down to the engine room anymore when the lights went out and back on again after the stand by unit took over.
"Ah, seized again; we'll sort that out tomorrow".
We even tried fitting the top ring upside down, without any noticable effect. (couldn't get any worse if it didn't help, was our idea); they were a strange triangular shape. Something they must have abandoned soon after, because I have never seen them on any other engine.

Hubert