Hello;
If I can locate and buy a crankcase somewhere in North America, I’d like to move forward with assembling a static Merlin for display. It would be a “Frankenstein” as the parts I have are likely different Mks, but the supercharger is the two stage one, so it would be something like a Merlin 60 series, or Packard Dash 3, 7, 9 etc.
There is damage to some of the parts, such as broken bolt bosses, and one area on the supercharger intake “bum” that has a hole corroded or worn right through. Before I got the parts, they were stored very carelessly.
I know nothing about welding, so I was hoping for a little guidance from those who have done this, on what filler rod to use for Merlin parts. I would have a capable person do this, not me.
So, anyone have any knowledge on this? Merlin Pete? (who, I assume, is Peter Grieve??) I think I recall that Peter cast, then welded a whole new reduction gear case to the front of one broken crankcase, but this was years ago and perhaps I’m overstating the extent of the repair.
Thanks for any assistance. Tom, Ottawa.
By: MerlinPete - 13th December 2014 at 17:08
We still do welded repairs to airworthy engines. Merlins are still quite plentiful, but certain parts are becoming very hard to locate.
Pete
By: Flying_Pencil - 12th December 2014 at 21:39
Flying Pencil,
You have obviously not seen the Rolls Royce Merlin Repair and Salvage manuals then. There are procedures for weld repairs on most parts of the engine and even how to cast insitu new sections of crankcase that have been ‘windowed’ by thrown rods.
I have a copy of the cylinder bank and head repair volume, and I would dearly like to locate copies of the rest. Does anyone else have these?
No I have no, interesting.
However I would surmise this was emergency short term repairs in war conditions, not long term permanent repairs.
By: Avro Avian - 12th December 2014 at 20:43
Flying Pencil,
You have obviously not seen the Rolls Royce Merlin Repair and Salvage manuals then. There are procedures for weld repairs on most parts of the engine and even how to cast insitu new sections of crankcase that have been ‘windowed’ by thrown rods.
I have a copy of the cylinder bank and head repair volume, and I would dearly like to locate copies of the rest. Does anyone else have these?
By: Flying_Pencil - 12th December 2014 at 20:30
As for the epoxy paste, I may consider that, but I like the idea of repairing things properly. The supercharger and wheelcase I have are otherwise functional, and if the cost is not brutal, I’d consider proper welding.
Properly for what? A cracked case/damaged part can never be airworthy again.
Cases are usually cast Al, and welding will change the structure at the weld. On top of that impurities will be introduced that will promote corrosive action.
What’s more if you do have serviceable parts see if you can trade them in for more unservicable parts to assemble a good looking display engine (and the usable parts will live on a flying airplane).
Of course you could go the slightly more pricey path and make a functioning engine.
By: MerlinPete - 12th December 2014 at 18:08
Hi Tom
We find that 5356 filler works best, but it is down to the person doing the welding. Most repairs can be invisible once painted, but it can be time consuming too. We have the advantage of having a large quantity of broken Merlin bits to use as repair parts, but sometimes we machine up the missing bit from raw material, and yes, we did cast a major section for the front end once, I posted some photos on a thread on here about a month ago, can’t recall the title.
The best bet might be to find a sympathetic welder who likes the idea of the job, larger companies often don’t want to know.
Pete
By: Tom Kay - 12th December 2014 at 17:34
Think these lot have any scrap parts?
Yes, when ever I visit that site, my job drops and I start to drool. I have called them, and one of their guys is asking the boss if they have a hopeless crankcase for sale.
As for the epoxy paste, I may consider that, but I like the idea of repairing things properly. The supercharger and wheelcase I have are otherwise functional, and if the cost is not brutal, I’d consider proper welding.
Cheers, Tom.
By: Flying_Pencil - 12th December 2014 at 14:50
use Epoxy.
There are also epoxy pastes (clay like stuff) to fill in missing holes you can smooth out and even sand if needed.
For a display engine a much neater and easier path to a good looking display.
By: TonyT - 12th December 2014 at 14:49
Think these lot have any scrap parts?
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December 12, 2014 at 2:29 pm