Quiet here innit?

There's not much going on here, so I thought I'd describe my afternoon's frustrations.

One of my jobs at the moment is overhauling the fuel injection pumps on a Crossley HR4. This is a 4-cyl 2-stroke 'scavenge pump' direct reversing diesel, from memory 285 bhp @ 300 rpm, built 1948. It's something like 10.5" bore by 15" stroke. The scavenge pump is a big single cylinder piston pump in line with the four power cylinders.

It's in a vessel which had been idle for 10 years, I helped to get it going again about 5 years ago. Part of getting it going involved freeing up the badly rusted injection pump.

We've finally got around to doing something a bit better with the pump, so I've tracked down some new control valves and excellent used main pump plungers and bores. These pumps are a bit different from the usual CAV/Bosch or Simms in-line pump, which use a plunger with a helical groove to control the amount of fuel delivered per stroke. These Crossley pumps have a simple pumping element whch connects to the control valve, which controls the fuel delivery. The pump plungers are 3/4" dia., the control valves 3/8 dia. The various bores are lightly pressed into a chunky cast steel (guessing) block, with copper sealing washers. I unpacked the control valves & checked they were OK. They're like the usual fuel pump elements in that they rely on a very close fit to keep the fuel in. I tapped out the old ones, cleaned everything & blew out the block thoroughly, before tapping in the new bores. Then came to fit the control valve plungers into their bores, disaster - two of them wouldn't fit (without persuasion).

To cut a long story short, I tapped these out two bores out of the block again and measured the OD's at the critical points & compared them with the old ones. The worst of the new ones was about 8 tenths of a thou bigger than the one it replaced on the OD. I put it in the lathe and polished, carefully, a similar amount from the body of the new valve bore. Refitted it to the block, hey presto, all is well, the plungers fit as they should

Tomorrows job is to refit to the engine and see if I can make it go again. Both this vessel and the 'day job' at the dry-dock are being taken by their respective owners to a commemorative bash for their builders (Yarwoods of Northwich) next weekend, so no rest for the wicked for a few days!

Cheers Tim

Dutton Dry-Dock Traditional & Modern canal craft repairs Vintage diesel engine service

Reply to
Tim Leech
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I've spent the weekend playing in a field with my engine, no internet connection in the grass I'm afraid.

Mart> There's not much going on here, so I thought I'd describe my

Reply to

I've put up a few pics of the engine,

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The pump elements are the lower row in the pic, the control valves the upper row.

Had an interesting if frustrating time yesterday inventing some settings for the pump without the special gauges which were supplied new with the engine. There are two main settings, the pump plunger heights (affects timing) and the pecker clearance (affects delivery amount). Both are slightly different for each cylinder, I assume this is to take account of the variations in scavenge pressure and exhaust back pressure, though the book doesn't explain that. I did some calculations based on the measured plunger heights so that I could achieve the required differences while using the same shims which were in the engine before. I have no way of knowing what the actual height should be, half the gauge is missing & Crossleys seem to have no idea (or no interest ). The pecker gauge is also missing, I'd arived at some workable settings before through trial & error, but those settings no longer apply so more trial & error needed.

Anyway, it does run but it'll need some more tweaking as it won't idle below about 100 rpm, it ought to go down to nearer 50 or 60. That'll have to wait for another day.

Finished just before 9pm, that was enough for me on a Sunday!

OK, I know it's a marine engine but these were also used for stationary applications.

Cheers Tim. Dutton Dry-Dock Traditional & Modern canal craft repairs Vintage diesel engine service

Reply to
Tim Leech

Bloody hell Tim how did you get that up the cut ?

From experience pecker clearance increases with age and delivery is reduced.

-- Regards,

John Stevenson Nottingham, England.

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Reply to
John Stevenson

They recommend using an indicator for the final settings. Maybe at that age it would be a waste of time?

There was a diesel engine indicator in the club sale at Astle Park, but I didn't know whether it would be suitable for this type of engine, or whether it had the right springs, & I decided it was too much money just to sit on the shelf as an ornament. The owners of the vessel might have been willing to reimburse me if it turned out to be suitable, but I don't suppose they would if it hadn't!

Cheers Tim Dutton Dry-Dock Traditional & Modern canal craft repairs Vintage diesel engine service

Reply to
Tim Leech

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