9 New bushings

Hmmm a little bit of an disappointment. All 9 bushings (that’s what was being measured this week) need to be replaced. One bushing in the master con rod and one on each end for the remaining 4 con rods.

The whole reason I did send them to Tony from CAMS in Blenheim, is that my plane certification guy Evan, expected that they were worn. Tony measured them and confirmed it. He had a second opinion and again the same answer, so 3 guys can’t be wrong.

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Now luckily that is not a mayor job, but adds cost to the rebuild. But again, is this is all that needs to be done, apart from the 3 new bearings, then I am not complaining I suppose.

To the left you can see what I am talking about. Clearly you can see here a lining made from brass, for the steel piston pin in this case to go into. The other side is identical (almost) the same lining, bushing for the crank pin.

As there is no bearing there, something needs to wear. We don’t want the pin to wear so the bushing will, as its softer than the steel!
And it did wear, so that’s why it needs to be replaced with a new one.

New bearings on crank shaft

And here are 3 new crankshaft bearings. Cleaned the grease from them with petrol. Nice and shiny !

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Heated up the bearings in some oil to 100 degC in a little pot on the tramping gas cooker (in the garage) to expand the bearings a bit, so they will slide easily over the crank shaft. I was a bit nervous, but it went really easy ๐Ÿ™‚ see below.

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Now its waiting for the con rods to com back from being measured.

Crank shaft OK

Yesterday picked up the crank shaft as it had a bit more testing to be done. All fine, so that’s really good!!
But the bearing that was on it had to be forced of it and need to be replaced. Now I was thinking of putting 3 new bearings on, so now I am forced to do, I am sort of happy that I don’t have to make decision anymore, its going to happen!

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Oil pump

Ooops, yes finished the pistons.

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Today I started cutting gaskets, for the oil pump and carburetor. Not sure about the gasket in the oil pump. Might be a little to thick and not getting the pressure high enough. Going to test the pump anyway and find out how it performs, before it goes on the engine.

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Also started cleaning the first cylinder. All looking good so far (see valve on the right).

Just an hour ago, got an email from Jack who sold me the engine. One of his friends saw my pictures and was surprised to see what looked like a gasket on the cylinder flange where it bolts to the crankcase.

He had always heard that this wasn’t done because the constant pounding would compress the gasket and cause loss of torque at the attached nuts and eventual failure of the studs. So checking that out….

5 min later,
Already had a reply from my propeller guy, who has a Velie:

A thin paper gasket, not more then .015″ (= .38mm) with sealant was common on low compression engines of that era. I used that with no problems for 100 hrs. Neverย compare modern aircraft engine methodology to antique engine methodology. There are many dissimilarities.
So yes that’s what I will do.

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