Sunday, 21 December 2014

1930's Wolseley 15hp Spl..

Some further preparation of the new cylinder block and running parts.
There is always a lot of "prototype" work when an engine of many new parts is assembled. It is so easy for "one off" items of such complexity to have a small error and sometimes, more surreptitiously, an accumulation of small errors. We cannot take anything for granted, and that is certainly not a criticism of those involved in the manufacture.

Here we have prepared and given the outside of the block a coating of Suncorite phosphating primer, a product developed for military use on gun barrels and precision items to protect, when used in conjunction with oil coatings or paint top coating it is extremely tough. The new block will go through further cylinder boring work and the primer will help to stop some oil deposits lying in the porous material surface. Internally all items have been painted with Glyptal for the same reason and the added benefit of free oil flow and to seal in the sand that migrates from the casting during the engines use and temperature cycles. A word of caution, from experience of seeing many engines coated in this paint,it is important that if applied to aluminium, it has to have been chemically or some form of very thorough cleaning. In service, aluminium items do seem to reject the Glyptal unless absolutely clean and I have noticed, it adheres more to some form of rough or cast finish. Glyptal flakes floating in the sump is a worrying sight!
Always think carefully with internal engine paint regarding the benefits and the risks, consider the heat cycles and the heat dissipation requirements and consider the fuels in use.
Incidentally, during the period, many companies used a form of shellac to paint the internal areas. Often it still resists even chemical removal after all of these years of use, even on aluminium (Rolls Royce).

The differing oil pumps fitted to variants of this engine may offer some advantages especially when limited by the availability of parts. We are considering using deep pump internal gears to offer a little more capacity, the same pump has an extended drive shaft bearing housing which would allow better support for the skew gears when compared to the standard items. Of course this will require further, time consuming modifications.

As loads and revs increase, it will be prudent to upgrade to a Duplex timing chain which will require some further test fitting and alteration.

The new crankshaft counter weights will not allow pistons to enter from the bottom of the engine with the crank fitted. The conrods cannot pass down through the bores from the top as the big end section exceeds the bore diameter. All rods and pistons will have to enter into and up through the bores prior to fitting the crank and bearing housings.

Cam phasing has been carried out and some general cam index position notes taken for final assembly. The cylinder head has yet to go for new bronze guides, slightly larger inlet valves and new valve seats which will have three angle cuts and blending to aid a little gas flow and valve to seat contact.

Combustion chambers have been cleaned and brightened and each chamber volume measured and dressed equal to that of the largest volume.

There are many areas of casting seam "flash", I missed this one so some more careful fettling will be required. (Below)

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