AJF,


This engine is clearly the predecessor of the later 1.50.

It is supposed to be an ABC (the 1.50 is) and has the same angled ports as the 1.50.


This engine has probably been run, with the pressure tap powering a pump.
The OS 7D is a suction carburettor, which would probably get enough pressure from the exhaust, if the fuel tank is small enough and is located very snuggly behind the engine.

...If your plane's fuel tank is situated on the C/G, you must use a fuel pump (Perry VP-30) and use that pressure nipple to power it.
(I cannot see it in the photos, BTW).

The original MVVS header for the 1.50, had a pressure nipple welded on the header.

This would not be ideal, but would offer a positive average pressure. You can try that, but don't even bother if the model has a C/G tank.


The proper prop for this engine would depend on the application, but the load class would be that of a 17x6.
On a model designed for the F3A pattern, I would suggest something in the vicinity of a 15x10.

You should be getting around 8,500 RPM. If you are seeing more, or less RPM, use an appropriately larger, or smaller prop.


The engine was sold to you by a merchant.
I doubt he had the time to actually run this engine (with over 2,400 ads placed in 3.5 years).

But with only positive feed-back, he's probably selling reasonably good items.