Mystic IHC Mogul Engine — Part 3

1916 1 HP IHC Mogul is put back together … and runs again — Part 3 of 3

| October/November 2012

This is the third part in a three part series on Peter Rooke's restoration of a 1 HP IHC Mogul engine. You can read part 1 in Mystic IHC Mogul and part 2 in Mystic IHC Mogul Engine — Part 2. 

Fuel Pump 

The IHC Mogul’s fuel pump was seized and looked a little worse for wear. When I stripped down the fuel pump I found that the check balls were stuck, the plunger was bent and badly worn around the packing, and an ordinary flat washer was the only thing holding the gland packing in place.

I thoroughly cleaned the pump and lapped the seats for the check balls using grinding paste and a steel ball that I super glued to a length of brass tube. The bore of the pump looked a bit rough so I reamed it out to 0.0625 inches over size. I made a new plunger to fit the bore, replacing the 0.3125-inch original, which had worn down to less than 0.30 inches around the packing.

Making the new pump plunger on the IHC Mogul was a simple turning task; I used brass rod, with a 0.125-inch cross hole drilled 0.15 inches from the top for the split pin to hold the spring end cap.

The washer that had been used to hold the packing around the pump plunger was only doing half a job: It was keeping the packing in place but it was not compressing it around the plunger.

To make a new packing ring I turned some brass rod to 0.75-inch diameter to fit the recess in the pump body and then drilled the rod through so the new piston was a good sliding fit. I cut a recess 0.625 inches in diameter and 0.125 inches deep in the top of the packing ring for a seat for the spring, and then I cut a 30-degree taper in the bottom side. This taper compresses the packing around the piston when the ring is under tension from the spring. I cut some new 0.125-inch diameter graphite packing to fit, although mop string and soap work equally well. I fit new check balls, and after painting I reassembled the pump.