The Mery Explosive Engine Kit Project

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  The "Mery Explosive Engine" was a very unique design, originating from the machine shop and foundry of Mr. Michael Mery back in 1895. Located in Chico, CA, Mr. Mery patented his design around the main idea that it was best to completely purge the combustion chambers with clean air in between each charge and firing. It was on this premise that he added a 5th and 6th stroke to the newly established 4 stroke design in order to accomplish the task of purging the engine. Another unique feature of Mr. Mery's design, was to incorporate the "compound" design already existing in most steam engines of the day, whereby both sides of the piston were used to produce power. To do this, Mr. Mery used the steam engine design of using a crosshead between the connecting rod and piston. This allows the shaft to the piston to be sealed using a compressed packing or "Stuffing Box", creating the ability to have a second combustion chamber on the bottom side of the piston.
  Currently, only one known full size original complete and running Mery Explosive Engine exists, and it was that engine that was used to create the machinist kit version used here.

Video available at http://www.oldengineshed.com/videos/mery.mpg

Sound available at http://www.oldengineshed.com/waves/mery.wav

A note about the sound byte: What might sound garbled to you is actually an accurate representation of the exhaust sounds of the engine. Notably missing is the strong 'pop' of the exhaust since the valves are operated by a slow moving eccentric rather than the quick lift of a camshaft lobe, and that the valves are opened at the very bottom of the power stroke with very little compression remaining. The other impulses you will hear are created by the rush of air in and out of the exhaust stacks during the 5th and 6th cycles. Hence, each stack will produce 3 distinct sounds for each group of 6 cycles.



The kit fresh from the foundry...


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You might also notice some of the nomenclature used might sound a little odd. Back in the late 19th century when the Mery was designed, many of the part names were taken from the steam engine realm.


Surfacing the Base. Milling the Body (Block) legs flat. Milling the back leg. First cut across the main bearings.


Little by little... Now just to cut to width. And on to the main bearing studs. Finishing the Cylinder end.


Boring the Timing Gear boss. Base and Body almost complete. Different view. Setting up the Cylinder for its first cut.


Surfacing the Explosion Chamber bosses. Surfacing the exhaust flanges. Boring the Cylinder for the sleeve. Rough boring the Cylinder Sleeve.


Turning the Cylinder Sleeve to fit the Cylinder casting. Turning the end surfaces of the Cylinder, now with the sleeve installed. First work on the main caps. Line boring the Body for the main bearings.


A final reaming to size. The Crosshead (right end) still attached to the casting tree. The Crosshead being milled. Making the bronze shoes for the Crosshead.


The completed Cylinder with Sleeve, Stuffing Box and studs. Steel plate with a Crankshaft hidden inside... First the Crankshaft is machined to thickness. After center holes are located in each end...


...the first set of centers are used to turn the rod journal. The excess material is removed... Finally, cut the key ways. Viola! I knew that Crankshaft was in there somewhere!




The results, so far . . . (with just over 67 hours machine time)