# Mery Explosive Engine



## oldengineguy (Oct 16, 2022)

This is a video of my Mery engine's first run. I started building this in March 2022. There is still MUCH to do to finish and tune this engine, but  a runner on first attempt is always a good thing! Colin


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## propclock (Oct 16, 2022)

Fantastic , I can relate, first time ? that is very impressive.


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## kuhncw (Oct 16, 2022)

Well done Colin.  A runner from first start is a great way to end a build. 

Chuck


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## oldengineguy (Oct 16, 2022)

In the cold hard light of the next day , I have found that the covers to the explosion chambers leak, the flywheel needs better securing to the crank, the inlet valve springs are too strong, cylinder oiler needs a redesign ,and on and on, but yes, a start on the first day of trying seems to erase the memory of previous engines that took forever to cough into life. Still much to do before I sign off on this one though.   Colin


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## Brian Rupnow (Oct 16, 2022)

Very nice.---Brian


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## GreenTwin (Oct 16, 2022)

I really like the looks of that engine.
Sort of a Corliss meets IC engine construction.
Awesome runner !

.


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## Richard Hed (Oct 16, 2022)

oldengineguy said:


> In the cold hard light of the next day , I have found that the covers to the explosion chambers leak, the flywheel needs better securing to the crank, the inlet valve springs are too strong, cylinder oiler needs a redesign ,and on and on, but yes, a start on the first day of trying seems to erase the memory of previous engines that took forever to cough into life. Still much to do before I sign off on this one though.   Colin


Even so, it sounds wonderful,not noisy and looks to run extremely well


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## karlw144 (Oct 17, 2022)

Way to go Colin! Your engine looks great. A few of your fixes and just slow that baby down! You’ll love that engine.


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## a41capt (Oct 17, 2022)

Beautiful build Colin!

John W


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## cl350rr (Oct 17, 2022)

Good looking and running engine


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## delalio (Oct 17, 2022)

That is a lovely looking and running engine! Great work.
Is it to your own design, or do you have plans / castings kit?

Do you have any details of the build? Pics/videos etc.

I'd love to get a hold of some plans if you have some available, or point to a vendor.

Well done again! Beautiful craftmanship!


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## ShopShoe (Oct 17, 2022)

That's an admirable piece of work. Congratulations.

Thank You for posting.

--ShopShoe


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## marvin hedberg (Oct 17, 2022)

delalio said:


> That is a lovely looking and running engine! Great work.
> Is it to your own design, or do you have plans / castings kit?
> 
> Do you have any details of the build? Pics/videos etc.
> ...











						Mery Engine Casting Set
					

The Mery Explosive Engine is a truly unique and beautiful replica of the double acting gas engine patented by Michael Mery in 1895. Envision a spark plug and combustion chamber on both sides of a single piston - similar to a double acting steam engine. The Mery is a 6 cycle engine, achieving...



					www.martinmodel.com


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## oldengineguy (Oct 17, 2022)

Marvin: this is a kit from Martin Models in Oregon I received it in the mail  in Feb 2022 and began the build  in March. The first things to do were to make a boring bar and table to fit my12x36 lathe in order to bore the main housing and cylinder. There are good drawings with this kit  but absolutely no "hand holding" directions on how to go about the build. You must figure out for yourself.  I just recently learned how to post pictures and although I did not make notes of of the build I did take a few pictures of set ups and procedures along the way. If there is interest I will post a couple of those pics and comment on what I'm doing . It may or may not be of help to someone who wants to make this unusual 6 stroke explosive engine.    Colin


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## aka9950202 (Oct 18, 2022)

Please share the pictures. 

Cheers, 

Andrew


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## oldengineguy (Oct 18, 2022)

There are 3 machined tabs on the frame that I assumed were made to parallel the bore, NEVER assume. All set ups were made with this as datum. The end result is that the bore "slopes" approx. .015 toward the crank end. This did not appear to be a major disaster at this time. Further work on the frame proved this wrong. Later set up to locate the main bearing  (there is a Joe Pie Video  explaining this, I don't know how to link)   resulted in there being very little material to thread for main bearing bolts. I put 4 extra 4-40 studs and nuts on each main cap to spread the load.


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## oldengineguy (Oct 19, 2022)

Picture 1041 shows the set up to locate the centre line of the crankshaft. I made a plywood fixture to hold the frame at 45 deg. to machine the bearing seats. Take time to set fixture accurately to all 3 axis. 54&56 show set up used to drill and bore for main bearings and camshaft. At this point the error in initial set up became really bothersome.  There is not a lot of extra "meat" in the boss for the camshaft. Drawing calls for 32P gears of 50 and150 teeth  and pitch circle of 3.125". Because the crank sits lower in the frame, this meant that the camshaft would be to far off centre to look right.  I chose to make the gears  32P 48&144 teeth ,still a 3-1 ratio but with centre to centre distance of 3.0" which fit the casting better. This "fix"  ended the compounding of errors related to the initial set-up. The engine looks and runs fine, unless someone counts the teeth or it sits next to another Mery, no one would ever know.
Oops, I told you. Can you keep a secret?


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## oldengineguy (Oct 22, 2022)

I prefer the look of crankshaft with counterweights rather than plain "blocks" as called out. Cut two discs of appropriate size then set up on rotary table to add features as desired.  Shafts are 1/2" TGP steel .#1064 shows spacer blocks to hold parts together for silver soldering. Once soldered and cleaned up, I drilled and pinned the main shafts to the webs. They are straight1/8 tool steel in reamed .126 holes pressed in with green Loctite. Cut out  centre of main shaft and mill flat.


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## oldengineguy (Oct 23, 2022)

Pics 72&73  show the crosshead and conrod. Must have forgotten to take pics of these while making,. The conrod is straight forward turning a taper between two square shoulders. The crosshead is nerve wracking! The bronze shoes on the cross head are each held in place with a single 4-40 stud and nut, only 3 threads engaged. Then the assembly is centered and held on the 1/4 " piston rod while turning the shoes to fit the 1 1/2" bore.  With every interrupted cut rotation I expected disaster, but all worked out O.K.  Fly wheel is set up on a faceplate but even with a12x36 lathe the compound had to be reversed to get the tool out far enough to machine the rim The finished flywheel on the frame mounted on the base spins the crank nicely pushing the crosshead back and forth.


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## oldengineguy (Oct 27, 2022)

Set up  to  machine the faces for the inlet (explosion) chambers to use as a datum to bore the cylinder barrel. There are protrusions inside the barrel to locate the liner so this is an interrupted cut taking many fine cut passes. 1097 shows turning the O.D. of the liner to be a shrink fit(.002) in the barrel .After shrinking the parts together a pressure test of the water jacket revealed 2 blow holes in the casting. As I had many hours invested in this part I chose to repair rather than replace. I did contact Martin Models, Gary wished me luck with the repair and commented that sometimes problems don't show up until later in manufacture. I followed the  direction of the holes and drilled/tapped for 6-32 brass screws Loctited in place. This fixed the problem. 1101 shows the barrel set up again to machine to length, I used a fly-cutter to do this.


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## oldengineguy (Nov 22, 2022)

1089 shows the cam gear.  Drawing calls for .281 dia. shaft with 1/16 key. I do not have a 1/16 broach so silver soldered a bushing to the shaft then turned to 1/2in. and machined for an 1/8 key  which I have a keyway broach for. Kit includes casting for eccentrics ,however  it was easier to make these from bar stock. 1091 & 1092 are machining the eccentric straps ready to bore and relieve for locating rib. 1093 is the set-up on face plate to bore the inside diameters of the straps. 1102 shows he set-up to drill the holes in the frame to mount the cylinder.  1103 is the drill guide with holes to locate cyl.-base and cyl.-head joints which are different bolt circles.1105 is the set-up in the lathe to machine the back face of the frame where the cylinder bolts on. This was "tense" machining with no room for error with the mount foot rotating so close to the tool. I put a bar on the ways between  the headstock and carriage as well as the clamp -on stop to ensure that tooling could not contact the foot.1107 shows final cosmetic matching of frame to cylinder diameters


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## oldengineguy (Nov 28, 2022)

1109 shows the exhaust rocker temporarily installed to measure the fitted length of the connecting link between the eccentric strap 1111 and rocker1112. I chose to make the connecting links with left and right hand threads to allow for easy adjustment. 1113 shows the partially finished explosion chambers. These are straight forward  mill and drill/tap operations. I chose to mount the chambers to the cylinder  with 4-40 studs and nuts rather than the 3-48 bolts called for  It looks and feels more substantial. 1115 shows the chambers with 6  3-48 holes for the cover as called out. After a very short initial run the gaskets burnt through at the centre holes which are very close to the inside of the chamber. The fix to this was to drill/tap2 extra holes between the end and centre holes ,closer to the outer edge and assemble with high- temp silicone and no gasket. I don't have pictures of this "repair" ,but have not had any problem with leaks ever since. I used the silicone in place of the gaskets between cyl. and chambers on both intake and exhaust with no leaks  1117 shows CM6 plugs fitted to temporary covers in order to get 'er going .There was still a long way to go from this point but I have had success with these plugs before and knew they would work when time came for start-up. These build notes are "after  the fact", the engine has been running since early Oct. but hopefully they are of some use.


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## karlw144 (Nov 28, 2022)

Colin, enjoying your pictures and explanations. Sure are a lot of different ways to get the job done. I’ve started my next project; 1/8 scale Meyers Ryder Ericsson. Think I’m in for a challenge!


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## oldengineguy (Dec 9, 2022)

Inlet and exhaust chambers are cast in pairs. I found it easier to separate the inlets but machined the exhaust together until they needed to be cut apart for finishing. Drawings call for 2 piece valves, cast head with pressed in O-1 stem. I chose to make valves from 303 stainless instead .Exhaust chambers call for threaded cast iron "plug" in the top to seal the chamber. I did not have a suitable tap and did not fancy internal single point threading, so made plugs of cold rolled steel to bolt into chamber instead 1134 and 1146  Valve stems are supposed to be drilled through and have pins installed as retainers. I have used "E" clips in machined grooves in these valves and many others  with no problems. Seems like an easier way to do the job.


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## oldengineguy (Dec 13, 2022)

Both of the inlet pipes  are screwed into the chambers so a method of attaching  the mixer block was needed. The block is 2 pieces of brass machined flat &  smooth clamped together then drill/reamed to match inlet pipes (5/16). 4  4-40  machine screws clamp the 2 pieces together sealing tightly on "O" rings in grooves on the pipes. The block is drilled/tapped to accept an adapter for the mixer


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## oldengineguy (Dec 14, 2022)

Drawings call for a Buzz coil operated by a complicated brass strip and advance/ retard lever arrangement triggered by 2 screws in the cam gear, or a Hall effect  CDI system. I didn't like either option so designed a "distributor" with points and coil/condenser. To drive this distributor  I machined the camshaft housing on the flywheel side  approx. 1/2 narrower to accept a drive gear. The driven gear has the same number of teeth (60) to give a 1-1 ratio. The dist. housing is bolted to the base under the back of the  main frame. A points mounting plate and points from an old Honda along with a shop made 2 lobe cam complete this assembly. Any points and method of mounting would work, I just had these parts available. A 70s era Ski-doo ignition coil and an unknown source condenser mounted inside the base completes the system. Again any suitable coil/condenser would work. 1148 shows the distributor with advance/ retard lever mounted on the base prior to the main frame installation. I drilled locating dowel holes in both parts after fitting and adjusting gear mesh so that future assembly would be easier. A nice fat blue spark to fire propane, works well!


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## Brian Rupnow (Dec 14, 2022)

Very nice work. The engine looks and runs super good. Congratulations.----Brian


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