Mery 6-stroke kit.

[PhilL]

Looking great Jack!
"First one was piece of cake, the second one made me make a third" <--- I seriously laughed out loud at that!! But oh so true.

 

[Jack3M]

The skids are essentially done, will put some planking in some areas down the road.
Don't have to worry about it tipping over onto the flywheel side and fall off the bench anymore now.

After several days of research, conversation with Phil, and looking ahead to parts and fixin's that the explosion chambers need for completion the process was begun.

First they were cut apart and the boxes squared up. Then the mount face was brought to dimension which is from the center of the valve stem. The overall length is not critical and I chose 2" as an equal number.

The holes for mounting are not critical in my method, so marked out all around for them, and drilled them so as to use as guide for location of mount bolts on the cylinder. These were then glued to the cylinder with the shown locktite.

These were then marked with a punch when dry (can't think of right name of the set for doing this right now). Then the chambers were tapped off the cylinder and I found a new advantage. Originally the plan was to get the cylinder side all set and make the gasket and use that to locate the hole into the cylinder. The loctite made a great location mark and these were drilled out from the one side only.

So probably after the weekend the plan is gets involved. The cylinder will have to be removed to drill for the mounting studs. Quite a few things to disassemble and not loose parts LOL. Have a day folks

 

[Jack3M]

Maybe I should do the basic exhaust chambers too so it is only necessary to disassemble this on time for these processes. Will still need to remove the piston and do some creative removal of material from the solid chunk. Apparently one has to think about the fact there is a shaft on one side taking up volume, and not the other meaning that there is big difference in volume. Might need to get my engineer son to do the numbers for me.

 

[PhilL]

Looking fantastic Jack.

 

[Philipintexas]

When it comes to “balancing” compression in both cylinders, I fashioned a simple compression gauge and spun the wheel with a drill motor and aimed for equal readings from each end. I made extra long threads on the rod and could position the piston as needed.

I noticed you have a key to hook-up the flywheel and 1/2” shaft. My engine fired with some authority and given the mass of the 10” flywheel, quickly loosened the key. I ended up drilling & threading an Allen bolt into the junction, half in the shaft & half in the wheel. This holds well but makes re-assembly a little complicated as the wheel must be in the exact location to assemble.

 

[Jack3M]

Ah, so that is why you had the plugs for those holes. That is a way, but Gary says it has too much compression, so this will also help along with making the stroke as equal as possible for balance purposes. Kind of chilling a bit on this, the last fishing is as soon as the fish get here and will only be a few days, then to get the boat out of the slip and winterize before I get into something I don't want any distraction from. Am certainly itchin' to go on it, but that only increases the value down the road.

 

[PhilL]

Jack,
Read the newsletters. They speak about the compression. If I recall, you'll need to cut the piston nearly 1/2 the thickness to reduce the compression. DON'T rely on leaks as a reduction method.

PhilipinTexas,
You said your flywheel key came loose. Did you use a tapered key? A correctly fitted tapered key should stay.

 

[Jack3M]

Working slowly on explosion chambers. Made the tops from hard 1/8 brass. Did the glue on thing and drilled a pair of holes to tap and use as insurance against the cover getting loose and messing with alignment. All drilled and tapped to 2.5 mm. Then drilled the valve stem hole from the bottom, relocated from the top with a shaft to center. Drilled first the relief and then the press fit area for the valve guide. Took and reworked a drill bit to get the angle for the face that the valve seats against. Also the fuel inlet was drilled and tapped. Not certain on where I want to put the spark plugs yet so have not tapped the other hole as yet.
.

 

[Philipintexas]

They must have changed the castings, mine had very little sealing surface around the edges. Blew gaskets too easily. Yours has a much smaller chamber with lots of area around the periphery.

I tried several key configurations on mine before giving up and doing it a different way.. I really think the great mass of the wheel relative to the 1/2" shaft makes a key pretty hard to fit effectively..

 

[Jack3M]

Did either of you try loctite in addition to the key?

 

[Jack3M]

Valve guides should have been an easy one two. Instead it was a hellish 6 pair before I got a pair that I could use. Funny how some of the simple stuff can be so difficult. But they got done and reamed. That rod is just a piece of the stainless that will be used for the stem of the valve testing for smooth fit. Note the two extra holes that were off, fortunately could work around them.

 

[Jack3M]

Not dead here, just having issue with the guide, stem, and seal. ...

 

[Jack3M]

So this problem is due to the guides not being true to the seat face, but just the guide as without the guide in place the valve seals. There is .035" difference in plans from valve stem being less diameter by that over the reamed guide. I did not adhere to that, I have about .002". Got to make a tool that will align all this for reaming the guide.

 

[Jack3M]

No idea how many hours this took to sort out. Was totally unable to get the valves to seat with the guides in place. Seated just fine without them. Redid and same problem. Then the 'thinkin' on it began'. So if the guide is the issue, and there is spare room down in the cavity, this can be set up with a leather gasket between a screw down 'plate'. I am sure that makes no sense.

Essentially I made a threaded washer (and threaded the chamber) that squishes down on a leather packing to seal the valve stem from leaking gas in the closed valve situation. This was done by drilling a slightly oversized hole so the valve stem would not touch the 'guide', which is no longer a guide in essence. That was threaded and then cut off, 3/32 thick. Then there had to be a tool made to screw it into the chamber. Some pins were placed in a rod and corresponding holes in the 'washers'. Also had to make a tool to cut the round leather.

The leather was soaked in oil and sandwiched in. Then the stem hole was cleared out and the valves lapped. No leakage at all.

 

[Jack3M]

For those that have already built. .... The plans do not have any numbers for the wire size, spring length, or mandrel size for the valve springs. Any of you folks remember? Thanks

 

[Jack3M]

Just went and tried stuff. Settled on .020" music wire over a 1/8 mandrel. Made length to suit just closing valve. Minimal pressure at closed.

 

[PhilL]

Sorry Jack,
I zoned out for a bit and missed the last updates.
You're on the right track for the .02 wire. .015 is in my mind for some reason but you have the right idea, minimal pressure to open.

 

[Jack3M]

Thanks Phil.

Been making several small parts, washers, nuts, a shaft. Not much to photo or discuss, all simple one of type stuff. The next big step is the exhaust chambers and getting my head wrapped around the drawings is proving to be challenging.

 

[PhilL]

Like the explosion chambers, don't lose sleep over those slots. They're decoration at this point.

 

[Jack3M]

Hey folks. This first photo is the shaft the rocking levers attach to, with it's accoutrements. Drill rod.


Started on the exhaust chambers. Dang I don't want to have to buy an 11/16-32 tap and die for just these. I have a friend who has the same lathe as I do and knows how to thread, so I may ask him. But for now;

The chambers come as a pair that need cut apart

Here they are held together by a filament and came right apart.
Filed off the gross flashing on the parting line. Used the 4 jaw to hold the round(exhaust pipe) end. Indicated (on both) at the round part just beyond the round flange to within a couple thousandths which I was impress with due to rough casting. Head side was finished first and the 1/2 hole to .375 drilled. Filpped it around and did the pipe side, indicating on the same area, facing to correct total length and again drilling the 1/2 hole. These will later get angled holes one each above and below valve seat.