Briggs & Stratton 6S - A Beginnig

[zeeprogrammer]

Beautiful. And like Dean said...great posts.

 

[b.lindsey]

Thanks Zee...and Dean too. Hope you are seeing the light at the end of that mulch tunnel zee, I'm anxious to see more of your little engine too...its looking great so far.

Bill

 

[arnoldb]

Great work Bill - this engine will be a little beauty! I like your way of cold-forming of the rings.

Regards, Arnold

 

[b.lindsey]

Thanks Arnold. Obvioiusly if this engine were going to be run for thousands of hours, this method might not be the best, but for model use and ease of making the rings, Doug swears by this method now. I guess if they ever do wear out, I'll just make some new ones.

I did forget to mention in the earlier posts...the oil ring still has to be drilled in 8 places as does the oil ring groove in the piston to allow oil to pass from the crankcase through the piston and oil ring to the cylinder wall.

Bill

 

[mu38&Bg#]

I like this method to make rings. Thanks for posting. I'm going to try it. Did you put a groove in the oil ring face? The project looks excellent.

 

[b.lindsey]

Greg, I did not...mainly due to concern over weakening the already thin ring prior to "stretching" it in order to get it over the piston and into the groove. Same reason as to not drilling the holes in advance. I plan on drilling the holes with the ring on the piston in a similar fixture to the one used for finishing the ring ID. I may try to come up with something else along that same line to put a shallow groove in it as well. That would definitely make the oil flow more evenly. Good observation though and if you have any suggestions and experiences along this line I am all ears . I am wondering just how effective the oil ring will be and whether that is typical for other model IC engines.

Bill

 

[b.lindsey]

Also along the lines of lubrication the little "finger" thingy which attaches to the bottom of the con rod to thrash the oil about on each revolution was made yesterday and is shown in the top two photos below. Actually the B & S service manual calls this a "dipper" which makes sense i suppose. The two socket head cap screws which have been used thus far will be replaced with hex cap screws as soon as i order them and make a thin brass "keeper" as in the prototype to supposedly keep them from loosening under opperating conditions. That should be a real trick to make out of some .009" brass shim stock. The last pic is a very rouched out block from which the main crankcase is to be fabricated.

 

[tel]

The whole thing is a remarkable piece of work Bill, I've delved into the innards of quite a few Briggs' in my time, and your parts appear to be indistinguishable.

 

[b.lindsey]

Thanks for the kind words Tel. Looks are one thing and have been one of my goals from the start...I just hope the darn thing will work and that looming question is still a ways out there. Way too much time to end up with a static model for sure!!

Bill

 

[Deanofid]

Static model?
Why would you think such a thing, Bill?
You're making it just like an engine, so, it will do just like and engine, 'cause it is one!
That's how it works.

I remember the first time I saw the dipper on a B&S engine. I couldn't figure what on earth it was for.
Was about 10 at the time. Dad explained it to me, and then put the engine back together...

This will run, Bill. The way you're going, you won't have any trouble with the mechanicals. Carb might
be hard to scale, but you'll get it!

Dean

 

[rake60]

Beautiful scale reproduction of the connecting rod Bill! :bow:

An NOS, "New Old Stock" connecting rod for that engine sells for
somewhere between $25 and $55 USD.

If you'll make them, I'll sell them!

I know it isn't about a profit for you and I have no interest in any
personal, monetary gains here.

I'm just pointing out........

Rick

 

[b.lindsey]

Thanks again Dean for the vote of confidence. I couldn't ever be satisfied until it does work. Mostly i have concerns since this is my first IC engine and I have no idea how forgiving the mechanicals can be as compared to the compressed air/stirling engines I am far more familiar with. Another concern is the greater forces acting on and in the components from a wear standpoint. Far different that a few psi of air pressure I would imagine.

The carb doesn't worry me much from a modeling standpoint. Whether the modeled version will actually work as well I don't know yet, but I don't know why it shouldn't as long as it will siphon from the tank.

Don't worry, I have no plans on giving up or giving in whatever it takes. After all, its just getting to the fun stage!!

Bill

 

[b.lindsey]

Rick, given the amount of time in that part (from bar stock) even $55 would be a losing proposition. Now if it could be done from a casting like the original,about 95% of the machining could be eliminated.

Too bad there isn't a NOS half scale con rod out there, I would have given a pretty penny for one of those :big:

Bill

 

[joe d]

Bill

Can't add anything to the carburetor discussion, as I know next to nothing about it... so I will address something I do know:

This project is outstanding! Still following happily along.

Thanks, Joe

 

[b.lindsey]

Joe, thanks so much for folowing along and for your kind comments.

Bill

 

[b.lindsey]

After a short haitus, have been able to spend a little time in the shop though its been miserably hot and humid. While drawing work continues on the main housing, I have done some minor layout work on the plate that fits on the flywheel side of the housing and to which the shroud (flywheel cover) will be attached. Unfortunately this proved to be a bit large for the Sherline and my 4" RT so the RT work will have to wait until tomorrow at work on the full size mill and 10" RT. Meanwhile there is a small aluminum cover that fits to this plate beneath the flywheel which covers the points and condenser in the full size engine. This was a nice little job for the Sherline lathe and was fairly straightforward, hence no machining photos. The photos below, show the layout of the plate, front and back views of the small inner cover with the original part, and how it will eventually fit into the scheme of things. I hope to pick the pace back up so for those following along, thanks for your patience.

 

[slick95]

Good to see ya back at it Bill...

I was thinking about your build yesterday and thought of pinging you but you beat me too it.

Jeff

 

[Deanofid]

Yes, it's good to see you got more shop time, Bill. The new parts look good, as always!

Dean

 

[b.lindsey]

Thanks Jeff and Dean. Shop time got curtailed this afternoon as we have had tickets for months for the Charlotte presentation of the musical "Wicked," and that was a most pleasant diversion. I'll be back at it tomorrow getting the rough outline of the plate cut out. Thanks for checking in!

Bill

 

[b.lindsey]

Just a couple of progress pictures on the cover plate. Its roughed out and hope to get the mounting holes and other cutouts done today. The top pic shows cutting the top arc where the top of the flywheel cover will fit near the head cover. The second pic is after cutting the bottom radius and pasting the template to the aluminum as a rough guide, hopefully so I don't do something dumb. ;D