A new engine for fall---

[EddyCurr]

Another project I thoroughly enjoyed. Well done !

Ken R.

[George Bulliss]

Thanks for following.---Brian

Thank you Brian for taking the time to share. Another great thread.

[The Artful Bodger]

Very nice engine Brian!

Hmmm, it looks big enough to power assist a bicycle?

[brian Rupnow]

Artful Bodger.--Possibly.--It has only a 1" bore though. Now that I have built a successful prototype, I see many ways that the physical size of the engine could be reduced while still keeping the bore and stroke it currently has. This is simply a great engine for older guys like myself who like to take on machine shop projects but have old eyes. All of the parts are large enough to machine without a magnifying glass.---Brian

[brian Rupnow]

Judging by the number of downloads I have had for the plans of this engine, someone, somewhere , is going to build it. I am going ahead with a gas tank bracket and gas tank for it, so will post them as "supplementary drawings" to the main download package. The bracket is located right in the center of the engine block, and the underside of the bracket is 1" below the top of the block. This will place the top of the tank about 1/8" below the center of the carburetor.

[sasquatch]

Looks pretty darn nice Brian!! And yes, thanks again for posting all the interesting follow alongs!!

[brian Rupnow]

I spent all of yesterday fighting "gas tank wars". What should have been a very simple and straightforeward silver soldering job left me frustrated. All of the joints looked good, but when I put a rubber tube on the outlet spigot, then put the tank underwater and blew into the tube, I got a stream of bubbles coming out of the one end. I resoldered it twice, with the same result each time. Finally I set the whole tank up in the lathe and drilled/bored the leaking end completely away, made a new brass end insert and silver soldered it again before I went to bed. As of right now it doesn't leak, as per the "blow test" but I haven't filed away the excess silver solder either. I am waiting for my wife to get up before I start any power equipment in my shop, but I sincerely hope that when I get my last solder joint "cosmeticized" that I don't see any more bubbles!!

[brian Rupnow]

I used a piece of my bronze stockpile to carve out a gas tank mount. I set it up to have a 1 1/4" i.d. and chose a 6" long 1" pipe nipple which has an o.d. of 1 5/16" to make the tank from. The pipe is galvanized, but that doesn't matter, because when I turn the o.d. down to 1 1/4", the galvanized will be all machined away. I also picked up a brass 1/2" pipe nipple to become the gas tank filler spout. I could have bought the 6" long pipe nipple in brass, but it would have cost $21 as opposed to the $3 I paid for the galvanized steel one.

[brian Rupnow]

Here we are machining the o.d. of the pipe in my lathe, after cutting the threaded ends off. I don't like machining with something sticking out of the jaws that far, but the "thru the spindle" hole in my lathe is only 1 3/16" and the o.d. of the pipe was 1 5/16". So---Take light cuts and hold your breath a lot, being ready at all times to "Duck and cover". Once I got the o.d. turned to a finished diameter, I pulled out my seldom used steady rest and set it up to counterbore the ends of the pipe for brass end caps.
I used a piece of my bronze stockpile to carve out a gas tank mount. I set it up to have a 1 1/4" i.d. and chose a 6" long 1" pipe nipple which has an o.d. of 1 5/16" to make the tank from. The pipe is galvanized, but that doesn't matter, because when I turn the o.d. down to 1 1/4", the galvanized will be all machined away. I also picked up a brass 1/2" pipe nipple to become the gas tank filler spout. I could have bought the 6" long pipe nipple in brass, but it would have cost $21 as opposed to the $3 I paid for the galvanized steel one.

[brian Rupnow]

And finally, after an absolute bear of a time getting one of the soldered in ends to be leak-tight, we have a custom fitted gas tank.

[RichR]

Hi Brian
That engine looks fantastic. A couple of questions. Are you going to apply any kind of finish to the outside of the tank so it can't rust? How will the tank
be secured to the bracket so it can't slide out?

[brian Rupnow]

Rich--I use a bit of 2 cycle oil with my gasoline, and that tends to keep the outside of the tank rust free. Of course it doesn't rain much in my office where I display these finished engines. As for how the tank is attached to the bracket---you can use Loctite, or you can drill and tap a pair of #5-40 holes in the far side of the bracket, down near the bottom where they won't show for a pair of set screws to hold the tank in place.

[Duffy]

Brian, did you perhaps overlook the fact that galvanized pipe is zinc-coated both inside AND out?
An update on lubricating needle bearings. The other day my neighbor dropped off his chainsaw for me to sharpen Since it was not only dull but jammed up tight, I had to completely dismantle it to remove the safety brake. This saw, by the way, is about 20 years old and a Mastercraft brand. The drive sprocket is mounted to a moulded plastic, (Delrin maybe?) internal gear, driven directly by the motor spur gear in a 56/11 ratio. Why they use a hunting tooth beats me, but there you are. OF significance to you Brian, is the fact that the sprocket runs on a pair of F64910 needle bearings and turns about three grand. There was absolutely NO evidence of ANY lubricant, and the bearings were just fine! These little devils, (about 0.390" ID,) have had a HARD life; I gave them a wipe of lithium grease for luck, reassembled and sharpened the saw and told my neighbor that when it got dull next time to toss it as the motor bearings were stiff.

[brian Rupnow]

Duffy--I knew the pipe was galvanized on the inside. why should that matter?---Brian

[Duffy]

Brian, I thought that you had not completely removed the inner coating, and a bit of zinc vapor would play havoc with a silver soldered joint.