Opposed twin Onan engine in half scale

[ignator]

More work on the Onan opposed twin half scale engine. I have reached the point where I can start on the cylinder sleeves but need to be sure I can fit a friends steam engine pistons and rings into the available cast iron bar and still have enough for my two sleeves. Made up a tool to get the cylinder directly under the mill head. Picture 1 & 2 measuring tool, accuracy questionable, 3 upsiddown parting a steam engine piston, 4 turning off the rings with a tungsten carbide saw tooth.

I know the tool you need;
https://www.ebay.com.au/itm/Coaxial...m1c46cb977f:g:uvAAAOSwRNpdUzQi&frcectupt=trueBut $93AU does not grow on trees (and there's probably a VAT, that is not shown on my computer screen).
Is making a cylindrical disk that is maybe .01mm smaller then your bore, with a flange to prevent it dropping down in the bore hole, with a small drill hole through the center, the intent to located the center of this cast iron sleeve material source, then use a pointed edge finder to locate under your mill spindle center a method you've thought of to get real close? (sorry for the runon sentence).

 

[teeleevs]

A couple of videos, Making a steam engine piston using an upsiddown parting tool. Making piston rings using a carbide saw tooth.
Today I made two cylinder sleeves for the Onan, 3 photos

 

[teeleevs]

Today I stripped the Onan opposed twin half scale down, final assembly of the crankshaft all trued up with conrods and pistons, Locktite was used as the final belt and braces.

 

[teeleevs]

Then was I in for a shock!!! Impossible to fit the crankshaft assembly into the housing with the pistons attached, no matter which way I tried. I finally resorted to cutting a piece out, firstly I drilled and threaded M4 x
2 holes then sawed down the threaded holes, fitted the crankshaft through, then fitted the piece back in and Liktited M4 grub screws to hold it in its original place, this patch finishes up inside the timing case, so no fear of an oil leak. I turned the register at the bottom of the sleeves 1.5mm off centre to the bore so they could be turned until the pistons run free. I will cut the air fins after I know where the bolts go and after fitting the valves etc.
Thanks for watching, Ted from down under

 

[teeleevs]

Making piston rings using a carbide saw tooth.
Don't know what's going on but I managed to
Upload one video here
Ted

https://m.youtube.com/watch?v=qfyHxjln7WE

 

[teeleevs]

https://youtube.com/playlist?list=PLvhASOpnmtAXqUMrh6gHJr4OyIhBSPKL4
Ok got it Parting off a steam engine piston using an upsiddown parting tool
With my 19th century lathe
Ted

 

[teeleevs]

Maybe this link will work

 

[mnay]

I worked for an Onan distributor many years ago. Most people don't know but they were a division of Studebaker.
Mike

 

[teeleevs]

I worked for an Onan distributor many years ago. Most people don't know but they were a division of Studebaker.
Mike

Yes Mike, David Onan began building the opposed twin towards the end of WW2, he passed away 1958, the company was sold in 1960, Studebaker tried to change the name but Onan was so well known that people wanted to buy Onan. The name now belongs to Cummins, although the engine is no longer built, Cummins have guaranteed the supply of spare parts for as long as there is demand. My first involvement was with an Onan powered Lincoln welder in the Queensland Australia Main Roads Dept workshop in Central Queensland in 1963 and in 1974 I owned one myself. Very smooth running engine.

 

[teeleevs]

The last few days, finally getting the cylinders in place, heads drilled and threaded. Photo 1 setup for drilling the valve positions, 2 came out exactly in line with the camshaft tunnel, looking good 4 and 5 beginning to look like an engine, 6 close-up of cylinder one.
Ted

 

[teeleevs]

Yes Mike, David Onan began building the opposed twin towards the end of WW2, he passed away 1958, the company was sold in 1960, Studebaker tried to change the name but Onan was so well known that people wanted to buy Onan. The name now belongs to Cummins, although the engine is no longer built, Cummins have guaranteed the supply of spare parts for as long as there is demand. My first involvement was with an Onan powered Lincoln welder in the Queensland Australia Main Roads Dept workshop in Central Queensland in 1963 and in 1974 I owned one myself. Very smooth running engine.

Actually I stand corrected, Cummins have stopped support of all existing Onan engines.

 

[teeleevs]

Another day on the Onan opposed twin half scale, got the other side done and started cutting air fins with a blade made from a tungsten carbide saw blade, two photos.

 

[teeleevs]

Latest update on the Onan opposed twin half scale, cutting the air fins, photo 1,2 and 3, 4 trial assembly 5 the heads and cam followers. I have opted to leave the fins as cast, polished and lacquered in order to preserve maximum heat transfer.
Thanks for watching Ted from down under

 

[teeleevs]

Just another day in the shop, photo 1, these are destined to become engine valves, 2 too small and too tough for normal latheing, cutting with an angle grinder, 3 I showed one to my ships engineer friend, his reaction, "We used to sit around it playing cards on top of it, " 4 this shot shows the dipstick.
Thanks
Ted from down under

 

[ignator]

That's a clever use of construction screws for valves. They are pretty hard steel. Looks like your technique of using a cutoff wheel did a nice machining finish. Looks like your next task is to make valve seat inserts. A press fit. That's where my full size Onan had failure with the exhaust seat coming loose.

 

[teeleevs]

Sorry didn't take photos today but I have made up the seat in a long tube with a step, the tube will have a bushing bronz insert then I can cut the seat and drill the guide in the one setting, JB Weld it in the hole then bore the port. Will show photos when more advanced, searched through 5 boxes of old springs and found 2 pairs suitable.
Ted

 

[ignator]

Sorry didn't take photos today but I have made up the seat in a long tube with a step, the tube will have a bushing bronz insert then I can cut the seat and drill the guide in the one setting, JB Weld it in the hole then bore the port. Will show photos when more advanced, searched through 5 boxes of old springs and found 2 pairs suitable.
Ted

JB Weld, I didn't know that same epoxy was available there. I used that to fix the valve seat on my Onan, and I was surprised it took the heat so well. I used starter fluid (spray can with either, to clean the parts, it's my favorite cleaning solution for everything greasy, used it yesterday to clean ball bearings of old grease).

 

[teeleevs]

I thought starting fluid has a small oil content, I use Acetone for real serious cleaning. I learned that in my gem faceting hobby where even a fingerprintwas a no no, found that Ride on model trains are easier to see these days. JB weld I used to hold the gem on the stick, it's available at Jaycar stores and eBay sales in Oz, it will stand 600 degrees ie to the melting point of aluminium.
Ted

 

[ignator]

I like acetone as well, but my skin does not. If there is oil in that either, I've never seen it, my skin is always left oil free, and I don't have any reaction to it. I also use denatured alcohol for cleaning engine grease off the truck I'm restoring. I just seem to get reactions to the real good solvents, you know, the ones that eat through nitrile gloves. When I was young I would use gasoline, but it too causes skin reaction. And I don't like the smell afterward, as well it's so darn volatile vapor wise, and heavier then air, so the fire risk is too great.
When I powder coat parts for the truck, I bake them at 400 degrees to burn off any left over hydro carbons, that seems to be the trick to a good paint job.
The JB weld failed on a gasoline filler tube repair I did on my previous car, it is incompatible with the ethyl alcohol that is added to our fuel here (10-15%).

 

[teeleevs]

I like acetone as well, but my skin does not. If there is oil in that either, I've never seen it, my skin is always left oil free, and I don't have any reaction to it. I also use denatured alcohol for cleaning engine grease off the truck I'm restoring. I just seem to get reactions to the real good solvents, you know, the ones that eat through nitrile gloves. When I was young I would use gasoline, but it too causes skin reaction. And I don't like the smell afterward, as well it's so darn volatile vapor wise, and heavier then air, so the fire risk is too great.
When I powder coat parts for the truck, I bake them at 400 degrees to burn off any left over hydro carbons, that seems to be the trick to a good paint job.
The JB weld failed on a gasoline filler tube repair I did on my previous car, it is incompatible with the ethyl alcohol that is added to our fuel here (10-15%).

We have 10% alcohol here but we can still use 91 or 96 octane without alcohol, also alcohol is OK for cars used every day but things like Weed Wackers the alcohol soaks up moisture which reacts to the alloy carby and really fouls things up.