Thumper--a new 1 3/8" bore i.c. engine

[Brian Rupnow]

Today seen the completion of the side plates and first assembly of the overall frame. Everything goes together and everything clears. I will now order my piston rings. I don't want to make the piston until I have the rings and I don't want to make the cylinder until I have the piston. While I wait for the rings I will make the next part which sets on top, where the bearing caps would usually go.

[Ye-Ole Steam Dude]

Hello Brian,

Looking really good....

Have a great day,
Thomas

[Johnmcc69]

 
 It's looking good Brian! Nice work & a neat design.

 John

[Brian Rupnow]

Thank you Thomas and John--The next part that sets where the bearing caps would normally go is going to make my old heart go Pitter-Patter!! It is going to be a cam box, which has the camshaft bearings, camshaft and cams in it. The bolts which thread into the rest of the frame on each side of the main bearings pass thru this in clearance holes. The "window" cut into the side allows me access to the cams to set them at the proper rotational aspect.

[Brian Rupnow]

Today I machined the cam box. It is finished except for the bores for the camshaft and bearings and the recess and clearance for the crankshaft bearings. I'm not sure if I can get #10 bolts that are long enough, but if I can't, then studs and nuts will work.

[zeeprogrammer]

I've been following your threads. A lot of progress in the few recent days I missed!

Looking forward to more.

[Brian Rupnow]

No machining today. Drove up north to see my mom. She will be 100 in August. She is still doing okay---Fading a bit, but then a century is one heck of a long time to live.---Brian

[Brian Rupnow]

I was able to buy #10-24 shcs x 3" long today, and shortened them to 2 3/8". They worked fine and had enough thread that I didn't need to extend the thread with my #10-24 die. I've had some other stuff going on today, so didn't get any real machining time in on my project. Tomorrow I will set everything up on my milling machine and drill/bore the clearance for the crankshaft and the recessed bore for the crankshaft bearings, as well as the bores for the camshaft and bearings.

[Brian Rupnow]

This morning was time to bore the cam box. I have learned thru experience, that this should be done with the cam box attached to the engine. First step was to attach the entire engine to an angle plate, set up square to the mill bed. The cam box was removed, and the bearing which sets in the sideplate recess was loctited to a piece of 1/2" shaft and held in the mill chuck. This allowed me to move the mill bed in both the x and y axis until the bearing was an exact fit into the recess cut for it. the DRO was set to "0" and the cam box was securely bolted in place. That allowed me to put in both the clearance hole for the crankshaft and the bore in the exact place it should be.  Then it was time to move the mill table the required amount to put in the clearance hole in the cam box for the camshaft and cam bearing. I will now flip the engine over and repeat for the far side holes. I had to use a boring head to prepare the recess for the crankshaft. I got lucky and had an endmill of the exact size I needed for the camshaft bearing recess.

[Brian Rupnow]

And here we are with all of the ball bearings and dummy shafts in place.

[Brian Rupnow]

I can't reach Dave Reed at Ringspacers.com. I have emailed him and tried to telephone him, but nada. I want to buy a set of two rings for this engine I'm building but I can't reach Dave, who I've dealt with before. Are there any other reputable dealers that sell 1 3/8" dia x 3/32" thick piston rings for a 4 cycle i.c. engine?---Brian

[Brian Rupnow]

Regardless of whether I go with 1 3/8" bore or have to change over to a metric semi equivalent 35 mm (in order to get rings), the gears won't change. I have the material on hand to make the small gear from mild steel, and the large gear from cast iron. I would rather make the large gear from brass, but it's gotten too spendy $$$ for my blood.

[Brian Rupnow]

I just sent an inquiery to Debolt about his rings. There is nowhere on his order form to say that you are Canadian, so I sent him an email.

[Johnmcc69]

It's looking good Brian!
  

 John

[gunna]

Is it just me or is anyone else getting Brian's pictures about 4 foot wide?
Ian.