Silver Bullet Back to Work Progress

[Mosey]

Finally got back to work in the shop on the Silver Bullet after the real job quieted down.
Here is some real progress for me. I finished/remade the water pump, and it has turned out very pleasing for me. This really has the juices flowing again. A senior guy on this forum generously helped me out with the gear stock.
The pump entailed boring out for the twin pump gears, shafts, and the crossflow water piping. I am especially proud that the backing plate with it's 2 mounting tabs was milled in 1 piece going around the tabs and the circular plate without manually blending the tangents into 1 smooth curve.


I also made a new fan hub, and will make a new, better fan.
So, it ain't much for most of you, but for this guy, it is wonderful, as I am learning and getting better.

 

[Mosey]

Well, I'm getting closer to completion, and I need some advise on how to fit everything for the final clearances and assembly. Should I assemble the entire engine, put oil in it, and then turn it under an auxiliary power source such as an electric drill to run in all of the bearing points? Or, should I attempt to fit each pair of piecee separately and get each pair of surfaces run in to each other? Help here!

 

[ProdEng]

I would be inclined to build a bit at a time to find any problems without backtracking. Once I rebuilt a four cylinder car engine, dropped it into the car only to find it would not go around :'( In my defense, I was only 16 at the time but the lesson was learned.

Jan

 

[gbritnell]

Hi Mosey,
When you build something to close tolerances it doesn't hurt to run it in a little. I would rather do that then build 'loose' and have everything rattling around after a little bit of running time. Normally if fit as I go but I still spin it over once assembled.
gbritnell

 

[Mosey]

Here is where things stand.
I have measured the crank journals and the bearing blanks, and they are as follows:

Rear crank journal 0.37360" inside bearing 0.37520" delta 0.0016" maybe too much slop?

Front crank journal 0.37340" inside bearing 0.37640 delta 0.0030" too much slop
So, I guess I should make bearings that are closer fitting to the crank, right? How about 0.0005"? then run them in on the lathe between centers?
what do the sages think?

I should mention that the bearings are oil-impregnated bronze on steel crank.

 

[steamer]

Thats looking great Mosey! :bow:

F1 working for ya?

Dave

 

[Don1966]

Heh! Mosey I am a newbie and I think that is great work. I am going to follow you on this. I have the plans for the Silver Angel another Bob Shores project.

Don

 

[Mosey]

I'm the Rip Van Winkle of modeling. It may take me more years to finish! But, I'm trying.
Dave, Yes, the F1 is great for the really little stuff.

 

[Mosey]

Peckin away at it.
Here are some new progress shots.
I took a day to align my lathe so that I can make better, tighter main bearings. That is done. Strange feeling of well being having your lathe turning straight.
Well, I got some brackets from Mrs. Shores, and milled them up to be better looking. Next I drilled and bolted them to accept the pan.Now it looks like an engine.
Later still, I will mill them so that they are I beam like in cross section.
Oh, and that is the new fan you see.

Forgot to mention, that I milled out the broken 2-56 tap in the head for one of the carburetor mounting bolts. Had to mill with a large carbide mill and fill the hole with an alum plug, the re-tap. Came out OK. You'll never see it.

 

[Don1966]

Aww! You see Mosey I knew you had it in you. A little push goes a long way. Just keep plugging at it and before you know it it will be finished. As they say "one perfect piece at a time". Can,t You just see it sitting on your mantle.

Don

 

[Mosey]

Thanks for the encouragement. I'll keep going.

 

[lazylathe]

Mosey,

If you paint it just right it will look like a rocket sled!!! :big:

Looks awesome so far!!
Way beyond anything a lot of us can do!
Keep it up, we now expect regular updates! ;D

Andrew

 

[Mosey]

I don't care for the sled look, so you can expect something to change as I go along. I am now concentrating on getting it done, and refinements will come later if at all.
Work just exploded again, so I hope I can keep up the momentum.
I am going to build the engine from the bottom up, making all parts fit properly, starting with the crank, bearings, etc.
i'll try to show better pics, and do them as I go on the ma :bow:chine.

 

[ProdEng]

Mosey,

I noticed that there was no comment on your bearing clearances so I got out my 1971 Machinery's Handbook and had a look. I would imagine main bearings would need a medium running fit RC5 giving a clearance range of .001 to .0025. Both of your bearings would probably work fine with your larger clearance only slightly bigger than this spec. Hope that helps.

Jan

 

[Mosey]

That does help, but my ego says try to do better. As the bearings are simple turning operations, why not give it a go. I've already told production to go ahead with this order, hah!
Big thanks.

 

[Don1966]

You sound like me, when I set set something in my mind it will not go away till I do it. Awww! But it is all good, this is how we get things done. Sometimes we get those €£¥+%# moment, and you blow it off, and get after it again. This is what I call regrouping. Take a deep breath and breathe easy.

Don

 

[Mosey]

Armed with my new confidence from lurking on this site, and a little help from Steve Huck, I made new crank bearings today. Took about 20 minutes. Crank diameter 0.37370", Drilled 0.365", then reamed nominally 3/8" slow and lots of lube, inside new bearing 0.37390". It slid on. Nice.
Pictures to follow.

 

[stevehuckss396]

I suspect the bearings being over sized was caused by the tail stock being mis-aligned. As the reamer goes in it pushes to the side and opens the hole up bigger but also will taper the hole. If your hole is actually .3739 it would seem your reamer is getting old.

 

[Mosey]

Yup, so am I.
Actually, I aligned the tailstock first, then tested the reamer in a spare part, and then reamed the new bearing.

 

[Mosey]

Pictures worth a thousand words.