Silver Bullet Back to Work Progress

[Mosey]

All kidding aside, I think it is important to point out that
I made the crank journals too small.

I made the bearings too large and tapered.

Both typical of my beginner work.

Steve Huck points out that the offset tail-stock leads to tapered reaming, thanks Steve.

Now, with aligned tail-stock, the reaming is within limits and the bearing just slides right onto the crank, with no excess clearance.

I think I've graduated to "Beginner 2" level. I hope to extend this to the rest of the engine. Stay tuned.

 

[Don1966]

Hey mosey I will be here with you, now you are starting to get you confidence back. On the right track here bud. I want to see progress here continue.

Don

 

[Mosey]

Thanks, Don, it is appreciated.
Progress: I am now about to fit the pistons. They are aluminum with Cast Iron rings into cast iron cylinder sleeves. The pistons are 0.7495" and the cylinders are presently 0.7480-.7490" diameter. So, I intend to polish the pistons on the lathe to about 0.7425"?? Sound OK? I will use fine emory paper and oil to reduce theer diameter. Is this the right approach?
The pistons have spigots attached to mount in the lathe. See below.

 

[stevehuckss396]

Hey Mosey!

If they are 6061 go about 1 to 1-1/2 (.0015) smaller than the bore. If they are 7075 you can go 3/4 to 1 thou under size.

.748 cylinder - .747 to .7465 piston (6061)
.749 cylinder - .748 to .7475 piston (6061)

That is what I would shoot for. My opinion only.

 

[Mosey]

Truthfully, I don't remember, but I think they are 7075. I'm going .001" under. I'm gaining on it.


OK, here is where I now am with the piston to cylinder fitting.

Remeasured both cylinders very carefully...Rear 0.75000"- 0.75065" Piston 0.74920" difference 0.00080"-0.00145"
Front o.75000" -0.75020" 0.74890" 0.00110"-0.00130"

I think it's time to stop.
Next. I'm going to fit the pistons to the wrist pin/small ends, hoping to space the pistons to center on the cylinders

 

[Don1966]

Mosey I do not know much about IC engines as I have not built any yet. Hoping to learn here as you do yours.i do know Bob Shores used cast iron on a lot of his projects and fitted the piston to the liner. And I do know aluminum expands a lot more then cast iron, but I have no clue other then what I have been reading. Steve's suggustions I would follow because he has built these. Bob Shores leaves it to the builder as to what to use, but tells you how to do it with CI. Are we going to see more progress soon?

Regards Don

 

[Mosey]

Don,
Nice to know that you are interested and watching.

Yes, progress is coming. I have fitted the pistons and as soon as I receive the wrist pin blanks from EBay, I will put the entire block together and post some pics and comments.
I know I am slow, but that's the best I can do, with work getting hot again, and other stuff. Patience is it's own reward?
Then, it's on to fitting the valves, cutting the seats, and that stuff. The show goes on.
I did follow Bob Shores directions pretty faithfully so far, and will continue that way. CI liners, rings, and alum pistons.

I have had a look at the radiator also, and made a jig for soldering the fins. It was great to finally have a serious setup to cut the numerous parallel slots using the horizontal head on my little F1 mill. Pictures will come later.

 

[steamer]

I'm watching Mosey.... ;D

Dave

 

[vcutajar]

Hi Mosey

Just to let you know that I am also following your work on the Silver Bullet. Keep it up and no hurry. I good piece at a time.

Vince

 

[ozzie46]

I'm here also. Keep sloggin. One piece at a time. ;D ;D ;D

Ron

 

[Mosey]

Thanks guys, I'll do my best.
I feel almost like Britney Spears, with everyone watching.

 

[Mosey]

Today I had a look at the valves. I have about a dozen of them nearly finished. The stems are 0.112" in diameter, and the plans call for reaming the guides to 0.109" . I assume that I must match them by lapping down the stems or enlarging the guides to a close fit. How about 0.0005" for clearance? Steve?
By the way, my ultra-cheapo imported plug gages measure about 0.00020" under. Gotta watch out for that.
Hopefully here is a picture of them unfinished. I have to grind them to length, removing that little tit on the head, and cut them to length. some are rejects. I made little keepers and will be using store bought e-clips. Gotta turn those slots just right.

 

[Don1966]

Great job Mosey now were are on the right track. Keep up the great work bud you are making good progress. It always help to get a little extra practice just keep thinking ahead like you are doing. This engine will be running before you know it.

Don

 

[Mosey]

I will be traveling for a couple of weeks in June, so I hope to get a lot done before then, otherwise, the shop will be quiet. Let's see how much can happen.

 

[idahoan]

Hi Mosey

It sounds like you have a minus set of plug gages; the minus sets are usually lapped 2 tenths under. All the ones I have here at home are minus sets; at work we have minus sets, plus sets and right on the money sets. ;D

For general inspection I prefer the minus pins.

Keep up the great work on the Silver Bullet!

Dave

 

[Mosey]

Reporting in:
Today we got the 0.156" reamer blank to make wrist pins.
I reamed the small-end bearings with my .156" reamer, but it is undersize...about 0.154". What to do?
I put the reamer in the drill press and ran it inside the bearing hole, moving it around by hand as if I was filing the hole. Gently. Voila, I got it to exactly 0.156".
Then I put the wrist pin in the drill press and ran it with a little lube inside the hole and it came out perfectly fit to the pin. Wow, that was nice.
Now I just have to cut the pins to length and mill a little flat on them to accept the tiny bolt inside the piston skirt to hold the pins in place.
The pistons swing back and forth on the pins smoothly with no play. Perfect!

 

[steamer]

Hi Mosey,

Looks like a chucking reamer...it has about a .002" taper on the nose....that's probably what you ran into.

Dave

 

[Mosey]

You had me worried...so I measured the reamer and it is 0.15580-0.15600 all the way up the straight flutes. But it seems to cut smaller than that???!! I have to work it in the hole to get full size. Strange.
Anyhow, I am now done with the pistons, wrist pins, rods.
I will put it all together.

 

[Mosey]

Rome wasn't built in a day.

 

[tvoght]

Keep up the good work!