Straight 8

[cobra428]

Looking Good Steve
Man you moving along on it!

Tony

 

[Tad Wicks]

Boy, between you and gbritnell I think that I will go and throw rocks at my junk ;D, no not really. Looking at the Bugatti emblem, I would probably spell it wrong : Great job, very impressive, I look forward to more. Tad

 

[stevehuckss396]

Boy, between you and gbritnell I think that I will go and throw rocks at my junk ;D, no not really. Looking at the Bugatti emblem, I would probably spell it wrong : Great job, very impressive, I look forward to more. Tad

I'm not exactly on the same plain as G but i do want to be him when i grow up.

Thanks Tad!

 

[arnoldb]

Awesome progress Steve :bow:

Kind regards, Arnold

 

[kendo]

Hi Steve
I've been watching this post for a while now, it just keeps getting
better. really nice piece of CNC work on them plates, they look
fantastic. Looking forward to the rest of the build.

Ken

 

[NickG]

I can bet there's a bunch of people saying they wish it was them posting this thread.

Too right, amazing stuff Steve :bow:

 

[stevehuckss396]

Thanks!

Life has been crazy so nothing has been happening out in the garage. Hope to get back at it next week.

 

[stevehuckss396]

Ironman!!

You are correct about the slow down. I have been reading alot about piston rings. I decided to get a front loader kiln to use as a heat treating oven. It was ordered over the weekend so I wont see it for a while.

I have made the rings and the fixture to George Trimble's specs. The article is layed out over 3 issues of Strictly I.C. numbers 7-9. Covers a ton of theory and all the math to design the fixture. The fixture changes with the size of the ring.

There is some newer theory about the temperatures used to stress relieve the rings. Lower temps are used but have to be controlled between 475 - 525C for as much as an hour. I'm going to go that route because the lower temps almost eliminate the need for anti scalant.

Also I took on a club build of a 5 cylinder air engine. 10 members made a few pieces each and this saturday we will assemble and debug. Hope to have that running at NAMES.

Also tried to modify the carb on the peewee so it would lean out a little at idle. Screwed that up and now I might have to make a new carb.

Also need to make some kind of air manifold for NAMES so i can run a few air things. It never ends. After NAMES things should ramp back up again. Maybe sooner.

 

[stevehuckss396]

The oven made it here friday so the rings are progressing. I split all the rings with a pair of wire nippers. They work very well and give a nice clean crack. Then I loaded up the rings on the fixture.

There are 2 methods that I have read about. One is to heat the rings to a glow and let cool. This method requires that an anti-scalant be used to protect the rings from forming scale on the surface. The second method is to heat the rings to just below 1000 degrees for about 30-60 minutes. The lower temp will keep scale at bay but requires an oven with temp control that most people don't have. It is said to be less destructive to the rings to heat to a lower temp.

The first batch I used some brown paper and aluminum foil as the antiscalant as a test. The second batch went right in with no protection. Other than a slight color difference, I could not tell a difference in surface finish. I cooked the rings for 1 hour at 950 degrees.

I have some work to do still. I need to make a small tool to hold the rings and polish the sides and then do some gap setting. If these work well, The peewee may end up with a new set also.

 

[kcmillin]

You make 17 seperate pieces. Some are just a disc and some have a crank throw and a race in the center with a square milled on the end. The disks have a square milled in the center. The piece with the crrank throw is pressed into the disk using the square to index the throws at 90 degrees from each other. Oh yah, dont forget to slip the bearings on as you go. Ask me how i know! :-[

How do you mill square holes in the crank disks?

I am verry impressed with this engine. I love the fact you designed it yourself. I too design my own engines, well as much as my knowledge will allow anyway. Nothing like this so far. I beleive you just set the bar a little higher, or lower if your into limbo.

How did you determin the correct position for the cam lobes? Is there a rule of thumb that one can follow when desiging a cam?

thanks

Kel

 

[steamer]

Steve!

Awesome looking build man! love what your doing! I really need to get an oven...but I need a bigger shop first...

Dave

 

[stevehuckss396]

How do you mill square holes in the crank disks?

I used a very small endmill to keep the radius in the corners to a minimum and then relieve the corners of the square part going into the square hole.

How did you determin the correct position for the cam lobes? Is there a rule of thumb that one can follow when desiging a cam?

I make my cams based on real cams. My exhaust lobe always leads the intake lobe by 110 degrees. I typically use 280 degrees duration. I make the flank radius about 2 times the base circle. Then I go to the Model Engine News site and run my numbers thru the camcalc program to double check my numbers.

 

[stevehuckss396]

Steve!

Awesome looking build man! love what your doing! I really need to get an oven...but I need a bigger shop first...

Dave

Just do what I did and buy a tiny one. The hot box is only a 6 inch cube. Fits almost anywhere.

Thanks Steamer!

 

[steamer]

its called the "Hot Box" ?

Who makes it?

Dave

 

[stevehuckss396]

its called the "Hot Box" ?

Who makes it?

It's called a pottery kiln and it's made by paragon. They have a unit specifically for treating metal and you can inject gas into the oven but they are 3 times the money.

http://www.clay-king.com/paragon_q11a.html

 

[kcmillin]

Can a kiln like that be used to melt aluminum in a steel crucible?

would rather buy that than make one.

kel

 

[shred]

Can a kiln like that be used to melt aluminum in a steel crucible?

would rather buy that than make one.

kel

Yes it can, but the consequences of a crucible failure (which seems to happen much more often than I'd like, from what I read) are not pretty at all.

 

[stevehuckss396]

Can a kiln like that be used to melt aluminum in a steel crucible?

would rather buy that than make one.

kel

I would think it can. It can go to as high as 2350F

 

[cfellows]

Yes it can, but the consequences of a crucible failure (which seems to happen much more often than I'd like, from what I read) are not pretty at all.

I would think the likelihood of a crucible failure in an electric kiln would be pretty remote. The Nichrome or Kanthal heating elements, which are usually rated up to around 2300 deg F would fail first. Steel melts at something over 2700 deg F.

Having said that, I would use steel that is at least 1/8" thick.

Chuck

 

[kcmillin]

Thanks Guys. Ive been throwing around the idea of making a trash can forge for some time. But I like this oven idea much better, and I can do it inside.

thanks

kel