startin' on a Webster

[dgjessing]

So I'm thinking maybe I'm ready to do my first IC engine, and the Webster seems like a good place to start. Kinda apprehensive to start a build thread on it, as I don't intend to hurry or anything... but what the heck

Since I had a suitable hunk of cast iron on hand (from a boat anchor) I have begun with the cylinder. First I turned down the 1" dia head end, holding it somewhat precariously in the outside jaws of my 7x lathe:

That done, I was able to swap to the inside jaws (much better) and start on the cooling fins:

Fins done, turned the other end down to 1.125" dia:

Progressively larger drill bits ending with a 13/16" Silver & Deming:

Ready to bore to the final size (another day):

 

[rudydubya]

Following with interest Dave. Glad you decided to share a build thread. Thm:

Regards,
Rudy

 

[Blogwitch]

Dave,

You're off to a good start, and if you do hit a problem later, there have been a few built on here already, so no shortage of builds to look at and of course the builders themselves will be only too willing to help out.

This is one I will be following.


John

 

[vcutajar]

Hi Dave

I will be following you also in your journey.

as I don't intend to hurry or anything...

Take your time, after all it's a hobby

Vince

 

[dgjessing]

Thanks, you guys

Continuing with the cylinder, bored it out to about .872":

I then turned a piece of 1" aluminum down to about .870", slathered WD40 and valve grinding compound on it, and proceeded to hone the bore. Wrapped part of it in electrical tape and gripped it with pliers, as it would really "catch" with each fresh application of grinding compound:

I think it's good enough; I've got a slight taper, from .8735" at the bottom to .874" at the top. This according to my cheap-o Harbor freight bore gauges and digital caliper - who know what it really is, eh?

There is some discoloration in spots; I've talked myself into believing this is due to impurities in the boat anchor quality cast iron. Am I kidding myself, or does that sound plausible?

Need to hit the salvage yard and resupply on aluminum plate.

What's the consensus on iron piston rings versus high-temp "O" rings? Is there going to be anybody at the NAMES show next weekend selling either of those?

 

[Brian Rupnow]

I used a Viton o-ring on mine and it worked great.

 

[Harold Lee]

Dave - When you start discussing CI rings VS O rings you are getting into a religious argument with strong feelings on both sides. I agree with Brian. I have built four IC engines and helped others get theirs running and I have always used O rings. They are cheap, seal very well and will last for a long time. When they wear out it takes about 3 minutes and cost about .03 cents to replace.

Just my opinion....
Harold

 

[Brian Rupnow]

I wouldn't go so far as to imply that o-rings were "better" than cast iron. Its just that there is a certain ammount of elemental magic involved with making cast iron rings that I didn't posess when I built my Webster.

 

[Longboy]

I'll be watching Dave. Webster was my 1st I/C too! Dave.

 

[Bob Parker]

Dave
The Webster was my first IC engine. I never did get it running. I used cast iron rings, which produced very low compression. My next IC engine Lil Brother which also had cast iron rings and low compression. I finally installed an O Ring in the lil Brother which produced great compression and a good runner. Your post may inspire me to go back to the webster and try an O ring.
Presently working on a Olds 1/2 scale.
Maybe someday my machining will improve to the level that will allow use of Cast iron rings.
Bob

 

[rhitee93]

I hope to start on my first IC engine project soon, and will be following along here with keen interest.

Thanks for doing this log!

 

[cfellows]

Nice project! You're starting a great love/hate relationship. When it finally works, and it will, you'll love it. Before you get it running, you may have a few moments here and there that will give you second thoughts. Stay with it and the rewards will be worth it.

Chuck

 

[dgjessing]

Well since the cylinder would be lonely without a piston (no innuendo whatsoever intended!) I've done that today. Turned it to size and used a 3/8" end mill to bore down to 3/4" deep:

Then bored the recess in the skirt 1/4" x 3/4":

Didn't take any pictures of fitting the O ring, but here it is. I've used a common nitrile ring for fitting; sure hope a vitron one exactly the same size is available!:

Drilled and reamed the wrist pin hole:

...then with a piece of 3/16" music wire inserted, used that to eyeball alignment for milling the rest of the rod recess:

Indicated the center and milled the rest of the slot:

Done!

Well, except for the oil hole. Probably tomorrow.

 

[crankshafter]

Dave.
The webster was the first IC engine that I buildt, and get me hooked. And it's still my favorite-build
BTW you are doing some nice work. keep on posting pic's

Best regards
CS

 

[dgjessing]

After a successful trip to the scrap yard this afternoon I've started on the frame:

This mystery alloy plate is .333" thick instead of the .313 called for on the plans, so I'll have to adjust here and there.

On to the head! ;D

 

[rudydubya]

... I've used a common nitrile ring for fitting; sure hope a vitron one exactly the same size is available!...

Dave, I've used both kinds of O rings in my Upshur, both supposedly the same 3/4" size. But the Viton rings were a few thousandths smaller than the Nitriles I used when I was making the engine. I wanted to use the Viton rings but didn't want to make a new piston, so I just wrapped a couple of turns of thin aluminum foil strip in the ring groove to shim the Viton rings and get an equivalent seal. Yes, I know, the coward's way out, but it works fine and I haven't had to change rings since.

Regards,
Rudy

 

[dgjessing]

Nothing to show tonight... I've got the head squared up & ready for more work. I've made it out of a piece of 1" thick stuff instead of 3/4", thinking that I'll cut some cooling fins in the extra quarter inch.

The neighborhood Autozone is supposed to have the '69 Charger points for me tomorrow. I'm thinking junk yard for a coil.

Does anyone know the overall outside diameter of the gears specified? I'm going to be making my own... I can figure it out myself, but it would be cool to have a rough idea.

I saw a perfect piece of stainless steel for the flywheel today at the scrap yard (yes, went there two days in a row) but then I thought "do I really want the aggravation of trying to machine a stainless flywheel?", and passed it up. I'll hold out for CRS or cast iron.

What do We think of using propane instead of liquid fuel? It seems kinda appealing... I've got a nice valve that fits on top of a propane torch cylinder, and I've also got an acetylene regulator from an old torch. Seems like I could control the flow pretty well with all that stuff, but other than that I have no idea what I'm talking about.

 

[Maryak]

OD = (N+2)/P

Where N = No of Teeth and P = Diametral Pitch.

e.g. OD = (40+2)/32 = 1.3125" and OD = (20+2)/32 = 0.6875" or OD = (40+2)/40 = 1.050" and OD = (20+2)/40 = 0.550"

Hope this helps

Best Regards
Bob

 

[Blogwitch]

Dave,

You can download programs that will work it out very easily for you, just enter number of teeth and whatever MOD or DP number and it will give you a readout of everything you ever needed to know about your gears.

http://www.homemodelenginemachinist.com/index.php?topic=17916.0

For running these small engines on gas, you really need to have a home made small pressure regulator and also a demand valve that automatically turns the gas flow off if the engine stops.

Plans for these are available free of charge if you have a good search about on the net, but if you have no joy, and still want to go down that route, email me and I will sort out some diagrams or plans for you.
The demand valves usually require you to buy some bits to build them, I got a dozen sets of needle valves and diaphragms off eblay from the US for about 70 bucks, incl. postage.


John

 

[gmac]

Dave;

There are plans for a Propane Demand Regulator on the FAME website. http://www.floridaame.org/

Check under "Tips and Links" then "Assorted Model Engine Building Tips", check

TIP 3 by Richard Williams 11/12/2002
Propane Demand Regulator

I've never used propane but assume this is what you're looking for. Hope it helps.

Cheers Garry