Horizontal Air Cooled Engine

[Brian Rupnow]

When you can take a heat treated ring and bend it like this, it's a pretty good indicator that you have used the wrong cast iron to make the ring. It will also bend like that before heat treat. It will work as rings---I have two engines operating quite fine using rings made from this material. Today I am going to use the two remaining cast iron rings that were made in that batch to see if they will run my engine. I am also going to take steps to buy the correct cast iron for ring making. My local supplier doesn't know squat about the cast iron he is selling.

 

[Gordon]

I am interested in what you find on the correct cast iron. Trimble says centrifugally cast moly iron but nobody seems to knows what that is. Others seem to use whatever junk they can find and everything works just fine. I am not against spending a little more money if it gets good results but I don't know what to ask for or where to get it.

 

[werowance]

i wonder if the the guy at otto engine works that supplies the rings for the webster would be willing to share what CI he uses on his rings?

 

[Brian Rupnow]

I have spent the morning googling, and the top choice for iron to make rings from is Grade 17 Meehanite. I have been searching for a source for it in Ontario, but haven't found one yet.---Will keep you posted on what I find.---Brian

 

[aka9950202]

My Webster rings we made from the rear brake cylinder of a mini. I know that they would be good quality metal.

Should I do it again I would make a mandrel to match the inside bore, super glue the brake cylinder them turn the outside round. Last time I used the 4 jaw chuck and it was a pita!

Cheers,

Andrew in Melbourne

 

[Brian Rupnow]

A little help here please--from North America--I have determined that the material I am using for piston rings is the wrong kind. I buy it from a local steel supply shop and they don't really seem to know much about the cast iron which they are selling me. I am sure they are selling me ductile iron, because when piston rings are made from it, they bend easily. Not break!!! Even after heat treat they bend. I have just about worn out the internet this morning searching for correct ring material. My research tells me that cast iron material for rings should be A--Pearlitic grey cast iron with a low modulus of elasticity. B--centrifugally cast, not ductile C--Durabar cast grey iron D ---fine grained grey cast iron E--pulltruded .
If you live in the U.K. you should use class 17 Mehanite (I don't live in the U.K.)
I need a foot of this material in 1" diameter (well actually it's a bit more than 1" because it is cast) but I am having a terrible time figuring where to buy this stuff in Canada. It's heavy, so shipping charges will be high. If I buy from USA and can get a foot of the proper material I can probably eat the shipping cost. What I really need to know is where the heck I can buy this material (preferably in Canada but USA will do).---and what exactly is it that it's called when I go to order it?---Brian Rupnow

 

[L98fiero]

A little help here please--from North America--I have determined that the material I am using for piston rings is the wrong kind. I buy it from a local steel supply shop and they don't really seem to know much about the cast iron which they are selling me. I am sure they are selling me ductile iron, because when piston rings are made from it, they bend easily. Not break!!! Even after heat treat they bend. I have just about worn out the internet this morning searching for correct ring material. My research tells me that cast iron material for rings should be A--Pearlitic grey cast iron with a low modulus of elasticity. B--centrifugally cast, not ductile C--Durabar cast grey iron D ---fine grained grey cast iron E--pulltruded .
If you live in the U.K. you should use class 17 Mehanite (I don't live in the U.K.)
I need a foot of this material in 1" diameter (well actually it's a bit more than 1" because it is cast) but I am having a terrible time figuring where to buy this stuff in Canada. It's heavy, so shipping charges will be high. If I buy from USA and can get a foot of the proper material I can probably eat the shipping cost. What I really need to know is where the heck I can buy this material (preferably in Canada but USA will do).---and what exactly is it that it's called when I go to order it?---Brian Rupnow

Call Terra Nova Steel & Iron, 3595 Hawkestone Rd, Mississauga, ON L5C 2V1, (905) 273-3872, they are distributors for Durabar

 

[Brian Rupnow]

I talked to Bernie at https://hobbymetalkits.com/ and this man seems to know what he's talking about. I ordered a foot of the 1" diameter cast iron which meets all of the specs for making rings. The material itself is only about $14, USA but the shipping from Wisconsin is going to be horrendous. This will last me for the rest of my life making rings. I'm sure that there are companies in Ontario that sell exactly the same material, but I haven't been able to find them or contact them.

 

[CFLBob]

FWIW, I've had good luck with Hobby Metal Kits in overall quality, fast shipping and all that.

The only issue I've had is they tend to have a smaller selection than either Online or Speedy Metals. If Bernie told me he had an alloy that was good, I'd trust him.

 

[dnalot]

Hi

I use cast iron from McMaster Carr and it makes very nice rings. their smallest rod is 1.25 inches and cost is about $17 for 12".

Mark T

 

[L98fiero]

Hi

I use cast iron from McMaster Carr and it makes very nice rings. their smallest rod is 1.25 inches and cost is about $17 for 12".

Mark T

McMaster-Carr doesn't sell to individuals in Canada, with few exceptions, you have to be an educational institute of some sort or a business.

 

[dnalot]

McMaster-Carr doesn't sell to individuals in Canada, with few exceptions, you have to be an educational institute of some sort or a business.

That sucks. I refuse to buy from a business that refuses to sell to me.

Mark T

 

[dsage]

Brian:
Read back a bit (post 247)
L98fiero gave you a place in Mississauga. That's where I get it and all the model makers in the Toronto and Hamilton clubs go there too. You could drive there.
They usually deal with BIG quantities but I have walked in the door and picked a piece from their cutoffs. If you walk in I suggest you should take what you can get (size/length) within reason. Rather than bother them with cutting. They don't usually deal with small quantities but they have been accommodating. If you order it ahead you should have no problems with any order. Order it as a cash sale. They usually deal with their account customers. But I've had no problems.

From above:
Call Terra Nova Steel & Iron, 3595 Hawkestone Rd, Mississauga, ON L5C 2V1, (905) 273-3872, they are distributors for Durabar

 

[Brian Rupnow]

dsage--Sometimes living in Barrie is like living on the dark side of the moon. Mississauga is an hour away from me and I have never heard of Terra Nova Steel and Iron and I'm buying something that I'm not 100% sure of what to ask for. The man I bought my cast iron from specializes in metal for model engines, and when I spoke to him he knew exactly what I wanted. I may die of a heart attack when I see what the shipping charges are from Wisconsin, but at least I will know that I ambuying the correct material.---Brian

 

[Gordon]

Is the problem with shipping costs to Canada due to actual shipping costs or duty coming into Canada. If it is duty could someone in the US receive it and reship it? I am not familiar with the relationship between USPS and Canada Post.

 

[Brian Rupnow]

Today is a "machining free" day. Hooray!!! My little machine shop doesn't have a spare inch of room anywhere in it. I wanted to have some dedicated cabinets for small bits and bobs that were important, and didn't have room for anymore cabinets inside my shop. I didn't want them too far away either. A quick survey of the wall space I had available outside of the machine shop showed that I had a 12" wide area of free wall space between my shop door and the wall adjacent to it. A quick search thru the Princess Auto website showed almost exactly what I wanted 11" wide for $14. I bought two of them and mounted them in the wall space, and spent a good part of this morning moving things and making labels so I would know what was in the cabinets. As much as I like machining things, it's quite nice to have a rather laid back day where I do something else that needed doing.

 

[Brian Rupnow]

Gordon--I have to spend $1.27 to buy one USA dollar. Shipping from USA to Canada costs anywhere from $15 to $45 depending on the weight and size of the thing being shipped. If the border authorities get involved and decide that my package may be full of illicit drugs, they open it and charge me $50 for border inspection. Then I have to pay %13 sales tax for being a good Canadian boy. Canada is a great place to live, but it isn't cheap.----Brian

 

[Iampappabear]

Resource Metals in Oakville supply Class 40 cast iron, they will happily sell to the general public and are and easy group of guys to deal with.

Home

I have been very please with the cast iron purchased there but no idea how it would perform as piston rings.

 

[Brian Rupnow]

And now---I have a strange story to tell (but it has a happy ending). Couple of days ago I had the engine setting on my side desk, chugging away happily, and I was congratulating myself on what a clever fellow I was to build an engine like that. And then----it quit!!!
Well Poop!!--Must be out of gas. Opened my fancy blue gas tank, and it had lots of fuel. Okay, if it isn't fuel. it has to be spark. I pulled the sparkplug out and laid it on the cylinder head and cranked the engine. Lots of spark!! Well sir--What do I do now? The automotive gasoline in the tank had been changed out for Coleman fuel, because Coleman fuel doesn't stink when it's being burned. Maybe the engine was seizing up, but I've never really had that happen. I grabbed the flywheel and gave it a couple of spins, and it turned freely, so determined that the engine hadn't seized. Maybe the set screws in my ignition cam had slipped and the engine had "jumped time". Checked those screws out and they were tight. Maybe the set screws in one of my timing gears had slipped and the valve timing had gone screwball. Checked those set screws and they were still tight. Maybe the Viton piston ring had failed and I had lost compression--but no, engine still has terrific compression when turned over by hand. Maybe something wrong with the carburetor--but no, those carbs don't have any small moving parts that can fail or vibrate out of place. How strange!! My engine won't run, and I can't diagnose what is wrong. Had some serious thoughts about making another head with a vertical sparkplug in it (A 1/4-32 sparkplug would fit beside the valve cages)--I laid it out on my 3D program and it would work, but Damn, there's a lot of work in making a cylinder head. I looked at my files from ten or eleven years ago when I built my own sparkplug for the Kerzel engine, but I really didn't want to do that. Went to bed, disgusted with small engines in general. Today I thought, "If the engine ran okay (which it did) and the engine then stopped without any clanks or bangs or obvious signs of distress (which it did), then what can possibly have changed? I pulled the sparkplug out and looked at it under my lighted magnifier, and seen that the spark gap was only about .005". Enough to give a bright spark when laying out on the cylinder head but not enough to light the charge of fuel under compression. Fetched out my trusty jacknife and opened the gap to about .025" and reinstalled the plug. Engine started right up and ran like a race horse. Relief, relief!!! I have no idea what closed the spark gap up while in the engine. Maybe a piece of dirt from when I was trying the piston with the cast iron rings. Maybe it was the bad engine fairy.--I don't know, but man, I'm glad I got it sorted out without having to remake anything.

 

[Brian Rupnow]

Lampapabear--thank you. I will give them a call.---Brian