Home-made 2 cylinder 4 stroke engine. Part 4 - Rings and gudgeon pins

I machined a bunch of rings from cast iron and heat treated them. The internet states the ring needs to be stretched open by 15% and heated to red hot.
I also turned a pair of
gudgeon pins from aluminium. I am not sure if this will last very long when and if this motor runs. But it still is fun to play.

[@wess3842]

The content you upload is great and I'm surprised that you don't more subscribers. The production quality and content is definitely on par with the bigger machine shop channels. I'm glad I found your channel

[@YooProjects]

Great job dear man 👍

[@peejay6855]

Please do not listen to the "experts" telling you that alloy piston pins are not going to work... They'll be fine. Its not like you're going to run this engine in a Formula 1 race car... You're doing this for fun and learning. Go for it have fun and do what you can the best you can. Wonderful work!

[@TheXSpitfire]

Thank you very much. I will be over the moon if it ends up just looking like a engine. I wish I knew all the things I have learned when I started, but I also understand how much more there is to learn. Humbling and so much respect for the gentlemen building bike engines in the early 1900s (and while wearing a hat and tie).

[@Voidingo]

You're a legend

[@nocommentstillnothing5970]

Love that there's still a passion for making your own pistons I wanna do a higher compression piston of my own or have one custom made any recommendations ?

[@jakobv8]

I just discovered your videos and love every minute of it. Keep em coming:-) Greetings from Sweden

[@manishpoudel4540]

wau cant wait to see this engine complete

[@Dymitr_Nawrocki]

As always, great job. I'm curious how long aluminum gudgeon pin will last. Can't wait for the casting part, also in first couple seconds of video you wrote Rings, gudgeon pin & conrods but there is no conrods in video, and the most important thing, you forgot to put Hedgehog in video!

[@TheXSpitfire]

Ahh. I wanted to put the conrods in, but the video became way to long. Ellie was not in a mood for video, and it's better for my health to respect that. The aluminum should last long enough to get the motor to a running state. Thank you for watching and noticing the mistakes.

[@nishithpshetty]

can u give me the plans of this engine plsssss.

[@dans5595]

where did you get your design/plans? your own?

[@Dymitr_Nawrocki]

It's already a month since last upload, when can we expect new video? Did you already cast engine block and cylinder head? Sorry that I'm a bit impatient but it's very interesting build.

[@TheXSpitfire]

Hey Dymitr. I am sorry about the delay. I am also itching to get going again. I have had a few personal setbacks BUT I am planning on finishing a kilm to cast the block this week. I am collecting the element wire tomorrow and will be filming the weekend. Thank you for the interest.

[@mirandadonovan1272]

Do you think a cast iron pipe of appropriate dimensions could be used to avoid having to remove so much material by boring?

[@ravanabhiblog8536]

bro why you heat the rings ???

[@ktd_project2975]

how can I buy from you? I need piston size 63mm pin 14mm for 2strok

[@oh8wingman]

I fail to understand how your rings are going to work. You machined the blank to .05mm (.002") undersized from the bore. Then you cut the ring gap with a grinding disc about .1016mm (.0625"). Finally, you heat them to expand them. Here's the problem. The rule of thumb says that you need .1016mm (.004") per inch of diameter for a ring gap when installed. Since you are already undersized with your ring diameter to start with and then you take an additional 1.5875mm (.0625") off when you cut them you are already way beyond .1016mm (.004") per inch of bore. Heating them up changes nothing since you do not have sufficient circumference on the ring to fit the bore tight enough to get a good seal. Do the math: Previously you machined your pistons to 33.98mm (1.3377") for a bore of 34mm (1.3385"). A bore of 34mm (1.3385") is 106.76mm (4.2031") circumference and would require a ring with a circumference of 106.6165mm (4.1975") assuming a gap of .1016mm (.004") per inch of bore. Your ring blank started at 33.98mm (1.3378") for a circumference of 106.6972mm (4.2007") which you then foreshortened by an additional .1016mm (.0625") when you cut it for a total ring circumference of 103.5956mm (4.1967"). Your required ring circumference is 106.6165mm (4.1975") minus your actual ring circumference of 103.5956mm (4.1967") leaves you with a ring gap of 3.0209mm (.1189") instead of the .136mm (.0054") used as a rule of thumb for a 34mm (1.3385") bore. In other words your rings are way too small to get a reasonable seal because the end gap is too large. And yes, I do have practical experience. I worked for an engine rebuilder at one time and literally rebuilt hundreds of car engines.

[@gallupcustomknives2293]

Excellent! Only one question, your gudgeon pin, you used aluminum alloy? Why not steel? Most production engine gudgeon pins are hollow hardened steel. You chose aluminum for it’s lighter weight? Building this for extremely high rpm?

[@TheXSpitfire]

My little mini lathe, and more my skill, has not been tested on steel....yet alone hardened steel. I chose the aluminum because its easy to machine and will be quick to redo a part if need be. I understand that when (if) the engine runs, that the pins will suffer and wear quickly, but hopefully by that time I will be able to make some from steel.

[@gallupcustomknives2293]

You cut cast iron, and more importantly, heat treat it... some annealed or half hard steel should be no problem for you. What hp is your spindle motor? Even 1/3hp motor is adequate for cutting annealed high carbon steel with small depth passes, like .1mm, and even in the annealed state, it is more than double the wear resistance of aluminum... try it. You may surprise yourself.

[@TheXSpitfire]

@@gallupcustomknives2293 Its about 0.5hp...350w. I am getting ready to build a kilm for casting the block and head. There is a lot to learn still, so by the time the engine is assembled, I might have steel pins.

[@gallupcustomknives2293]

If they are a specific size, say 10 or 12 mm, you could likely get some hardened steel dowel pins, then fabricate a toolpost grinding method to just cut your snap ring grooves in the pins... just bouncing ideas around. Would be terrible to put all this time and effort into building it if it has zero longevity.

[@thelongranger55]

Do you have interest in making custom parts for my 2 stroke bicycle engine kits ?

[@TheXSpitfire]

I would love to, but unfortunately this is just a hobby outside work. If had my way in life this would be what I would do for a living.

[@ahaikepo7984]

only made, try use it?

[@lukebranco3685]

Man that’s awesome! What material did you use for the gudgeon pin?

[@TheXSpitfire]

I used aluminum for the pin, but will make it from something harder soon.

[@user-pq8pu7sr9b]

Все нормально, но нам не по карману.

[@ravanabhiblog8536]

can u make a piston for yamaha r15 v2.0 😍😍😍😍😍😍 can you send me a number pls