Horizontal freelance IC engine

[Chaffe]

Hi, after joining this site it has given me some motivation to re-start my IC project! so i have dug out the parts previously made and am now going to carry on making the engine. The cylinder is finished and is of air cooled design, the crankshaft im using is from a stihl chainsaw (cheating i know, but it will do for a first engine) the engine frame is also made. The flywheels are fabricated items and are mostly complete, I am in two minds weather or not to make it hit and miss or throttle governed yet, hit and miss does appeal to me though. Here is a few pics of what i have done soo far, please feel free to comment. James

 

[hitandmissman]

Looks like a good start. Will be looking forward to your progress.

 

[Fingers]

Welcome to the forum ,
I like the way you made your spoked flywheels any pictures of how you made them,
Regards jamie

 

[Dave G]

Hi James, I cast my vote for hit-miss. Very nice start by the way, Dave

 

[Chaffe]

Welcome to the forum ,
I like the way you made your spoked flywheels any pictures of how you made them,
Regards jamie

Thanks, i have no pictures im affraid. I started with a central boss and drilled and tapped it in six positions, @ 60 degrees around its circumference. Then i machined the two outer rings from 13%cr (was lying around at my work) and drilled six equi spaced holes in these rings, a good fit for the bolts. I then cut off most of the threads on my 6 bolts and screwed them in until they bottomed out on the threads, cut off the excess and turned the od again in the lathe. (one flywheel has yet to have the OD skimmed).

 

[Chaffe]

Looks like a good start. Will be looking forward to your progress.

Thank you, i too am looking forward to posting my work

 

[Chaffe]

Hi James, I cast my vote for hit-miss. Very nice start by the way, Dave

Thanks, im pretty sure hit and miss also

 

[compspecial]

Hi Chaffe, I'm just wondering if the engine frame is of built-up welded construction. If so, you have made a wonderful job of making the welds invisible lovely work!
Stew

 

[Chaffe]

Hi Chaffe, I'm just wondering if the engine frame is of built-up welded construction. If so, you have made a wonderful job of making the welds invisible lovely work!
Stew

It is yes, and to be entirly honest im not that happy with the way it is just now. I feel i need to add more weld and smooth it off more. The problem being is that if i put too much heat into it at once then the two side peices will "warp" and no longer be square, this evenings mission is to get the frame looking more satisfactory and prehaps turn the main crank bearings. I have a nice peice of 1" cast iron bar that i think will do fine for these bearings, i dont have any brass this size or that would of been my first choice. Thanks James.

 

[Chaffe]

Well ive just come in from the garage after turning the flywheels, machining some brass mains bearings. Here is a few pictures to show some progress. I think the piston and con-rod will be next on the agenda, then prehaps start on the head.

 

[Chaffe]

The crank rotates a good six times freely when flicked by hand, im going "hit and miss" for sure, but i still need to decide if im going OHV or seperate bolt on vavle block with long rocker, i think the second option would be a simpler solution.

 

[NickG]

Nice work, looking very good. If you are going for hit & miss you want to get the friction as low as possible. Could you put it on ball bearings? Unfortunately spinning over 6 times is probably not free enough, you'll find with ball bearings it will spin over for more than 10 seconds which is what you should aim for if going the hit & miss route.

 

[Jack B]

Hi James: Nice Project: Good luck Jack

 

[Chaffe]

Nice work, looking very good. If you are going for hit & miss you want to get the friction as low as possible. Could you put it on ball bearings? Unfortunately spinning over 6 times is probably not free enough, you'll find with ball bearings it will spin over for more than 10 seconds which is what you should aim for if going the hit & miss route.

thanks, im sure it will spin for longer at a higher speed BBs are a good idea thou if i get problems

 

[Chaffe]

Hi James: Nice Project: Good luck Jack

thank you, i need to get cracking with some more work on it!

 

[Chaffe]

Been brainstorming a bit, think ive decided on a gearless hit and miss design, similar to an olds design with my own twist. Here is a sketch i did to show the rough principal.

 

[compspecial]

A brilliant idea Chaffe, no need for timing gears or an exhaust cam! Why couldn't I think of something like that?

 

[Chaffe]

It worked on the olds gearless engine, so i think i can make it work. The critical areas are clearance, and stroke. As the indexer has to index whilst away from the pushrod, eccentric timing is important too.