IC engines for beginners

[hacklordsniper]

After countless hours lost on the Jan Ridders Debbie which refused to work whatever i tried i scrapped the engine for parts and materials.

I'm guessing the main problem was a bad cylinder from the start. As my lathe is small i needed to use reverse jaws which hold the workpiece with much shorter grip and because of that there was quite too big taper in it.

Second problem is my short boring bars which had to be help on the last few centimeters to be long enough and the setup was not enough rigid.

I want to build an IC engine but feel to skip the Jan Ridders one for now and try an other engine ( just to avoid building same engine twice)

Any recommendations for more simple two stroke engines? Plans don't have to be free, but should be metric.

 

[Jasonb]

How about a glow ignition 2-stroke like the Firefly, this is my build thread

Drawings are on the web and in metric, just spend some time lapping the parts to fit each other and it should run well

 

[Speedy]

I had absolutely no machining experience prior to this build.
also wanted to make a IC engine as steam doesnt do it for me.

jerry james has these plans published for free on his webpage and a detailed build log on steps.

I was able to do everything but the threading, the engine itself is fairly straight forward if you have a friend that knows how to thread on a lathe it will be a walk in the park.

http://www.homemodelenginemachinist.com/f31/speedys-inline-twin-18799/

 

[Gedeon Spilett]

As my lathe is small i needed to use reverse jaws which hold the workpiece with much shorter grip and because of that there was quite too big taper in it.

why things will be different with another engine ?
you may use a steady to fix this problem, and use a larger and longer boring bar, I had the same problem last year, with a cast iron cylinder and my engine is running now

 

[AussieJimG]

It is a pity that you scrapped your Debbie. John Somers and I both had lots of difficulty getting ours to run. From memory, mine took 6 weeks to build and 5 to get running. The problem turned out to be lack of compression. Once the problem was diagnosed by one of my neighbours, I re-designed the piston and my engine and John's both ran. You can see mine here: [ame]http://www.youtube.com/watch?v=o-zo52flDbI[/ame]. John's is here: http://start-model-engineering.co.uk/category/jan-ridders-simple-two-stroke/

Jan is a superb craftsman and I think his models have much less friction than mine and therefore they run on less power. I needed to increase the compression ratio to get enough power to overcome the other deficiencies in the construction.

If you would like the new piston design, send me a PM. I think I still have it somewhere.

Jim

 

[gus]

Hi AussieJim.

Please advise plan source. Nice engine you there running.
Right now leaking my wounds incurred by the failure of the Firefly refusing to run. About to start all over again. Believed I made some very fatal mistakes. The vital fits is a must.
Right now DIY a new Quick Release Tool Post .Upgrading from existing QRTP.

SOS SOS SOS
Need help.Forgotten how to post hew threads. Got some new threads to post.

 

[AussieJimG]

Hi Gus,

Here is the link to Jan Ridders' page on the two stroke engine. If it is in Dutch, just click on the link for English. Jan will send you the plans if you email a request to him; there is a link on this page for that as well.

I changed a few things as you can see. The major one was to use a CDI from S/S Engineering instead of Jan's arrangement. They are expensive but at least I know they are not the problem if the engine doesn't run. I also changed the transfer port arrangements because the angles on the original gave me lots of problems; I just don't have the skills. Other cosmetic changes for the same reason.

And lastly, as I mentioned, I re-designed the piston to give different (better?) port timing and higher compression. I might have overdone the compression bit because it jumps around a lot. But it runs and I am not going to meddle with it.

Jim

Link: http://heetgasmodelbouw.ridders.nu/Webpaginas/pagina_tweetakt_motor/tweetakt_frameset.htm

 

[Tin Falcon]

After countless hours lost on the Jan Ridders Debbie which refused to work whatever i tried i scrapped the engine for parts and materials.

I can honestly say I never scraped or canabalized an engine. I have had a few set on a shelf for years before I went back to finish them . And I have had to make the same part 3 or maybe four times before I got one good enough.
In this hobby you sometimes need to make practice pieces. sometimes you get lucky and the first part comes out ok. FYI "Luck: does improve with practice.

Part of this hobby is learning perseverance. and patience.
It can take years to become an overnight success!!

I like the **** Upshur designs myself by mot in metric.
Tin

 

[gus]

Hi Tin

Thanks for the good advice on perseverance and patience.
The Firefly IC Engine is now shelved as a Mantle Piece. Plan to build this engine all over again. I made some fatal errors on the vital fits though on the whole I have stayed with the planned dimensions.
Slide valve engines I now build runs on first start with usual valve timing adjustment.Prior to this previous engines did not run well at low speed.Now taking my sweet time to build a Quick Change Tool Post.

 

[gus]

Hi Gus,

Here is the link to Jan Ridders' page on the two stroke engine. If it is in Dutch, just click on the link for English. Jan will send you the plans if you email a request to him; there is a link on this page for that as well.

I changed a few things as you can see. The major one was to use a CDI from S/S Engineering instead of Jan's arrangement. They are expensive but at least I know they are not the problem if the engine doesn't run. I also changed the transfer port arrangements because the angles on the original gave me lots of problems; I just don't have the skills. Other cosmetic changes for the same reason.

And lastly, as I mentioned, I re-designed the piston to give different (better?) port timing and higher compression. I might have overdone the compression bit because it jumps around a lot. But it runs and I am not going to meddle with it.

Jim

Link: http://heetgasmodelbouw.ridders.nu/Webpaginas/pagina_tweetakt_motor/tweetakt_frameset.htm

Thanks Jim. I have a small Japanese Sakai Lathe and a Sakai Vertical Mill.
Please advise if these will do the job??

 

[AussieJimG]

I am not familiar with your lathe and mill Gus but you can get an idea of the size of this engine from the cylinder which is 50mm outside diameter.

Sorry folks, we seem to have hijacked the thread. Please excuse.

Jim

 

[lensman57]

Hi Gus,

These are very high quality lathes and mills and highly accurate. Many of the present day import mills and lathes are based on their design including the expensive proxxons. Rudy kouhoupt had one these ( ML360 I think ), depending on which model you have building small engines should not be a problem.

Regards,

A.G

 

[AussieJimG]

Hi Gus, I am not familiar with the Sakai lathe and mill so I can't advise you. The cylinder on the engine is 50mm diameter so you might be able to get some idea of the size from that and to make a judgement.

Jim

 

[Tin Falcon]

http://www.lathes.co.uk/toyo/index.html

Gus a good friend of mine from the Cabin fever shows builds fine engines on his sherline tools. if the engine is too big for his lathe he just scales them down. small but beautiful little engines.
tin

 

[gus]

Hi Tin Falcon,
Just measured up balcony workshop.Its 48" W x 15'L . Very limited in space. I am worrried about the floor load.So heavier lathe and mill is off the list. New house is off the list. Present walkup flat bought 1977 for S$70 is now S$1M.
However I am looking forward to put in the next size up Japanese Sakai Vertical Mill plus replacing the Sakai Lathe with a new lathe same Sakai.Old 8 year old lathe goes FOC to a friend who is a far better turner than Gus.He is professional turner.

 

[hacklordsniper]

I can honestly say I never scraped or canabalized an engine. I have had a few set on a shelf for years before I went back to finish them . And I have had to make the same part 3 or maybe four times before I got one good enough.
In this hobby you sometimes need to make practice pieces. sometimes you get lucky and the first part comes out ok. FYI "Luck: does improve with practice.

Part of this hobby is learning perseverance. and patience.
It can take years to become an overnight success!!

I like the **** Upshur designs myself by mot in metric.
Tin

Some metal was reused at other projects and since most of it was scrap at beginning there was not much loss. Im just informing myself now about possible spring/summer project for a new/next engine which could/could not work. Problem is my machine shop is in middle of house and cant I play with IC engines inside because of petrol smell. Outside is -13, and 30-50 cm of snow.

I just decided to build projects and parts i can/need now so i can improve my skills when i will try to build an IC engine again.

Also every day i understand i bought too small lathe again