Author Topic: Side Valve i.c. engine from Bar stock  (Read 58131 times)

Offline Brian Rupnow

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Re: Side Valve i.c. engine from Bar stock
« Reply #100 on: September 07, 2014, 06:12:56 PM »
This is going to be---well--tricky. There is no great science in the cylinder itself, other than having to hold my breath for minutes at a time while I plunge cut the 3/8" deep grooves with my .093" wide HSS parting off tool. The tricky bit will be in machining the three different levels of "flat" without breaking any fins in the process. I am told not to use cutting fluid when machining cast iron. Any good advice would be well appreciated before I get too deeply into this.---Brian

Offline Stilldrillin

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Re: Side Valve i.c. engine from Bar stock
« Reply #101 on: September 07, 2014, 06:13:24 PM »
That's a great pic, Brian!  :thumbup:

Tomorrow's the big day, for our Little One, to start, "big school".......   

David d
David.

Still drilling holes... Sometimes, in the right place!

Still modifying bits of metal... Occasionally, making an improvement!

Offline Brian Rupnow

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Re: Side Valve i.c. engine from Bar stock
« Reply #102 on: September 07, 2014, 08:34:15 PM »
As I understand it, grey pearlitic cast iron has a high graphite content, and as a consequence it is self lubricating. That is why it is popular for use in engine blocks and cylinder liners. Of course, this explains why you don't NEED coolant/lubrication when machining it, but it doesn't explain WHY you shouldn't use lubrication/coolant when machining it. I just googled it, and the Sandvic website confirmed what I thought about not needing lubricant, but it didn't say anything about not being supposed to use lubricant. On a deep plunge cut like the fins require, I would think that the use of lubricant would help flush out chips and keep the tool from grabbing and/or binding, but I don't know for sure.

Offline chipenter

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Re: Side Valve i.c. engine from Bar stock
« Reply #103 on: September 08, 2014, 02:47:34 AM »
Cutting cast iron prduces dust wich clumps up with coolant and just forms a paste , air will blow the swarf away and with a slow speed won't get to hot , or use a rear tool post .
Jeff

Offline philf

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Re: Side Valve i.c. engine from Bar stock
« Reply #104 on: September 08, 2014, 03:05:33 AM »
Brian,

Just a thought.

Have you considered using a slitting saw to machine the fins? You could machine the flats first and then set the cylinder up on a rotary table.

I am hoping that my grandson shows some interest in the workshop -  I've a long wait as he's only 21 months old!

Cheers.

Phil
Phil Fern
Location: Marple, Cheshire

Offline Brian Rupnow

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Re: Side Valve i.c. engine from Bar stock
« Reply #105 on: September 08, 2014, 07:17:17 AM »
Gentlemen--Thank you for your replies. I was looking at my engine collection this morning, and it seems that my Atkinson engine has .093 slots between the fins and the slots are 3/8" deep. I don't remember having any particular problems with that cylinder, and I machined it dry. I will machine this new cylinder dry and hope for the best. Philf--I did buy a .093" slitting saw, in case I ran into any problem with the cylinder machining, and because the part directly above the cylinder along with the cylinder head have a number of the same size slot, and they can not be turned. I couldn't imagine the time it would take to do these with a 3/32" endmill, so I have the slitting saw in reserve.---Brian

Offline Brian Rupnow

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Re: Side Valve i.c. engine from Bar stock
« Reply #106 on: September 09, 2014, 06:44:49 PM »
Made a mistake. Kissed a snake. How many cooling fins did I make??--Well okay, maybe you're not into skipping rhymes!!! However, if you are paying attention, you will see that I have one more cooling fin on there than the drawing calls for. To make it even worse, the top 3 cooling fins are skinny little devils, while the bottom 3 are full size. I have absolutely no excuse for it, other than encroaching old age and gross incompetence. By the time I noticed that the first cooling fin down from the top was too skinny, I had already advanced the tool .040" into the work, and there was no good way to hide it or cover it up. I'm still a bit baffled as to exactly what happened, but somewhere in there, the math let me down. At any rate, I have convinced myself that since this is a prototype, it really doesn't matter that much. The cylinder will still function just as well with one extra cooling fin. Everything seems to bolt together okay, although I did have to use a ball end hex wrench to tighten up the bolts holding the cylinder to the crankcase.---Probably would have had to do that even without the extra cooling fin. And for my next amazing stunt---I will be making the combustion chamber that mounts on top of the cylinder.---And, Oh yeah---I machined the cylinder dry, and there was absolutely no binding, galling, or "scare the crap out of me cut off tool breaking".


Offline Brian Rupnow

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Re: Side Valve i.c. engine from Bar stock
« Reply #107 on: September 09, 2014, 07:07:13 PM »
This is the part I will build next. I will probably mess with the cooling fin spacing a bit so it matches my miss-machined cylinder cooling fins.

Offline tekfab

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Re: Side Valve i.c. engine from Bar stock
« Reply #108 on: September 09, 2014, 08:31:35 PM »
Hi Brian, I'm too late getting here but if you have to do any similar fin cutting in cast iron we always used a compressed air jet to keep the cut clear and also cool the tool down always assuming you have access to a compressed air source.
Keep up the good work  !

Mike Young

Offline Brian Rupnow

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Re: Side Valve i.c. engine from Bar stock
« Reply #109 on: September 09, 2014, 08:58:22 PM »
Tekfab--Thanks for having a look and posting a comment. I do have compressed air in my shop, and as I said on one of the other forums I post on, it is a good solution but makes an awful mess of a small home shop. Another good solution is to rig a holder for the shop vac nozzle so it follows the cutting tool. Accomplishes the same thing but without the mess of cast iron dust blown all around the shop. Actually, I cut that cylinder dry with no compressed air or vacuum and didn't experience any problems.---Brian

Offline PekkaNF

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Re: Side Valve i.c. engine from Bar stock
« Reply #110 on: September 10, 2014, 05:20:01 AM »
Hi Brian,

did you first turn all fins round and then milled flat on them or other way round? I have some cat iron offcuts but ita allways machines beutiful, althoug pretty messy. I use shop vack pretty much all the time, specially if I am boring. I really don't like that mess on my chuck, backplate, spindle and all the way down to change gear.

Pekka

Offline Brian Rupnow

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Re: Side Valve i.c. engine from Bar stock
« Reply #111 on: September 10, 2014, 07:36:42 AM »
PeckaNF--I turned everything round first, then machined the flats. Experienced no trouble whatsoever. I machined it dry, no coolant. only trouble I encountered was the different sized fins, and that was my fault.---Brian

Offline Brian Rupnow

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Re: Side Valve i.c. engine from Bar stock
« Reply #112 on: September 10, 2014, 08:49:36 PM »
I don't post a lot of "in process" shots anymore, but tonight I thought I would put up a shot of the beginning of the aluminum combustion chamber. I have marked out the outer profile, bored the 1" through hole, and the 1.160" diameter counterbore. You can see the cylinder setting on the end of the work. When I bore holes to a critical fit, I do a lot of "try it and see if it fits yet" with the mating pieces. After a summer of engineering work avoidance, some of my customers are calling me up and asking to have their projects worked on "Right Now", and if I ignore these folks they find someone else and I never hear from them again. Between the engineering work and work fixing up the house I bought, I am sometimes hard pressed to find a bit of time to machine my own stuff.

Offline Manxmodder

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Re: Side Valve i.c. engine from Bar stock
« Reply #113 on: September 11, 2014, 07:33:40 AM »
Interesting project you're doing here Brian. I wondered what you plan to do for a spark ignition system,create something from scratch or use a flywheel magneto type from a petrol strimmer or chainsaw maybe?

Just a little thought on the error with machining the cylinder fins,if you machine a chamfer on the outer edges of the 3 thick fins at the bottom of the cylinder it would improve their proportional appearance to the thinner ones at the top.....OZ.
Helixes aren't always downward spirals,sometimes they're screwed up

Offline Brian Rupnow

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Re: Side Valve i.c. engine from Bar stock
« Reply #114 on: September 11, 2014, 08:01:16 AM »
Hello Manxmodder.--glad you stopped by to say hi. I am going to use a set of 1980`s Chrysler ignition points and condenser. I have about about 9 engines, so have made up a separate ``power box``containing a 12 volt coil and the appropriate wire leads that let me move it from engine to engine. That way it becomes inexpensive (less than $20) to buy a set of points and a condenser for each engine.

Offline Brian Rupnow

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Re: Side Valve i.c. engine from Bar stock
« Reply #115 on: September 11, 2014, 02:36:32 PM »
I still have some fin cutting and finessing to do, but this is getting quite exciting!!! I have to buy some material to make a fixture to mount this combustion chamber in the 3 jaw chuck on my rotary table to let me cut the cooling slot that runs around the perimeter. There is a lot of work in this part, but I am pleased with how it is turning out.

Offline philf

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Re: Side Valve i.c. engine from Bar stock
« Reply #116 on: September 11, 2014, 03:53:42 PM »
Brian,

It's looking good!

Are the valve seats just aluminium or is there a steel or iron insert?

I agree with Manxmodder's suggestion that you could chamfer the thicker webs to camouflage your error.

Cheers.

Phil.

Phil Fern
Location: Marple, Cheshire

Offline Brian Rupnow

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Re: Side Valve i.c. engine from Bar stock
« Reply #117 on: September 11, 2014, 05:08:41 PM »
If you look way back to post #30 you will see the answer to your question. I will be installing pressed in valve cages, made of brass. That way, if a valve seat goes funky, I don't have to replace the entire complex combustion chamber. I will post a drawing of the valve cages sometime in the next 2 or 3 days.---Brian

Offline Brian Rupnow

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Re: Side Valve i.c. engine from Bar stock
« Reply #118 on: September 12, 2014, 08:49:06 AM »
For those of you who wondered about the fixture I would make to cut the groove in the combustion chamber and to round the curved side of it, here is how I am going to do it. I found a suitable piece of 2" round aluminum and bored it for a hard press fit of a 3/4" crs shaft. I then set it up in the lath and turned a spigot on the face to be a precision fit into the 1" bore side of the combustion chamber. I then drilled and tapped five #5-40 holes in it and bolted the combustion chamber to it, using bolt holes which were already in the combustion chamber. The third picture shows it set up in my milling machine with a 0.093" slitting saw mounted in the spindle arbor. In order to take a quick picture, I put the slitting saw arbor in my 3 jaw chuck. In reality, it will be mounted in a collet held in the mill spindle by the drawbar.



Offline Brian Rupnow

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Re: Side Valve i.c. engine from Bar stock
« Reply #119 on: September 12, 2014, 03:52:11 PM »
I get a great sense of accomplishment (and sometimes astonishment) when everything actually bolts together, and all of those random lumps of steel and aluminum begin to look like an engine. Today I have reached that point. The combustion chamber turned out great, and my experience with the .093 slitting saw was a success. The two yellow pencils indicate where the valves and tappets are going to be.Although there are many different directions I could jump in right now, I am anxious to see what the "overall" engine is going to look like, so I think I will machine the cylinder head next.


Offline Brian Rupnow

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Re: Side Valve i.c. engine from Bar stock
« Reply #120 on: September 12, 2014, 04:08:56 PM »
This will be my weekend chore----

Offline Brian Rupnow

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Re: Side Valve i.c. engine from Bar stock
« Reply #121 on: September 13, 2014, 04:08:11 PM »
Now I know what I DON'T want to be when I grow up!!!---A cooling fin slot cutter!! The .093" slitting saw works amazingly well, but at 0.100" depth of cut, thats 4 passes per fin-slot x 11 slots = One heck of a lot of cranking on a manual mill. The sparkplug is a 1/4"-32 Rimfire plug from Roy Sholl. I didn't get too crazy finishing the bit of combustion chamber inside the head. It will work just as well the way I have it as it would polished.--In fact, it might work even better. I am really pleased with the way the engine is looking.---Brian



Offline Stilldrillin

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Re: Side Valve i.c. engine from Bar stock
« Reply #122 on: September 13, 2014, 04:56:34 PM »
Taking shape, and looking good Brian!  :thumbup: :clap: :clap:

David D
David.

Still drilling holes... Sometimes, in the right place!

Still modifying bits of metal... Occasionally, making an improvement!

Offline Brian Rupnow

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Re: Side Valve i.c. engine from Bar stock
« Reply #123 on: September 13, 2014, 07:18:14 PM »
It's a bit late in the game to be figuring this out, but just for the heck of it I  ran a quick calculation to see what the compression ratio on this engine was going to be. Without taking the heads of the valves into consideration, the compression ratio is a whopping 4.8:1----------That is about what I had figured it would be, but it's nice when the math confirms it.

Offline Manxmodder

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Re: Side Valve i.c. engine from Bar stock
« Reply #124 on: September 14, 2014, 06:28:34 AM »
 :clap: :clap: Looking really good now Brian,keep the updates coming......OZ.
Helixes aren't always downward spirals,sometimes they're screwed up