Author Topic: V-twin engine from scratch - yet another interpretation of how (not) to build a  (Read 72416 times)

Offline sorveltaja

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Rockers need still some shaping:


Currently, pedestals and rockers have an M3 threads, and I haven't yet figured out, how the fastening is going to be done :coffee:.

Rob.Wilson

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Looking great  :clap: :clap: :clap: :clap: :clap: :clap: :clap:

Chears Rob  :thumbup:

Offline sorveltaja

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Cylinder heads this far:


I used the above centering drill to make room for valves. Holes for valves/guides are to be drilled and reamed to 4mm(0.157").

Offline madjackghengis

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Cylinder head blanks in place:


Also connecting rods are in place. I did some run-in on the lathe with cylinders and pistons installed. Pistons are still bit stiff, but getting better.

Mad jack, good points. But there is seriously weak spot in my mill/drill construction. Being that the two pieces, which support the mill/drill head, are made of aluminum. So it is quite useless for steel milling.

Even on alu and brass, only light cuts can be taken.

That's the reason, why I preferably machine parts using lathe, as much as possible.
Sorveltaja, I understand, I had an 11 inch drill press which, with a cross slide table (four inch), I used for my first milling machine, with bronze bushings for bearings, and a five eighths spindle, it was not a power-house, but barely even acted like a mill.  If your lathe is of decent size, such as nine or ten inches, I found kits for T slotted cross slides, casting kits really, which allowed me to turn my ten inch Logan lathe into a horizontal mill, and with an angle block, a vertical mill too.  Mine came from a company called "Metal Lathe Accesories", and I ended up with two different cross slides, one with about ten inches of "T" slots, about six or so, and the other with three "T" slots in the rear, and a hole to put a top slide in, at the front, so it will do double duty.  I was able to machine a three by three by eight inch iron block accurately with the long "T" slot cross slide, the block having slots on two sides, and two different arrangements of dozens of holes on the other two sides, and being extremely stiff and rigid to hold stuff for milling in the lathe.  I hope this is of some help or value.  I know how hard it is when you don't have the right equipment, or even a good shed to put the wrong equipment in.  At least you get to work on what your hobby, cheers Mad Jack :beer:

Offline sorveltaja

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Mad jack, true words :thumbup:.

I hope to encourage others, even those with most modest machines and tools, that have the 'engine-itch', to make some chips.

It's easier to start building an engine, if kept in mind, that its technical functionality is most important. Ugly the appearance may be(ask me how I know).

With limited machining capacity, precision is to be used sparingly, only on critical parts.
« Last Edit: March 20, 2010, 02:44:50 PM by sorveltaja »

Offline sorveltaja

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Valve guides in place:


I warmed the heads some, and pressed guides in. At the moment, they have different length, and will be filed shorter, after valves are done.
Also the guide holes need to be reamed to 2mm(0.078").

Offline sorveltaja

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I enlarged the valve holes just bit too much, and had to fill them with brass buttons and silver solder:


I guess, that I have to be more patience, when machining the valve holes :wack:.

Offline madjackghengis

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Sorveltaja,  just to let you know, harley's from 1948 through 1965 used cast in place bronze valve seats, with good success, and they were commonly "built up" with a torch, when they had been machined too many times and needed renewal, so valves will readily seat in your "brass buttons", or in the head its self, if you get that far down.  Looking good, can't wait to see the finished engine.  Mad Jack :bugeye:

Offline sorveltaja

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Some progress with the valves:


They are made of two piece of stainless each. Shafts are from 2mm(0.078") bicycle wheel spoke, and lower parts are of some not so easily machinable stainless.

I prefer to make the one piece valves, but haven't got suitable material for that.

I also planned to drill 1mm(0.039")holes for valve shafts, to hold the valve cap, and spring. But the shaft material is very tough stuff to drill, as it's most definitely one of those famous notoriously easily work-hardening grade stainless.  

So, I had to make the grooves instead of holes. I used cheapo diamond cutting wheel disc for that.

Anyways, valves need to be made equal length, and the anglular working surfaces are also to be machined.
« Last Edit: March 24, 2010, 02:51:34 PM by sorveltaja »

Offline sorveltaja

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Sorveltaja,  just to let you know, harley's from 1948 through 1965 used cast in place bronze valve seats, with good success, and they were commonly "built up" with a torch, when they had been machined too many times and needed renewal, so valves will readily seat in your "brass buttons", or in the head its self, if you get that far down.  Looking good, can't wait to see the finished engine.  Mad Jack :bugeye:

Mad jack, that's quite nice detail to know about older engines :thumbup:, since I have always been fascinated of nowadays maybe simple techniques, that were used to make those engines.

Offline sorveltaja

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Valves are almost done. I made a valve seat cutter(below) also, and it worked just fine. Simple yet great tool ::).


Valves seat already quite nicely, and lapping process makes them hopefully even better.

Offline sorveltaja

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I made the circlips of 0.8mm(0.031") tinned copper wire, and caps are made of 4mm stainless.


Must be the smallest pieces on the assembly. Especially those circlips are quite challenging to get in place. The ones on the above pic are just practising pieces, so learning is on it's way :dremel:.

Offline NickG

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Looking good!  :thumbup:
Location: County Durham (North East England)

Offline sorveltaja

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Spark plug holes with an M6 threads:


There was just enough room for spark plug holes. I didn't make the threads all the way through, as that would have distorted the valve seating surfaces.

I did some flattening to remove machining marks from heads/cylinder body contacting surfaces.

Anyways, I guess that major machining work is done on the heads. What's left, is to make a fastening systems for carburetor and exhaust tubes.
« Last Edit: March 28, 2010, 01:34:20 PM by sorveltaja »

Offline Stilldrillin

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Looking good, and shaping up nicely!  :thumbup:

David D
David.

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

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

Offline sorveltaja

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I bored the cam housing holes on the lathe, and made brass bearings also.


Gears needed some fiddling, and lengthy run-in sessions on the lathe, and although they're still quite stiff to rotate, they finally fit in the place, and start to mesh together.

Overly long cam gear axles on the above pic are just part of the test setup.

Offline sorveltaja

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Cam pair blanks so far:


I'm not quite sure yet, how to form the cam shapes. Apparently by filing, although it requires a lot of beer   elbow grease.

Simple filing jig for the purpose is on my mind.

Offline Brass_Machine

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Shaping up quite nicely. Anxious to see/hear it run.

As far as doing the cam lobes... afraid I can't offer any advice. I think I have a link somewhere. Will look for it.

Eric
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We're all mad here. I'm mad. You're mad.

Offline sorveltaja

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I removed most of the excess cam material with that mighty diamond cutting disc, that was attached to lathe's chuck:


Rest was done by filing on the jig. Inlet lobes(the ones that point upwards) are almost finished, they only need some rounding and smoothing.

The exhaust lobes have still excess material in them, to give some room to 'tune' the final angle between lobes.

Atleast now I know, which direction the engine is going to run .

Offline madjackghengis

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Well Sorveltaja,  it looks like you figured out the cams all right, they look like they ought to work, and that puts you another big step closer to hearing this thing fire up.  Looking forward to the video, and seeing it run.  Good work!! :beer: Mad Jack

Offline sorveltaja

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Cams after smoothing and some polishing:


At this stage, they are ready to roll :wave:

But before that, cam housing needs the holes for tappets drilled first. And maybe tapped for M4, as I did on the test engine.

Offline sorveltaja

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Well Sorveltaja,  it looks like you figured out the cams all right, they look like they ought to work, and that puts you another big step closer to hearing this thing fire up.  Looking forward to the video, and seeing it run.  Good work!! :beer: Mad Jack

Mad jack, I hope so also :thumbup:.

Starting of tappet guides :


There wasn't enough room to make an M4 threads, as the cams are so close together. Instead they are made of 3mm(0.118") od, 2mm(0.078") id straight brass tube.

Valve push rods are to be made of 2mm stainless, so I'm going make tappets thicker than that, say 2.5-2.6mm. Tappet guides also need to be drilled to corresponding size.

That clear plexiglass piece was made at the beginning of this project. I use it as a guide, when angled drilling/milling is required.

Next things to do: tappet guide holes drilling, tappets, and push rods.

After that, the most, if not all major parts, should be ready for assembling, and maybe testing, how they fit together :nrocks:.

Offline sorveltaja

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After some minor fixes, first connecting rod is ready:


Tappets are just simple T-shaped ones, that have 2mm(0.078") concaves for con rods, machined with ball-nose cutter. Valve adjusting screws have also same size concave.

Con rods will have spherical surfaces at both ends. They need to be made one by one, as they all have different length.

One thing, that I was aware already, when making sketches, was quite big angle of left side con rods:


Don't know if that's an issue in the future, but if it is, modification is on the order :dremel:.

But in any case, when con rods are made, valve lapping takes place. Then the springs can be fitted, and whole valves/springs combo can be installed.

Offline dsquire

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sorveltaja

It looks like it is coming along nicely, one piece at a time. Soon you will have it all fitted together and time to fire it up. I know that I am not alone when I say that we are watching in anticipation of that day. Thanks for showing us what you have done to date.  :ddb: :ddb:

Cheers  :beer:

Don

Good, better, best.
Never let it rest,
'til your good is better,
and your better best

Offline Stilldrillin

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sorveltaja

It looks like it is coming along nicely, one piece at a time. Soon you will have it all fitted together and time to fire it up. I know that I am not alone when I say that we are watching in anticipation of that day. Thanks for showing us what you have done to date.  :ddb: :ddb:

Cheers  :beer:

Don

You`re certainly not alone Don!   :wave:


Watching, quietly waiting, enjoying.........

Thanks Sorveltja!  :thumbup:

David D
David.

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

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