Deutz D2 vertical Gas Engine (1895) from Castings

[Jasonb]

Pirmin sent me a couple of photos but I'll reply here as it may be useful for anyone else thinking of making this engine.

Ignore the actual sizes in the photo below which is about 3 times larger than the actual item as it is the differences between the pairs of sizes that matter.

The solid vertical line passes through the two punch marks indicating the ctr of the crank and cam shafts which I assume is lined up with the central axis of the jig and the hole in the casting. Looking at the numbers the botton pair are not that different, middle a bit more and the top pair have quite a difference. I had hoped it was just the round cast bosses that were off but it seems the whole of the fork is leaning to the left. The red circles show what the bosses may clean up like but they will not sit centrally between each side of teh casting and the bearing caps will be offset.

The dotted green line passes through the middle of the casting and the green dotted circles show how little work is needed to clean up the bosses if that line is used.

The cure will not be an easy setup but the casting needs to be held so that the bottom face can be skimmed true to the new dotted axis and the bore also machined to follow the axis which will then require it to be sleeved. As the bearings have not been bored yet they can just be Placed the correct height from the newly machined bottom.

[pirmin]

thank you very much jason. i have to see and try to come up with a creative solution how to resleeve the current upper part so that after a remachining the cylinder bore doesnt break out or will suffer from any faulty issues later on, also when i have to skim the bottom again, it will be interesting how much i would have to skim  etc . it will take quite some steps to get out of this ...i am now of course also at a poaint where i would have to alter and adjust all the linkages for the governor ( all those parts are already made   :'(

i wish i could just order a new casting from a online shop, but dealing with the emporium in a non UK country is quite a pain, they have no paypal etc, i think you understand what i mean. if i had the chance i would rather go for a new upper than try to salvage that one, but now i have to make the best out of it.

[Dave Otto]

Yes my thoughts exactly, for it to be right the the bottom face and bore need to be realigned as you have indicated.

Dave

[Jasonb]

I think there is a reason most of us tend to start with the castings. If there are any alterations needed then the cut from solid parts can be adjusted as they are made to fit.

[Dave Otto]

Pirmin, now that you have cut the bearing caps off, could you put the casting upside down in the mill vise and and work on it that way? It would require some extra support and you would have to accommodate for the parting line being off because it was cut parallel to the bottom surface which we know it not right at this time? The only parts that may need adjustment are the intake and exhaust push rods.

Dave

[Jasonb]

Could even be held the right way up with shims under the bottom to bring the forks vertical. You can then touch off the two outer edges of the bearings to get ctr in one axis and off the edges of the cap mating faces the other way.

Then use a boring head to open out the hole. Mount by the hole on an arbor in the lathe and skim the bottom true to the hole.

[pirmin]

@ Dave : After the Slitting saw operations the variation of the two flats where the Bearing Cap would sit is about 0,1mm . This happend because somehow the saw was pulled a little and i had to readjust the Z Axis postion again, by scratching off on one of the already machined flats when i did the first cap split, so before i could use the two "Flats" i would have to bring them down to the same height and machine of about 0,1mm ( i dont think it would show on the Split line because i already used a very thin slitting blade.

@ jason: i like the idea, but i have no real good Boring head and the Quil from my Pm-25 Bnech mill is not very accurate, niether is the Z axis when i need more than 20mm travel, there is always some slight lean or drop , and for boring operations i am always concerned i would integrate the error . i already shimmed my Mill Z axis but a year later it appears its still moving ...however, the rest of your suggestions sounds very logic, re-align the casting  the right way and plug the existing bore with a heavy sleeve and then skimm and rebore, i was also thinking of an expanding arbor similiar to the lapping tool i used for the cylinder liner...it just has to hold for one operation

[pirmin]

jason made a very  good illustration what's the fault here.

I installed sharpy in my mill spindle and marked out the lines just to make it visible for me to understand better ...

According to the red lines you see ,the centered line references from my current Bore ,this should also be my crankshaft centerline,the two outer lines would show where my Bronze Bushings would sit on their outer diameter (12mm)

Now that the Error is visible its a bit easier to understand what has to be corrected.

[pirmin]

And here some more pics...

[pirmin]

And one more

[Roger B]

That's a trick fix however it looks possible with sleeving the bore   

[pirmin]

Small Update: Until i can visit my friend and use his wohlhaupter UPA1 to bore out the upper i thought i could make the Piston and the Piston Rings.

It was a close one, 2 rings snapped, and the material i had was just enough to make 2 other Rings.i spoke with a good friend who builds race engines and he told me i could chamfer the upper Inner Edge of the rings with a 45° Bevel,so i did that, it should prevent bind ups. My nominal bore size is 25,07mm  and the first set of rings just wouldnt fit , i made them at 25,065 ,so on my second try i made the rings 25,045mm and i heated them with a 2mm steel washer so that i was left with a nice ring gap and upon installing and inserting them into the cylinder i felt some nice slight friction from the rings pressing against the bore, i am 100% convinced that this will be an absolute perfect fit .

 i couldnt be more happy. i am sure after a good Break in cycle this will make a nice Engine...but there s still some work ahead of me ....

[pirmin]

Small Update from my Shop :

i managed to machine the Conecting Rod and make the split bearings ( everything turned out well, but that Pre cut conecting rod blank the emporium supplied could be improved slightly , it was cut undersize , basically the laser was cutting at the exact dimensions wich lead that the surface at the target dimension was hardend and had bad grooves, so i had to make use of my Handfile collection and file it to a good looking blank and then change a few dimensions and it turned out well.

the split bearings where a first timer for me , the first set was spotless but i forgot that i had altered the rod thickness so a second pair had to be made in the nightshift tonight.

i had to put the whole assembly together to get some thrill out of it in the morning , but that was a very rewarding moment to see Rod,crankshaft, and the piston/liner assembly in all its glory.


at 6:15 in the morning also a strange pehnomenom occured, the sky was literally pink , and i can assure i wasnt on Magic Mushrooms, it is also not a Camera effect. i assume its due to the fog and above the fog was a lot of red light from the sun coming out. i try to add a photo here 

[RReid]

Nice work Pirmin. Those are some great looking little parts, with beautiful surface finish.
That really is a very odd looking sky color.

[pirmin]

thx Ron. yes, this color was realy a interesting thing to wittnes. i have never seen anything like it.

the surface finish is now in pre final state, i will go over every part before assembly , check all corners and sand and maybe polish those surfaces that are visible . i think that makes a model pop out.