Office of Steam Forum for Model & Toy Steam Gas & Hot Air Engines
The Regular Stuff: Chat, Buy, Sell, Off Topic, etc. => General Discussion - Scale Model Gas Engines - Hit & Miss - Throttle Governed - Non-Compression – etc => Topic started by: yozhek on April 18, 2020, 01:51:27 pm
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Thanks Dave, after that video i made a more suitable muffler for it.
[attachimg=1]
Ade
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What a fantastic job you have done on this engine.
I started watching a while back but must have missed the finals.
the switch in running speed is brilliant.
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Thanks Charlie, i'm glad you liked it :)
Best wishes
Ade
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Ade:
I just went back and read our entire build thread.
You did a wonderful job and overcame many issues.
Lots of excellent learnings here.
Thank you for an excellent build thread.
Regards,
Charlie
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Hi Trevor,
The adjusting the mixture thing is because the carb venturi size is too large, there is not enough suction in hit and miss mode therefore they have to richen the mixture. To fix this and the 'off governor' speed i remade the carb with and adjustable throttle slide so i could find the sweet spot, was easier than making lots of carbs with different size throats :D
Thanks for your support
Ade
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Well done Ade,most of the videos I've seen on youtube when they move from continuous to
hit and miss need to adjust the carb, what did you do to not need any adjustment ?
If you do send in a photo for engine of the month you've got my vote.
Regards Trevor.
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Very nice engine Ade, I hope you'll send a picture of this into Gil next month as I would love to vote for this as "Engine of the Month", would look great up at the top of the forum ;)
Thanks for your support through this project Nick :D , not sure if it is fit to be up there but i will send a picture anyhows.
Kind regards
Ade
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Well done on your final success and beating the problems into submission .
You should be very pleased with your result .
Cheers
Dennis
Hi Dennis,
A big thank you for pointing me in the direction of the taper pins. I made a test piece still with the brass and solder but with as much thickness as i had room for and of course the taper pin driven in with Loctite and it was much stronger so i went ahead and made a new crank, so far so good ;D
Kind regards
Ade
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Bonjour Adrian,
Congratulations ! I envy your skillness because I am not able to do the same.
Now, wht will be your next project ;) ?
Bonjour Raphael,
I'm not sure what to make next, i really enjoyed making this engine, maybe a 'Domestic' from Bob Herder but it is expensive with the shipping.
Kind regards
Ade
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Very nice engine Ade, I hope you'll send a picture of this into Gil next month as I would love to vote for this as "Engine of the Month", would look great up at the top of the forum ;)
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Well done on your final success and beating the problems into submission .
You should be very pleased with your result .
Cheers
Dennis
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Bonjour Adrian,
Congratulations ! I envy your skillness because I am not able to do the same.
Now, wht will be your next project ;) ?
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Karl is finally finished, new crank made, carb finished and a muffler.
Here is a rather poor video of it running, the sound is a bit 'intense' as you can probably tell making videos is not one of my hobbies.
https://youtu.be/L6ZXKpZGpUU
A big thank you to all who followed this thread ;D
Kind regards
Ade
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Hello Ade,
The M91 is running fine on some temporary governor springs,new ones on order from China
when they arrive I will send you couple if you want ?.
Cheers Trevor.
If you have 2 spare that would be nice, thanks.
Cheers
Ade
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Hello Ade,
The M91 is running fine on some temporary governor springs,new ones on order from China
when they arrive I will send you couple if you want ?.
Cheers Trevor.
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That's a great engine you've got there Ade.
Best of luck with your next build.
Regards Trevor (eec1910).
Thanks Trevor :D
Is the M91 ok now?
Best wishes
Ade
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That's a great engine you've got there Ade.
Best of luck with your next build.
Regards Trevor (eec1910).
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Bonjour Ade,
Great work indeed ! Important warning for you : my friend Max who has made his karl before you has had recently a very bad surprise.
The transparent porthole of the gas tank is not made of glass and the gas SP95 with a drop of 2 stroke oil he put in has slowly dissolved it :(
He has discovered this issue late because he does not use his engine frequently and keeps the tank dry when not in demonstration.
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Thanks Nick and Gil :D
As if i did not have enough brass splinters in my hands, i had a go at making a new carb today with a variable size venturi so i could get a nice speed when not in hit and miss mode. Funny enough i was sipping coffee and thinking of a plan and fuel started dripping from the sight glass on the tank, well no big deal it was coming off anyway, but it turned out the piece of perspex supplied for the sight glass melts in petrol...very good! lucky my mate had a sheet of 2mm glass so i could make a new sight glass.
Once the sight glass was fixed i got back to plan A and started of by making a throttle slide and needle
(https://i.vgy.me/HXrUN3.jpg)
Then a stand alone venturi and fuel tank mount/fuel pick up
(https://i.vgy.me/P9mLrg.jpg)
The idea being the venturi as an assy. will be easily removable from the carb body to make mods easier
(https://i.vgy.me/9RMKiw.jpg)
Next came a complete new carb body and refitting back to the engine for test
(https://i.vgy.me/cRzGMS.jpg)
It suprisingly worked pretty well considering the needle taper was just a guess
(https://i.vgy.me/3jC71K.jpg)
I could find a nice off governor speed and then turn on the governor and have it run all without adjusting the mixture needle. Just got to think of a method of adjusting the slide without holding it with my poor splinter infested fingers ;D
Ade
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Great to see it running already 8)
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Runs great, Ade. Looks great, too...!!!
Nice work..!!
Gil
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Bonjour Raphael,
Thank you for the 'heads up', i am not familiar with uploading videos on youtube.
I love your picture with the little steam boat pulling you in the dinghy BTW, you must be a real craftsman to make such magnificent models.
Did your friend try increasing the strength of the inlet valve spring? it made a big difference to how mine runs, maybe this would help him?
Kind regards and thanks
Ade
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Bonjour Ade,
Your video is private, we may not see it ;)
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Lena looked at the boxes of wooden flooring planks in the hall then turned her attention to my engine sitting proudly on the workbence and said "have you finished that thing now?" followed by "what is it for anyway" ... This means 'time is up'! Well she was working today so i ripped off some of the skirting in the living room and half the carpet to assess how much of a task it is going to be, and make it look like i made an effort ;D
Did the washing too, cleaned the carpet in the office, then hurried off into the workshop to play :D
Despite the broken crank the engine still ran to a fashion. Without the govenor it had a real bark and sounded rich but would cut if i tried to lean it out, re-maching the inlet valve collar to add more sping tension fixed that, infact it fixed it too well, the next run saw it rev to about 2000rpm and i just managed to shut it off before one of the flywheels came shooting off the end of the crank. Remember the wobbly flywheel? i had to machine a bit more off the rim to true it so it was slightly narrower. Well the flywheel that jumped off was the straight one so while it was off i turned it to the same size as the smaller one and made a new locking collet using the know how i gained from the ex-wobbly flywheel. I think 2000 rpm is a 'bit' much so i need to remake the carb with a smaller venturi.
I put the governor back on and tried it in hit and miss mode. The crank needs to be replaced as one of the crankpin solder joints has failed hence the wobbling flywheels and i need to make a muffler.
https://youtu.be/QtrJorL3hpY
Thank you all for the support and following along
Ade
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Hi Dennis,
Thank you for the advice, much appreciated. I have some 10mm 304 stainless flat bar which is wide enough to make some new crankwebs out of, this would allow me to do away with the 5mm brass webs and soldered in support collars, might be the way to go? Have ordered some taper pins and reamer ;D
Many thanks
Ade
Sounds like a plan but stainless can be a pig to work with and i am not sure if it can be silver soldered
Cheers
Dennis
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Dennis,
No disagreement here, my skills are limited (never used Loctite without pins and agree it is a shoddy practice). Should not have suggested it, Ade is doing well without my advice.
Len.
Len.
Your suggestions are always welcome Len, thank you ;D
Best wishes
Ade
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This is just my opinion and at the end of the day what would i know .
You have done well with your engine and are to be congratulated.
The crank shaft ?
I would throw the brass webs away. And also the roll pins .
Steel webs and taper pins and the silver solder ( in that order ) ( not soft solder and the roll pin )
And no loctite . loctite is a glue and you do not glue metal together
Crank webs are to be a tight fit on the shaft and heating webs and cooling shaft will make it a bit easier to press into place .
Ok i will no resume my sideline seat
Cheers
Dennis
Hi Dennis,
Thank you for the advice, much appreciated. I have some 10mm 304 stainless flat bar which is wide enough to make some new crankwebs out of, this would allow me to do away with the 5mm brass webs and soldered in support collars, might be the way to go? Have ordered some taper pins and reamer ;D
Many thanks
Ade
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Dennis,
No disagreement here, my skills are limited (never used Loctite without pins and agree it is a shoddy practice). Should not have suggested it, Ade is doing well without my advice.
Len.
Len.
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This is just my opinion and at the end of the day what would i know .
You have done well with your engine and are to be congratulated.
The crank shaft ?
I would throw the brass webs away. And also the roll pins .
Steel webs and taper pins and the silver solder ( in that order ) ( not soft solder and the roll pin )
And no loctite . loctite is a glue and you do not glue metal together
Crank webs are to be a tight fit on the shaft and heating webs and cooling shaft will make it a bit easier to press into place .
Ok i will no resume my sideline seat
Cheers
Dennis
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Hi Len,
I don't think there is enough surface area for Loctite, this is the issue with the soft solder too and there is no space to widen the joints.
Good news is that after reseating the valves it actually runs! Nothing seized and after 5mins the compression is really good.
Just gotta be patient now and wait for some metal bits from Bengs before crankshaft No2 :-)
Ade
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Ade,
I was told all it takes to build an engine is the willingness to fill a 55 gallon drum with botched parts. I have seen silver solder used with success with steel, but a quick search on google had puddle in the results. Have you considered Loctite? Have seen it hold fine in a pinch if fits are tight, but maybe a kludge too far with your nice work so far.
Len.
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Ade,
Your progress is excellent! Your current issues seem familiar to me and I am sure you will overcome. To build 3 engines I built 7 or so cranks and more than six valve/valve guide assemblies.
My machining skills are rudimentary, but do you have a four jaw chuck?
Len.
Hi Len,
Thanks for that, i don't feel like i am wasting metal knowing others had a few shots to get it right. Yes i have a 4 jaw chuck.
The crank webs are brass on this engine, i guess i will anneal the brass if it get it hot enough to use silver solder on the joints?
My machining skills are rudimentary to say the least, but i have learned a lot doing this build, lots more to learn of course, but i got one foot on the bottom rung of the ladder now ;D
Kind regards
Ade
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Ade,
Your progress is excellent! Your current issues seem familiar to me and I am sure you will overcome. To build 3 engines I built 7 or so cranks and more than six valve/valve guide assemblies.
My machining skills are rudimentary, but do you have a four jaw chuck?
Len.
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I am really enjoying your build thread Ade.
Looking forward to the next update.
Cheers,
Charlie
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Getting close to finishing this thing now, got the water hopper finished and painted.
(https://i.vgy.me/RYuUqI.jpg)
And wasted a pound of silver steel rod learning how to make long thin valve stems, still ended up with the stem finish of an old nail but at least the ridges are smooth and the stem parallel and a good fit.
(https://i.vgy.me/ldKb6u.jpg)
The valves run direct in the aluminium head so i guess they will wear loose quickly, but i can always go back and add proper valve guides later.
(https://i.vgy.me/REyOn5.jpg)
The fuel tank is quite heavy and the carb design had it all hanging on a 4mm threaded piece of brass rod with a hole up the middle, seemed a bit weak to me, plus the plan had the jet (and tank) soldered into one half of the carb and a separate piece for the adjusting needle assy soldered opposite. After making the carb to the original design i decided to start over and redesign with a larger one piece jet assy. holding the tank with an M6 thread instead.
(https://i.vgy.me/RauhZ3.jpg)
Finished carb
(https://i.vgy.me/JlHtkV.jpg)
With tank ready to fit
(https://i.vgy.me/67Vj9v.jpg)
Well after the pushrod guides were done, so fiddley, i was itching to see if it would run. Put some petrol oil mix in the tank and gave it a spin, it fired but the valves were seating poorly and did not have enough compression to keep running. This was not the worst though, the crank quickly started to run out of true and upon inspection i found the soft soldered joint to one side of the crankpin had loosened :(
If anyone has any advice they can give me on how to make a stronger crankshaft it would be gratefully recieved. In the meantime i have ordered a milling slide for the lathe (i don't have the money for a proper mill) and will be scratching my head trying to think of ways to make a more rigid crank, preferably without the soft solder.
Best wishes
Ade
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Looking great, Ade...!!!
Thank you for the updates.
Gil
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Amazing progress, appreciate the tight fit of valve seats in small bore.
Len.
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Sunday, this is the day things usually go wrong, but never the less the cylinder head needs to be done.
First job was to make a mod to the lathe so can mark out 90 degrees and 60 degrees
(https://i.vgy.me/eZ4Vg4.jpg)
So far so good
(https://i.vgy.me/wZKrUv.jpg)
So the head could get some cooling i machined a water channel (complete with chatter marks) and a cover to seal it
(https://i.vgy.me/r9pCow.jpg)
(https://i.vgy.me/r2nC9t.jpg)
Still retains the dimensions in the plans but was a tight squeeze
(https://i.vgy.me/EA4Txv.jpg)
The valve seats, ports and plug were a tight fit in the space of the 25mm bore
(https://i.vgy.me/mZ0ps3.jpg)
(https://i.vgy.me/2BygGu.jpg)
Well the head went without a hitch, i think this project is teaching me to work more precisely and less slap dash ;D
The Aluminium glue had dried so next step was to rough sand the water hopper, make a centering sleeve and fit the head and cylinder assy together and drill the holes to mount it all on the crankcase
(https://i.vgy.me/G6XP2O.jpg)
It ia actually looking like and engine for the first time
(https://i.vgy.me/37mXMH.jpg)
Everything fitted beautifully, the piston and rings fit well and make a nice crisp sound, the crank and rod do their job with no play or binding, feels like i'm getting somewhere now ;D
(https://i.vgy.me/1xYRwX.jpg)
Thanks for watching
Ade
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Looks like you are making better progress on your project than i am on mine
Keep up the good work
Cheers
Dennis
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Great Progress 8) Thank you for all the pictures and keeping us updated :)
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Hey it is Saturday again! time for some more Bengs engine fun for me :-)
There was some free time in the week which allowed me to machine a new governor spool, trim the crank and final fit the govenor side flywheel. With this done the governor was finished off with the weights and spings made.
(https://i.vgy.me/sGHBwc.jpg)
(https://i.vgy.me/S3D5CO.jpg)
Here is the crude water hopper i made from two pieces of Aluminium angle, hopefully once the top is made and it is sanded to shape it will look a bit nicer.
(https://i.vgy.me/WqM3QL.jpg)
I was torn whether to try to Aluminium solder the hopper to the water jacket or use some aircraft aluminium epoxy a friend gave me, in the end i went with the glue. Keyed the surface and bonded the hopper to the jacket.
(https://i.vgy.me/bZWkHh.jpg)
The Piston rings i ordered turned up so next step was to try and make the conrod and piston. Making the big end halves on the lathe was OK but filing the flats on either side was a mare. I filed one side close but the was not enough material to hold it in the vice to do the other side, after a bit of head scratching and some four letter words it ended up in the pillar drill vice and a dremel bit in the chuck as a makeshift mill. That pillar drill has been a Godsend throughout this project.
(https://i.vgy.me/3cvOOU.jpg)
Eventually the rod was done, and it was straight and a good tolerance on the bearings
(https://i.vgy.me/KgwG4R.jpg)
The plans show the piston as a heavy old lump of brass screwed to a cast iron piston with no rings, obviously it works but it kinda made me feel queasy, so i set to work making a normal aluminium piston with the rings i bought, should be lighter and easier as the piston to bore tolerance is not so tight.
Piston went well, ring grooves machined, good fit in the bore, small end marked out.
(https://i.vgy.me/kD0ab1.jpg)
Then came the hard bit, again i wished for a mill to hollow out the centre of the piston.
(https://i.vgy.me/z4tYLS.jpg)
In the end (in desperation!) the slot was chain drilled and chewed out with a dremel, bit rough and ready but i have to make do here. Piston done and a lovely fit in the bore and suprisingly parallel ;D
(https://i.vgy.me/b8or4k.jpg)
Hopefully tomorrow i can get the cylinder head done...maybe ;D
Thanks for following the rather long thread.
Ade
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Think i must have spent roughly 8 hours on the right hand flywheel, plugged the centre and re turned it so it ran true on the shaft, then as soon as the tapered collet was tightend it ran out of true again. Didn't make any difference where it was positioned on the crank, so in the end i dressed the taper collet by hand with a fine file until the flywheel ran true 'enough' not be noticable.
(https://i.vgy.me/7Fp3dP.jpg)
So now the bottom end is complete, it all spins freely with no play. Got to make an 'adjusted' govenor spool and trim the crank to length on the left side once some brass rod arrives from the suppliers.
(https://i.vgy.me/pluMN9.jpg)
A new cylinder liner from Bengs arrived the other day and this one was much better and has a good surface once honed. I decided to change the design so the liner is trapped between the head and water jacket rather than the head and crankcase, so this liner was turned to just have a 4mm lip at the top for location.
(https://i.vgy.me/IVNubw.jpg)
Next to start on the water jacket and make a hopper.
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Sunday Blues...
The paint was dry on the flywheels so Sunday started with finish machining these.
(https://i.vgy.me/9FGRMI.jpg)
And the govener arms
(https://i.vgy.me/bYBNqM.jpg)
And the flywheel locking collets
(https://i.vgy.me/921SfE.jpg)
And this is where is started to go a bit wrong. The govenor side flywheel was nice and true when mounted, as is the PTO pully, but the other flywheel wasn't true, so i have to sleeve the centre bore and machine it again.
(https://i.vgy.me/vExvrA.jpg)
At least one is straight :-)
(https://i.vgy.me/ZG07tr.jpg)
Ade
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You are making great progress, Ade!
Your attention to detail really shows up nicely.
Gil
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Great project and great progress, this is a joy to watch. :)
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Bonjour Ade,
This kit is definitely intended for experienced builders and you are one of them, I envy you.
I know that my friend Max has encountered many difficulties and he has overcome them, as you do. I can't wait to see it work, the highlight of your work
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Its Saturday, wife is at work, time to get some progress ;D
Backtracking a bit, Thursday gave me a few hours spare workshop time, There was a spare electonic ignition from one of Jin's M90s on the shelf, better than the points and big coil supplied with the kit IMHO as the unit and battery can all be hidden in the base. A mounting plate was needed to position the Hall effect sensor inside the crankcase and a magnet fitted to the crankweb.
The 2k paint on the base was now dry, so time to mount the crankcase square on the base and line ream the main bearings, things were going well again :-)
(https://i.vgy.me/rFtbQo.jpg)
Next was the crank. The crank webs are pre milled but top hat bushes need to be turned to increase the surface area of the soft soldered bond.
(https://i.vgy.me/9tzKBT.jpg)
And this is where the good luck run stopped, everything fluxed and fitted together ready for soldering, heat applied and the solder flowed nicely on the brass parts but refused to flow onto the silver steel shaft, clearly time to stop for the day.
After work on Friday it was time to clean up the mess, the shaft was still straight and cleaned up pretty well and with many applications of flux in finally tinned with solder. This time i had to assemble it hot, a piece at a time which was not easy, but got there in the end. The crank was still reasonably straight even after drilling the webs and hammering in the roll pins to give it strength.
I forgot to take pictures of the crank nightmare, was too concentrated on trying to recover the the disaster.
(https://i.vgy.me/bBespG.jpg)
A few well plced hammer blows had the crank down to less than 1 thou runout. Had to shim it to get the crankpin central to the bore (i measured with the main bearing inside out and machined 1mm too much off the collar... duh)
OK back to Saturday, crank was done, next were the timing gears, again the gears were pre made but bushes had to be turned to fit them on the shafts. The camshaft has only one bush bearing and with the thrust of the cam was already wobbling, time for a mod! Needs a longer bush me thinks, but can't move the cam gear inwards as it hits the crank. In the end i added 2mm on the inside of the bush and recessed the cam gear to sit 'over' the end of the bush so the gear was only 1mm further toward the crank. The outside of the bush gained an additional 2mm and the cam follower fork on the inside opened up to slide over it. This gave me an extra 4mm of bearing area. The pic below shows the new and old bushes.
(https://i.vgy.me/ck8q02.jpg)
Recessed cam gear
(https://i.vgy.me/AId4qb.jpg)
Cam follower fork opened up to ride over the outer edge of extended bush
(https://i.vgy.me/V70S2W.jpg)
All went together nicely with no wobble this time ;D
(https://i.vgy.me/NcXecl.jpg)
The govenor spool was turned and fitted
(https://i.vgy.me/3LqCqy.jpg)
Next up are the flywheels, i rough turned them and painted, couple of days for the paint to go off and i can finish em off.
(https://i.vgy.me/E7XAUU.jpg)
And that was a very enjoyable Saturday, time to get a shower and something to eat and off to pick Lena up from work.
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Bonjour Raphael,
Thank you for the video from your friend, this is very helpful and sets the bar high :)
Making the carburettor looks like a headache, your friend will find the sweet spot soon i hope.
Kind regards and thanks
Ade
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Bonjour Ade,
My friend Max has just finished his one, he now has to adjust the timing and carburetion which are very sensitive:
https://www.youtube.com/watch?v=MDbSt3i3azs
You know now you objective ;)
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haha Dennis, it does look kind of blood coloured doesn't it ;D
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Making great progress .
Is this one of “ Blood sweat and tears “ projects ?
Blood for the colour.
Sweating for the fiddly bits
Tears for the eyesight gone west ? .
Cheers
Dennis
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Managed to get a few hours in the workshop this week, but i am still waiting for a 10mm reamer so there is much i cannot do at present.
I did ream the main bearing holders and make the main bearing bushes which are now in place ready to line ream them.
In the mean time i have been moving on with some horrid fiddly bits, my eyesight is making this very hard going and i am not getting the quality i had hoped for, but it will work.
Govenor arm and lock out assy done.
(https://i.vgy.me/ksZZQg.jpg)
Finished and fitted.
(https://i.vgy.me/5lonat.jpg)
And my paint turned up, so i have the base painted. i wanted to get this done so i can mount the rather flexible crankcase square on the base before reaming the main bearings to ensure everything is in good alignment.
(https://i.vgy.me/5KP6yc.jpg)
Kind regards
Ade
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I would like to thank you all for your kind words of encouragement :)
Probably won't get much done in the week because i am still working, for my sins.
Hopefully the paint will arrive tomorrow and the reamers before the weekend, fingers crossed.
Kind regards
Ade
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Great job and following with interest.
I bought the Danni years ago and quickly realised it was beyond my skill set.
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looks GOOD.Jin
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I don't feel so bad now Dennis :-)
Kind regards
Ade
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Interesting project and you have made a quick start .
As for drilling and tapping your face plate ?? Nothing wrong with that as I have seen many a face plate with tapped holes in it .
Cheers
Dennis
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More screw up Sunday.
No broken taps today, but i got impatient waiting for the reamers i ordered to arrive and i found an old prop reamer which i thought was metric, haha it did a lovely job reaming the cam, only trouble it must be imperial as the hole i made was too big for the shaft, oh well ream it out bigger and make a sleeve for the shaft.
(https://i.vgy.me/nPrOkG.jpg)
While i was on a roll i found a bearing and made the cam follower
(https://i.vgy.me/ouFrBQ.jpg)
and the camshaft bush, think i will wait for the reamer this time :-)
(https://i.vgy.me/WuzeHi.jpg)
The plans/dimension drawings are all jumbled up with non related items on each page which makes finding parts in a logical order very hard, so i'm trying to knock off the obvious items first so i can cross them off the plans to make finding dimensions for parts i'm working on easier.
(https://i.vgy.me/hK4fQt.jpg)
Ade
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Hi,
Please keep posting your progress! I have used DOM tubing as liner with some success, not sure that this would be any advantage than ordering part from Bengs.
Len.
http://www.speedymetals.com/information/material17.html
Thanks for the info Len
Kind regards
Ade
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Hi,
Please keep posting your progress! I have used DOM tubing as liner with some success, not sure that this would be any advantage than ordering part from Bengs.
Len.
http://www.speedymetals.com/information/material17.html
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Found my first major issue today, thought i would see how i got on with the cylinder jacket and liner.
I would like to make this a water cooled hopper type engine rather than air cooled, there is some pictures online of a lovely job someone has done on one of these engines with hopper cooling and it is very inspiring, plus after the M90 i realise these things get hot if you work them. I don't have a real plan so drifted into machining the jacket and liner. The plans step the liner about halfway down so the liner is trapped between the cooling jacket and crankcase, i decided to reduce the length of the step but keep the same way of retaining the liner, with the jacket holding the liner in place at the rear and a 3mm lip to hold the front of the liner allowing me to hollow out the centre section of the jacket for the water cooling.
Machining the liner went well
(https://i.vgy.me/0BsMdt.jpg)
As did the jacket
(https://i.vgy.me/Eumgeu.jpg)
Got a perfect fit of the liner in the jacket, more by luck than good jugement ;)
It was then i noticed the problem, the inside of the liner is 'supposed' to be finished as supplied, but running my finger around the inside revealed a raised flat spot where the tube was welded dagnabbit! Another mod i had planned was to use piston rings and and aluminium piston rather than the rather odd and heavy looking affair outlined in the plans, to do this i ordered a pair of the 25mm rings that Bengs offer, and this is my problem, the bore is already 25mm so i have no room to clean up the ridge in the bore. I don't think a hone will remove the ridge before oversizing the bore, so i either have to order another liner from Bengs and hope it is better or make a liner from scratch, any advice here would be gratefully received :)
This picture does not show it too well, but you can just see the weld undercut on the right
(https://i.vgy.me/uhRylf.jpg)
Ade
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Off to a really great start - looking forward to following you through this build.
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It's looking good and I'm enjoying this thread Thanks.
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Looking good and Thanks for the pictures! You should have this finished by this afternoon ;) :D
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The fact that you made the time to work on it and seeing the progress that you made on it speaks volumes for the Quality and Your Enjoyment!!!
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looks really good so far Ade...I'm on the edge of my seat for more pictures :)
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With some encoragement from the folks here i bought a Bengs modellbau 'Karl' hit and miss engine kit, as i don't have a mill and this kit comes with all the milled parts then i hope it is going to be a good first engine to build.
Didn't take long to get here, this morning i found a heavy box in my porch :-) So everything i had planned for today got postponed and i waded in.
Everything looks good, the base is heavy with no blow holes in the casting and all the parts are numbered and vacuum packed. The instructions/drawings leave plenty to the imagination but that is half the fun to figure it all out.
Anyways, i couldn't resist and made a start on the crankcases. There is quite a bit of flash on the brass parts where they have been cut so i started by dressing this off with a file.
(https://i.vgy.me/l21G7l.jpg)
Then using a sharpie marker for engineers blue i started marking the holes to be drilled. At this point i realise how cruel age has been on my eyesight, but soon i had enough fairly accurate holes to bolt the two halfs together so i could file both crankcase halves to be identical...ish
(https://i.vgy.me/5ajO8R.jpg)
Using a socket as a guide i drilled and tapped the main bearing caps, good old fasioned pillar drill and digital engineers level was a life saver here to get the holes vertical and true.
(https://i.vgy.me/w1zhNC.jpg)
More drilling and tapping and only one M2 tap broken off in the hole with could be punched out of the brass with no lasting damage
(https://i.vgy.me/R1L27e.jpg)
(https://i.vgy.me/fljEDb.jpg)
Before my wife realised something was going on in the garage both crankcase side plates were done.
(https://i.vgy.me/fpL7ih.jpg)
Next job was to join the two halfs, to my suprise it turned out square and level, turning out to be quite a good day!
(https://i.vgy.me/nuhA6T.jpg)
As luck seemed to be on my side today i turned both faces of the baseplate on the lathe and drilled the mounting holes.
(https://i.vgy.me/49YeAB.jpg)
(https://i.vgy.me/d0reFD.jpg)
I guess drilling and tapping the faceplate of my lathe to mount the base for turning will make all you engineers out there cry but it got the job done :-)
Before i knew it was 7 o'clock and time to quit, but i had a really fun day doing the easy bits and at the end i have the crankcase bolted to the base and all is square :-)
(https://i.vgy.me/AeLlGg.jpg)
Kind regards
Ade