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supercharged V12 2 stroke

Methanol burning beast!!

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Jens Eirik Skogstad21/12/2013 15:33:16
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370 forum posts
22 photos

As the picture of the difference 2 stroke engines is showing clearly the pressure in cylinder will be disappeared after the transfer port is closed while the exhaust port is still open, "Supercharging" is incorrect to use in 2 stroke engine. Also we will call it for blower/scavenge blower instead "supercharger". 4 stroke engine with supercharger will give more power due there is enough pressure in cylinder before compression stroke begins.

Muzzer21/12/2013 18:27:50
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2904 forum posts
448 photos

Yes, you can't really "supercharge" a 2-stroke even with exhaust valves and proper injection. The blowers and turbochargers are primarily to ensure scavenging. However, when you have a V engine like this, you aren't going to get any effective crankcase pressure when you need it, so the transfer ports aren't going to do much for you. The use of a supercharger (scavenge pump?) is probably a sensible choice here, given that Dean is aiming to get this impressive beast working. At least there is a decent chance of the cylinders getting some mixture........as he explained back on the 8th.

Is this a CI (diesel) or will it have spark plugs? That's a lot of parts either way! Good luck, lots of people watching and wishing you well - no pressure, then!! It'll make a fantastic noise / smell....

Edited By Muzzer on 21/12/2013 18:28:33

dean clarke 221/12/2013 23:59:36
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154 forum posts
330 photos

Hi guys and thanks for the comments and info etc. Hi jen, I accept what you are saying about 2 strokes with the port timing etc, and if you want to call it a scavenge pump then thats fine with me, each to his own, i will use the term supercharger as it will be forcing more mix into the engine than could otherwise be done. however without going into too much detail (secret squiral suff etc) LOL. the engine is arranged with porting and exhaust dimensions to allow some amount of positive charge in the combustion chamber, this is managed by using the rather large expansion pressure of combustion to act as a back door as it escapes out the exhaust system to allow positive transfer pressure to reach the combustion chamber. it is somewhat more involved than what i've just said but it does work. there are a few variables that need a bit more experimentation to finalise as it becomes a balancing act of appropriate pressures which will dictate drive speeds etc. Oh well i guess thats all for now will keep you all posted on the progress. The exhaust back pressure is also what helps stop excessive fuel consumption to a certain extent.

cheers for now

dean

p.s. before anyone asks i have done some experiments and yes the theory is sound and will run, actually it will run very well i think but like my nanna always used to say " the proof is in the pudding" so we shall see.

dean clarke 222/12/2013 00:01:25
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154 forum posts
330 photos

Oh yea sorry i forgot to answer you muzzer, this is a glo engine running on methanol and nitro methane with a bit of good ole caster oil to stop the welding of internal parts.

dean

Doubletop22/12/2013 07:05:24
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409 forum posts
4 photos
Posted by dean clarke 2 on 21/12/2013 23:59:36:
 
" the proof is in the pudding" so we shall see.

Can't wait; and with the progress so far I can't see us having to wait until until Christmas 2014 for the pudding

One of the many watching with interest....

Pete

Edited By Doubletop on 22/12/2013 07:09:19

dean clarke 228/12/2013 03:04:13
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154 forum posts
330 photos

Ok so a quick update to let you know where I'm up to. I have made the fixture to turn the crank big end journels and found a slight problem, the fixture, with the crank in, was too big for the inside dia of my 3 jaw chuck. bugga!! now what to do. Luckily i have a larger 4 jaw self centering chuck so with a slight modification with a boring bar i can now machine the big ends, yay!! So i am now in the middle of making the tools to turn the journels. will post the photos if all goes well, maybee in the next few days depending on how much shed time my wife lets me have. LOL.

cheers

for now

dean

Edited By dean clarke 2 on 28/12/2013 03:06:20

David Tweddle 128/12/2013 14:10:05
3 forum posts

Hi Dean if you need a test bed to run it in, my 72" Piper Cub is nearly completed and needs a decent power unit.

Keep up the brilliant work and I will sit back and learn from a true maestro .

Regards Davidyes

dean clarke 201/01/2014 05:52:09
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154 forum posts
330 photos

LOL yea sure no problem David just cruise on down to cambridge N.Z and we'll bolt it in. I was thinking that I might actually build an ME 109 to put it in, control line of course, about 76" span, what do you think? LOL. Hopefully i will have the crank finished tonight. I am in the middle of building a custom tool post for the lathe to eliminate the toolpost flex from the standard (not very ridged) toolpost. I knew i should have got the bigger lathe. oh well. will post the photo update later tonight all going well

dean

Doubletop01/01/2014 06:06:04
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409 forum posts
4 photos

Dean

Cambridge NZ? That means there is some chance of seeing this creation in the flesh. ME109 or just on the bench

Pete (Wellington NZ)

dean clarke 201/01/2014 07:14:52
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154 forum posts
330 photos

Sure mate no problem, just drive on up, send me a p.m. i'll give you my contact details etc, lets arrange to hook up and have a show and tell. i have a few models (all c/l) and a few engines too. could run the v8 up again too. now off too the shed to finish this tool post and get the blimmin crank done, really want to see it finished tonight!!

dean

Edited By dean clarke 2 on 01/01/2014 07:15:36

dean clarke 201/01/2014 16:33:05
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154 forum posts
330 photos

WELL I finally got the big ends all finished, Wot a saga!!! well got the late afternoon and all night,way into the early just before sunrise time, in the shed and was able to get the tooling and problems solved for the big end journel turning and finishing setups. below is a group of photos showing the tools and set ups i used to turn and finish grind and polish all the big end journels. next mission is the same treatment for the mains and the final champhering and polishing. here's the end result.....................

big ends all finished yay!!!!!!.jpg

here's the tooling etc

dean clarke 201/01/2014 16:34:13
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154 forum posts
330 photos

Actually............here's the tooling etc

custom toolpost setup and crankfixture for big end turning and grinding,polishing.jpg

here's the nibbling of the journels being done

roughing out the first big end with a nibbler tool.jpg

here's the flywheel faces being machined and radiuses applied to journel corners

custom toolpost in use.jpg

so here's the fixture with the finished crank........

crankshaft and offset turning fixture.jpg

sorry but i forgot to take a photo of the grinder setup, but here's a close up of the finished big end journels

closeup of polished big end journels.jpg

So i will now go and get a few hours sleep and hopefully be up before my wife gets home, later today, and get the main bearings all finished as well. that would be just fantastic!!!!!

ny nyz all (briefly anyway). lol

dean

 

Edited By dean clarke 2 on 01/01/2014 16:45:24

Edited By dean clarke 2 on 01/01/2014 16:46:07

Edited By dean clarke 2 on 01/01/2014 16:50:10

Stub Mandrel01/01/2014 19:35:05
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4306 forum posts
291 photos

I hate it when people's jigs and fixtures look better than my finished work...

Neil

dean clarke 204/01/2014 04:36:23
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154 forum posts
330 photos

Well here's the finished crank, YAY!!!!!!!!!!!!!!!!!!

finished v12 crankshaft.jpg

now its onto the next parts, carbys i think

cheers

for now

dean

dean clarke 210/01/2014 08:14:18
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154 forum posts
330 photos

Well been very busy this last week, unfortunately just not in the engine build department. I have been able to start the cylinder fin and head blocks. There is also a photo showing the crank finished and fitted to the block.

crank laid up in block.jpg

cylinder blocks and head blanks.jpg

cylinder block and head blanks squared up.jpg

Off on holiday for 2 weeks now so wont be back in the shed till we get home, will upload the progress shots for the heads etc when they are all done.

cheers

dean

dean clarke 228/01/2014 08:20:47
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154 forum posts
330 photos

well, home again after a lovely trip to Aussie,Gold Coast with theme parks galor. Unpacked my bag and straight back into the shed to continue working on the 2 cylinder fin and head blocks. these are machined and drilled as one piece and then separated, surfaced and then bolted to the engine block and the cylinder bore holes machined in situ. here are some photos of the progress so far.

dean

drilling the bolt holes 2.jpg

both head blanks drillind and rebated.jpg

cylinder head and fin block squared and drilled.jpg

setup to seperate cylinder head and fin blocks.jpg

cylinder head removed from fin block.jpg

fin blocks and heads ready to machine cylinder bores.jpg

will post the rest of the photos in a little while, duty calls

cheers for now

dean

Michael Gilligan28/01/2014 08:49:37
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13975 forum posts
605 photos

Dean,

Nice work with that Slitting Saw !!

MichaelG.

dean clarke 228/01/2014 21:44:03
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154 forum posts
330 photos

Hey thanks had a bit of practice i must admit. here are a few more photos of the next stage of the fin/head block machining

cheers

deancenter drilling cylinder holes.jpg

cylinder pilot holes drilled.jpg

the pilot holes were drilled 10mm then milled to 12mm for the glo plug clearance.

milling the cylinder bore ready to ream.jpg

reaming the cylinder bores to size..jpg

next step is to set the cylinder heads and fin blocks up bolted together to the engine block and machine all the external shapes,ports and fins. will upload these later tonight.

cheers for now

dean

Edited By dean clarke 2 on 28/01/2014 21:45:16

Edited By dean clarke 2 on 28/01/2014 21:48:00

dean clarke 202/02/2014 00:17:24
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154 forum posts
330 photos

So it has been a very busy time in the shed lately, have managed to make and finish all 12 cylinder liners, all thats left to do to them is  hone and polish with diamond lapping.v12 liners.jpg

I have also managed to machine the transfer ports into the cylinder fin blocks and machine the external profile shape to the heads and fin blocks

milling the transfer ports into fin blocks.jpg

fin blocks and heads ready to profile and port..jpg

fin blocks and heads ported,profiled and starting to machine the fins, heads finished.jpg

Next step is the machining of the exhaust ports and fins into the cylinder fin blocks. i will upload the photos as soon as i have finished this last step. I think i will tackle the elbow exhaust stubs after these are finished.

Cheers for now

Dean

Edited By dean clarke 2 on 02/02/2014 00:18:08

dean clarke 207/02/2014 21:38:30
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154 forum posts
330 photos

Well I have finally finished all the exhaust stubs, what a mission! This step of the build was probably the most challenging for me in many ways as I wanted to have the typical aero v12 looking stubs, but how to do that without castings. So i machined a bar stock to the top view profile and then cut off the correct number of biscuit slabs. These were then set up in the mill after marking out all the relevant dimensions for drilling the internal holes. The first slab was set up to a jig formation and the others just inserted to repeat the process. This saved a great deal of set up time as i had to do it only once for each step. Once both holes were drilled I made a mandrel to mount the stubs on for turning both ends. When all the lathe work was completed I then finished them off with a file to final shape and cleaned up with emery tape. here are some photos of the parts etc

exhaust stub bar stock and turning tool.jpg

exhaust stub biscuit and turning tool.jpg

finished cylinder fin and head assembly.jpg

finished heads and fin blocks with exhaust stubs fitted.jpg

So next its onto machining up the split main bearings and backplate along with the prop driver and spinner nut. This will complete the bottom end of the engine.

Cheers for now

Dean

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