Ahh nice. More toys to play with.
This is AWESOME!!! I always wanted to know about this stuff
I would love to do an IDI diesel head in cast Iron or steel, anyway that I can get a digitized version for rapid prototyping? CAD etc. I would love to CNC a head, and I know a Machinist ho is hurting for work and if the demand is high enough and he has the specs He can CNC anything.
Cnc heads are extremely hard to design due to tooling access above the combustion chamber where the waterways are. You could drill it and insert heat pipes as used to cool moulds in the injection moulding industry but that gets complex and messy. For every axcess point you make to get a tool in to cut a waterway you need to close it up to cover your tracks.
Below is a typical core for forming the coolant path inside the head, as you can see its complex, and I have to say figuring how to make a mould box for one of these, and getting it out of there took me a while to figure out. But its very possible using removable parts and slides along with co2 cure sand.
You could perhaps make the head in 3 layers and pin/bolt them together but that gets messy if you have to jig up a lot of times.
I thought about billet for a long time, but put it out of my head and am going cast instead, just my two cents, maybe you could come up with a way.
I have a router.......just...and ok Ive 3 lathes and a mill but I use them only when I have to, which I think I haven't so far
If you stare long enough a the tools you have you'll figure out how to make them work for you!
I seem to be doing a lot of talking of late Ill post up the latest asap
Here you go so
Onto the pulley....
Standard crank pulley off a 2.0l, this will end up being my pump pulley as it has the correct amount of teeth I need so Im going to use it. I will have to make the pulley for the crank but thats minor.
Ill let the pictures do the talking as the pictures were taken at the important cutting steps, pay no heed to the homemade cutting tools for the time being, Ive a few insert tools on order...
The boring head, I talked about this before, its adjustable via the screw on the side, everyone should have one!
Turned and checked with the dial gauge, onto cleaning up the outside,
And finished up, pulley is a lot lighter now and the width I need,
Next up, the centre of pulley, this will be alloy and mount onto pump spindle, I could use some billet here but Im all out, so, its the perfect time to do a casting test by casting a blank from some scrap and seeing how it turns, check for internal gas pockets inside the blank, etc. I have noticed a fair few bubbles inside the heads I cut up for testing/analysis so I want to see If I can get my parts as good as them(if thats how you'd say it)
Bubbles inside the castings are a result of turbulence as the alloy is poured into mould and also the temperature of the metal both as its being heated, and the temperature its poured at.
So onto the blank, the pattern for this is an old aerosol can I taped the ends up to rid the concave ends and negative draft angles.
For anyone just joining this thread now its a good insight into casting again as I photgraphed the stages a bit better since I was in no panic as such as the part was basic, and didn't really matter how long the mould was left closed for(sand can collapse inside mould if left for too long before pour)
Cope(top) filled and lifted off, gate and riser cut and fill sprue also,
The scrap metal,
Approx 3min after ignition,
You can see the amount of dross on top after alloy has melted, this has to be raked off and is useless and not good inside your part,
And raked off,
Flux is then stirred in, this de-gasses the alloy even more and gets rid of more impurities(dross)
You can see the extra that has now come to the top again,
And raked, you dont want to touch the alloy anymore than you need to, the metal skins over by its self, stirring it breaks this skin allowing more air to contaminate the molten metal,
And out, not good to boil the metal either, just enough dwell time and no more,
And poured, pic taken approx 10 seconds after pour,
Did someone say ''The T1000''!..
Blank removed, its dog rough as the tape made lines but it doesnt matter a bit for this as its being turned anyway, its nice converting useless scrap into usable blanks(free) I have to say!
Gates cut, and blank cut in half and mounted in the 3 jaw,
Slow speed until its a bit truer, it wasnt that far off surprisingly,
Trued and end parted off, all rough cuts as yet,
Getting there, no voids or excessive pores to be seen,
Boring the bore hole, I have to get a chuck for the tailstock yet for holes under 12mm, but Im doing fine as yet!
Boring hole to shaft clearance fit,
Done, Ive have to finish up this tomorrow, wont take long, and then I can set about locking rotos to shaft, that'll be the pump done then bar chemical treatment which Ill prob do last when Ive all the other bits done to save setting up all that lark multiple times.
Oh, and heres a picture of the gearbox, 02A, Ill be converting this to fully sequential with some carbon fibre and titanium thrown in now that Ive figured how to bond titanium bearing housings to composite. Thats a while of, but its something for you to think about sure, Ive the thinking bit done on it!
Great updates as usual. This thread remains one of my favorites to read. Have you finished up with the slide throttle intake? I can't remember if that was on this thread or a different one.
I have also been thinking, or more like dreaming, of converting a standard transmission to a fully sequential, but I still have more to learn about transmission design.
You are inspiring and an amazing engineer/machinist.
Ive very little to finish on slide throttles, I was going to wait until I had skimmer done to precision bore the 4 intake holes, but, I can do it on the lathe too so I might, I want to start finishing out each unit part so they dont run into eachother too much, and making it easier to follow also...maybe not
Im going to just put it all in here to keep things handy, so you shouldn't miss it. The title of thread isn't too relative sometimes but who cares sure
Finished out the pulley,
Parted off and turned around,
Removing a bit of excess material that has no business being there, lighten it up a bit,
Im going to lock this to the shaft by grinding a slight flat spot in it and using a grub screw to secure, when I also know correct position I may apply some bond lock too, designed exactly for this, but Ill see, things are a good fit as is, and once the grub screw is tightened It wont stir.
Boring head this time in the chuck and the pulley centre bolted to tool post, you can use the boring head as a mill/flycutter this way also.
In progress, this flat makes it easier to start the bit for grub pilot, Notice the fine pores present in the cast, this is normal and Im happy with there size, below this Image is the lifter bore of a 16v vw head, notice the pores there too.
Drilling on the vee-block,
Filing out the 'U's for the bolts,
Like so, the bolts just keep the pulley together, the centre bore keeps it true, a small bit holds it really,
The rotors have to be locked to shaft obviously so I need to cut keyways if you like into the rotors to be able to locate them on the shaft, I did not want a solid fixing as its the bearings that will take the axial force and not the rotors, so the rotors will float axially slightly on the shaft, but still stay engaged. I feel doing it this way is safer as they will take there own positions then inside the casing, and will have an equal oil film both ends. Ill be driving the rotors with 3mm case hardened ductile pegs installed in the shaft, protruding say, 2mm.
Anyway, onto the cutting,
Rotor clamped lightly in the toolpost, I was lucky, it clamped up directly,
The cutter, this is a diamond and tungsten grit 3mm ball, these are pretty dear(10euro) but worth it when it comes to stuff like this. I could have broached the keyway in the rotors too but that would not be easy. Broaching is basically a file with teeth like a rough hacksaw blade, you fit a centre to rotor, the centre has a slot in it and you drive the broaching blade into this, as you drive the tapered broach in it cuts a bit more as each tooth is higher, in the end your left with a slot 1mm deep, you pull the broach up again and fit a spacer shim behind it and start again until you have a 3mm deep 'saw cut' made for key. Broaching these would not be possible as they are hardened, I would have to remove this via heat treatment, cut the key, and then case harden again, not ideal as the final grinding is done after all these treatments are carried out so it may change dimensionally after the re-treatment.
So ya, thats why I did it this way..
Four light passes and its cut, 8mm deep,
And both cut,
your techniques and skills are endless , like i said before , i want my own machine shop !!!!
with good deals on stuff i could equip myself for less than 10k$ but then i would need a space !!
hey im very interested in the 02A transmission sequential transformation , i want details on how you will modify the existing parts. are you gonna mess up the internals or engineer the shifter arm in order to drive the forks in a sequencial manner? ?
10k.......you'll do it for 1k if your smart!
As for the gearbox, Ill be totally re-engineering the entire box but using the shafts and gears, its going to take a long time and be pretty complex but thats what Im going to do.
Decided to bore out the slide throttles as I needed a 3mm bit to bore pump shaft which I hadn't got and cant get until Tuesday. Its probably no harm as the throttles will then be ready for treatment then also.
Im boring them out on the lathe as I haven't skimmer finished, I need to finish this off soon now too for when the time comes to tackle head, but Ill get it done...
I had to make a mount in order to bolt throttle assembly to tool post,
Setting height of carrier,
Assembling slide throttles once more with some water paper in there to clamp brass for boring once assembled,
Boring hole to pin all three to make sure the brass does not stir,
Bored them all out rough first with a holesaw, its the nearest size I had as the next one up was too big, I could have got a bigger one next week but thats more delays...the boring head will make quick work of the excess...
You can now see the tickover drillings,
Onto the boring, mounting the rear plate on the jig making sure everything is bang on,
And the brass throttle plate,
And a poor picture of the top plate bolted on, and the lot pinned again with the small drill bit,
All heavy enough cuts at this stage, Ill finish up with a fine cut on the last pass, the drillings are now easier see, one above and one below plate, by-passing it in order to fine tune idle speed independently,
Ive bring them all to the correct size tomorrow, but thats where I left it for this eve,
Thanks guys, finish size is 41mm.
As for anodising head, ....no....to bling for me, and it would look weird as its cast
A few more snaps of the finish bore and operation,
One pair finish bored,
Taken apart again to re-mount in order to bore the other pair of holes using the same jig,
With the bits held roughly in place and the plate now at half throttle you can get the idea,
With the top plate removed and wide open,
And at Idle, notice I still have a few mm between throttle plate tab and alloy to allow adjustment further closing air space to valves,
The rear, needing to be de-burred but you get the idea, Ill be cleaning this up and cutting the o-ring grooves next.
And remounting/setting to bore the other pair,
Its not a typical size you can buy you mean.. I ran a lot of figures and did a lot of calculations, as well as simulations(for this combo) and thats what I arrived at on all them. As always throttle cross-section a compromise, but the 41 will hold in the lower rpm range also, when I say lower I mean high 3ks, For what I was gaining up high going larger I was loosing more lower down, air speed is everything.
(your car is 16v also, these are going on an 8v dont forget, then Ill be tailor making a 16v set, same design, different bores!)
Last edited by Brian.G; 06-10-2010 at 03:17 PM.
Although I follow all your threads... I'm very interested in this. Amazing work as always.heres a picture of the gearbox, 02A, Ill be converting this to fully sequential
Pretty boring update....
Got the parts de-burred and the plate blended a little for when its in the tickover position, Im not sure but Id imagine the sharp edge on the plate would make tickover air choppy with the possibility of it whistling a little so I smoothed it over,
Rounding over with the sanding drum,
And a quick buff,
Got this de-burred too,
The brake booster vac slot again, this will be closed off with a 'lid' to form a rectangular 'tube',
And a close-up of it in the idle position, but this time with the plate rounded over as above,
And to give you a quick update of what I plan to do next,
The slide throttle is more or less ready for chemical finishing at this stage.
I have to drill the oil pump shaft and insert pins to locate rotors and do one final check and assembly, it will then be ready for chemical finishing them also.
Once that's out of the way Ill be making the patterns for the intake runners from throttles to head and casting them, the throttles wont be chemically treated at this stage so I dont mind handling them for the mock up/patten making, that way I can give them a final check after all that's done and then treat them.
Ill be mounting the block to the engine stand then and figure out where exactly Ill mount the pump, Ill then make the pattern for the bracket and cast that.
After thats done Ill be making the sump pan, Im still not 100% sure if Ill cast it or not, but Im veering towards casting at the minute, but Ill see.
Its a bit all over the place, but as I said, I want to try and do all the treating/anodising in the one go as its not something you can easily set-up and tidy away in 5min.
Theres plenty of variety that's for sure... Im looking forward to the intake runners as the mould setup is not something Ive done before, the 'tubes' curve slightly in both planes which makes mould set-up 'interesting'.
Ill get there though, sometime.