In the last post, I wrote that I needed to attach the trigger wheel to the crank somehow in order for it to be able to be used to fire the ignition system. The logical place to attach this to is the crankshaft damper. This is a big lump of nodular iron that is attached to the front of the crank with the aim of contributing to (1) the balance of the engine, (2) the flywheel effect and (3) damping the effects of the crank's turning the up-and-down motion of the pistons into rotational motion.
The 'easy' option is to bolt it to the front of the damper, but the problem here is that the bottom pulley attaches to the damper. That's OK, but anything the belts touch (alternator, water pump, power steering) would need spacing forward 5mm (the thickness of the steel of the trigger wheel), which is a pain. My solution to this is to turn a register in the damper and attach the trigger wheel that way. I am aiming for an interference fit, so I'll have to cut the register pretty accurately (within a thou or so) I think. I reckon to be having to put the damper in the freezer and the timing ring in the oven to get the two things to mate together.
Probably some of you are thinking about the consequences of attaching the timing wheel now on the timing. So basically the question is "how do you know where TDC on pot one is without the engine together?" Well, I don't. I could build the engine up and do this prior to balancing (and I may yet do), but with the software the Emerald ECU runs, you can supply an offset. So perhaps I position the timing wheel 90Deg from where it should be, I can correct this out in the software.
So, in terms of pics, here we are - the damper mounted in the four jaw on the lathe:
On the four jaw chuck, the jaws move independently of one another.This means you can set jobs up in the lathe with great accuracy. You can see the dial gauge mounted on the cross slide here. It took a while, but the damper spins in the chuck with less than 1 thou run out. That's pretty true.
Unfortunately my digital vernier let me down. It was a cheapie, and it was a bit old, so I got what I deserved - cheap tools always let you down when you want them. This meant I couldn't complete the cutting of the register because I can't measure with anything like enough accuracy how much to take off.
Here's the cut so far:
Lots to go. Here's a pic with the trigger wheel:
There's a slight risk in the way I'm doing this. That ring you can see outside the bolt holes on the crank damper is a ring of rubber that's bonded to either half of the damper. Obviously the wheel will be able to move fractionally. However, I'm betting that in real life, this makes sod all difference.
I logged into my own blog the other day. It's a useful resource (at least for me). I was looking for something about the camshaft I'd bought for the V8, and noticed that the last blog post was 7 months ago! That's what having another ankle biter does. Anyway, I did say (way, way back) that I wouldn't say when I'd just been accumulating parts, but I would blog when I'd actually done something with them. Well, rest assured the parts accumulation is ongoing. The aim right now is to get the bottom end built. However, that means balancing it. There's a load of bits to get in order to get this done. Basically, anything that hangs off the crankshaft needs to be balanced, so although I had the entire bottom end of the engine bought, I still needed to get the crankshaft damper, bottom pulley, flywheel, clutch and all associated nuts and bolts in a state where they could be balanced.
As I want to run a proper ECU controlled injection and ignition system (I already have an Emerald ECU bought), I need a trigger wheel. These are basically a toothed wheel which has tooth missing. A magnetic sensor detects each tooth as it passes, and through the missing tooth, the ECU can tell where the engine is on its firing cycle.
This is the one I have:
It's a laser cut ring-gear style 7.5" job from www.triggerwheels.com, who have this base covered pretty well.
Basically though, you need to attach it to the crank somehow, and this is where I've shown great forward planning in investing in a lathe.
A small digression:
Last time I used the three jaw chuck that came with the lathe, I noticed a bit of run-out (basically whatever's in the chuck wobbles ever so slightly). With a three jaw this is going to happen, and run out of a about about a thousandth of an inch in each inch you move away from the chuck is about what you get. Which is about what I have. Still, I have a decent quality chuck, and didn't see a reason why I shouldn't give it a clean and see if this makes is a little more accurate.
Here's the chuck off the machine:
And the machine chuckless:
That bit of wood on the ways is because the collar you can see in the pic (which is what holds the chuck on the taper) can eventually force the chuck off the taper as it's spun. Chucks are heavy - you don't want one landing on the ways of the lathe.
I took the chuck to bits and gave it a clean and regrease.
It really wasn't at all filthy, so I'm expecting zero as a result of my efforts!
Unfortunately the phone ran out of battery at this point, so the rest of the process will not be documented, but overall I took it to bits, cleaned the scrolls and put everything back exactly how I found it.
Just for fun, I mounted the faceplate in the lathe:
Earlier this week, I found a 10" four jaw chuck locally to me (same guy who sold me the lathe), so snapped it up. I didn't quite appreciate how big it would be - it's a big lump and no mistake. Here it is next to the cleaned and reassembled 3 jaw:
I've always wanted a lathe. Been messing about wanting to get one, doing various ebay searches and occasionally bids, but never really got serious. Well, those days are over. I have a lathe.
It's a Colchester Student. It's got that curved end on the left hand side, which means it's a 'round head' model. It was made in 1962 (I'm informed by the dealer who sold it to me), and in a small amount of family coincidence, the motor inside it was more than likely made by a firm that my wife's great uncle owned.
Now the fun part is to start to use it. I've got a piece of aluminium bar that I'm just messing about with at the moment. I've bought a few lathe tools. They're the indexable kind and I've done something like some parting and a small amount of turning. Right now though the tools are set too low, but I haven't got any shim steel (ebay will correct that), so the result is that the turning isn't that great, and an attempt to face the bar left a nub.
I've also only got a 3 jaw chuck at the moment (although I do have a faceplate too), and although the three jaw is a good quality one, it's got a bit of run-out and I will need to take it off, take it to bits, clean it thoroughly and put it back together again. I could really do with a 4 jaw chuck, but these things are expensive, and they're heavy, which means that postage is chunky too via the 'bay.
Anyway, I do have a small job to do for a mate, so I will need that shim steel and then I'll have a crack at that.
It would appear that I'll be back in the world of gainful employment very soon, so I thought I'd do a little retail therapy. I bought pretty well everything I need to get the Enfield working again (bar some odds and sods that I've not planned for, obviously). I also took the front forks down to a place in Rochester to get them rebuilt/reconditioned - I'll see what sort of job they do and see if I farm any other jobs out to them. Now I have 2 kids, time for doing it all myself is short.
Remembering that the aim of this work is to get the bike up and running, reliable as any old Brit bike will be and to have fun, I've not gone for originality (although everything I do will be reversible) and I'm certainly not shelling out loads of cash when I can make do with what I have. The exhaust is pretty ropey, and really needs rechroming. I'm not on for this just now (although I will rechrome at some point, I think). Anyway, I ordered plain black exhaust wrap, and a set of megaphone silencers and got to it. I did one side in the exhaust wrap and I just left the silencer hanging off there so I could see the effect. I like it!
The photo is a bit crap as it's from my phone, and the crap around the bike distracts from the main point. Anyway, a couple more.
There's no baffling at all in that silencer! I can't wait to fire it up!
In this one you can see I've removed the loom now:
I'm going to build a new loom. The old one is a bit crusty and is home to a few scotchloks and other dodginess. I'm going to incorporate some relays, I think as I don't want to have the whole current of the electrics going through the switchgear, even though I suppose it's designed for it. I have also bought a little box of tricks that is supposed to do away with the rectifier and the Zener diode on the bike. Again, simplicity has to be the key to reliability. It's fair to say that although what was there could work, I don't know it does right now, so might as well put something in place that's more modern.
It is a little one step forward and two back with the bike, but I feel now I'm moving again, and that's the main thing. I'd like to go to the Goodwood revival on it, so that's the aim. We'll see though....
Posts on this blog have been few and far between. It's down to a combination of 2 things. Firstly, there was too much work. I was working too hard at my job to make any progress on the engine/car. Secondly there was not enough work; my role was made redundant, and I was no longer required by my firm. This has been the case since mid-November 2012.
Anyhow, why am I posting then? Well, I figured as I'd done something interesting(ish), I'd post it. I built a potato cannon. This was really to cheer myself up after a spot of root canal work. I'd spend 2 hours at the dentists, and had moped about the house most of the day, finally settling down to do some internet surfing about 2.30pm. I ended up in a sort of 'what the flip was I looking for again?' type moment on a page on youTube with someone firing a potato cannon. I'd been interested in this for some time, and, thinking I'd got a spare couple of hours, I searched for a UK page where someone who'd done the same thing. Nothing against the US footage/pages I'd seen, just that I knew that if I got the UK page and there was the detail on how to make one, I'd know that I wouldn't confuse the guys in the builder's merchant with some US speak widget I was trying to order. I found this site which looked like it had promise. So I ended up with this:
Which is has the essential 2 parts to it - the below, which is the breech end, is the combustion chamber and firing mechanism, and the big long bit, which is the barrel.
My propellant is this:
My original plan was to pretty well gently lob potatoes over the garden next to mine, into the next-but-one. The idea was that I'd be able to judge it well enough so that I could call my neighbour and ask him about potato rain or something. He's ex-navy and well up for some lads type laughs with this type of thing. In the event, my test firing was so ferocious that I ran straight round there to get him round and help me test it properly.
We used this field as a range:
On firing we fired test shots with increasing amounts of spray. The first went 70 yards, the second 120, the third 150 (which is that tree line you can see at the far end of the field) and then we managed to lob a few more over the trees into the next field. Over 200 yards.
The next day we had some friends come round. Clearly a toy like this was too good not to show off. Mobile phone footage was taken!
Note that we back onto farmer's fields!
The pieces of ply in the foreground are from previous firings. A piece of potato shot from this can do serious damage!
Looking at other sites, there seems to be massive over-elaboration with these things. There's compressed air and electronic igniter circuits and all sorts. While interesting to make (no doubt), the essential parts of the fun are (1) big loud bang and (2) potato propulsion over unexpectedly long distances.
If you wish to emulate exactly what I did (and if it doesn't work out well for you, it's your look out - I take no responsibility for you maiming the neighbour's dog or whatever) you will need something like the following:
1) A length of 2" bore solvent weld waste pipe (it's sold as 55mm, but do not buy it metric - it just makes things awkward as there are odd sizes that are 'metric' and these do not fit most other waste systems). This is for the barrel. I used 70cm, as it looked about right to me. I think you could go longer, and perhaps that gives more range. You could certainly go smaller bore, and this would mean (a) your potato should achieve a higher velocity and (b) you get more 'rounds' from each spud.
2) A length of 4" bore solvent weld waste pipe (it's sold as 110mm). I used about 30 cm of this, and it's for the combustion chamber. I also used a second piece to wrap round the first - I'll explain why later.
3) 2 x 4" solvent weld straight connectors. You'll find that the other bits you need do not marry up directly to the 4" pipe, their outside dia is too great.
4) A solvent weld screw in inspection lid. This is for the breech lid.
5) A solvent weld reducer to go from 4" to 2" (or whatever bore you used - if you go lower than 2" you might need to buy 2 adaptors - 1 to go from 4" to 2", and another to go from 2" to 1.5" or whatever.
6) Solvent weld cement
7) Epoxy glue
I had the waste pipe lying around at home - the rest of the above I bought from my local Travis Perkins, along with the electrical tape and gaffer tape mentioned below.
8) A piezoelectric oven igniter. These are cheap off ebay, you can see from the pics that you need the push button type.
9) 2 x 5mm bolts, 2 x nuts to suit (for the electrodes), 2 lengths of decently thick wire (something like a bit of main beam cable from a car), a good roll of insulating tape, and a roll of gaffer tape.
10) Tools - a drill, a 5mm drill bit, a spanner for the above bolts, a pair of pliers, a soldering iron (maybe) and some solder, some sandpaper, a good woodsaw or hacksaw (to cut the pipe)
11) Hairspray (I used Tesco own brand in a blue tin), Potatoes.
12) A broom handle
What you do (read the whole set of directions before starting):
A) Put the plumbing stuff together with solvent cement.
i) The screw-in inspection lid goes on to the first straight-on connector
ii) The first straight-on connector goes onto the 4" pipe
iii) The second straight-on connector goes onto the other end of the 4" pipe
iv) The reducer goes onto the second straight-on connector
v) The 2" pipe goes into the reducer.
B) Make the igniter (the cannon's trigger)
i) Take 2 40cm-ish lengths of isulated wire, strip both ends of both pieces.
ii) Attach both pieces to the piezoelectric button (it's kind of obvious, but one connector is in the bottom of the igniter, the other is on the side.). I used solder for this, but if you have the right spade connector for the bottom terminal, you could get away with not soldering things.
iii) Loop the wire from the side terminal up and away from the one at the bottom, and wind electrical tape around the piece of the igniter below the thread generously to ensure that the two terminals are well away from each other.
iv) Loop the other stripped end of each piece of wire around the threads of each bolt and tighten the nut onto the wire to ensure good contact. You should now have a button smothered in insulating tape, but with two wires hanging away from each other with a bolt hanging off each one.
v) Liberally wrap each of the nut and bolts in insulating tape, leaving the remaining thread below the nut free of tape.
C) Putting it all together:
i) Drill two 5mm holes in the first straight-on connector such that when you poke the bolts through them, the bolt tips end up about 7mm apart. You should be drilling such that the drill bit is going through the connector and the 4" pipe. The spark should jump that with no issue.
ii) Use the epoxy glue to secure the bolts in the holes.
iii) Run the wires down either side of the combustion chamber (the 4" pipe) so that they are on opposite sides. This is important, the spark will otherwise jump between the wires, meaning no spark at the electrodes (the bolts). Wrap the combustion chamber in insulating tape to hold the wires where they are.
iv) Take 15cm of 4" pipe and cut one side lengthways. Open this up and fit it around the combustion chamber and the wires. Secure this with gaffer tape (mine was pink - gaffer tape was sold in aid of breast cancer). This may well be optional, but this is exactly what I did. I did it mostly to insulate the wires from each other.
v) Use more insulating tape to attach the button to the combustion chamber - again making sure the two wires are well away from each other.
vi) Use sandpaper to chamfer the end of the barrel down so that it will cut into a potato (see the pics)
D) Do some testing:
i) You should do this test before drilling any holes probably, but you should test that the spark will jump the 7mm. Ensure the wires from the button are well away from each other, and test using an off cut of the 4" pipe. Drill two holes and then poke the bolts through and press the button. Keep away from both the wires and the electrodes. If it wont' jump, try sanding the bolt tips a bit to clean them. Ensure the electrodes are insulated from each other as much as possible. I added the silicone sealant you can see in the photos between the electrodes for this reason.
After all of this, I waited until the next day before firing. This meant I knew all the glue was set.
Firing (make sure that there is nothing you don't mind destroying anywhere in front of the muzzle line):
i) Take the inspection lid off the breech.
ii) Push a potato down on the barrel such that the barrel cuts a hole in the potato
iii) Use the broom handle to push the potato down to the bottom of the barrel - obviously avoid pushing it all the way out into the combustion chamber.
iv) Spray hairspray for a second or so into the combustion chamber - try to avoid the electrodes.
v) Screw the inspection lid back on
vi) Position the cannon firmly so that it cannot move in any direction
vii) Press the button.
viii) Be surprised!
If it doesn't work, be careful of opening the breech and pressing the button - the flame will shoot out the back of the cannon. Fortunately my neighbour was fine about losing the odd bit of hair/eyebrow when this happened.
I also used butane/propane mix from a blowtorch, and that worked well, but no real discernible advantage over hairspray in terms of propulsion.
Started to prep the block today. Here's the block as I picked it up from the machine shop. Covered in 2 layers of protective plastic and parcel tape.
Basically, the below is the plan. These are all POR-15 products. The Marine Clean (green label) is an industrial strength degreaser, which needs to be diluted 1:1 and sprayed on, brushed in and then rinsed off. It's water soluble, so it's easy enough. Then the Prep and Ready (blue label), which is a rust converter and stabiliser. It's supposed to help the next coat adhere. Again, it's spray on, keep wet by more spraying for 30 mins, and then dry back off. The result is that you end up masking and taking off, masking and taking off.
Here's the block, upside-down with the bores and bottom end masked up ready for the spraying of the degreaser/prep.
Another view:
The block came with a base coat of satin black. I've been scrubbing at this to see if it will come off. It won't.
From the top. Again masked up like the gimp:
Unmasked from bottom:
Unmasked from top:
Down the bores shot:
Big aren't they?
Anyway that's it. The problem with water based products is that machined surfaces and water are not good. The surfaces rust just as soon as there's a hint of water. So this means all water needs to be wiped off, and then WD40 applied to keep the rust at bay. Trouble is then that you need to keep the WD40 off the recently degreased and prepped outside of the block, otherwise all that effort in prepping is wasted!
Paint next weekend!
Today I went to get the Ford small block V8 block back from the machinists. To remind ourselves, I'm building a 347 cubic inch engine using a 302 small block Ford V8 as a base unit. The kit that I have actually builds a 348 cu in engine, as mine is bored +40thou. This gives a 5.7litre capacity. The engine has been at a local machinists (Modus Engine Services - good bunch of guys) for the last 7 months. This really isn't anyone's fault, it's just the way things turned out. I was in no rush anyway. During that time, I'd bought the camshaft, the crank, the rods, the pistons, the main bearings, the rod bearings, the cam bearings, the core plug kit and the piston rings.
So, now the block is back (no photos - everything is wrapped in plastic to keep it really clean for the build). The work that has been done is:
* Hot pressure test block (looking for cracks) - passed!
* Strip all core plugs, oil plugs.
* Hot wash, chemical dip, and hot wash again.
* Refit core plugs, fit screw in oil plugs to replace press in versions
* Prep all mating surfaces and housings
* Hone bores to piston size
* Fit new cam bearings
* Machine block for conversion to hydraulic roller cam
* Dummy build short motor to check clearances and piston to deck measure
* Skim decks so pistons level with tops of bore
* Relieve block to clearance for long-throw crank
* Dummy build again for final checks, and strip back down.
As you can see, I've (they've!) been quite thorough on the prep for the build. In my opinion, it's folly to spend a shedload on hi-perf bits and bobs and then not giving a thought for the prep of the block. It wasn't cheap, mind you. The machining cost as much as most of the bits I've bought so far added together!
