Wow, long time. Just thought id post up before I move into the new blog system.
right firstly I need to big up the main man that is "FRANK" for his help in finding parts and his blog for all his useful experiments.
Started acquiring parts for a CG conversion 18 months ago, got a CG13 bottom end off of squarepants back then, did a few experiments with it, (above). but more important things came up over the backend of last year, (I bought my first house in June, its our family home been there since I was born, massive back garden, really good neighbors can do anything anytime, all mine and my dads w/shops etc, off road parking for 4 cars, (or 1 van and 2 cars lol), it was being auctioned off and we would most definitely been evicted if I didn’t buy it) anyway, autumn time last year I mentioned to frank I was after a CG10 complete engine, low and behold he pm's me back, there’s one here, bla bla bla. few days later I had a complete CG10 engine flywheel and a few other bits, that sat in the shed for a while as I was busy building my new workshop, next months pay came in and I advertised on here for a CGA3 crank, no one replied. But reading franks blog one day and I noticed he had 2 CGA3 engines, so a quick pm to him and a few days later had a CGA3 crank and shells, that too sat around for a while.
Got my w/shop up and weatherproof, got to the inside,
right off topic slightly the w'shop is 10 meters long, 1 long building, but my plan is to sub divide it up internally, 1st 1/3rd machine shop, lathe drilling welding etc, 2nd 1/3rd clean w'shop my electronics and clean things, 3rd 1/3rd storage for my fishing tackle and my dads wood working machinery etc. got the 1st 1/3rd done, put the first partition wall up then ran out of pennies this was about November time, decided not to spend any more just yet as I needed to catch up on my credit card.
Back on topic.
List of things I had at my disposal
CG13 bottom end, block, pistons, crank, shells, etc, etc.
CG10 complete engine,
CG13 cams
spare CG head
CG13 flywheel
CG10 flywheel
CGA3 crank
probably other stuff too
one evening, got bored nothing else constructive to do so I dragged the CG10 engine in the w'shop up onto my specially made stainless steel topped 'engine rebuild and welding bench' couple of hours saw it stripped the bare bones and everything in labeled bags
stripped the CG13 bottom end also into labeled bags.
right bit of tech now.
as can be found on wikipedia or other places Haynes etc,
CG10 is 998cc
CG13 is 1275cc
CGA3 is 1348cc
The CG10 and 13 have the same bore, 71mm,
However the strokes are different, 63 and 80.5 for the CG10 and CG13 respectively,
The CG3a has a bore of 72mm and a stroke of 82.8
My original plan was CG10 block CG10 pistons CG13 rods CG13 crank, giving me a high compression 1275cc in a CG10 engine number.
However my plans changed somewhat when I discovered the CGA3 shared the same bearing spacing’s and sizes as the CG10 and CG13.
The new plan was CG10 block, CGA3 crank, CG13 rods and CG13 pistons.
Giving a potential 1311cc, however this was going to run into a problem as the longer stroke pushed the pistons out of the top of the block, some head scratching later and I came up with 2 possible options and my dad came up with 1, my 2 were get some CGA3 rods, but ill talk about that below, the other was machine some off the crown of the piston with my newly acquired lathe.
For the record my dad’s idea was a crap idea, it will never work, don’t waste any more time or money on it, you have an engine in your car that works bla, bla, bla.
I opted for turning the top off the pistons, so a few calculations later I came up with how much needed taking off, but seeing as I only had 4 pistons and couldn’t afford to ruin one I put the crank in the engine with a piston and actually measured how much needed taking off, this corresponded with what I had calculated, cant remember exactly how much but it was more than 1mm but less then 2mm.
Made a tool for taking the gudgeon pins out, its sort of a press as drifting just wasn’t working.
I gingerly machined one of the pistons, refitted it and it was bang on then machined the other 3.
Re-fitted the rods and pins, now onto the reassembly of the engine, I’m not going to go into details as it was an ordinary engine build, honed the bores etc checked everything with the Haynes etc, refitted the old piston rings the exact opposite way the Haynes tells you.
Finally ended up with a complete engine once again
I mentioned above about CGA3 rods, there’s 2 reasons I didn’t use them, 1, I didn’t have any, 2 by machining the CG13 pistons I was removing the dish and making them more flat topped thus upping the compression
Summary of what it is:
CG10 block with custom machined CG13 pistons, CG13 rods, CG series head with CG13 cams.
In simple terms a high ish compression 1311cc motor.
Once it was complete I made an adapter collar to make the k10 dizzy fit into the k11 head, also I made a piece that fist onto the k10 dizzy to make the drive the same as the k11 cam.
I made an aluminum plate that bolts onto where the k11 dizzy fits, with holes in it so the k10 dizzy can be adjusted and locked.
Months and months ago I made an adapter plate to enable the k10 carb to fit onto the k11 inlet manifold.
I also made a custom 35mm ID 4-1 manifold that comes out of the collector at 47mm ID and onto the rest of the system in 47mm ID but i've yet to fabricate this.
While the engine was on the bench I got a k10 block and drivers engine mount and made a jig that bolted onto the gearbox holes for reference and the engine mount, I bolted this onto the CG10 block so I knew where the engine mount needed to be, I had a spare k10 engine mounting chopped it up, got some 1” x ¼” flat bar and made a driver side engine mount.
I had the engine completed mid December, but was waiting for the Christmas break off work to get it in and running, I decided to start it the week between Christmas and new year. I couldn’t believe how well the installation went I never really ran into any trouble the engine mated with the k10 gearbox, my jig made engine mount lined up perfectly, had a bit of an issue with the heater hoses but all came good, used a k10 bottom hose a k11 top hose, the matrix pipes were a bit more tricky though, the fittings on the engine are ¾” so off to the motor factors came back with some ¾ inch pipe, cut to length pushed on the engine, came to put on the matrix, too big, the k10 heater matrix is 5/8”, back off again got some 5/8” pipe, fitted on the matrix fine but a bit tight onto the engine, had to warm it up in hot water but it was ok.
Got the inlet manifold and k10 carb on, had to buy an electric fuel pump as the k10 one is mechanical and obviously the k11 isn’t.
Came to put the exhaust manifold on, as I had used quite long radius bends to aid flow it stuck out quite far from the engine, it his the god dam radiator, only by about 5mm too. So for the time being I got my k10 4-2-1 and re-drilled the flange to the k11 bolt pattern (the ports are the same) and fitted that.
The k10 alternator is 3 wires, main to battery, to light and excitation current. The k11 one I had was only 1 wire, as I couldn’t be bothered with altering the wiring I altered the bracket and had to make a top bracket so I could fit a k10 alternator onto the CG engine.
Time came to fire her up, double checked all connections etc, turned key, bit of gas, never really fired, at which point my dad wondered out, giving it all I told you so, etc as they do, turned over again bit more gas, bang flame out of carb.
Now I’m like yea it’s definitely got fuel and spark, it’s just in the wrong order, plug 1 our, dipstick in hole turn engine till at TDC, dizzy cap off is the rotor arm pointing at plug lead 1, no, well turn it so it is then, right cap back on, plug back in, turn key again, right were cooking on gas now, but lumpy, had to turn the idle up but at least it was running, I was happy for the day, was getting dark and very cold and tea was ready. After tea and a good night sleep, got up early straight into w’shop altered the new 4-1 manifold to make it fit, fitted that, and now armed with my strobe gun fired the motor up and let it warm up, disconnected the vacuum advance to the dizzy, turned off connected strobe gun and kicked her up, turn on strobe gun, crap its about 35 deg advanced, quick adjust dizzy, adjusted it to around 10deg BTDC.
Fitted bonnet and bumper back on, took her for a spin, it wasn’t right but it was running, the carb wasn’t jetted correctly (which is obvious as the cams are different there’s twice as many valves and it’s a bigger engine), over the next couple of weekends I experimented with jetting, i’ve got it now where its almost bang on, but with out a rolling road session it wont get any better.
The standard carb is only a stop gap anyway as i’ve got a set of bike car'bs which i’m going to make a manifold for and also i’ve got a set of 2 twin choke Weber 36dcnf’s (the same type that Curtis and speedle had on there car).
If you got this far well done, i'm sure I wrote less than this for my final college project ha-ha.
