My 2TG was originaly assembled from old parts I sourced from several places. This engine used normal stock 2TG parts, with normal bore and stroke and old 8.8 pistons. I am using the 11111-88222 head with the large valves. I am using early 40mm Mukuni Solex duel sidedraft carbies. To save money I used a 2T head gasket, as the 2TG one costs heaps and the 2T one works fine, only I have to use extra gasket bits and liquid sealer at the front timing cover. I have used a 2T-GEU distributor which has normal mechanical/vacuum advance, but has magnetic points. To run this I got a NiponDenso electronic igniter/coil off a Holden Shuttle. I have the plugs gapped out to about 1.1mm. I could get the full 2T-GEU EFI system running one day if I can find a airflow meter and computer and stuff. The 3TGTE exhaust manifold and turbo will bolt up to the 2TG head, or any 2T/3T engine.
2TG engine light tune up
First make sure you have a good motor mechanicaly and the valve clearances and cam timing is ok:
intake : 0.009 - 0.013"
exhaust: 0.011 - 0.015"
Both the square notches in the camshafts should face straigth up when No. 1 is at TDC.
Check compression, should be 165psi and all about the same. Limit is 142psi. This will vary with the compression ratio and cams you have.
set ingition timing to about 12 degrees BTDC, or a bit more if you dare
check that mechanical and vacume advance is working
get the fuel levels in the carbies right. 20-21mm from fuel level to top of main jet holder with the holder removed
next get the throttles in sync at about 2000rpm using vacume gauges, OR use your ear at idle to get the slowest speed (depends on your linkage setup)
get the idle screws out 1 1/2 turns from closed
adjust idle mixture screws with the vacume gauge to get max vacume reading, or adjust with ear at idle for fastest speed without being rich
readjust idle to about 1000rpm
repeat all steps till its going good
make sure your return spring is strong enough and you don't have slack in the linkages
I have just rebuilt my 2T-G, and included many of the common upgrades and modifications to get more power and revability out of the motor. Mostly, this just means useing a 3T bottom end for a longer stroke which means more capasity which means more power. Also the motor can be bored out from 85mm to 89mm, or anything inbetween. The other main things to do is lighten the flywheel and use larger duration camshafts.
3T bottom end
Asuming you already have a complete 2T-G engine, these are the details of what you need to do to build the common "3T-G" motor. You need to also buy a old 3T (or 13T) motor, as cheap as you can get because we only need the block and crank, and maybe the pistons. Everything else in the motor is good to us as well, but will only be spare parts if you have a 2T-G already. 3T motors are found in TE72 and TE71 corollas (read T-18 SE in Australia, or Corolla SR-5 in America, or Levin in Japan/ NewZealand). You can use a 2T-GEU block also, or a old 2T block and grind the bit that would touch the conrods. 3T crank, used for the 78mm stroke. 2T has 70mm stroke. 3T crank has 8 counterweights. 3T-C pistons, are needed for the different pin height due to the longer stroke. The 3T-C pistons can be bought new, up to 86mm size which is what I got. The exhaust valve releif needs to be machined similar to the 2T-G pistons so the valves do not hit. Aftermarket forged pistons can be bought for this aplication, from Weisco, Aires, KB etc. Mostly avaliable in 89mm, 88.5mm or 86mm. This pistons already have releifs for the big valves, and make for a higher compression ratio also. All 2T and 3T conrods are the same length so you can use whichever ones you want. Some may be thicker or stronger than others, but they all fit. Most people say to ue ARP conrod bolts, which are easy enough to buy. Many people also say the standard Toyota conrod bolts are good for 8000rpm so if you don't go over that there may not be any point in getting ARP. I am also told that up to 8500rpm the stock conrods will fail, even with ARP rod bolts.
Timing gear and head
The dummy cam in the 2T-G must be used. The camshaft bearings in the 3T block that the dummy cam does not use need to be removed and turned around to block the oil holes. New timing chain and sprocket kits for the 3T can be bought new and used. I bought a new top chain for my engine also, but the 3 sprockets for the top are not avaliable as far as I know. Also, the top 3 chain dampers can not be bought anymore either, so take care of those. 2T-G gasket kits are avaliable, but can sometimes be expencive. I got mine cheap on e-bay, but previously I had used a regular 2T/3T head gasket and used extra gasket bits and silicon to seal the front of the head around the timing cover.
Camshafts and valve timing
It is often surgested to use a cam of about 290 degrees duration, for some reason 288 is a common number, as is 304. 288 cams should be good for alot more high range power while still being drivable on the street. I am using 305 degree cams which should be fairly wild and give good power at the race track. Care needs to be taken when installing different camshafts, and a degree wheel should be used.
I lightened a standard 3T flywheel from about 12kg to about 6.5kg. I am told the genuine 2T-G flywheel is lighter at about 8kg, but I did not have one of these, I was using a heavy 2T flywheed 12kg. Do not do this! The heavy flywheel will suck so much performace out of our little engine, it just won't feel fast at all. I ended up starting with a 3T flywheel (it does not matter which), and lightened it on the lathe to about 6.5kg, then had it surface machined and ballanced with the clutch and crank. Make sure you know exactly what you are doing when lightening a flywheel, usualy only trust a experienced automotive machine shop to do this.
3T-C pistons and rings Forged 3T pisotns and rings ARP conrod bolts cranks and conrod bearings 2T-G gasket kit 2T/3T lower chain and sprocket kit 2T-G top chain (sprockets and dampers not avaliable)
Items to recondition: head plained, valve regrind pollish crank machine flywheel bore and hone block regrind camshafts