The biggest differences I see between the LG3 timing cover and the series 2 cover is that the lower heater hose port is way different and the hose piece it uses hits the power steering pump. I'd have to double check, I think the cam sensor location was different too.
I think the L27 timing cover moved the cam sensor to the same location as the series 2, I don't have one just sitting around to check it's exactly the same, but it's really close. But the lower heater hose port has the same issue, points straight back into the power steering pump.
While those are not impossible challenges, you're basically reworking the entire lower heater hose area in a way that basically screws anybody else over that has to work on it, and I'd bet you'll spend way too much time on it. After taking some measurements however I think I found a better way, not reliant on spending a bunch of money and time finding and modifying a stupid timing cover (which requires welding to do it right).
The thrust plate for the oil pump is the same across the series 1 and 2. The pump itself looks like it's OD is 0.3mm (0.011") larger. I need to check 'new' parts to verify, but that might just be due to wear. The pump sections have the same pump pattern machined in them - the series 2 internal piece fits the series 1 external piece perfectly. The crankshaft nose that drives the timing sprocket is the same between series 1 and 2. LG3/LN3/L27 share the same oil pump that is 1.8mm wider than the series 2+. The series 2 oil pump drive grooves are different than series 1.
So what I've settled on tries to re-use as many parts as possible, buying as few parts as possible, and machining as little as possible.
Parts needed:
Melling K135 - LG3/LN3/L27 oil pump repair kit. Comes with a new oil pump, thrust plate.
Cloyes S729 - LG3/LN3/L27 crankshaft timing sprocket
All your old parts that the above replaces.
The spacer:
First, you need to get your old thrust plate reduced to 1.8mm thickness (flatness tolerance very tight) and then bore the center to 89.8mm ID (about 0.030 over the OD of the pumps which are 3.5"OD). You will probably need the help of your local friendly machine shop, I can't tell you shop rates, but I expect this to be the most expensive part of the process, probably around $100, and is likely cheaper than making something new from raw stock. What is critical is that it clearances the oil pump OD and that it's flat. Anybody that's ever removed their old one can see just how worn out and grooved the OD of the pump can get without adverse effects, so I don't see .030 clearance being a problem. Basically you're turning it into a spacer plate to take up the 1.8mm difference.
You can then install the oil pump repair kit with the spacer in your timing cover. Half-way there!
The pump drive:
Next, cut off the timing chain teeth from the Cloyes S729. All you need is the complete pump drive section, ideally it should be machined so the cut end is square, but I'm sure the creative among you would find another way. If you have a SINGLE roller set already, the length should match the pump drive from your roller kit, all you do is drop it in and button everything up.
The timing chain drive:
If you have a regular timing set, you have one last step. This is probably a good time for a new set if you need to do that too. Remove your crank timing sprocket, measure it's overall length. You are going to cut the oil pump drive off it, this is best done on a lathe to protect the timing sprocket teeth and make a square cut, but again...improvisation possible. Note that only remove as much material as needed so that the pump drive you created above and the 'new' timing chain drive are the same overall length as what you started with. Then you re-install your timing chain drive section, the pump drive sections, and re-assemble as normal.
The issues with this method is that anybody running a double roller is basically out of luck.... But I think I have a solution for that as well, and you can get a double roller for a lot less than the series 2 rollers cost! I need to verify it first, but I can share what I do know.
The Double Roller:
Additional parts needed:
Grand national double roller timing set
LG3 specific camshaft (all you need is the end plate, not the whole cam, so a damaged/used cam should be fine)
Possibly a machined oil pump cover and double up the timing cover gaskets
Cam Sprocket adapter:
Simple. Cut the end plate off the camshaft. Use it to make an adapter to fit the cam sprocket from the GN to the camshaft of the series 2.
You can see that while it has adequate clearance to the stock series 2 oil pump (much more than the series 2 rollmaster does), it would be tight with the added 1.8mm to the oil pump. The ZZP machined oil pump cover is 0.6mm thinner, and the extra gasket would get you another 1mm. So, it's really close, but until I measure and test fit I won't know for sure.
