After the MGA had sat for a week with the cylinders and valve-train lubed I was ready to see if the engine was free. The big question being – would this long dormant car start and even drive?
With the plugs out (and thus no compression) when the car is in neutral the engine should turn easily on the crank. Alas, the MGA did not come with the hand crank, so I put it into gear and gently pushed the car forward by the rear bumper attachment points. The engine seemed to turn with the wheels. So far so good. At this point I made sure the fuel pump wiring was disconnected, patched in a small 12 volt battery in place of the twin 6 volts and was ready to see if it would turn on the starter. I kept the plugs out. The nice thing about the MGA is that like the TD etc. there is a starter solenoid with button in the engine compartment. The starter engaged and spun the engine easily. I was feeling really good now.
Ok – to start an internal combustion engine you need fuel, spark and compression. So, the next stage was to think about fuel. I opened up the stop at the bottom of the tank and it was dry. It looked to be a brand new tank – so I was not surprised. I then put about a have gallon in the tank and disconnected the non-original rubber gas line between the non-original glass filter and the carbs. I aimed the hose into a container. Then hooked up the fuel pump and ran it until gas began to flow through the filter and into the container. The filter stayed clean and the gas looked clean. At this point I hooked the line back onto the carbs. I had already made sure the floats, carb pistons and linkage was free.
Now for spark… I opened the distributor. The cap was dusty, but it, and the rotor and points looked new. I replaced the old plugs – which looked serviceable anyway – with new ones. I tested the low voltage ignition circuit and got a bit over 12 volts coming into the coil with the ignition key on. I assumed I would have spark so long as the coil was ok.
Here are the specs on the plugs I used –
NGK BR6ES Specifications:
Thread Size: 14mm
Thread Pitch: 1.25mm
Seat Type: Gasket
Resistor Value: 5K Ohm
Reach: 19mm (3/4″)
Hex Size: 13/16″ (21mm)
Terminal Type: Removable Nut
Overall Height: ISO
Gap: .035″ (0.9mm) – You can regap to .025 mm which is spec for MGA
I had runs the engine on the starter a bit to make sure things were lubed. I then did a compression check. This is always a little scary as you can have an engine that spins freely, but has a hole in a piston or two, a dropped valve or similar issues and have low to no compression in a cylinder of two. Then is teardown and rebuild time. I was very happy to see the compression on all 4 cylinders was in the range of the low to mid 130 lbs psi. Not bad for a stock 1500 MGA.
I put the plugs in, put a fire extinguisher close by, turned on the key and ran the fuel pump to get gas to the bowls. I made sure I had no leaks. I grabbed the choke linkage in one hand and then hit the starter button on the solenoid. I expected s slow dance of a churning starter gasping engine, hopefully eventual slow start through fits and bursts. I almost jumped out of my skin when the engine fired up immediately and ran like clockwork with a strong smooth idle. I actually, turned the key off and started the engine again to make sure I was not hallucinating. The little MGA 4-banger was alive and sounded very well indeed – hallelujah!