1953 Rover P4 75

June 2018 - Engine and transmission tear down

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One of the biggest unknowns in this whole project was the condition of the Toyota 22R engine and Aisin-Warner A43D transmission. I had never heard the engine run and had no idea of its mileage because there were no records about the 1982 Toyota Celica donor. If the Rover passed Texas safety inspection in 2013 then it must have been able to drive and stop. My first step was to do a compression test so I attempted to turn over the engine by hand using a breaker bar. Unfortunately the crankshaft did not turn even an iota. All 4 spark plugs were removed and each cylinder was filled with rust dissolver. After a few days to allow the dissolver to do its work, the engine was still stuck. At this point, I started researching other options such as possibly sourcing the original Rover engine and transmission to the USA. Turns out the best chance of finding one is over in the UK and I wasn't going to pay to ship several hundred pounds of engine from the UK to the USA. That'd far outstrip the value of the car.

The alternative was to stick with the Toyota since the frame was already modified for the existing configuration. I checked prices of rebuilt long blocks around the USA and local rebuild costs. I ultimately opted for a long block rebuild done by Performance Machine in Thrall, Texas. To avoid the tear down charge, I tore down the engine myself.

Toyota 22R engine

Lot of soot on the head. Carburetor was probably not tuned properly and engine ran way too rich.

Still stuck even with no transmission and head in the way. Trying more rust dissolver in the cylinders.

Pulled the number 1 and 2 pistons, but 3 and 4 are still stubbornly stuck. The rings rusted to the cylinder walls.

Finally pulled all pistons out. What ultimately worked was applying more rust dissolver on the back side of the pistons and using a lot of force on the flywheel with a large breaker bar.

Engine all torn down and ready to be sent off to the rebuilder.

I held off until late August to send off the engine to the rebuilder until after progress was made on the P4 body. The turn around time for the rebuild was about 3 weeks so I didn't want the engine sitting around wasting warranty time while I was busy with the body. Total cost for the 22R long block rebuild was about $1100 including boring all cylinders, crankshaft and valve grinding.

Toyota A43D transmission

I don't have photos of the transmission being disassembled to show here. Being an automatic transmission, I wanted to do as little disassembly as possible because there is no inexpensive way to bench test the transmission to determine if it's functional or worn out. The fluids were drained and remained red so that's a good sign of no overheating. Who knows if those are fresh fluids since the transmission was one of the biggest sources of leaks. I pulled the oil pump and the first overdrive gear to inspect the clutch packs to get an idea of age. The pump looked pretty clean and not worn out. The overdrive clutch pack probably wasn't a good indicator of the first 3 gears if it's hardly used, but the plates looked fairly new and not brown or black from burning. So I decided to go ahead and reassemble the transmission and gamble that it still is functional especially if the Rover had been running and driving before.

The transmission original to the 1982 Toyota Celica was a 4-speed A40D automatic. From what I gather, the A43D that came from a late 1980s Toyota Pickup and was used in the Rover is a beefier version of the A40D to better handle heavier loads. Finding any rebuilt 1980s-era Toyota transmission turned out to not be easy nor cheap so I was hopeful the existing A43D transmission was still OK. I would find out later when the engine comes back from the rebuilder. In the meantime, I ordered a kit for the transmission to replace all seals and transmission filter.