Here's a fun diversion that I decided to take care of while the car is already down for parts. (waiting for some headlight-related parts so I can button that all up)
The oil filter on this car is attached to an adapter. Looks a lot like a sandwich adapter for an oil cooler, but I guess it's not. It's an offset adapter that changes the position and angle of the oil filter. It seems that nobody really knows for sure why it exists! The original Midget engine doesn't have it. Completely different engine, I'm not even sure where the filter is located on that engine, but it's probably on the other side.
This engine, you may recall, is the Triumph engine out of a Spitfire. Exactly the same engine and transmission, lifted out of the Spitfire, stuffed into the Midget. They did that because they needed an engine that could handle the US emissions requirements and still deliver some performance. The MG engine was tapped out, the Triumph engine was at max bore, but was able to be stroked from 1300 to 1500 for additional torques. Mmmm... torques. So, that's why they did it.
I'm guessing there are two possible reasons for this filter adapter. One is the oil filter itself. The original Spitfire oil filter just plain wouldn't clear the steering shaft, and there may not have been a smaller alternative at the time. Another possibility is that maybe they crash-tested it and found that the steering shaft can puncture the oil filter spraying hot oil in a collision. (doesn't seem likely, but it's possible) One more possibility is that they had to fit the air pump (pumps air into the exhaust manifolds for some dumb emissions reason), and it's right there in that vicinity. So, for whatever reason, they fitted this stupid filter adapter thingy on the Midget 1500 engine.
The filter hangs off of the left side of the engine and looks a little like this:
Notice that little bracket hanging out in the air in front of it? That's the air pump bracket. I need to remember to remove that while I have the filter out. (can't get the bolt out with the filter in place)
And that's not the original filter! The original Triumph filter is still available, but it's hard to get in the US, and expensive. I think the original filter is a little fatter and slightly shorter. Almost everybody has converted the car by replacing the threaded adapter that goes between the block and the filter, and replacing it with one that converts the thread from 5/8-18 to a much more common 3/4-16 thread. There are MANY readily available filters that fit that thread and will work just fine.
Because it fits in this application, the filter they used is a long, skinny 3/4-16 filter. Namely a PL20252. It's about the biggest commonly available filter that will easily fit. Cool.
Why am I talking about all of this? Well, the oil filter adapter is LEAKING. I could replace the O-rings in it and fix that. Or... maybe, I could just eliminate the thing altogether? Man, it was hard to find clear answers about whether it was possible to do that or not! But, it appears that some people have done it by removing the adapter, and fitting a shorter PL10241 filter. That's a 3/4-16 filter, so it has to use that threaded adapter. Cool.
So, I dug into it last night. Took the filter off, no issues there. Found a suitable socket (29mm worked), and got out my 1/2" breaker bar, prepared to put some grunt to it. Turned out to be barely more than finger tight. No wonder it was leaking! Once I got it out, I found that the main o-ring was mashed completely flat and level with the housing, and was hard as a rock.
The banjo bolt that holds the thing in place also has an o-ring. It was also mashed flat and aged to a crispness far beyond what one would expect of rubber. If you've ever done a CAS o-ring on a Miata... yeah, like that.
Here's the threaded adapter:
Something I learned from a YouTube video... the 3/4-16 end is too short to engage the threads of the filter if you thread the 5/8 end all the way into the block. So, I need some kind of spacer to keep that from threading all the way in. No biggie, just another part to order.
I slapped the old filter on there just to see if it would work. Nah. I could get the threads started, but it's WAY too close to the steering shaft. Hangs over the top of it with like 1/8" of clearance. No bueno.
Measured the space between the flange on the block and the steering shaft. It's right about 3.25" at its closest point. Most filters are longest right in the middle of their diameter and taper off around the sides. So, call it 3.5".
Thinkng... The PL10241 filter that others have used here is 3.36" long. So, yeah, it'll fit... just. And I have to wonder if my completely shot transmission mounts (trans is sagging and resting on the crossmember) and my engine mounts of unknown condition have compromised my clearance a little bit. I could be at "worse case" right now, I bet that's the case. Anyway, I don't like having less than 1/4" clearance between the oil filter and hard objects.
Research... I found that the smallest commonly available 3/4-16 filter is a PL14476. It's 2.88" long. Much better. It's a common Toyota filter used in engine up to at least 2.0 liters, I think it'll be just fine on the 1500. I did fine an even smaller filter, about 2.25" long. But, it's spec'd for small tractors, and seemed to have a lower bypass valve pressure, don't want that.
So, I've ordered the PL14476 filter, and I opted to use a 5/8-18 jam nut as a spacer on the adapter. Once those parts arrive, I'll go ahead and do an oil change and fit them. That SHOULD take care of my most significant oil leak. Whilst simplifying and adding lightness, of course. (should have used an aluminum spacer)