By Dean Sprague
It seems that if I am not working on mine I am working on somebody else’s old British car. No matter the ailment it usually requires replacing something. This means finding replacement parts. When I was young and these cars were younger too, you could get factory or replacement parts over the counter most of the time. These parts were wonderful, you bought them, you installed them and you drove the car again. In fact, back then I drove my British sports cars every day using them as my only driver. I traveled all over North America with confidence and limited mishap.
What happened? Today, two things seem to have happened. One: you may not be able to get the part at all. It is now in that category known as “unobtainium”. When this occurs it may require finding it in a salvage yard, E bay and/or rebuilding or manufacturing the part if you can. Two: if you can get the aftermarket part (NOS parts are typically long gone) it may or may not fit. If it fits it still may not be sustainable. Here is the problem. Today many of the “replacement” parts are being made in 3rd world countries. This in itself would not be problem if there were better quality control. I am not sure but the conversions from thousandths to millimeters may create problems for them. Further many aftermarket parts are being fabricated or manufactured from measurements taken from original used parts that are worn, distorted or otherwise no longer an accurate representation of their original selves. Thereby rendering them substandard out of the box.
I can give you several examples: A simple replacement rotor that sits under the distributer cap used to transmit power from the coil to the plugs sometimes fail right after you put them in. Why do they fail? I learned that you must buy the ones that are red in color the new black ones fail because they are produced from a plastic material that allows high tensile voltage to leak in all directions. My Son learned this the hard way on his classic Mini. He put in a complete new ignition. It ran for about a month then it just wouldn’t start. We replaced the rotor with a nice red one and it ran like a deer. Of course he spent about a month trying to figure out what was wrong. By the way they still sell the black ones so buyers beware.
We bought new rear brake drums for an Austin Healey Sprite. They looked good and it fact bolted right on. The problem is they were made about .035 deeper than the originals and rubbed against the backing plates. Solution, you have to turn them to fit.
I recently purchased aftermarket brake calipers for my “British” P1800 Volvo. They looked like the Girling brakes I took off but when installed they actually rubbed on one side of the rotor. They are supposed to provide equal distance on each side so the brake pads work together. This meant I could either send them back hoping another set might fit better or just have them re-machined to really fit. I opted for plan B, much less risk and continued aggravation.
We are currently rebuilding two old Morris XPAG (MG T series) engines. I admit that these are old design engines but getting parts that will actually fit can be quite a challenge. I have rebuilt a few of these but within the last 20 years or so I have never found a sump gasket that actually matches the sump without having to elongate the bolt holes in the gasket. Further, replacement-bearing shells always require shaving to prevent dragging on the crank journal radii. The upgraded rear main oil seal either works well or it fails spectacularly. No one is sure why, not even the vendor. There are hundreds of examples just like these that don’t seem to get addressed by aftermarket part manufactures. Anyone who tries to keep LBCs on the road knows what I am talking about.
Corky’s Note: While rebuilding one of those XPAG engines (mine), we couldn’t fully seat the rebuilt distributor. The cause was an incorrectly machined distributor drive gear. It should be at a 90 degree angle to the cam when the gears are fully meshed. Replacement was the only choice. Took two more tries to get a correct one. Different vendor from the brake drums.
Since David Ahrendt and myself offer a solid-state digital alternative to the Lucas regulator I would be remiss if I didn’t mention it. We were responding to the poor quality and reliably of the Taiwanese built ones. These look-a-likes are cheap but never last very long or regulate amperage demands accurately. Actually, our conversion is much more accurate than the original Lucas offering was. We are not geniuses we just have the benefit of modern electronics that was not afforded Lucas in his day.
This is not to suggest that all these aftermarket parts are problematic. Many, most in fact fit and work just fine but just to be prudent I have adopted a new attitude when I work on these cars. I assume that the part will not fit so I measure it against the original (never ever throw away the original part). Also if possible I only replace one thing at a time so if it fails I know what to revisit again and/or send back without spending hours conducting more needless diagnostics. This technique addresses the size and fit issues but not the material quality problems i.e. the rotor failure, incorrect rubber composition of gaskets or seals, poor amalgams of various metals that render them to weak or too strong for their respective applications etc. When this happens you have to simply send them back and seek other solutions or vendors.
In closing, if you really want to restore a car for reliability you have to be prepared to sometimes remanufacture a new part or at least do some minor micro-machining or adjustment to get that perfect fit. Remember in order to move one step forward sometimes you have to move two steps backwards. I guess it’s all in the pleasure of making something old new again and knowing it was your uncompromising determination and commitment that made it all possible. So “keep a stiff upper lip and carry on”. Oh, and don’t forget to enjoy the experience, this is supposed to be fun!
