Determining the Age of an Antique Gas Engine

By Staff
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An early (older) Reid, for instance, has a water pipe plumbed into a plain tapped hole in the cylinder casting.
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A later (newer) Reid has a boss cast into the cylinder casting to reinforce the area where the pipe enters the cylinder.
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An early plain-type bedplate.
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A later-type bedplate with a dam cast around the bottom to collect oil.
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What I consider features for later Reid engines, such as a ring oiler for the journal bearing, chain oilers with oil sumps and access plates.

People often ask me about the age of their engine. While it’s nice to know what year an engine was manufactured, it’s not always easy to determine.

Many people like to think an engine they own is older than it might actually be. Sometimes people proclaim with absolute certainty the date of their engine. But how do they do that without hard evidence? The more I learn about the engine hobby, the less I become certain of anything. I take self-proclaimed experts on antique oil field engines with a grain of salt, because most of the real experts who knew these things first-hand are no longer with us.

Let me state that I’m not an expert. But I will share with you things I think are accurate based on my own experience and the help of many knowledgeable friends.

To date an engine with certain accuracy, use records that may still survive from the manufacturer that list serial numbers and dates. It’s often rare that we have that convenience, but it’s worth trying to locate these records, nonetheless. If the date is cast into the engine or the nameplate, if you have a bill of sale or you’re able to get first-hand verbal testimony from an owner, this type of information is more than likely pretty accurate. If you can’t find any of this information, then finding your engine’s age is a guessing game.

Reid by Example
The experienced eye will learn to recognize an early- or late-model engine – this is often the best I can do. Let’s use a Reid engine for example, since many oil field engine enthusiasts own one. In order to tell if a Reid is an early or late model, I look for design improvements made through the years of production. An early (older) Reid, for instance, has a water pipe plumbed into a plain tapped hole in the cylinder casting as in photo 1. A later (newer) Reid has a boss cast into the cylinder casting to reinforce the area where the pipe enters the cylinder as in photo 2. I’ve seen newer Reids that attach the water pipe with a flange and four bolts.

I can also tell the relative age of a Reid engine by the bedplate. Photo 3 shows an early plain-type bedplate, and photo 4 shows a later-type bedplate with a dam cast around the bottom to collect oil. Photo 4 also shows a later-type governor: The earliest Reid governors had round weights instead of the more-common egg-shaped governor seen in this photo. Photo 5 shows what I consider features for later Reid engines such as a ring oiler for the journal bearing, chain oilers with oil sumps and access plates.

Another detail peculiar to Reid engines is the extra webbing cast between the flywheel spokes to reinforce the charging cylinder journal pin. The early Reids had none at all, but by the end of Reid production this webbing was enormous. Also, early Reids may not have a hole tapped for a backfire valve in the charge cylinder. Further complicating the issue, dating Reid engines by dates cast into the flywheel on the inside of the counterbalance can be misleading, as I’ve heard manufacturers often set castings outdoors for extended periods of time to ‘season’ the casting. If so, your flywheel might say 1923, but the engine might not have been assembled and sold until 1925.

This subject often raises more questions than answers. In a sense, learning the fine points of each engine is only academic. It’s important to document an engine’s history to the best of our knowledge, but don’t let it consume you. The real point is that even if you don’t have an exact casting date, learn to look for clues pointing to the general period your engine was produced – and above everything else, have fun learning about your engine!

Contact the Oil Field Engine Society at: 1231 Banta’s Creek Road, Eaton, OH 45320-9701; oilengine@voyager.net www.oilfieldengine.com

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