brokenenglish

OK Here are the photos showing the engine id. Looking from the front, you can see E & D on the left and right, and Mk III below the shaft. Again, yours should be like this (it may be Mk II).

Again, I think there's misunderstanding. Re-read my post. The front bearing is the casting bolted onto the front of the crankcase. If you look between the bolt heads, on the front of the engine, you should see an "E" and a "D", in the top part of the casting (above the shaft), and "Mk II" or "Mk III" below the shaft. Are those markings not there? I'll attach a photo within the next few minutes (I hope!).

I've just noticed that you think your engine is "unmarked" (apart from the s/n). Surely it should be marked "ED" and "Mk II" or "Mk III" on the front bearing.

Good !

Sorry John, there's a misunderstanding. Your engine should have the dish-shaped prop driver like my photo. This driver has a square hole that locates on the crankshaft. On your engine, the prop driver has been lost and replaced by odd washers with square holes cut to match the shaft. Those washers aren't original! All Comp Specials have a dish-shaped prop driver with a square hole, no exceptions. And all prop washers, that go on the front of the propeller (only one per engine!) have normal round holes. Like I said, your engine's original prop driver and washer have been lost and replaced by several odd washers with square holes. In fact, I think the reason you have several washers is simply to cover the square length on the shaft. No Comp Special ever had a front end like that.

Your engine is from September 1948. Apart from the points already mentioned, the bits around the prop driver are not at all the way they should be. Here's one that's the same vintage as yours. Your engine should look like this. You can see the various differences for yourself. It's quite likely that your engine may run well. In good condition, they're super engines.

Jeff, I thought your propeller choice seemed a bit big, so I checked the original article. Laurie Sparey obtained best results with a 13x6, but his 13x6 must have been wood, i.e. far lighter than your MA & APC stuff (and easier on the fingers!). I'm lucky to have a huge collection of old propellers, and I would never use a modern composite prop on an old engine. Wood is best, or old soft plastic in the smaller sizes. Maybe a little more ether and a little less compression would be a good idea.

Shame the photo cuts off the top of your Owat.

The photo is a bit "untidy", but I don't see anything of any significant value that would interest a collector.

22 is a Majesco 2cc - Very rare indeed. 20 is a Dyne 10cc 18 is a Dyne 6cc 15 is an HP 3.5cc 23 is a Hallam diesel (I think!) All forties vintage rare English (and Welsh!) engines. I'll need to dig through documentation to identify the others.

TBH, I'd rather have my ED Bees.

Yes, you're right about the serial number. I forgot about the "L" and I'd run out of fingers. The S/N couldn't be '57. By 1957 the serial numbers were on the side of the case and I think the lugs were no longer scalloped. I'm not sure of the exact year they stopped scalloping the lugs, but it was before 1957.

There's no reason to think that it might have been "marine", the M prefix on the serial number is just the production month (December). Mike, this photo shows the way your engine should be. It's the first production configuration.

ED, just a bit of info. Not all Comp Specials have scalloped lugs. It was done to differentiate in relation to the Penny Slot (the Mk II). When ED stopped making the Penny Slot, they stopped scalloping Comp Special lugs, so "later" Comp Specials have normal straight lugs, probably around 50% of total production. The serial number on the OP engine is a normal Comp Special serial number (Dec. '47). So it's very early production (looks like the 64th Comp Special made). Finally, I tried an RC carb on a Comp Special, around 40 years ago and IIRC, it wasn't very successful.

Normally, I think your Comp Special should have sub-piston induction.