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I am attempting to replicate a couple of Berkeley Models ducted fan kits and need to identify what "Mk" number each of these engines are. One is obviously a pull-start version, Mk version unknown. The other looks to be a Spring Start (with Pulley?), Mk version unknown.
Drawings are dated 1958 for the pull string, and 1957 for the spring start. I am probably going to have to piece these, so having the verision numbers would be real helpful, or if that pulley on the spring start is some kind of extra that was put on the drawing.
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Joined: 12/20/2004 From: Corvallis,
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jetpack:
The engine should be marked with a MK# on the left hand side of the crankcase ( the side oposite that shown in your drawings). MK's I, II, III, V are common. I didn't know they produced a pull starter but live and learn. They must have been whimpy models to fly with a Wen Mac fan. Spring starters were or were not rivited to the crank case as I sure the recoil starter would have been.
I do have an OK Cub with a pull starter on it if that helps.
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Hi Steve, Thanks for your response...it does help some. I never owned either of these style engines and have no idea if any of the parts that involve the recoils are repairable or removable or what to really look for. The drawings are a little non-descript as far as that would concern, but knowing how they are marked is a help.
So far my engine collection does include the OK CUB 049S which is the pull-start with the red anodized tank, never used and picked it up for 30 dollars. I felt lucky when I won it but I think they are still available. Not really sure if they are the pull start version or not, but either way I was happy to find one in new condition with its origins comming from the 50's and not very popular.
I have a Thermal Hopper that I bought in good used condition also, that one is reserved for the Sky-Ray kit that I have to copy. Now that Sky-Ray kit shows both engines, the Cox and the Cub. The Tiger gets a PeeWee that I have new that really haven't changed a bit since the day they started making them.
The Crusader and the Shooting Star are the only two that call for a Wen-Mac brand. I could replace the ducted fan idea with the Crusader because oddly enough, the plans suggest a Space Bug on the front as an alternative way of powering it with just a standard propeller and a nose cone. I have the tank assembly if I wanted to sacrifice the Thermal Hopper from the Sky-Ray for the Crusader, but then it's not a ducted fan.
So, anyways, all this leaves me with is finding the two Wen-Mac versions, and I would be able to replicate to the drawing each of the planes as far as the engines are concerned.
Now that I think about the entire deal, I would need an extra blade for one of the 049 versions if I want to stay with my desire to keep the kit contents intact, plus that PeeWee blade.
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Joined: 10/9/2002 From: Austin, TX, USA Status: offline
Apparently this didn't get posted. I have a 3 inch six blade aluminum fan. Probably OkKfor a PeeWee or a Wen Mac. If you want it, PM me your address and I'll send same. I may actually have two of them.
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Hi Jim,
I think I seen double too. Maybe it was that other thread I mentioned I started that you replied, but I did see your offer and I replied. I'll give you a PM. I have two posts going because I didnt know what would be a better place to post it.
< Message edited by jetpack -- 5/18/2007 2:53:24 AM >
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Well, here are the few Wenmac/McCoy engines I have. All are MkII except the Testors engine. The pull start engine also has a throttle baffle in the exhaust. I have never seen the tanks fuel tanks shown on drawing but I am sure someone would have made them. As for performance.... A Cox Tee Dee .020 will out perform any of these engines. You may do better with the Tee Dee .049 or Norvel.
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Nice Bob, Thank You.
Yes it is strange about the tanks, as I have never seen a Wen-Mac with one. Knowing the Cub engine that I have I wonder if that is the same. Was there any common ties with OK Cub and Wen-Mac as companies?
I have seen Cub engines with and without tanks installed, and the backplates on them all have a tapped center hole for adding the tank. Do all Wen-Mac's have these stubs also? I wonder about that.
I saved all your pics in my collection so I have a solid reference to the MkII's now.
As far as power is concerned, I'll agree with what you said there. I run PeeWee's before and have to say it seemed as strong as a Wen-Mack P-40 control line model my buddy had as we were growing up. I'm not really as much concerned about that though, as I'm striving to build the four of these all period correct right to the drawings motor and all. It's not an easy project but having a decent time getting there so far.
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The first drawing is an "OK Cub .074" pull start engine. The second drawing is a "Wen Mac .049 Mk II" engine. Wen Mac did indeed produce engines with the pull starter ( I have at least three .049 MkII "Wen Mac" engines with pull starters), the "Wen Mac" starter is almost exactly like the OK Cub starter except the front prop drives are a bit different. It is said by many that "Ok Cub" (Herkimer) either bought the rights to the starter from "Wen Mac" or they simply stole it ..... I might have read about the pull-starter thing in the "They Should Have Kept The Bear" publication, I can't remember, or it could have been from one of the many "Gas Toy Collector" publications? I have several of the "Wen Mac .049" engines with tanks, they even had a nice red anodized one once upon a time ..... no, the "OK Cub .049B" tanks will not interchange.
< Message edited by injunnut1 -- 5/18/2007 12:33:53 PM >
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Thank You injunnut,
Looks like you found a descrepancy in the drawing with how the motor is called out and how it is drawn up. Interesting! That I will have to keep in mind. What would be the clue? I wondered about how stubby the intake is on it. Seems every 049 I've looked at never had them cut flush to the casting rib like that.
< Message edited by jetpack -- 5/19/2007 10:06:53 AM >
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Jetpack,
I don't think you will find engines that match either outline. I believe the draftsman took a bit of license, perhaps to avoid lawsuits. The first appears to be "mostly" Cub, although Cubs have straight fins, and the old crankcase had a different tank. Can't speak for the pull-starter, don't have one of those. The one on the right looks mostly Wen Mac Mk-II. I have one of those out of an old Aeromite. How are you coming on your quest to build those Duct fan models. Feel fortunate that you are building from the plans and are not handicapped by a Berkeley kit.
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Hiya George,
Well your right about being fortunate about not building from the kit, the die-cut isnt the best but man-o-man the wood thats stacked in one. For such small planes I've never seen so much wood. And it's not just all planking either. They were'nt shy on balsa.
My quest has so far turned up a Thermal Hopper (Sky-Ray), and OK Cub Pull-Start with Tank (Shooting Star), Cox PeeWee (Tiger), two extra fan blades and a contact for my mono-line units. I have two of the four kits complete that use the ducted fan idea, and full prints for the two others that I don't. I am hoping to bump into someone that has the missing templates for those two (Crusader and Tiger) or I am facing having to loft my own. I have re-drawn what decals have come with those two kits, but still have to do the decals for the two prints I recently got.
I've contacted Midwest Balsa and have 1/20" balsa sheet on their special cut list, and have all the materials and methods for replicating the vacuu-form parts. Other bits I've collected are some midget tanks and enough Perfect brand rubber streamlined wheels with the aluminum hubs.
So I'm almost there to start laying out parts and building, so I thought it would be a good idea to start motor hunting for the two remainders. I have been doing my rc powerboat hobbies in the meantime, thats another big job but have a full boat rack going now
< Message edited by jetpack -- 5/19/2007 7:45:50 AM >
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Great thread! I have been sitting back and following but have not had anything to be able to contribute. Till now.
I do see a drawback to one of the materials. This would be the "duct paper" shown in that last picture. Seems to me that this would be a major problem area when it comes to exhaust residue from the engine!
Another interesting thing I noticed was the very important plastic "nose cone" or bubble that goes over the engine to help streamline the air entering the duct. Very cool. Or may be not so cool, as it may be detrimental to the engine cooling to some degree.
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Early Wen-Mac Identification - 
