huey-pilot

My Feedback: (17)

I just purchased a few crankcases from BME that will be used to make small twin engines using Echo weedwhacker engines. The parts that I received from BME are a nice anodized blue and the machining is very good. I am starting to get together the parts that I need to make an engine, it looks like I will have to use the 21.2 pistons and cylinders since I haven't had any luck in finding the 23.6 engines, if anyone has the 23.6 cylinders and pistons I would be interested in making a purchase. I started this thread hoping that there would be some other RCU members starting the same project and we could share information.

tim220225

My Feedback: (4)

Huey-pilot, I am in Mobile and have a bunch of new 23.6cc short blocks. How many do you want? I thought about making a twin myself when I saw the post by BME. Not sure how I would do the crank to make it secure and strong and not warp from welding it. Do you have any pictures of the case?

Tim

huey-pilot

My Feedback: (17)

Thanks Tim, I sent you a PM

foamcut

My Feedback: (40)

Huey-pilot,

Keep us informed as you progress. I saw the post as well but decided the project was too complex for my current skill set.

airbornrc

My Feedback: (9)

Tim is sending me two short blocks and the case is on its way from BME. I can't wait to get started on this project. Everyone that is putting one of these together needs to post progress reports and photos to this thread. Then we can help each other out.

captinjohn

I wish some-one would post some photos of the crankcase and also a photo of what the crank is to look like when finished. If that was done this project would get off the ground a lot faster! Thanks Capt,n

av8tor1977

My Feedback: (6)

I'll try to put a pic of the crankcase up here later on. The crank part I haven't gotten to yet. Something about too many projects going on... ? []

AV8TOR

tim220225

My Feedback: (4)

Hey Capt,n I have two cases comming from Keith. The crank is easy now that I talked to him. Cut one end of a crank off flush with the counter weight. Bore a hole into the counter wieght to accept the other cranks end. Cut another crank down so that you allow for and have a flush fit when pressing that nub into the bored hole in the crank. Line up the cranks so that you are opposed 180 degrees and both rods will be at TDC at the same time. The counter weights are ground flat so when you pair them up all you need to do is tack weld them together in a couple areas. I will figure some way to make a jig or some setup to indicate them in as close as possible. Keith indicated to me that if you were off a bit it will not make a difference. I may for safety sake drill the front journal area and pin it. Keith said there were some that would walk and get out of line when welded. My welder friend said he can do the tig welding no problem and keep heat to a minimum too. I may have to try this before I tear down my machines to move them to my new house and shop. We will see. I am trying to finish assembling my new Carden 35% Edge now before I move. A few more nights wiring and a little time with the spray gun and I will be set. Maybe!!

tim220225

My Feedback: (4)

These cases are setup for the Homelite pyramid reed system Problem is that all the parts are obsolete and not available from Homelite. I found a guy who has these parts in limited supply. There are 5 part numbers that make up one reed assembly, sans the petals. Boyeson has these or will make them. I have 3 assemblies for my 61cc twins and will be getting more for these smaller twins. I will be getting some as spare parts just in case as these things are on the bottom of the engine. Whever is interested in these parts let me know. The guy is digging up the parts and will be calling me back to let me know how many complete assemblies he can put together. There are some other reed assemblies that may work. Echo has some in current saws but they are 30 to 33cc. Don't know how they would work here. My guess is they will be fine. Other than that you may need to machine an adapter to mate to the case.

av8tor1977

My Feedback: (6)

Hey Tim,

Put me down for a reed set for the BME twin we're all working on as well!! Please let me know when I can get it and how much. E-mail me if that's easier/better. UPS tracking says the two Echo 23.6cc engines I got from you should be here tomorrow.

Thanks!
AV8TOR

tim220225

My Feedback: (4)

Sure will Av8tor. This guy is a one man band fir sales with a few parts pullers. He has my number and is supposed to get back to me with the available bumbers of compete assemblies.

av8tor1977

My Feedback: (6)

Ok, thanks guy!!

<- (Happy camper, uh, flyer...)

AV8TOR

Antique

My Feedback: (4)

The Brison 6.4 twins used the same reed setup, and maybe the D&B and Fox twins too...One of those companies should know....
The original reeds were metal...The Brison used the metal reeds, I think D&B had some made from fiberglass...
Just worked on two different Brison 6.4s, both had the same reeds, SDC 80 carbs, but different crank designs...

tim220225

My Feedback: (4)

Her you go guys. Got the cases and other parts today. Look real nice. When the time comes I think I can shave a little weight off the top of the case. We shall see. I would like to remove the anodizing too. I may try the bead blast cabinet and see what it brings me as I prefer the plain aluminum look. Otherwise these things are outstanding. Thanks to Keith for making them available to us. Will try to post the weight later.

foamcut

My Feedback: (40)

Tim,

I just ordered a couple of crankcases from BME as well. I'm going gas / glow on mine.
Please keep us updated on the crank splicing technique. I think this part is going to be outside of my current skill set.

Thanks

captinjohn

tim220225: I do not see a split line. Does the crank install from the rear? Is the bushing for endplay? Thanks Capt,n

tim220225

My Feedback: (4)

There is a split line, very well hidden with the fine CNC machining.Where the BME logo is there is a prop outline and the split cuts right through the center of the prop. The crank works the same as anything else for installation. Exception being the rear bearing presses in from the inside like always but no seal is needed as the crank stub for the clutch gets cut shorter. The other unanodized piece goes over a third bearing that installs on the crank after the crank is installed. Slide the bearing on then the piece of aluminum and drill and tap the three holes to hold the bearing block in place. The milled slot is for the timing sensor to glue to. Now I wish I could come up with one or two cases like these for the 61cc twins I have here.

tim220225

My Feedback: (4)

Well I just weighed the case and it comes in at 11.7 ounces. The reed assembly weighs .7 ounces less gaskets. Here are two pictures showing the 3 pieces that make up the reed assembly, and another showing it assembled. The black spacer could be machined if need be.

captinjohn

tim220225: Is there a option on joining crank parts? Instead of welding, could we send parts to a machine shop and have the crank broched for a spline and use a short press fit spline joint? It probably is a long shot. Can you get a photo of a crank made for this engine? Thanks Capt,n

tim220225

My Feedback: (4)

There really isn't that much material there once you cut the shaft and bore the hole. Once you chuck the crank and indicate it in you should have a pretty rigid setup. I would chuck the hub end and cut off the clutch side. Plenty to grip to there on the hub end. Center drill the crank and go. Your hole will be rather shallow as I can see it. I looked at a crank I had here for reference. Before I did any of this I would rework the hub end to rid the crank of the LH threads. Don't know of any crank pictures out there yet. I think Huey-pilot will be closer than anyone. Wouldn't it be great if we all lived close by and could see things first hand? Here is a picture of two cranks I sent to Av8tor a while back. Maybe these being next to each other will help. Visuals always do for me. I think both you and foamcut can do it, just dig in.

airbornrc

My Feedback: (9)

I found what appears to be the correct reed assembleys. He has 6 left on Ebay. Item #140005316892.

Mark

captinjohn

Will the crank look simular to this one in photo? Capt,n

tim220225

My Feedback: (4)

Capt,n it will look somewhat similar. Ours will have four counterweights and no steel bar between them. That engine appears to me as though it would run kind of rough and be unbalanced. The counterweights on ours will be 180 degrees opposed. Look back at my crank picture and you will see what I mean. The crank on the left will have the clutch end cut flush and faced to the journal then bored. I plan on boring a flat bottom hole. I suppose you could bore through too. Wouldn't make a difference and be a little easier to do. The other crank will have one end cut off and faced to the depth of the hole. They should fit together nicely as the journals are ground flat. Align them and tack weld them together. Most of the stress will be on the front half or prop side of the completed crank so I assume that is the reason for the external third bearing.

captinjohn

What holds the piston pins in place on these cranks. Is it a press fit? Capt,n

tim220225

My Feedback: (4)

There is a pin that the rod and bearing ride on. Kind of like on a car engine crank. The pin in this case would be the journal of the car engine crank. The design on these little engines is very much like that of a Harley flywheel assembly. The pin is pressed in.