Can someone please e-mail me @ [email protected] the dimensions of the finished engine and a rough weight. That would be great, as i really need to know before i order a case. Cheers,
Sam

Would someone please post the weight and some performance figures.
A lot of people would like to know.

Now don't anyone get all excited, as this is just the "mock up" assembly to check clearances, etc. But it IS cool!!



AV8TOR

AV8tor dimensions and weight of the mockup please!!!!

Very nice. Someday mine will look like that also.

Everyone wants to know weight. Lets say it will probably be best in a airplane that needs nose-weight!!! Capt,n

Airbornrc posted a weight of 3-1/2 pounds sans mufflers and ignition. The 3W-56 has a claimed weight of just over 4 pounds. Whats a few ounces either way?

Hi,

Ok, it weighs 3 lbs., 8 oz. as pictured. Not too bad. What's a Ryboi weigh?? And remember, it's 48cc.

7 3/4" wide from the top of the head to the top of the other head. (If you run regular ignition, the plugs will stick out farther.)

6" from the backplate mount to the face of my prop adapter.

4 5/8" from crankcase bottom to the top of the carb bolts.

AV8TOR

As pictured...was all the internal parts needed inside? Capt,n

Yes, everything except the front oil seal, which weighs basically nothing.

AV8TOR

That is one sweet ***** looking engine. What was the price tag for all of the parts? I might look into building one myself. I would like to have something like that in my 1/3 Christen Eagle.

Don't think it would fly the Eagle. Smallest engine I have seen in one is a 50cc. I have 2 cases and when I get around to it I should have less than $150.00 in mine without ignition.

AV8TOR, Would you mind giving me the dimension from the center of the shaft to the top of the carby and the center of the shaft to the exhaust port. As i need to know these for clearances issues inside my cowl. Cheers, Sam

Ok, looks like it's approximately 3.5" from crank centerline to the top of the carb mounting screw, and 2 3/8" from centerline to the top of the exhaust port mounting flange.

My friends say I can't put mine on a cowled airplane cause it's "way too pretty to cover up and hide in a cowl"...

AV8TOR

It would look good on a old style Eindekker!!!! Capt,n

I have a big SR Batteries Eindekker, (kit). I have a Honda GX-31 four stroke for it, but I have worries that might not have enough power to fly how I like. (I like a definite surplus of power in everything I own.)

Maybe the twin will end up on the Eindekker some day. I am thinking I will test it out on my Giant Big Stik. That too ought to be fun...

Captain, I have a friend interested in those engines if you could do a bit better on the price...

AV8TOR

Are there other cylinders that would fit on these cases?

You would have to check deck heights, but I believe anything from 21 to 25cc engines will work. The 25cc engines might need a spacer made for below the cylinder to achieve the proper deck height as it has a longer stroke, but once again, I'm not sure....

AV8TOR

I was thinking Homie 33, Toro 25 or something like that.

The welder giveth and the milling machine taketh away.

The block is designed for the Echo 23.6cc engine. I doubt it would fit other brands. One would have to have one in hand and check all sizes, clearances, etc. to see if it could be modified to work with something else.

For one thing, a lot of the other engines have a cantilevered crank that would be tough to join with another crank. The Echo engines have a crankshaft with a shaft and bearing on both ends of the crank.

AV8TOR

I got my block today.
This thing is much smaller than I ever imagined.

I've been looking for parts but have come up short.
Please PM me if you have parts for one of these.

In doing research Keith from BME had converted a Echo 23.6 but used a crank out of an Echo 25.
This gave it a 2mm longer stroke and he gave the porting dimensions for the 23.6.
He didn't say how it turned out when completely finished.

Has anyone else came across hop up threads for this engine?

I have an Echo 23.6cc "stroker" done that way. It turns an APC 16 x 8 prop at over 9000 rpms.

If you use the 25cc crank with the 23.6cc cylinder, you have to make a spacer to raise the cylinder to accomodate the longer stroke.

AV8TOR

I think if you do the twin using 23.6cc parts you will have a fine engine. I know that the 44cc Echo saw engines I convert are real stump pullers. I expect my twin to be the same. Some day when I get my shop back in shape from moving. Painted the floor at the new one so now I hate to cover it up. But of course I will.

Here is an of Echo thread condensed:

BME 23.6cc

Most of you guys probably know that Echo was our base engine for most of our engines and no one probably knows them better than I do. If you want to get the most out of your little weedeater engines please follow my directions exactly. Forget the 21cc and the 25.4cc echo and buy the 23.6cc. The older the model the better. They changed the transfers on the later models that did not work well. The first thing you need to do is machine the cylider base down as far as you can. The piston should very lightly bump the head but when you recut the piston crown it should clear again. You want about .015-.020 squish clearance. After this take a dremel and a degree wheel. You want the exhaust to open at 98 degrees ATDC and you want the intake to open at 108 degrees ABDC. Cut the exhaust port a little wider or as wide as the port is at the outermost edge. Work slowly and and check your progress many times so that you dont go to far. After you cut the ports be sure to radius the inside edge so it wont hang the ring. We have done hundreds of these conversions and with the battery ignitions they are turning 8500 on a 17x8 APC.

Keith
BME

When cutting the piston you want to match the radius on the squish area of the combustion chamber. We do not cut the entire top of piston but mostly cut the outer edge. The piston ends up with a smaller radius or higher dome. You want all the compression you can get. I dont know the compression ratio but it runs fine on 87 octane gasoline. You can check the match fit from piston to head by turning and pushing the piston against the head. It will leave marks on the piston where it rubs and you will know where to cut the piston down at. As for the intake side(bottom skirt) we have cut the port on the cylinder on some and we have simply cut the piston skirt on the intake side only on others to obtain the 108 degree ABDC intake opening. These mods can be done on most any conversion engine if you intend on running it above 8000 rpm. If you want to run below 8000 rpm dont raise the exhaust port. Leave it at about 105 dgrees ATDC. I dont know about the different gaskets on the cylinder but I dont think you would want the ones with just holes in them. The good cylinders will have a transfer port opening that is the same size as the opening on the crankcase. Later models will have that opening smaller and it does not match the crankcase opening. I will see if I have time to do a conversion and take pictures for you guys.

I forgot to mention that the only difference between the 21cc echo and the 23.6cc echo is the piston and cylinder.

Keith
BME

Hey guys I am doing a new conversion hop up on the Echo 23.6cc engine. I have installed a crank shaft and piston from a 25.4cc engine in the 23.6cc crankcase and cylinder with the timing mods I mentioned before. This new crank gives the engine a 2mm stroke increase which is just right after you modify the piston to give maximum compression and now it will still travel down to the bottom edge of the exhaust port. I hope to gain as much as 400 rpm more with this set up as compaired to the standard stroke 23.6cc engine which is turning a 17x8 APC at 8500 rpm.


Keith
BME

You could do the same mods to the 25.4cc engine and gain power over the stock form. In my experience no mods I did to the 25.4cc equaled the power of the 23.6cc. When you drop the cylinder down to raise the compression you are also giving up your port time area. You gain it back by cutting the exhaust and intake but your transfers have lost area. With a stroke increase you can get this back plus gain some cc's and power.



Keith
BME

Well I have converted the Echo 23.6cc engine with the longer stroke crankshaft. I did gain some power but I was hoping for more. The engine weighs 1lb 15 ounces and it turns the 16x8 APC at 9100 rpm on the first run up. It should get about 200 more with break-in. Funny but I find they dont want more than about 25-26 degrees timing. I am going to try a bigger carb and see if it gains more.

Ran the stroked 23.6cc Echo again today. I put the carb from a g-23 on it and gained some power. Its now turning a 16x8 APC at 9300. Vibration is starting to show up at this rpm. It needs more counterweight on the crank to spin this fast. I think I will go to the 17x8 APC to drop the rpm down and pick up some thrust. These figures are with a stock box style muffler.


Keith
BME


Hope you enjoyed the read

Where can I find the specifications for these Echo engines?

I went to a couple of small engine repair shops yesterday
and picked up 7 engines some with on ID tags.

I'm thinking I need to know the bore and stroke so I can ID the engines.