07-08-2020, 07:46 PM
(This post was last modified: 07-27-2020, 03:32 AM by Terry Bentley.)
Well I just couldnt leave things alone. After dinner it was me back out in the garage tearing more engines apart. There is one engine I am fairly certain was an E-65 in its previous life. Mostly parts, but enough to possibly assemble as complete engine with donor pieces if needed.
That side cover from the D-2 chainsaw was much lighter than ones on the A-490's. There was also noticeable dark coloring on gasket surface that made me believe it to be magnesium, instead of aluminum. Time to do more digging.
I tore down the assumed E-65 block. This side cover is very similar to the D-2, except reverse rotation. Not totally a mirror version, but close to each other. The D-2 is right hand and E-65 is left hand. The weight difference is very obvious with the D-2 just like on the A-490.
Hard to tell, but that is a bronze bushing behind the needle bearing. Both are used to support the crank journal on D-2 chainsaw.
The A490 uses a single long bushing on flywheel side. I see the E-65 uses two short needle bearings. The part number on needle bearing housing is Torrington B-128. The crank journal is 3/4" and needle bearing width is 1/2". Outside diameter of bearing is one inch. But on the D-2 there is a really cool flanged bronze bushing and one B-128 needle bearing behind it. I guess you could say best of both worlds here. Or the limitations of both.
The D-2 side cover in on the left. E-65 on right. Appear to be very close mirrors of each other except for the D-2 is much lighter. I am certain now it is magnesium. The bronze flanged bushing seems to be a good idea for any thrust load from crank.
Not much different on the front side of these covers. This D-2 uses an earlier type ignition. But is directly interchangeable with the others. The more I dig the more there is to see in differences of these engines.
With the right and left hand drive components, it is so tempting to build up a matching pair of engines. Why does this have to be so difficult. I just want to race. The temptations I am facing here are off the scale. ARRGH!
I must come up with a plan. Then follow it to the end. Otherwise there will likely be a dozen modified engines in various stages of completion that may never make it to the track.
That side cover from the D-2 chainsaw was much lighter than ones on the A-490's. There was also noticeable dark coloring on gasket surface that made me believe it to be magnesium, instead of aluminum. Time to do more digging.
I tore down the assumed E-65 block. This side cover is very similar to the D-2, except reverse rotation. Not totally a mirror version, but close to each other. The D-2 is right hand and E-65 is left hand. The weight difference is very obvious with the D-2 just like on the A-490.
Hard to tell, but that is a bronze bushing behind the needle bearing. Both are used to support the crank journal on D-2 chainsaw.
The A490 uses a single long bushing on flywheel side. I see the E-65 uses two short needle bearings. The part number on needle bearing housing is Torrington B-128. The crank journal is 3/4" and needle bearing width is 1/2". Outside diameter of bearing is one inch. But on the D-2 there is a really cool flanged bronze bushing and one B-128 needle bearing behind it. I guess you could say best of both worlds here. Or the limitations of both.
The D-2 side cover in on the left. E-65 on right. Appear to be very close mirrors of each other except for the D-2 is much lighter. I am certain now it is magnesium. The bronze flanged bushing seems to be a good idea for any thrust load from crank.
Not much different on the front side of these covers. This D-2 uses an earlier type ignition. But is directly interchangeable with the others. The more I dig the more there is to see in differences of these engines.
With the right and left hand drive components, it is so tempting to build up a matching pair of engines. Why does this have to be so difficult. I just want to race. The temptations I am facing here are off the scale. ARRGH!
I must come up with a plan. Then follow it to the end. Otherwise there will likely be a dozen modified engines in various stages of completion that may never make it to the track.