Author Topic: mcculloch bp-1 bp1  (Read 1136 times)

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Offline mweba

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mcculloch bp-1 bp1
« on: October 20, 2012, 10:24:08 pm »
Started tear down on my project saw.  Will try to pile all things learned into this thread.


100_4956 by mweba1, on Flickr


100_4957 by mweba1, on Flickr


100_4958 by mweba1, on Flickr


100_4961 by mweba1, on Flickr

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Offline mweba

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Re: bp-1
« Reply #1 on: October 20, 2012, 10:30:01 pm »
Balanced piston/valve


100_4959 by mweba1, on Flickr

B piston sleeve.


Bp-1 balanced piston sleave by mweba1, on Flickr

Cylinder


Bp-1 cylinder by mweba1, on Flickr

Crank assembly.


Bp-1 crank by mweba1, on Flickr

Offline mweba

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Re: bp-1
« Reply #2 on: October 20, 2012, 10:32:23 pm »

Offline Cut4fun .

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Re: bp-1
« Reply #3 on: October 20, 2012, 11:02:27 pm »
I would have took one look  at that and ran. 

Will be watching to learn more.
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Offline pete

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Re: bp-1
« Reply #4 on: October 21, 2012, 06:20:02 am »
Man I"M green with envy  to me a bp1 would be the icing on the cake for my collection  keep it  and thanks for the vids and pics

Offline Al Smith

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Re: bp-1
« Reply #5 on: October 21, 2012, 11:23:33 pm »
I've seen several but never one that actually ran .

Offline mweba

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Re: bp-1
« Reply #6 on: October 24, 2012, 09:26:29 am »
I've seen several but never one that actually ran .
  I've run one that has been gone through.  They have surprising power and rev quite high.

Offline Al Smith

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Re: bp-1
« Reply #7 on: October 24, 2012, 06:58:01 pm »
Oh they made a big deal about it ,something like 14,000 RPM .I suppose they thought it was something for time  but I've got some 10 series that will crank on at over 15,000 .

That said though a very interesting design .

Offline pete

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Re: bp-1
« Reply #8 on: October 29, 2012, 08:38:47 am »
 I had the great pleasure of seeing my first BP! s  this weekend got to hold one and have my photo taken with it
Both are runners  I really enjoyed my day

Offline Al Smith

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Re: bp-1
« Reply #9 on: October 30, 2012, 09:40:24 am »
Now I kind of wonder what the real reason was they abandoned that design .Supposidley it was because of fear the throttle could stick and  engine blow up like a stick of tnt .

I'm not sure that theory is really why  and the reason  being even that long ago they knew about zener diodes that break down on a reverse bias voltage build up .

Any magneto at speed produces a higher voltage as RPMs' increase until point of coil saturation .I should have thought they could have built a limiting coil if they really had wanted to .It'simple ,once you cut off the spark the engine can only run as fast as the spark can get there .

I doubt we'll ever know the real reason because anybody involved with it has long ago went to the here after .So it will remain as the never answered question .


 

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