Author Topic: ID these pistons for me....  (Read 825 times)

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Offline Geeto67

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ID these pistons for me....
« on: December 04, 2012, 06:34:15 AM »
Got these with a cb750 bottom end I purchased a while back, No barrels. 70mm at crown (970cc), might be wider at skirt. no makers marks inside. Only a 287 SS casting mark in the underside of each one.





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Offline 754

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Re: ID these pistons for me....
« Reply #1 on: December 04, 2012, 07:16:16 AM »
Forged Alcoa,s probably a 1000 kit.
 What kind of rods are in there.
Maker of the WELDLESS 750 Frame Kit
dodogas99@gmail.com
Kelowna B.C.       Canada

My next bike will be a ..ANFOB.....

It's All part of the ADVENTURE...

73 836cc.. Green, had it for 3 decades!!
Lost quite a few CB 750's along the way

Offline Geeto67

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Re: ID these pistons for me....
« Reply #2 on: December 04, 2012, 07:54:31 AM »
What kind of rods are in there.

Forged Alcoa Aluminum Con Rods. I always thought Alcoa was the blank supplier - that a company like RC, MTC, etc did the finishing work. Did they supply finished cb750 pistons?

I know you are supposed to measure the bore but I didn't get a cyl block with this setup. I also know pistons tapier out toward the bottom but I had a senior moment and only measured the crown (70.54mm).
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Offline 754

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Re: ID these pistons for me....
« Reply #3 on: December 04, 2012, 08:08:58 AM »
 The piston companies finished them after they got the forging blanks.
Maker of the WELDLESS 750 Frame Kit
dodogas99@gmail.com
Kelowna B.C.       Canada

My next bike will be a ..ANFOB.....

It's All part of the ADVENTURE...

73 836cc.. Green, had it for 3 decades!!
Lost quite a few CB 750's along the way

Offline Geeto67

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Re: ID these pistons for me....
« Reply #4 on: December 04, 2012, 09:58:55 AM »
I was kinda hoping someone would know what piston company dressed these out. I think RC used Alcoa blanks, not sure who else.
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Offline jaguar

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Re: ID these pistons for me....
« Reply #5 on: December 04, 2012, 01:05:06 PM »



They look like my RCs

Offline Geeto67

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Re: ID these pistons for me....
« Reply #6 on: December 04, 2012, 01:46:02 PM »
that's because they all used the same blanks.
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