K&B 3.25 questions

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  • #79700
    Robin Beckford
    Participant

    Sorting through some K&B 3.5 engines I’ve acquired over time, I found that one is,in fact, a 3.25. It has the shorter stroke crank, and the face of the head has been machined to get the correct clearance.
    The 3.5 on the side has been removed and left blank. The side of one lug has been engraved with the word ‘small’. There’s also what looks like ‘SS’ or ’55’ in the case.
    Also the conrod is different to those on my other engines, having a single oilway on the top of the big end.
    It’s the later type case with the larger 0.765″ sleeve.
    Any K&B experts out there know if this a factory engine, or could it be a conversion from a 3.5?
    Also, there is some slight conrod play. I’ll order a new one from MECOA, unless anyone has an unwanted spare one to sell.

    Robin

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    #79729
    MikeThompson
    Participant

    Hi Robin, The difference from 3.5 and 3.25 is that K&B off set the crank pin .010 and adjusted head clearness. The cases were cast with 3.5 and 3.25 as by the pics. I have no idea of what you have.

    #79730
    MikeThompson
    Participant

    Robin, The pic I took is to big to put on here if you what to see it give me your email and I will send it to you.

    #79731
    MikeThompson
    Participant

    My email is all small caps mrmikef1a@pacbell.net

    #79784
    Robin Beckford
    Participant

    Thanks, Mike.
    Robin

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