The 68 is confusing, 6T = Thunderbird and could the 68 be 58 as that would make it a 1958 Thunderbird Also there should be other numbers, do you have pics as this would help.
Hi, Christopher. Have a look at www.tri-corengland.com as they show how to date an engine. I agree with darkman of this parish that it is a Thunderbird 650cc engine. As you have the rest of the number you will probably be able to make more sense of it than we can! Or am I missing something .... again?!
I have seen debates about it in the past on forums but don't remember if they ever came up with a definitive answer, should i have any more info i will let you know.
Right, i found the answer in my huge list lol, i'm more a unit engine guy but it was to inform engine builder etc to fit a 17 tooth sprocket for combination set up.
I hope this doesn't serve to confuse - it's not meant to - but the "wheel" symbol in your engine number stamping does have some significance ..... problem is I can't remember EXACTLY what the significance is, other than having a vague recollection that it refers to the cam profile and/or timing. I mention it only in case you intend stripping the engine as the cam timing may appear different.
