More Bantics... BSA Bantam D7 Top End Rebuild, Part One.

First part of the Top End Rebuild on the D7 Bantam Engine. Unfortunately I was unable to complete the job in this video...all will be explained.
I also take the opportunity to talk about my Grandad, Frank Wilson who was a great mentor and Father to my brother and I, teaching us many things and instilling a life long passion for things mechanical.
Thanks for watching,
Dean.
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[@Steviegtr52]

Nice work. I built a lot of Bantam engines back in the 60's. The fastest was a D14:4 I fitted a george tod head. A expansion chamber exhaust & a padded flyweel. I think from memory a 376 upjetted Amel carb. It went great until one day it sheared the crankshaft. I pushed it some miles to home with the chain removed. I then fitted a Villiers 2t engine in the frame & ran it for 2 years with no issues. Keep up the good work. Steve.

[@nbrettoner]

Nice end tribute and comments regarding your grandfather. And a great series addition in this Bantam restoration. My first bike was a 123?cc BSA Bantam. I vaguely recall that when I bought it from a fellow-trainee (I was 2nd year 530 miles from home, and he a fourth year PMG trainee), that it had the rubber bulb 'horn'. I eventually ordered a speedo for it. I guess the bike was circa 1952/4-ish?. A slight headwind at say 10 oclock meant screwing it's neck in 2nd, quickly popping it into 3rd, where it rapidly lost momentum within seconds, requiring downchanging back to 2nd. This recycling event enabled me one day to do a 30 mile southern sojourn south from Deniliquin to just somewhere beyond Mathoura (towards Echuca). But that was eons ago. Around late? 1962. Aftre that experience "the bug had bitten", and my 16 year over 200,000 mile motorcycling life began in earnest. Well, after I bought the Sunbeam S8. My #2 steed shall we say 'earnest' 🙃🤠

[@retromechanicalengineer]

Thanks for sharing your experiences, it's great to hear real life tales of 'Bantics'! Best wishes, Dean.

[@angry7518]

Great info and insights Deano, thoroughly enjoyed that. Nice to reflect on the positive influences in your life. He will be smiling down on you.

[@LarryBees]

Carefully done Dean so far apart from Base gasket. but not a disaster !! 😃

[@MrFactotum]

Nice one RM It took me back to building my super rocket and shooting star, both long gone now , still got my original shooting star though.Great to hear you were close to your grandad. see you on the next part take care Kev

[@retromechanicalengineer]

Thanks Kev, best wishes, Dean.

[@montana2strokeracer]

Nice work Dean, 3 rings on a two stroke, haven't seen that in a while. I like your idea of supporting the piston with parallels. I always struggle with starting the cylinder on the piston. Great work.

[@retromechanicalengineer]

Thanks Dale, yes, definitely older technology on this engine. Thanks for the support and encouragement, it means a great deal. Best wishes, Dean.

[@carlwilson1772]

Absolutely excellent video as per. Clear and concise information and a meticulous rebuild. I expected nothing less. You will see I now have Grandad as my channel image. I can send you some gasket paper if you like, let me know what thickness.

[@retromechanicalengineer]

Thank you very much. I do have some gasket paper, I just need to dig for it. I like the new image on your channel, it was taken in Torquay. I look at the viewer that contains it every day. Best wishes, Dean.

[@carlwilson1772]

@@retromechanicalengineer So do I. Let me know if you need paper.

[@davidheathfield1461]

I was 17 and refiting gudgeon pin 1 ciciclip fitted as you show on fitting second clip it sprung of pliers never to be found i thought 1 out of 2 ok . igot half a mile down rd and engine stopped ,on nspection i found the gudgin pin had machined a nice groove into bore

[@retromechanicalengineer]

Oh no! What a way to learn. Best wishes, Dean.

[@AGEngineering]

Great info especially piston orientation, it would be so easy to put the piston on with the 040 reading looking from the rear as most modern engines do, sound information and training from grandad Wilson there.

[@retromechanicalengineer]

Thanks Ade, its interesting about the piston, I read the Service Sheet a couple of times to be sure. There are a number of differences between the D1-D3 and the D5-D7 models. Life could have been very different without Grandad to teach us the right way. 26 years have passed quickly but we still miss him as much. Best wishes, Dean.

[@carlwilson1772]

Hi Ade, sorry I could not stop by when I was down south. I passed by Burton on Trent on my way back from Dean's place, but it was about 19:00 by then. Hope you are well.

[@OzBSABantams]

Nice work and nice explanation of all these very critical processes required for a successful engine rebuild. Your fin repair looks great too.

[@retromechanicalengineer]

Thanks Bones, that's very kind of you.

[@cainbeeping8480]

Looks good brother. It’s coming along.

[@retromechanicalengineer]

Thanks Cain, pity I couldn't get the barrel fitted this time.

[@davew9360]

Very nice and informative but I would measure the ring gaps in the top of the cylinder , then mid stroke of the piston ,where most wear would occur and then at the bottom of the stroke of the piston ,but never at the very bottom as the rings will not travel that far down the cylinder when in use .

[@retromechanicalengineer]

Thanks very much, as it was a newly bored barrel I took it on faith a little and just measured in the one place. Too trusting perhaps! Best wishes, Dean.

[@davew9360]

@@retromechanicalengineer You are absolutely right , it was a bored barrel so should be correct . As I said your clip was very informative as this is exactly how I go about top end builds on championship winning engines for twin shock MX . Again I will say nice clip and I am going to watch more of these , All the best .

[@retromechanicalengineer]

@@davew9360 Thanks Dave, I really appreciate the feedback. Great to welcome you aboard, no doubt you will have some top tips to share. Those twin shock and pre 65 MX machines don't take prisoners!

[@neilclements3929]

Great material but far too slow going for me

[@yvonnetaylor6274]

ring gaps should not be measured with the rings in the cut outs in the barrel lower spigot (they will expand and give incorrect measurement) and as the rings will never run on this part of the bore it is a point less measurement.

[@retromechanicalengineer]

Thanks for your comment. It was a fresh rebore, so the measurement would be aribtrary anywhere in the bore. I agree that the ring would be better supported in a solid portion. Best wishes, Dean.