Plenty of cylinder head information,well done!

Hello Angus! I like the Surface of the ultrasonic cleaned head, the blasted head will never get that original look,

@BSAPowerSet

4 жыл бұрын

Hi Torbjorn - yes indeed I’m really pleased with it - quite a big investment with a 30L volume but well worthwhile.

I see working on BSA's is like slaying a hydra, for each head you bin, 2 more arrive in the mail.

@BSAPowerSet

4 жыл бұрын

Hi Hank - thanks for the interest and comment. Indeed, but I can't abide broken/repaired fins so it had to be done. The scrap heads did provide good valve gear though so all not in vain but rather a longer journey than I had anticipated. There are loads of A65 heads on eBay, but just focus in on the condition ..... Thanks again.

Angus, I guess this is together and going, but I'm interested in the later Lightning inlet ports, and as you have other late heads you may like to measure. I have one OIF head that has std inlet ports. They measure like the specials done for the 1968 Spitfires in having a deeper bowl and are much wider at the guide. The end of the port is 30mm rather than 32mm. On the Spitfire it had more hp on 9-1 compression than earlier Spitfires with 10-1 or 10,5-1 compression, because they breath so much better. Better than the best std Commando. From memory this one I have is around 32mm wide near the guide. And ports flow around 139cfm compared to 109cfrm for the 68-701 without carb. Both 30mm ports, so one is faster and will give more punch and more top end, though the carb probably limits it. But I don't know if all were ported that way, it's easy to see the difference looking at the width near the guide, it's about 10mm wider than a 68-701. It may be a special as the cast number pad was factory erased. I can port them to around 38.9mm wide without breaking through and alter the shape more and get 150 out of a 30mm port or around 180 from a 34mm port, using a 42mm valve. Black diamond make nitrided valves that last, the best I have used. So BSA knew and were heading down that track, but inherent vibration was the problem for them. They needed rubber mounting or a 90degree with 74mm stroke, which does about the same.

@BSAPowerSet

Жыл бұрын

Hi Mark thanks the the interest and this fascinating technical comment. Yes the A70 is up and running and I don’t now have any spare OIF heads to measure up. What you describe makes sense but I’m no engineer so cannot add to that. Thanks again.

👍😜

That OE Head Steady is a hell of a find! You had good luck with the (4th!) head too pleased to note and excellent repair to stop the crack propagating. Your Ultrasonic Cleaner does a 1st Class job, regrettably you have just cost me money as just have to have one. Just a thought, could Coopers Rings be an idea for your head to negate blowing between cylinders? I have used this company.......www.atlas-gaskets.net/head-gaskets.php for competition engines. Valve Spring Seats Shim info if of help.....www.classicbritishspares.com/blogs/news/valve-spring-shims. Apologies if I am 'teaching you to suck eggs' as you are so much more competent than me Angus, just fascinated by your attention to detail and trying to help.

@BSAPowerSet

4 жыл бұрын

Hi Paul. Thanks for the kind comments and helpful links/info as always. Apologies re the cleaner and forthcoming cost - a good investment though! The head mating face is OK against a flat so I think a new standard head gasket with annealing and a correct torque down should be fine but thanks for the tip. Also thanks for the link to the info regarding valve spring seat shims - all makes sense. Fortunately, as you'll see in next video, valve springs are within tolerance, but I still used the shims to take up a little slack from valve seat cutting and grinding (and previous wear!). Thanks again.

ive never seen a tool to press in the valve guides, where do you get that thing?

@BSAPowerSet

Жыл бұрын

Hello Jack - saw one of these in use a motorcycle dealers that I worked at as a student at weekends in the late 70s and managed to source one off ebay relatively recently. Thanks for interest.

@stevenrowley9481

Ай бұрын

Hi Angus. I remember that in one of your videos, you said you were a 'Lincolnshire lad'. In this one, you said you worked at a dealer's when you were a student. I just wondered who the dealer was as I am also a 'Lincolnshire lad' and worked at a dealer's in Lincoln, Sharpes m/c, from about '72 and remember most of the dealer's around the area.

Hi, yo its a 10 minute vid man wtf

@BSAPowerSet

4 жыл бұрын

Hi David - thanks for the comment and interest. I presume you mean that the content could have been condensed into 10 mins?