Interstate Freshening

john robert bould said:

Bearing scraping was/is standard pratice ...i was doing it 40 years ago.but modern maching as almost elimated it today. Three corner scraper and engineers blue.

hobot said:

Splat [what a handle ugh] I had to learn this ancient accepted skill-task and it worked out better than expected. Should look it up in case it happens to someone you know. If you are a real mechanic you put in the check tape stuff what ever they call it and torque down the remove and place on scale to get clarance at that spot. The shade tree way is assemble and turn then scrap off the witness marks in cycles till all even as can be by hand job.

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You scrape a modern overlayed bearing and you fuck it you may as well assemble it in the sand pit, old white metal bearing WERE fitted by hand scrapping, caps WERE filed down to take up the clearance.Todays, even 40years ago bearing is a precsion manufactured part with a thin bearing metal overlay or of a aluminium tin constructions if you need to scrape the bearing you have another problem, and NO I don't need to look it up, the 20 years I spent reconditioning showed me what sort of moron destroyed a perfectly good set of bearings

Depends who is holding the scraper, A wood chisel in the hands of a monkey...or in the hands of Chippendale..big, BIG differance .
The bearings i fitted where 6 inch bronze split shells for power presss's...i have not scraped any modern engine stuff....Velocette rocker split caps ..yes. The cap is reduced a few thou and the bore is restored with a three corner....i think someone on here may have done this :?:
I have also scraped in a few BSA A7 main bearing bush's...old skills passed down from the old war lads.

Enough about old people scraping bearings and all...


That is one sexy cam. Somehow I don't think it will have the same problems as the last one.


Resurfaced lifters.


Rebuilt head. New Black Diamond valves and new springs.


Exhaust port inserts. One was buggered but might as well do both. It's a shame you'll never see these again as they are a work of art.



The crankcase breather didn't fit. Jim has sent a revised one. I recall him mentioning that it might interfere with some engines.

You are so right, those are beautiful exhaust ports! Nice thread, thanks for the posts/photos.

There are really three people to thank for this: my brother for all the hard work, Jim for all his work and parts and my dad for funding the adventure. :mrgreen:

I'm just sharing.

Did Jim do the exhaust port work? It IS nice. Hang a picture of that on your garage wall.

On to Dave's crankshaft.
It miked out very good. About 1/4 thousandths wear. Superblends are good for another go-around.
Cleaned the sludgetrap -I found that missing cam lobe.
Got out a new package of bolts.



Decided to see how they compared to the originals.

Here is an original.


Here is a replacement.


Here is a grade 5 bolt from the bin.


Here is a grade 8 bolt from the bin.


Here is an ARP bolt.


So it went back together with the original studs after using a die to clean the burr's where they had been staked. I used new nuts from the kit. They measure the same hardness as the originals. I tossed out the tab washers. They are dead soft and squash under the nut with use causing loose nuts. Used lots of red locktite instead and made sure the locating pin was a tight fit in the flywheel.





Now a bit of magnaflux on the rod bolts. They look good.


And back together with new rod nuts and a set of standard inserts.

Swoosh dave, for your info..
I scraped many press bearings, these bearings powered the British Clearing press's that where used to produce the parts on Brit bikes and cars back in the sixties and seventie's in the west Midlands, proberly your commando parts, Tanks. oi ltanks all formed tin wear....so without the "OLD MEN " with scrapers..you woun't have a commando!
But ,yes lets keep to Commando's , your post is interesting..keep up your good work. Kind regards Old man. :wink:

swooshdave said:

Enough about old people scraping bearings and all...

That is one sexy cam. Somehow I don't think it will have the same problems as the last one.

Resurfaced lifters.

Rebuilt head. New Black Diamond valves and new springs.

Exhaust port inserts. One was buggered but might as well do both. It's a shame you'll never see these again as they are a work of art.

The crankcase breather didn't fit. Jim has sent a revised one. I recall him mentioning that it might interfere with some engines.

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Do you saftey wire that Circlip . :mrgreen:

Scrapeing ? a friend did a set of .020s for His Trident :shock: as Std. wernt then available in the pre computer days at that time there .
Cant remember if He said it took two days or two weeks , or both . But grim steeley determination saw Him through , in the day .
Used Blue , & ' re - checked ' untill right . :wink: :x

Matt,
It was a art form, saddy lost forever, Now old swooshy dont like his thread going off track..so we will leave it there!

Matt Spencer said:

Do you saftey wire that Circlip . :mrgreen:

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If Jim doesn't think it needs safety wired, it probably doesn't.

My brother has been very busy. I don't know how he finds the time.


End play.


Timing side.





Report is that it's running very nice. My brother is trying to get it broken in before the Barber trip. He's hoping to get at least 500 miles in the next couple weeks.

Glad to see it all went back together. See you at Barbers, Jim

I have about 350 miles on it now. It is running very sweetly. Only issue so far was being reminded on my way in to work that both taps are 'reserve' type, so there is no reserve. Had to lean the bike all the way over to let a splash or two of gas flow over to one side. Fortunately, I managed to make it to a gas station.

Thanks for your help Jim!