Death of an SF2

arancia said:
on the subject of really rusty bits:

I acquired this triple crank with other miscellaneous bits that aren't in quite such a bad state and this forum chain inspired me to ask the experts here if there's a reasonable chance to revive it, Clearly the pins, rods, bearings and primary end sleeve are gone but can the webs, slingers, and other bits etc be saved to a rebuilt crank? The outer webs have been tack welded to the pins.

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You're a black catter!
 
those tack weld make me think that the pin has been machined off, then bored out and a new one pressed into the web, but I cant remember which side has the web and pin as one, and the side which just has the accepting hole, I am looking at the three blobs on the big end outer, maybe a clearer photo will show something else, but for sure you wont know if the pins are scrap until the thing is dismantled, rust eats away nicely at hardening. The rods can be scrapped anyway in favour of Carrilo or Arrow, or others that I dont know about, bearings are available, it just has to worth a shot, I would take it on if you choose not to, but then again Arizona to UK postage will stop that quicker than a moped trying a head on with a steam train.
CLEM
 
Tippie said:
Donate it to one of our reputable crank rebuilders, anything salvageable can help someone.
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Reckon there is NOTHING in there to be salvaged. Best to use it for decorative purposes.

Have just disassembled a 500 crank that had only superficial rust, at first glance. Lots of moisture had lots of time to do its thing, rod big ends and crank pins are too far gone, so 95% junk. Good thing the steel scrap price is on the rise. ;)

piet
 
pf1 said:
Well I took the SF2 project I paid far too much for to Ged at GCS and he started stripping the engine. In his opinion it is completely Donald Ducked. It's a shame because it has done very few km and it's the first time the engine has been opened but he estimated the rectification cost to be very high. It isn't economically viable to fix it so it's probably had its chips. Condensation inside the engine has devoured it. The castings are good but that's about it, although the starter motor still works :)
I have a couple of choices, selling isn't an option because I won't get my money back so I am thinking of taking everything from the bike that is compatible with a 3C making myself another wire wheeled triple and selling the UK registered SF2 rump for what I can get or scrounging up some SF2 engine parts and restoring it. It seems to be no decent crank, no dice.
Has anyone got anything I could use at a price that would be viable?
Cheers Pat.
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The bike looks pretty good ,It's too bad the engine is toast, I saved a SF1 from a damp basement ,was there for 30 yrs, the bike looked much worse than this ,but inside the engine was spotless, can't imagine what happened to this one, hopefully you can get a running engine in it and just clean it up a bit and ride it as is, good luck
 
One way or another I think the bike will be done but not by me. Ged said get this piece of effing shit out of my workshop pronto so it won't be him either but there is definitely serious interest in the poor old thing.
 
CLEMTOG said:
those tack weld make me think that the pin has been machined off, then bored out and a new one pressed into the web, but I cant remember which side has the web and pin as one, and the side which just has the accepting hole
CLEM
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Webs 2 & 5 have integral crankpins - I doubt very much you could bore out those integral pins and still have sufficient metal to allow the fitment of a separate pin - only the middle cylinder uses a separate pin. Until the crank is pressed apart you'd have to assume that Piet is entirely correct and there's nowt to be salvaged from any of it.
 
Despite my lack of facilities the SF2 is rising (sort of) from the ashes. I will try provide pictures of my butchery of the original engine later, it certainly hasn't been a pleasure o_O I have acquired another bottom end from and SF0 which was supplied by a kind ILOC member and at the moment I'm trying to separate everything from the original crankcases.
The whole lot was a disgusting rusty slimy mess with solidified lumps of black gunge sitting in the bottom of the cases. Every bearing was rusted solid and in the end I gave up trying to batter the pistons from the bores and sawed through a con rod to get the cases apart. Ged Shorten told me you can't buy them anymore but I'd had enough.
All the gears are eaten into, I used heavy duty degreaser and the citric acid that Cam advised but even that didn't shift the scabrous rust from the cogs. The clutch is absolutely corroded together, you would have to saw the drum up to free it.
So after this, what is left? I think maybe the starter motor, carbs, perhaps the dynamo, some casings but luckily, the cam followers, cams, valves etc and the cylinder head itself. One valve seat has a bit eaten away but it's not terminal I don't think, I'll ask Ged.
Today it took me all afternoon to get the rusted up locating pin out of the gear selector shaft and to pull the shaft out of the selector drum. The oil pump screws aren't going to give up without a battle either. Soon the cases will be cleaned and ready for assembly, I don't have any pistons yet but at least I have a spare set of barrels. Some fancy pistons going cheap in Sweden I believe (joke).
I don't know whether the bike will finish me first or I will finish the bike.
By the way those crankcase castings look rough as a dogs bottom internally but I suppose that's normal?
 
I don’t purvey dogs bottoms very often, but even if the cases internally have corroded a bit it shouldn’t matter, as long as you can’t put your finger through it (nothing to the with the dogs bottom previously mentioned, mind you)
 
Maybe this can cheer you up a bit, Pat. The "pond" engine I mentioned earlier has cleaned up nicely, see pics. I did have to attack the cases with quite course aluminium oxide to shift the corrosion, but it cleaned up great after a shot of new glass beads. "After" pic is before bead blasting.

The insides of the cases are always rough, just clean everything with solvents and leave as is. Don't be tempted to blast the insides, this usually has more than disastrous results!

piet


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I almost bought a gallon of carpet cleaner to do the cleaning job by accident, luckily the girl in the Screwfix shop asked me if that was what I wanted before she handed it over.
 
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