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That's an awful of blow-by there even for an oldie- has obviously not been sealing well for a good whileHarry wrote: Sun Mar 29, 2020 4:31 pm Part of the problem was my own doing, I'd been racing a bloke on a Bonneville and had been on a long flat road, running with the throttle on the stop for a good few miles and eventually I felt it start to lose power and then it nipped up just as I coasted in.
I knew it was shagged anyway, so I'd lost any mechanical sympathy anyway, but after it had cooled down it got me back to the camp site.
This was a the result though...
IMG_0715 by Iccy, on Flickr
One broken ring and clear evidence of a seizure.
IMG_0711 by Iccy, on Flickr
Are parts readily available for stuff like this?Just looking at it, and comparing it with the head I'd say that's correct - it looks like it would give a pretty high compression ratio. Normal road going bikes of the time (Rudge might be a bit different) were lucky to get more than 7 - 8 compression ratio on standard designs. That big dome looks like a hi-comp idea.Harry wrote: Mon Mar 30, 2020 4:40 am
The piston in mine is taken from a drawing that (I think) someone did in the 60's, someone in the club got hold of it, assumed it was the right one and had a batch made - but there is a lot of discussion to say that it isn't a great design and was done by a racer back in the day that wanted a specific application for his machine, so it's not the best design as a standard piston.
It’s amazing you can still keep them running if the factory closed so long ago, impressiveHarry wrote: Mon Mar 30, 2020 4:40 amYes and no.Bomble wrote: Sun Mar 29, 2020 8:38 pm Great threadAre parts readily available for stuff like this?
The club does commission parts such as pistons and things, and you can get some consumable parts, but often the knowledge to replicate original stuff just isn't there and drawings of the day (if they exist) are not accurate. The Rudge factory were never really in the money and quite often just used whatever was on the shelf, so two bikes leaving the factory on the same day might be different. The factory closed it's doors in 1939 and never made another bike.
There were lots of new things coming out back in the 1930's and from what I know it appears that they didn't always update drawings, or they did but the updated version got lost and then aftermarket post-production parts were made using the originals, which might be wrong.
The piston in mine is taken from a drawing that (I think) someone did in the 60's, someone in the club got hold of it, assumed it was the right one and had a batch made - but there is a lot of discussion to say that it isn't a great design and was done by a racer back in the day that wanted a specific application for his machine, so it's not the best design as a standard piston.
I think people mean well but there is a terrible amount of politics in the club, there are a lot of bitter rivalries going back decades, especially around parts, as soon as one faction has some parts made the other decries them as not suitable or not to original design, etc.
To be honest it's tiring, but that's classic bike clubs for you.
Crankcases, barrels, cylinder heads, etc, are difficult to come by.
I bought a lathe just to make bits for this bike.
What that club needs is an alpha male in charge of it.Harry wrote:I think people mean well but there is a terrible amount of politics in the club, there are a lot of bitter rivalries going back decades, especially around parts, as soon as one faction has some parts made the other decries them as not suitable or not to original design, etc.
To be honest it's tiring, but that's classic bike clubs for you.
I think that's the defining description of classic bike ownership.Harry wrote: Wed Sep 02, 2020 2:41 pm
It's a good job I really love this bike, it needs a lot of attention and it eats money.
Yeah well what does a routine service on a Ducati cost?Harry wrote:It's a good job I really love this bike, it needs a lot of attention and it eats money.
This is true of my Kawasaki (1982 Z1000J based), the engine is very simple, and if it does need any machining work done there's people who can do it, from the mid 80s onwards bike engines improve massively from a reliability point of view, but they get a lot more complicated and the tolerances are a lot tighter, these engines seem to be a lot better if they've never been apart.Mr. Dazzle wrote: Wed Sep 02, 2020 9:21 pm The thing about these old bikes (my oldest is 'only' 1965) is that they take a lot of looking after, but it's all pretty simple.
You really can do 99% of stuff yourself with not that many tools.