Four stroke Nortons.

[Dell Boy]

Yesterday the L/H conrod in my 650 s.s. decided it was too long & fed up with being contained in an oily aluminium barrell so broke itself in halve & tried to batter its way out through the camshaft & cases making four holes but it got stuck so big lockup & skid only stopped by whipping the clutch in. Barrels have gone as well.Question, has anyone out there got a 500/600/650 Dominator engine they wish to dispose off or alternatively I might break the bike. It is a standard 1957 all original wideline rolling chassis if anyone is interested.Derek Fox

[FloridaMike]

Ouch. I've seen that happen on older (mid 60s) BSA's, makes an ungodly mess of the engine. I seem to recall it was caused by excessive advance.But now you have a rolling chassis just begging for an engine conversion - I've seen a Norton Dominator with a 500cc Kawasaki triple in it, all that space just aches for some kind of interesting engine swap - big v-twin out of some Japanese cruiser for instance, you'd have a reliable bike that handles well . . . (great, another project).One door closes, another opens. Sorry to hear about the mess, hope you can take lemons and make lemonade out of it.Best Regards,FloridaMike

[ZFD]

Actually not sure if it is possible to use it- I don't have a 650SS conrod to compare- but a Commando conrod might do the job? Same big end & small end diameter, same length I believe.I must admit ignorance of 650s, never had one, and they are pretty rare in ze Fatherland.Never had a Commando conrod fail, not even in racing.Joe

[Dell Boy]

Thanks Joe but there are four holes in the crankcases plus the barrell has cracked. Basically the engine is scrap.650 Nortons were/are prone to breaking rods. This is why some Tritons got built. There were ten times as many Triumph twin engines about as Nortons so in went a cheap Triumph engine when the Dommie engine went bang.Derek F.

[ZFD]

And I thought Tritons were built because the Triumph chassis was diabolical, and there were Manx chassis at the Forula 500 car builders stacked right to the ceiling that they had no use for.... and later, Model 50 owners sold their gutless wonders to desperate Triumph enthusiasts... but I may have gotten the history wrong!

[Dell Boy]

All that is also true Joe.Derek F.

[Richard Negus]

There's a nice-looking Aprilia 750 V-twin on fleabay at the moment, 1000 miles only............ You could make an Apron instead of a Norvin.

[Dell Boy]

Well Richard, I bought my dream bike in 1978, a Norvin twin, but was very dissapointed with it.Due to the engine being mounted high in the frame & towards the rear, entering a fast bend was always a gamble as to wether it could be wrestled round it or it punched a hole in the hedge.I remember going into Windy Corner at the T.T. in 1979 with brakes almost faded away,going a couple of feet up the embankment due to running out of road,scattering the ghouls who sat there waiting for crashes or to photograph there mates going round & bounced somehow back on the road & carried on only to overshoot governors bridge dip due to, now, non existent brakes.I decided the bike had to go before it killed me so I bought an Egli chassis & that transformed the handling & was much lighter.I still have the bike & it handles like a dream. I only have to think about going round a roundabout & I find myself coming out the other side with minimum effort & at a good rate of speed. This on trail knobbly tyres as the bike is built up as a Flat Tracker to upset the Vincent purists.I think the Aprilia would sit too high as well so ruining the featherbed handling.I am thinking of having a Model 50 engine I have under the bench built up by Mike Pemberton into a short stroke 520 c.c. which will have a bit of go in it & be quite light. As always it depends on finances. At present I do not know which way to go.Derek F.

[rustynuts]

Not that it matters as your engine is scrap, but just out of interest, commando rods will fit a 650. I have a pair in mine to replace the originals that melted and bent due to oil starvation. Fortunately the noise of the big ends clonking away got my attention and I stopped before it went bang.

[rustynuts]

p.s. I'll swap you my 650 engine for your Egli. Then I''l put that Aprilia engine in my empty chassis.

[Dell Boy]

Hello Rustynuts, I think I will decline your offer of a swap!!! After 30 years ownership it is hard to part with it anyway though logic often says to me sell it as it gets little use. I did go to the T.T. on it 4 years ago but it has a banana sprint tank fitted which only holds 8 litres so long runs are a gamble especially with petrol stations so few & far between. I have a bigger alloy tank but it isn`t very attractive & spoils the lines of the bike.Derek F.

[Dell Boy]

P.s., Interesting that commando rods are the same though.Derek F.