fucker, fuck off texas sucks ,sorry bout yert luck
i get it the brit shit can be knotchy specially when they put a high dome piston in a goldstar ,that is my xb33 and they just shake there hreadsNever met the man...... Actually I knew that, age I think playing with grey matter.
im know where you are man and agree with all its common good senseI regularly run over 12:1 on racing brit engines. Photo is a modified 2 ring Manx piston for use in a pre 56 manx head compression is well over 12:1. See the squish platform on the piston? If you draw a line about half way between the top ring groove and the squish platform the section above the line is how much fits into the cylinder head at TDC. Compression isn't subtle on brit racer.
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My comment with regards to the 650ss engine isn't suggesting they can't take it but rather the maintenance schedule can get rather busy and that with the higher revs required to take advantage of a big cam ad high comp pistons the valves have job to keep out of harms way.
Using a race engine on the road is a waist of money, you might take advantage of the extra horses once in a while but generally the engine is spinning at low-ish RPM and the engine works against itself. As I suggested earlier, stock springs and lower comp pistons around 9 to 9.5:1 is all you need to change and lower red line to around the peak torque point. With some confidence I can say the original race pistons will not be replaceable anyway, just put them in the heritage box.
indeed it is really amazing and pretty bitchen to witness"Hungry for spanners"..love that, I have a couple of those.
I don't know when I'll stop being amazed: a bike nut in Texas buys an odd ball British antique he knows nothing about and within a matter of hours is talking to a Brit, thousands of miles away, whom he's never met and knows the machine inside and out. Unbelievable.
on a side note do you use any slick coatings on parts that can benefit from it ?ie piston skirt thrust faces,cam lobes,non rolling element lifter faces etc ?i started usingI usually can't be arsed with shit like this.
A few facts here - Yes Norton twin cranks are forged but there was indeed a material change in Norton cranks around 1960, Norton published a bulletin in one off the weekly mags either Motorcycling or The Motorcycle. Norton cranks broke when pushed hard so did Triumph, AJS and Matchless just broke!!! But the same material was adopted by AJS and Matchless to cure their crank failure issues in from 1961 (works and TT marshals bikes got the stronger crank in earlier). I don't think Triumph ever changed they seemed to snap in the same place on unit T120 and T140!
Speaking of valve angles - everything is relative and I said "ish" referring to Norton, I wasn't comparing to Triumph or BSA you did that. Its a simple fact that engines from this period had little scope for generating big rear wheel HP increases over standard, stepping from mid 40's to mid 50's or perhaps a little more was about as much as you could get from a 650 unless grenades are your thing. Reducing cam base circles or altering follower radius are minor mods on standard kit which was normal stuff to do but that's hardly radical is it. Neither are raised dome Domi pistons. To reiterate my point there was little available so you worked with what you had or could get. If you would take the time to read what I wrote you might feel less inclined to shoot from the hip. I have built more "proper" race engines than I care to remember from 4 stroke GP singles and twins to 2 stroke multis and have a good knowledge of the fitting process. Stepping from a engine like a Manx in which much can be altered to a road pepped parallel twin is bit like getting off a thoroughbred and jumping an a cart horse so I can be a little dismissive or understate the work required to make a pushrod engine go well. And for God sakes don't mention the Norton domiracer....
Surprisingly I have never had a well sorted 99 / 650 make more power than a sorted unit T120 with its wide valve angles and high domed pistons - I have built quite a few of both. In fact the 31CSR I had with a head skim, sports cams and single carb would leave a 650ss for dead and pulled a healthy 126mph at Snetterton.
What are you building at the moment?
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Look we are both knowledgeable guys and with prostate permitting we can have a pissing competition but you can stuff the "but just enjoys hearing themselves talk the most" last word freak thing straight back up your arse.
once i dropped the cr down to a sane level for my use ,just cruising around here on public roads..once that was sorted it has never given me any starting issuesYour cams should be marked, if not you'll need to measure lift and duration but figures can vary due to wear and tear or just buy a new set to be sure. Vernier cams work well for perfect timing you can also alter timing to suit riding style or conditions. Goldies are notorious for not starting hot or cold. I have found that induction is lazy and the plug is often a dry as a bone despite carb/float flooding and kick priming. Remember cam form is a combination of cam, follower and rocker ratio.
Most British gearboxes are car like.
yep and harley pretty much everything was at one time a lay shaft type with input and output coaxialYour cams should be marked, if not you'll need to measure lift and duration but figures can vary due to wear and tear or just buy a new set to be sure. Vernier cams work well for perfect timing you can also alter timing to suit riding style or conditions. Goldies are notorious for not starting hot or cold. I have found that induction is lazy and the plug is often a dry as a bone despite carb/float flooding and kick priming. Remember cam form is a combination of cam, follower and rocker ratio.
Most British gearboxes are car like.