Norton 650SS engine rebuild woes
- Thread starter Caferider
- Start date
Good news is that all parts mic'd out to be standard, cam and crank looked very nice and wont need to be machined. On the flip side is the cylinder will need to be bored .020 over and I need to source new .020 pistons, which were shot anyway. The intake valves looked like new but the exhaust were pretty well scorched and the stems were worn out of spec. So Ill be looking for new valves also, I think M.A.P. had Black Diamond Valves and NASCAR 45 Guides for the 650.
It appears that the intermediate shaft was driven through and welded up. I'm not sure what Im going to do here.
After cleaning up all the mess and glass beading the cases, I noticed how nasty the connecting rods looked and started working on them. A quick peening with glass bead and a little sanding with 320, 400 and 600 grit, followed up with a few minuted on the wheel. The first one looks much nicer now. Not that this motor is going to be hammered on a lot I will have a little pleasure and peace knowing that the rods are nice and smooth and free of stress risers that could lead to cracks, and besides they look cool.
Now its time to head to the machine shop, and start looking for parts.
It appears that the intermediate shaft was driven through and welded up. I'm not sure what Im going to do here.
After cleaning up all the mess and glass beading the cases, I noticed how nasty the connecting rods looked and started working on them. A quick peening with glass bead and a little sanding with 320, 400 and 600 grit, followed up with a few minuted on the wheel. The first one looks much nicer now. Not that this motor is going to be hammered on a lot I will have a little pleasure and peace knowing that the rods are nice and smooth and free of stress risers that could lead to cracks, and besides they look cool.
Now its time to head to the machine shop, and start looking for parts.
I called an old timer who used to own the local Norton Dealership to see if he had a set of 650 pistons. He said that he didn't have any left but he did have a very early 750 top-end that would work, NOS 0 time 750 head cylinder and pistons. Anyone see a reason why it wont work?
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As long as you are using the entire top end (pushrods and all) if the base gasket shows the same bolt locations on both, it should be a straight swap. Fit up the cylinder and pistons first and check to see if the pistons leave the proper squish and clearance. If the strokes are different, you will need a 750 crank or be prepared to cut the motor down (cylinder height and pushrods) to make it work.
grandpaul
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You shouldn't just "eyeball" it, but completely assemble it with all gaskets, then GENTLY rotate it through 4 or 5 revolutions with the spark plugs out, no primary chain.
Carefully feel for the slightest binding and investigate where it's happening if you feel it snug up.
Carefully feel for the slightest binding and investigate where it's happening if you feel it snug up.
Black and polished Alloy. If I can find the Manx Alloy Petrol and oil tanks.I see a Norton 650ss headed for trouble.
It is nice that you cleaned all the slag off the outside of the cylinder, maybe the engine will cool a bit better now, that is if you don't plaster layers of paint or powdercoat on it in your anal pursuit of aesthetics. Smart Norton engine builders look for slag inside the pushrod tunnel where it can fall down and hurt the lifters, did you think of that?
Uh, a 750 Norton top end will not fit onto a 650 Norton crankcase. If you bother to look at the parts books for the bikes, even in the same year you will see that the cases, cylinder and head are different part numbers.
The head will be better hogged out to 32mm? The rods are better polished like mirrors? You sound like the hot-rod engine guys from the fifties and sixties where if it was shiny and bigger then it had to be better.
The fact about head porting is that by the time you know enough about it to be qualified to tell if someone is qualified to port your head, you will be able to port it yourself. Until then you are most likely to get screwed, not ported.
If you look at the inside of a Nascar engine, or any other modern successful and reliable racing engine, you will not see mirror-polished parts, they are many times more vulnerable to cracking that way than if they have a shot-peen finish. There is nothing on a polished surface to stop a crack from spreading, and the tiniest scratch on a polished surface is much more likely to turn into a crack than on a peened surface. Also, castings and forgings have a natural hard and/or compressed skin as they are produced, which you have removed with your sandpaper etc..
Somebody drove the timing shaft through the case and fixed it, so why do you have to fix it again? Isn't it shiny enough?
Your bike is on it's way to becoming over-restored, it will look like a dumb teenage girl plastered with too much makeup. And on top of that you also will probably make it less reliable and worse-performing than when it was stone stock.
The vintage bikes that are worth the most are of course un-restored originals. After that a restored bike will be worth a lot more if it is done in a manner that it is hard to tell if it is restored. The bottom of the barrel are bikes that are restored as if they went through a "restoration factory", where they are taken to bits, run through sandblasters, bead-blasters and powdercoat and polishing shops, then bolted back together. They all looks the same and they all look like shit, and they all actually need to be re-restored.
You should put that bike in a corner for five years and get something that is not so rare and special to "learn" on. Someday when if you are lucky enough to know what is what, you will be glad you did. Otherwise you will be sorry you did and you or someone else will be doing it over the right way someday.
It is nice that you cleaned all the slag off the outside of the cylinder, maybe the engine will cool a bit better now, that is if you don't plaster layers of paint or powdercoat on it in your anal pursuit of aesthetics. Smart Norton engine builders look for slag inside the pushrod tunnel where it can fall down and hurt the lifters, did you think of that?
Uh, a 750 Norton top end will not fit onto a 650 Norton crankcase. If you bother to look at the parts books for the bikes, even in the same year you will see that the cases, cylinder and head are different part numbers.
The head will be better hogged out to 32mm? The rods are better polished like mirrors? You sound like the hot-rod engine guys from the fifties and sixties where if it was shiny and bigger then it had to be better.
The fact about head porting is that by the time you know enough about it to be qualified to tell if someone is qualified to port your head, you will be able to port it yourself. Until then you are most likely to get screwed, not ported.
If you look at the inside of a Nascar engine, or any other modern successful and reliable racing engine, you will not see mirror-polished parts, they are many times more vulnerable to cracking that way than if they have a shot-peen finish. There is nothing on a polished surface to stop a crack from spreading, and the tiniest scratch on a polished surface is much more likely to turn into a crack than on a peened surface. Also, castings and forgings have a natural hard and/or compressed skin as they are produced, which you have removed with your sandpaper etc..
Somebody drove the timing shaft through the case and fixed it, so why do you have to fix it again? Isn't it shiny enough?
Your bike is on it's way to becoming over-restored, it will look like a dumb teenage girl plastered with too much makeup. And on top of that you also will probably make it less reliable and worse-performing than when it was stone stock.
The vintage bikes that are worth the most are of course un-restored originals. After that a restored bike will be worth a lot more if it is done in a manner that it is hard to tell if it is restored. The bottom of the barrel are bikes that are restored as if they went through a "restoration factory", where they are taken to bits, run through sandblasters, bead-blasters and powdercoat and polishing shops, then bolted back together. They all looks the same and they all look like shit, and they all actually need to be re-restored.
You should put that bike in a corner for five years and get something that is not so rare and special to "learn" on. Someday when if you are lucky enough to know what is what, you will be glad you did. Otherwise you will be sorry you did and you or someone else will be doing it over the right way someday.
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Post of the month there, from the irascible Mr G.
Yes I did and the inside is perfect, low milage, standard bore.beng said:
"All 650's and 750's Dominator have top oil feed, and share same casting 25319# " as per http://atlanticgreen.com/nhth.htm there is lots of good info here and some pretty pictures for you too, so you wont have too much reading to do.beng said:
beng said:
I had considered opening the intakes up but everyone I have spoken with on the subject felt that this would be a waste and that it would end up being too much carburetor for the displacement, and that included several learned and respected people here and a couple of slackers who have been building Norton motors professionally for over 25 years.
As for your input on porting, its the only correct thing you said in your entire post. Polishing ports is a waste of time because the shine will disappear the first time the motor is run. Having a smooth unobstructed surface for increased laminar flow is the desired result of polishing not how pretty it is, the more irregularities in the surface the more restrictions to flow you have. Shot peening will add strength to the surface of the metal but the angle it is peened from needs to be close to perpendicular to the surface, if the angle is too acute and results in a glancing blow the effect is more like a scratch defeating the purpose, and the tiny craters that give the surface its strength will reduce the laminar flow also.
Polishing has its purpose in function of increased air flow over strength
beng said:
Im still waiting for someone to come up with a solution that best fits the situation, Looks have nothing to do with the functionality of the part.
beng said:
I never said it was to be restored to showroom condition, I'm sure this bike will have a better performance record over the next 45 years of her life than she did in the first.
And I kinda like that slutty sexpot look.
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Caferider said:
Are there pics of BenG here somewhere?
Caferider said:
Some 650 and 750 engine parts do share the same castings, but they are machined differently. I guess neither pretty pictures nor text is any help to the "internet biker", I am sure that most of your rhetoric comes from google and wikipedia though. I was around British bikes forty years before I ever had a computer and found the differences in Norton twin engines by holding the parts in my hands.
If you want to provide more entertainment, you and the businessman "Grandpaul" can make a video for us while you try to fit 650 and 750 Norton parts together.
The internet can be a great tool, but like any tool having it in hand does not mean you know how to use it any more than having a book in your hand means you can read or comprehend what it is saying.
Caferider said:
I guess that is why a golf ball with dimples goes twice as far as a smooth one. Actually best flow is with a non-polished surface. A little bit of roughness creates less friction. Another google miss.
Caferider said:
Well I would hope that whoever did shotpeening for you would know that.... Google.
Caferider said:
Yes the number one worry about a connecting rod is airflow over it, brilliant. Google.
beng said:
I never said it was to be restored to showroom condition, I'm sure this bike will have a better performance record over the next 45 years of her life than she did in the first.
And I kinda like that slutty sexpot look.[/quote]
Well slutty sexpots are cheap, and your taste was obvious, I just put it in words. It doesn't matter if it is a resto a custom or a race-bike, in the end it will be a reflection of what the builder knows, in this case that is jack.....
bwolfie said:
My daughter has a blog and she was elated when she had her first haters, to her it meant she was important enough for someone to waste their time knocking her down. I like a good argument with ideas put forwards by each side but negativism for no reason and by someone with no credentials I can live without.
Jean
And thanks for the comments, much appreciatd.
All I did was add some information and try to help the bike and it's owner. Trouble is that along with people asking for help they also ask for an ego-stroke, and when they are shown to be wrong on points or offered opinions that don't go along with their ideals they get their feelings hurt and don't know how to handle it. Business as usual, everyone wants sunshine blown up their skirt.
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beng said:
I, for one, would like a little sunshine up my skirt. Heck, I'd post a video of that if I could. :mrgreen:
The real talent to getting folks to heed your advice is to wordsmith your knowledge in a way that they want to learn from you.
Ending with unwarranted criticism is not what we like to call "ideal". You don't like over-restored bikes? That's nice. It's been the debate for so long in the restoration world no one cares.
Now that you have painted yourself as a curmudgeon, sadly any information that you could have shared with your fellow enthusiasts may have been lost.
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Beng i sugest that you re read your posts and re consider what you have posted because you are coming across as a person with a serious attitude problem [i hope that is not correct] some of us have been around nortons and bikes in general as long if not longer than you, raced rallied and distroyed some good bikes, but beauty is in the eyes[hands] of the beholder[restorer] and our views are not all the same. I personnaly have a 650SS on my work bench and your comments offended me as you know nothing about me or what i have done [or restored], Though the awards that my restorations have gained speak for themselves, whats more i work in the industry and spend most of my recreational time playing with bikes as well so lets hear a little more about you.
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Ben knows his Nortons and posts some good stuff. When he posts tripe, it's so obvious that it's unlikely to mislead anyone. As for the judgemental stuff he posts about the owners and quoting out of context to score internet points- who cares? Don't complain about him and get him banned- he's useful and a good laugh.
Although he's probably going over the score in this thread, he has a point. Anyone who will destroy dozens of tools removing that slag sounds a bit obsessive to me. The "big ports and carbs" performance idea sounds so misguided that it makes you wonder about the owner's aptitude for old bike fixing. If you have a 650SS running properly as standard, it is about as fast as such a roadgoing british twin can practically and safely be: even if you know a power tuning trick that actually works, don't do it!
Although he's probably going over the score in this thread, he has a point. Anyone who will destroy dozens of tools removing that slag sounds a bit obsessive to me. The "big ports and carbs" performance idea sounds so misguided that it makes you wonder about the owner's aptitude for old bike fixing. If you have a 650SS running properly as standard, it is about as fast as such a roadgoing british twin can practically and safely be: even if you know a power tuning trick that actually works, don't do it!
