Engine noise

It would not be hard to take the primary drive and timing side cover and some of the timing mechanisms apart and see how much end play, or even radial play the crank might have on either end. Have you looked for shiny metal specs and bits in the oil filters?

Nice bike and a rare bike too. I would say it needs immediate looking into as you do not want to take a chance on blowing up the cases, especially if they are the originals with matching numbers to the frame.

I just put a 1962 650ss engine together, and got to see how very little room there is between that heavy spinning crank assembly and some parts of the cases. It would not take much to go wrong down there to completely destroy very much of the engine.

If you do take the engine apart, a 1962 Model 99 should have the "humpback" 650 style crankcases, which means that a 650/750 crank and rods could be swapped in with a little trimming of the stock piston skirts and the bottoms of the cylinders. It would give the bike a little more torque and reliability, and it is also easier to find parts for the 89mm stroke crank setups than it is for the 88/99 assemblies.

Previously wrote:

I am conscious of an engine noise in my '62 Dominator 99 recently. It is best described as a rumble low in the engine. It is not particularly loud and only noticeable when riding and not at idle. It sounds very much like a noise I had in my BSA A10 which turned out to be the timing side crankshaft bush which was easy enough to check by removing the timing cover and checking play in the bush. Before I start stripping is there any easy way to check the crankshaft bearings on the Dommi or should I be looking somewhere else entirely?.

Peter

Fair chance its mains , especialy if it stood for many years, the standard mains last a long time in a 99,I can't see any reason to fit superblends etc.Its about time someone made some rods for the 88/99 motors,I agree with Ben if you have the blister cases a 650 crank and new rods would take away the worry of the old rods.Check the primary chain has slack.

Previously wrote:

Thanks guys, I've only had the bike for about four years and it's been a daily runner since then. When I bought it from a dealer in the UK it looked as though it had had a complete restoration but the dealer was unable to confirm this. I change the oil regularly and have never noticed any particles stuck to the magnetic sump plug. I will do a partial strip to see if I can find the source of the noise in the next couple of weeks as I am just about finished a rebuild on the A10 after an extensive (and expensive) engine rebuild. From bitter experience I know that until a strip is done I will not know what previous owners have been up to over the years. Thanks also for the information on the possibilities of an upgrade, something to keep in mind if I go that deep.

Benjamin, they are indeed matching numbers, but out of curiosity what makes the model rare, I was under the impression that there were many 99's of this year on the road ?.

lots of 99's in the UK, not so many in the states.

Previously wrote:

I am conscious of an engine noise in my '62 Dominator 99 recently. It is best described as a rumble low in the engine. It is not particularly loud and only noticeable when riding and not at idle. It sounds very much like a noise I had in my BSA A10 which turned out to be the timing side crankshaft bush which was easy enough to check by removing the timing cover and checking play in the bush. Before I start stripping is there any easy way to check the crankshaft bearings on the Dommi or should I be looking somewhere else entirely?.

Peter

Hello I have the same problem it turned out to be the clutch bearings and the chain as well , If I were you when it come to changing your main bearings, I would stick to the standard R&M MRJA.30 roller and MJ30 ball timing side The Superblend part number 063906 R&M 6MRJA.30 witch is still available, And also look at RHP M306e. FAG Bearings Superblend take some setting up for the shims sizes to be fitted, Which I feel that superblend bearings in a 600 twin are unnecessary And fitting a crankshaft from a 650 twin is also is not a good idea as the bottom of the barrels are different the 650 barrels are hard to get hold of and they have cut outs for the connecting rods swing , the pistons are different to they are shorter and the boss is higher up the shirt . than the 600 pistons yours Anna J

THe 600 barrels can be slotted and shortened , and 650 pistons used, However the blister cases are not very common so I doubt you will be doing this.

Previously wrote:

THe 600 barrels can be slotted and shortened , and 650 pistons used, However the blister cases are not very common so I doubt you will be doing this.

Yes And BHB Standard Pistons That was fitted to Norton Motorcycles Originally are also hard to find , JP piston are the nearest to the Original pistons . and you have allot of work to do the cut outs its not a straight forward job machine them and it will be expensive . only to gain 8 to 10 bhp when the machine is just for road use , most A and B road in our days have speed limits on them, Its Not like the old days when you could do the Ton Ten On a A road and get away with it , Now there are too many Idiot Car Driver On the roads the biggest part of them cannot see us bikers even When your wearing Hi-vis jacket !

Hi Anna, No we are not looking to go as fast as your Manxman!, what we are about is to avoid useing the tired old Dommy 88/99 rods, Expensive aftermarket rods are around ,but if you are going to spend a lot it seems logical to upgrade to the 650/750 stuff. I have considered an Atlas motor but they are not cheap now.

Yes, you're talking about a serious amount of money for upgrading the engine using 650 parts and machining the barrels Is it worth it? I'm with Anna on this. We have far more restrictive speed limits in the UK now than when I started riding - the aim then was to get a "ton-up" - and I did on my 99! No motorways or 70mph limit then. If you really want to thrash the bike then new con-rods are pretty much a must. I'm not convinced of the efficacy of machined billet types. Forged are obviously the best way to go, (See Andover Norton's comments on this). Polish up the old ones and get them X-rayed first!

With an Atlas motor you get plenty of 'grunt' but the most vibration of all the twins - see the oldroad test in this month's RH299. Standard main bearings are more than adequate for a touring bike and not so expensive.

"Let's be careful out there"

Cheers, Lionel

Previously wrote:

Yes, you're talking about a serious amount of money for upgrading the engine using 650 parts and machining the barrels Is it worth it? I'm with Anna on this. We have far more restrictive speed limits in the UK now than when I started riding - the aim then was to get a "ton-up" - and I did on my 99! No motorways or 70mph limit then. If you really want to thrash the bike then new con-rods are pretty much a must. I'm not convinced of the efficacy of machined billet types. Forged are obviously the best way to go, (See Andover Norton's comments on this). Polish up the old ones and get them X-rayed first!

With an Atlas motor you get plenty of 'grunt' but the most vibration of all the twins - see the oldroad test in this month's RH299. Standard main bearings are more than adequate for a touring bike and not so expensive.

"Let's be careful out there"

Cheers, Lionel

Hello Lionel I been out On a VMCC run And my Bike did Not see over 55 mph And I was up and down the gear box like a Jo-jo if fact no one on the run went over 55 mph , I was glad to get home , Next time I go out on my own some were , I usually Hit speeds of over 80 mph but all depends on what you what out of you bike .But remember You can not By these bikes of the peg Any more there all getting thin on the ground Now after all there well over 55 year old . there just like us falling of the pruch . your old Anna J

Yes Anna, as I've said before - when we were 18 we were immortal, except for the few of us whose bike hit a tree or blew up. Now we (me!) are in our 60s we are a bit more circumspect about risking life and limb. Now this isn't necessarily because we are old f*rts; it's because of all the other crazy ba*tards out there who treat us as if we are invisible!! Apart from the fact that road traffic has probably more than quadrupled since the early 1960s. They even let poor people own cars!! I'm with Marie Antoinette - "Let them eat cake" !!

When I got married in 1968 and moved to our present address (Yep - never moved again!) there were only 3 cars in our road of 22 houses! About 25 now!

Cheers, Lionel

Later in the 1960s the Norton parts books list the same cylinders for both the 650ss and the Model 99. They were listed as separate part numbers in early 650 parts books because early 99 cylinders though having notches in them for connecting rod clearance like the 650cc cylinders the notches were not deep enough for use with the 650cc crank and rods.

Early Model 99 cylinders from the 1950s, especially those made for the dynamo engines, may have less clearance in the pushrod tunnels than the later cylinders which were used with the fat pushrods used by the 88SS and 99SS bikes of 1961.

The Norton 650 introduced the crankcases with a hump on the back for connecting rod clearance starting with bike serial# 93601. At what serial number all Norton motorcycles were switched over to the humpback crankcases is not known with certainty, but I do have two model 88ss bikes from 1962 with them, and it is not unknown for later Model 99 engines to have them.

Since Model 88 and 99 Norton SS bikes were used with the fat SS pushrods beginning in early 1961, it would suggest that all late Dominator cylinders were safe to use with them after a certain serial number.

50 years later, any sort of parts could have been swapped into a bike to keep it running, so a good and careful mechanic will check the running clearance the moving parts of his engine has while he is giving it an overhaul.

That said, if someone makes sure their pushrods have the clearance, a late Model 99 from 1962 should accept 650cc crank, rods and pistons with no more than grinding the clearance for the rods into the bottom of the cylinder sleeves which protrude down into the crankcase. Model 99 pistons have been used in 650cc Nortons very, very often simply by profiling their skirts for flywheel clearance. The domed Model 99 pistons will give close to 10:1 compression though.

See a photo comparing 88,99 and 650 cylinders here: http://www.facebook.com/photo.php?fbid=339740326073239&set=a.339739889406616.73975.187441501303123&type=1&theater

Email me a photo of the back of your engine and I will tell you if you have the 650cc style crankcases.

Benjamin previously wrote:

50 years later, any sort of parts could have been swapped into a bike to keep it running, so a good and careful mechanic will check the running clearance the moving parts of his engine has while he is giving it an overhaul.

Quite!

Hi, interesting reading! I would also check the Alternator Rotor, as they rust internally, and expand as the revs. build up. The other possibility is the Crankshaft is worn and the bearing spinning, or, and the crankcase housing is worn. Paul Dunstall always recommended pinning the outer races into the drive side case on his Dommiracers. I hope its no more than a worn bearing, much easier to sort. Regards, Paul

hello As i said earlier I had the same noise as you its Turned out too be the Spider worn in the clutch , so now I need a new spiders and new clutch rubbers too and I fit new roller bearings that fit at the back of the clutch drum , so you see you think its one think , but it turns out too be something completely different too what you think it is, And I will fit a new primary chain as well. I bet the Spider as been there since the Bike was built from new. yours ajd

Just adding a little personal experience to this interesting thread which, as usual, appears to be rapidly departing from the original question asked.

The bottom-end rumble could be mains but also the alternator rotor throwing a wobbly on the crankshaft. I would check out both.

Fitting two Superblends on a 99 engine is a total waste of time, effort and money unless the owner is planning to race his bike. By all means put one on the drive side as, size for size, they have a far greater load capacity than the original SKF/RHP or whatever.Fit anuprated ball race on the timing side. This saves the hassle of shimming and makes future dismantling so much easier.

Converting a 99 engine to a 650 is possible if a) the crankcases are the later bulged type or b) Carillo race rods (or similar) are fitted - as these rods still have clearance insidea standard 99 crankcase.

But................everyone please remember adding a crankshaft with a 89mm stroke makes the pistons travel further down the cylinder bore. Which, on a well used engine will have a wear lip similar to the top end. This will need removing or the pistons will knock chunks out of themselves very quickly.

99 pistons can usually be easily trimmed to give flywheel clearance.

Lots of people have been caught out fitting early 99 barrels when building a 659 motor. The pushrod tunnel clearance is critical when using the later, fatter SS pushrods.

650 engines are good fun but a 99SS is a very close second and actually easier to build, in the UK, at the moment. 99 engine pieces are still plentiful and cheap compared to 650 parts. The most expensive bit to get hold of would be a proper 650SS head. However, the later, larger valved and bigger ported99 heads can be given a twin carb set-up almostidentical tothe original 99SS.

My 650SS used to drink petrol, compared to my 99SSand never gave better than a50mpg average.

My Atlas gave similar fuel consumption figures and a free vibratory massage with each journey.

Fitting single carbs, to both bikes, helped improve the fuel figures but after 40 years of Nortons I have gone back to a 99SS for shortride fun and a 750Commando for seriously long journeys.

hello you have all forgotten one factor, Its maybe Ok To fit a 650 crank and rods ETC , But then You have To have Every thing Re-Balanced up , if you do not do this, your bike will have the shakes , and vibrate so much the nuts will undo them selfs and bike will fall apart , vibration is the one big factor in a rebuild of a Norton Motor , and Vibration is very harmful to your heath and your pocket too !!! Yours AJD