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More hp from 600 dominator? #272958 09/02/09 2:41 pm
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Juuhani Offline OP
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I have a -58 dominator 99 and wanted to get a little more power for street use.do anyone have suggestions for me?what carbs?wat cam?exhaust?anything else?
thanks.


1958 Norton Dominator
1986 Jawa 500 longtrack
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Re: More hp from 600 dominator? [Re: Juuhani] #272986 09/02/09 5:51 pm
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triton thrasher Online Content
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I put a Triumph 650 engine in mine.






Am I allowed to say that?


Amateur Loctite enthusiast.
Re: More hp from 600 dominator? [Re: triton thrasher] #272987 09/02/09 5:53 pm
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I'm going to put an Atlas motor in my '57.


"Beer is proof that God loves us and wants us to be happy" - Benjamin Franklin
Re: More hp from 600 dominator? [Re: Juuhani] #273005 09/02/09 8:42 pm
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Pete R - R.I.P. Offline
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Before you do anything radical,like changing a camshaft,try something along these lines:
28mm carbs ,on manifolds 17-1/8" long (from valve to carb bell-mouth),or as long as you can fit.
1-3/8" O.D. exhaust pipes,37" long,finishing at least 2"inside gutted mufflers.Mufflers should have a volume of 2 litres or more.On the outlet of the mufflers,use a 1" O.D. tube,starting well clear of the rear wall(2"or more),with a flared bell-mouth on the front of the tube.
This will be surprisingly quiet in neutral at any RPM,but will really bark under load at high speed.

If it all feels a bit "peaky",increase the pipe length to 50",this will get it working 1400 RPM earlier.

You probably won't want to change the cam,once the rest of it is"happening".
Some carburettor jetting will,of course,be in order.

CAM TIMING:Pual Dunstall used to offer a vernier adjustment kit.If it is un-available you will need offset keys for this.
Set the cam timing so intake valve is open 5 degrees to 10 degrees more than the exhaust at TDC (overlap). I.E. :the intake valve open 0.020" -0.040" more.This will wake up most engines and give good bottom-end torque as well.

Last edited by Pete R; 09/03/09 12:43 am. Reason: "CAM TIMING - - - -"
Re: More hp from 600 dominator? [Re: Pete R - R.I.P.] #273050 09/03/09 3:00 am
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norton bob Offline
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Petes settup sounds good, check ignition timing on both sides, fit 6start gears to pump, improve breathing and oil retention,rods are old now and will be vulnerable if you go for H/c and higher revs.Beware of slotted pistons.

Re: More hp from 600 dominator? [Re: ] #273085 09/03/09 10:05 am
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Juuhani Offline OP
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thanks for the help!
I am going to take the engine apart this winter.
it have some dunstall mufflers and pipes allready and a bth magneto.
ok,so I have to get a crank and rods and a better head..
do commando stuff fit into my crankcaces?
I am new to nortons,I had 2 triumps and 1 hd ironhead before.
I have a picture of my dominator in the picture thread.


1958 Norton Dominator
1986 Jawa 500 longtrack
Re: More hp from 600 dominator? [Re: ] #273086 09/03/09 10:06 am
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norton bob Offline
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Thats usefull information from p11m2,I understood that it was late 99 cases that had a blister that can be fitted with the 650 crank,so I will check mine now !! Its the way to go unless you can get new rods. If you use 600 barrels they will need to be slotted to clear the rods,600 long skirt pistons will need to be shortened,heads from about 59/60 got bigger valves and some think are as good as the downdraught heads.Not much from a commando fits.Looks like you have small valve head and dynamo cases,and a triumph primary case!!,Dont buy commando stuff ,threads changed ,easy mistake to make.Unless you go for complete engine.99 pipes wont fit later heads,angle changes.

Last edited by norton bob; 09/03/09 10:29 am.
Re: More hp from 600 dominator? [Re: norton bob] #273090 09/03/09 10:49 am
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norton bob Offline
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All sounds like a lot of money,The 99 weakness is the rods,which usually fail when the drive side big end lube drops off.So you could fit a set of aftermarket trick rods ,a 6 start gear set to the pump and a general tune up and keep it all.A conservative approach??.Oh yes, I dont think your primary case will accept an alternator motor.I would keep it as an authentic 60s cafe racer(which it is).Improve the lube and lessen the rods problems, set up the valve timing and carbs and pose plenty!!I was a ton-up boy in the 60s so i can say without contradiction that your 99 is spot on!!Warts and all.Its real and its history ,why build a new fake one?.

Last edited by norton bob; 09/03/09 11:32 am.
Re: More hp from 600 dominator? [Re: norton bob] #273132 09/03/09 6:14 pm
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Juuhani Offline OP
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yea,I think I check the condition of the engine and see what it has eaten.
the bike havent been used since 1982 and then again in 2008,so I think i get some surprises when i disassembles the engine...
even the tires are from -82!
I inform you then.


1958 Norton Dominator
1986 Jawa 500 longtrack
Re: More hp from 600 dominator? [Re: ] #273524 09/06/09 3:59 pm
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Juuhani Offline OP
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so,a 650 head fit on 600 cylinders?


1958 Norton Dominator
1986 Jawa 500 longtrack
Re: More hp from 600 dominator? [Re: ] #273613 09/07/09 8:30 am
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Juuhani Offline OP
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Thank you very much for good information!!
I think that the crank has exploded somtime,because the engine number is different to the frame number.
how do I identify the crank if it already are a better in it?


1958 Norton Dominator
1986 Jawa 500 longtrack
Re: More hp from 600 dominator? [Re: ] #273614 09/07/09 8:49 am
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norton bob Offline
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The vibration from a 99 will put you off high revs, I know of 99s that were thrashed for over 100000 miles and only had piston problems, I seized two myself at over 90 mph and didn't break any rods , thats not to say its ok to tune it up or rev the nuts off it, if you want to rev convert to 650 or even to an 88 if the parts are cheap, I raced an 88 and it was pretty bullet proof to 7200, and much smoother with a far better reliability.A little old guy called Harold Danniel(look it up) told me that that my old 88ss was the best bike Nortons ever made!!I don't think he lived to see a commando but knew his stuff.Fit a pair of used ally mudgaurds and enjoy what you have ,Its a time warp bike that will go great with a battered old leather jacket.

Last edited by norton bob; 09/07/09 8:51 am.
Re: More hp from 600 dominator? [Re: norton bob] #273616 09/07/09 9:06 am
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The motor could be 88 or 99 how many fins on the barrel? I used to swop motors and parts as did many back then.

Re: More hp from 600 dominator? [Re: norton bob] #273618 09/07/09 9:17 am
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Juuhani Offline OP
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It have 99 stamps on the cases.


1958 Norton Dominator
1986 Jawa 500 longtrack
Re: More hp from 600 dominator? [Re: Juuhani] #273623 09/07/09 10:00 am
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norton bob Offline
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99 Stamp means 99 case, but means little really, number of barrel fins will tell more 8 or 9 ?? heads,cases, rods,are all interchangeable between 88 and 99 , barrels and cranks differ.Common practise to mix and match!!I had a 500cc 99 and a 600cc 88 a friend had a 750cc 88 but the cases leaked well under the strain!!My 99 now has 650 pistons a modified 2s cam (not the best idea) and orriginal rods and crank which are now too old to work hard,if i want to go mad i take out a modern bike or my Ducati.

Last edited by norton bob; 09/07/09 10:41 am.
Re: More hp from 600 dominator? [Re: norton bob] #273682 09/07/09 6:14 pm
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Juuhani Offline OP
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9 fins


1958 Norton Dominator
1986 Jawa 500 longtrack
Re: More hp from 600 dominator? [Re: Juuhani] #274093 09/10/09 1:57 pm
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norton bob Offline
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Its a 600 barrel, so its likely the rest is too. The cases are dynamo type and won't be suitable to take a stator so a road conversion to 650 is not practical i dont think.If you want to go faster than 100 you will need to fit a later engine.A 500 barrel, pistons crank and pushrods will get you a revier faster bike to ride if set up right ,The engine wont be faster but the bike will be!! Cam timing is critical ,an ss cam is good.The 88 is a much better engine, and although uses the same rods didn't suffer rod and crank problems.650 head fits 88 I think.

Last edited by norton bob; 09/10/09 2:00 pm.
Re: More hp from 600 dominator? [Re: norton bob] #274114 09/10/09 5:12 pm
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Juuhani Offline OP
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ok.I am going to open the engine next week,so I post some pics then.


1958 Norton Dominator
1986 Jawa 500 longtrack
Re: More hp from 600 dominator? [Re: Juuhani] #274133 09/10/09 7:24 pm
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Hi,
here's my halfpenny worth,
The so called 'blisterback' crankcases came in during 1961 at about No.94500, very, very few 99s have them. The 650 crank won't fit in the earlier ones (Well actually the crank will, but if you put the rods on, it won't turn!).
The crankshaft is OK IMHO, the stuff about the rod failures being mostly due to lubrication problems is BS IMHO, I would call that a big end failure, I've had two go, both on the timing side about 1.5" below the small end, I've got one somewhere, will post a pic if I can find it, the shells were perfect, so much so that I used them again in another rod with the same crank in a spare case. I agree not to use Carillo rods but not for the same reason, I tried it and the vibration was HORRENDOUS even with the crank & rods dynamically balanced due to the greater reciprocating mass.
If you do put a 99 top end on a 650 be prepared to modify the barrel spigots as the rod cut outs need enlarging.
The 650 head goes straight on the 99 barrel, 1/2 true, the early ones will that have the spigot recesses will, not the later post 1966 ones.
With a 650 crank, change the oil pump for the later one with the wider internal gears, don't just speed up the small one, you'll just end up with a frothy oil tank (at best....).
I now run a hybrid 650/99 motor in my 99 (650SS bottom end with with new 850 type rods, married to a 1960 type big fin/valve pre-downdraught head and a single 30mm Mk1 Concentric. Pulls like a train with a 21 tooth sprocket, faster and smoother than the old 99.
Good Luck!


Oil is always cheaper than metal
Re: More hp from 600 dominator? [Re: oilyrag] #274138 09/10/09 8:29 pm
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hh Offline
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My '57 99 sheared its crank right at the driving side main radius in 1970. It was probably pulling a chair though since it has butt ugly sidecar lugs welded to the frame (the horror!)


"Beer is proof that God loves us and wants us to be happy" - Benjamin Franklin
Re: More hp from 600 dominator? [Re: hh] #274140 09/10/09 8:46 pm
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oilyrag Offline
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hh said:-
Quote
My '57 99 sheared its crank right at the driving side main radius in 1970. It was probably pulling a chair though since it has butt ugly sidecar lugs welded to the frame (the horror!)


fair comment mate, but to be fair that bit of the crankshaft is the same on them all, right up to the 850 mk 3. Pulling a chair for a few years would do it, I've had exactly the same thing happen on an R69 BMW outfit, and no-one said they had weak crankshafts.
The fact is that once you start tuning any old bike then reliability is compromised, and you just have to accept that, but inevitably you will find yourself following the same path as the factory did.
My other point was that when you convert a 99 to a 650, if you do it properly, then when you're done you don't have much 99 left....

Anyway here are some pics of a broken rod, all that was left of this engine which was usable was the head and timing gear.

[Linked Image]

[Linked Image]

[Linked Image]

And before anyone says, the cap WAS the right way round when it was in the engine.
Very expensive, so think carefully before raising the power output....

Last edited by oilyrag; 09/10/09 9:57 pm.

Oil is always cheaper than metal
Re: More hp from 600 dominator? [Re: oilyrag] #274583 09/14/09 4:45 pm
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Juuhani Offline OP
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Okay,now I took head and cylinders off...[Linked Image] [Linked Image] [Linked Image]..
polished rockerarms..


1958 Norton Dominator
1986 Jawa 500 longtrack
Re: More hp from 600 dominator? [Re: Juuhani] #274586 09/14/09 4:51 pm
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and the cylinders and pistons.....[Linked Image] [Linked Image] [Linked Image]
I think i have to get new pistons...and cylinders....


1958 Norton Dominator
1986 Jawa 500 longtrack
Re: More hp from 600 dominator? [Re: Juuhani] #274696 09/15/09 1:26 pm
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Pete R - R.I.P. Offline
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I'd be more concerned about the scratches running across the con-rod,which will need polishing out;and less concerned about a little bit of metal missing from the bottom of the barrel.

Re: More hp from 600 dominator? [Re: ] #275106 09/17/09 10:41 pm
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oilyrag Offline
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P11M2 wrote:
Quote
I have two sets of extra/orphan model 99 cases numbered 87xxx & 90xxx that are completely identical to the 936xx-95xxx 650cc cases I have.........
............Juu, I have two extra sets of late alternator type model 99 crankcase sets from 1960 bikes that I am not too fond of, they are the same as 650cc crankcases.


I'm sorry to contradict you P11M2, but I believe you are incorrect, here is a 1960 99 crankcase:-
[Linked Image]

Here is the back of it:-[Linked Image]

This is a 1961 99 crankcase, which is the same as a 650 case:-
[Linked Image]

Here is the back of that one, the arrows point to the bulge on the back to give the extra clearance required for the larger journal rods.[Linked Image]

Here is an internal view, (not too clear).
[Linked Image]

You wrote:-
Quote
Oilyrag, if you take a late 99, and just swap in the crank and rods from a 650, taking care to clearance the pistons and cylinder, then you have a 650cc model 99 by only changing the crank and rods, and that leaves quite a few model 99 parts doesn't it?

It would, if you could do that, but as I hope you will agree now, you can't just fit a 650 crank and rods into an ordinary 99 case except for the very few late ones which are actually 650 cases. You may well be right about the serial No. of the first 650, after all I did say 'about 94500', but I don't think you can have actually tried what you are advising Juu to do, or you would know that it is not that simple. I have actually built such an engine and run it, and by the time I had finished, and it took a few tries to get it right, there was more 650 there than 99. For instance, I found that the engine ran very poorly with the original camshaft and I sustituted a 650SS one, which meant new followers as well, and I wasn't happy with the oil pressure from a Dommy oil pump running a six start drive, I thought that this must have been due to cavitation, as I also got a lot of froth in the oil tank, so I fitted a pump from an Atlas and that cured the problem.What I found was that it would have been a lot quicker and simpler to just fit my 99 head onto a 650 bottom end, because that is what I finished up with, effectively.There was quite a bit of work involved in modifying the barrels and pistons and it would have been easier just to buy 650 ones, especially as Juuhani is going to have to replace his anyway.I'm sorry to go on, but I made just about every false assumption that I could have done on that project , mostly based on incorrect information from books, manuals etc, and found out the hard (expensive) way. Thats my knowledge base here, and I just want to save Juuhani from making the same mistakes.

Last edited by oilyrag; 09/17/09 10:45 pm.

Oil is always cheaper than metal

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