Cylinder head refurbishment9

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This morning I took the head off to reveal what looks like welded fins on the barrels. It looks like they had played football with it. The head well I will let you decide what you think of it.
 

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Something else which I am not sure about is the bolt (tightening sequence No. 1) has a long collar on it where as I thought this was a nut with a washer which pulled on a stud placed in the head.
 
Check the book or go to
andover-norton.co.uk

Andover Norton Parts Drawings - Genuine Andover Norton Factory Parts - Commando Parts

Andover Norton Parts are the only Norton spare parts in the market manufactured to original drawings, within the factory-approved tolerances, from the correct materials, and with the correct finish.
andover-norton.co.uk
You can see that the number one head bolt has a small washer same as on the four bolts
that are on the side of the head. Not a sleeve washer like in your pix.
The first bolt you nip up is this one and I think they want you to pull the head down against
the valve springs just enough to get the head down on the gasket surface, check your push
rods etc before torque up follow the pattern in the bookie.
 
Right Onder, but in comparison to AN's picture my No. 1 bolt is the same length as the other 4 head bolts and not shorter.
As it appears the collar was to take up the difference.
Any reasons against keeping it?
I am now at the stage anyway of pulling the cylinders.
 
Might have the collar added by a DPO to get the bolt head higher, easier to access with shorter socket?
Would certainly get the correct one and do it properly.
 
Barrels are off and the next object is to deter if the pistons are oversize but they and the cam and lifters look in good condition.
 

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Tornado said:
Might have the collar added by a DPO to get the bolt head higher, easier to access with shorter socket?
Would certainly get the correct one and do it properly.
Click to expand...
I think you are right there, better piece of mind with the right one.
I don't know what DPO means but I think it was the same headbanger who smashed both fins trying to extract the barrels.
 
Woody850 said:
I think you are right there, better piece of mind with the right one.
I don't know what DPO means but I think it was the same headbanger who smashed both fins trying to extract the barrels.
Click to expand...
DPO: Dreaded Previous Owner.
 
Tornado said:
Ah Ha! I think we now know who had Woody850's bike previously!! :p
Click to expand...
The more I delve into the poor girl I wonder seriously who really inflicted certain damage.

To continue pistons are removed and the barrels lifted quite easily, only thing is the base gasket sticks very well to the crankcase mouth.
Any clues how to release this without having debris fall into the crankcase.
I have a gasket scraper but it is pretty cumbersome with the base studs in the way.
One method I am considering is stuffing the opening full and spraying on gasket remover but I am worried about the other sealed joints being contaminated.
 
Just a question regarding the long bolts with Allan head which pass down through the cylinders. These bolts disappear under the head after being torqued the first time where as the smaller nuts remain to be continually torqued thereafter. Does the nature of the cast iron barrels and the 30 ft/lb torque suffice during the running in period.
 
Be careful with the spark plug replacement on the RH4 head. As a result of the distance between the plug hole and the valve seat there is/could be an issue with a helicoil or keensert.

I blew a plug out 100 miles from home on the way back from the 2019 Pure Michigan rally, stopped at a hardware store, bought some aluminum foil, wrapped the plug and made it home. Through some research and advice I found out about the potential spark plug repair problem and sent the head off to Jim Comstock nortonmachineshop.com

Jim makes and installs a special tapered insert that alleviates the problem. As expensive as a decent RH4 head is I figured it was worth it. If you send it to Jim I'd recommend helicoiling the head studs and have Jim check for cracks, etc. He can also blast the head for you. If you have exhaust thread issues he is also the best at that repair. If I'm not mistaken I think there is a video on his website regarding the spark plug repair.

Dave
 
Thanks for the valid information drp I am still waiting for my machine shop to begin the work. I will phone him this morning regarding the spark plug repair and the studs.
Had I lived in the US then I probably would have used your trusted service JC but I more for being able to speak personally to who should do the work.
 
If it hasn't been mentioned before, including myself, use ARP lube on your bolts and nuts upon reinstallation. It will make additional torquing easier and more accurate. I was amazed at the difference.
 
coloradonortonworks.net

cNw Head Mounting Kit

Type 3 5 ea ARP/cNw 12 point head bolts. 3/8 – 26 thread. ARP 300 series, heat-treated stainless that is rated at 180KSI (180,000 psi) The 5 bolts above are also cut down in the center or ‘waisted’ in order to accurately maintain a torque 3 ea ARP head studs. 3/8 – 16 x 3/8 – 24. ARP 8740...
coloradonortonworks.net coloradonortonworks.net
 
Onder said:
If it hasn't been mentioned before, including myself, use ARP lube on your bolts and nuts upon reinstallation. It will make additional torquing easier and more accurate. I was amazed at the difference.
Click to expand...
I was once advised by a mechanic, if you lubricate the threads, you reduce the friction, resulting in the same torque figure putting a greater stretching force on the stud. You therefore, reduce the torque level to suit. Never known if that's a big or little effect and how much to reduce it by, so I don't generally lube torque sensitive threads. You do hear of studs stretching / failing, but never heard of it being linked to them being lubed. May or may not be something in it, so I play it safe.

On the couple of occasions I've retorqued head bolts, I've used the clicking type torque wrench. I've loosened them off first, then the torque wrench gets a smoother run up to its setting. Maybe not necessary with the bending bar guage wrenches? Again, may be overkill, but can't see it does any harm.
 
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Mart UK said:
I was once advised by a mechanic, if you lubricate the threads, you reduce the friction, resulting in the same torque figure putting a greater stretching force on the stud. You therefore, reduce the torque level to suit. Never known if that's a big or little effect and how much to reduce it by, so I don't generally lube torque sensitive threads. You do hear of studs stretching / failing, but never heard of it being linked to them being lubed. May or may not be something in it, so I play it safe.
Click to expand...
I tend to follow your words, much time is taken to clean the threads to allow constant frictionless passage during torgue.
 
Woody850 said:
Brutally informative Tornado, I had a look at the Motion Pro and ordered one out of the US last night, reasonably priced too, I think that is what is missing in my toolbox. It should arrive when I get my head back.
Click to expand...
I have used this torque adapter many times and it works great.Simple set-up,etc.
 
The 850 should have NO base gasket, IIRC.

...and worry not about the welded fins.
 
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