Head Work Needed: SUGGESTIONS?

Hi everyone!
My 73 850 has about 15,000 miles since a partial head rebuild. I think it needs a major.
At that time I also had the bores out 20 over with new Hepolites fitted, I assume all is still well there to leave alone?
Under strong acceleration, riders behind me report some smoke coming out of the pipes, I suspect inlet valve guides.
As far as I know, the valves and springs are original, and the valves lapped with new guides 15,000 miles ago.
I suspect everything is loaded up and caked with carbon.
Seeing as how it is winter and time to do it right, and possessing no experience doing head work myself, I am soliciting
opinions!
Colorado Norton Works wants $1000 to do a real number on the head, new valves, guides, seals, springs, clean, equalize chambers, etc.
I am very sure they would do a really great job, I just cannot afford their price!
Is there anyone here who would be willing to do what CNW would do, but at a much less price?
Anyone looking for some work to make some money, or just retired and bored?
As usual, I really appreciate all thoughts and comments!
Thanks
John

Memphis Motor works will do it for about 1/2 that price.

Dave
69S

Were the guides replaced by an experienced Norton mechanic? You have a '73 850 which would have the 32mm RH4 head. This head is very thin around the spring perch area of the intake port. This can result in cracking around the guide and oil being sucked into the intake tract.

Great care must be taken when removing guides on these heads. Once the head is stripped and cleaned they should be checked with dye penetrant for cracks around the intake guide.

Bottom line is this head may have already been ruined with the installation of the present guides. New guides should not be worn at 15K. I would send it to an experienced Norton machinist. My personal recommendation is Leo Goff at Memphis Motor Works. You won't find anyone better. I haven't seen any prices from Leo lately, but I would expect they would be cheaper than CNW.

Leo Goff of Memphis Motorwerks

Ron beat me to it.

Good suggestions, thank you, just talked with Memphis Motowerks and Mike there quoted me around $500 for a very complete job!
Why would CNW be twice the price for the same job? Just feel the need to make more profit is my guess. I like their work, but gees.........

There's an old saying, "the more you pay, the more it's worth" :wink:

highdesert said:

Good suggestions, thank you, just talked with Memphis Motowerks and Mike there quoted me around $500 for a very complete job!
Why would CNW be twice the price for the same job? Just feel the need to make more profit is my guess. I like their work, but gees.........

Click to expand...

Because people will pay it.

There is nothing wrong with charging a certain amount. If customers want to go somewhere else, they can.

Memphis Motorworks and Leo may not be as well known to some of the newer Norton owners, although many old timers will be more familiar with them.

Couldn't agree more with the Memphis Motorwerks recommendation . I've got about 2500 miles on the ported , cammed , big-bore R90S Leo built for me and it 's great . He's currently going through my MK 3 giving it the blueprint treatment and portibg to go along with the VR 880 pistons . I would strongly suggest you do a leakdown test before you pull it apart to make sure your rings are still good after 15,000 miles .

Ron

I agree with Ludwig, 15,000 miles is not bad on an 850. Reporting some smoke when accelerating hard would more likely be the piston rings than the guides. Guides suck on throttle off and disappear as revs increase. How about you do a top end compression test? If you're getting around 130 to 150 PSI its OK. A further leakdown test can indicate valve seat efficiency. Carbon on piston tops is OK, its a thermal barrier and marginally increases compression ratio. If you get suspect test results, removing the head is no big deal, pop out the valves and have a real good look at the seats and faces and any slop in the valve train, scoring and scuffing. A professional head engineer will be able to advise the best course of action and relate it to the effects on the piston cylinder seal. You might end up having to re-ring as well.

Mick

thanks

highdesert said:

Good suggestions, thank you, just talked with Memphis Motowerks and Mike there quoted me around $500 for a very complete job!
Why would CNW be twice the price for the same job? Just feel the need to make more profit is my guess. I like their work, but gees.........

Click to expand...

Its pretty simple "overhead". It takes allot of money to run an outfit like CNW, and I can assure you the level of service and output is no better than that of Memphis Motor Werks when it comes to machine work and engine building. I just had allot of motor work done by Leo and I can honestly say that I have never been this impressed with anything that I have ever outsourced - period. I can assure you you will say HOLY **** when you open the returned box...

Not saying that the CNW stuff is not VERY nice, and I'm sure the results would more than likely be the same, but I really don't think that the extra $500 bucks is necessary.

You say it smokes on hard acceleration, low manifold vacum so it is less likely to be sucking oil down the guides, more likely a bit rich and fuel smoke, a compression test will be next to usless because if one side is oily its rings and valves will seal better and the reading will be higher, and it sounds like it still goes all right any way, do you use any oil :?: Does it smoke any other time, like big clouds on start up or sitting in traffic. If it uses very little oil and only smokes a bit on hard acceleration, then its as good as it left the factory so keep on thrashing it around the country side, although I think its your winter now isn't it :?:

My 850 had bad smoking under acceleration on the driveside after about 15K miles, just needed new rings and is running smoke free 10K later.

I am learning a lot from reading all your posts, thank you!
I have borrowed a compression gage and will use it today and report back.
I will check each side first cold and then when warm after a ride.
I will also put a teaspoon of motor oil in through the spark plug hole and then kick it over again to get those readings.
Here is another question: I used to start it, let it idle one minute, no smoke, when I took off and the revs got up to about 2500 before shifiting
to second, smoke would come out of the pipes for maybe a block or so until it burned away.
Nowadays, I let it idle around 1300 for a longer period, then when I take off there is very little smoke.
Is this caused by sucking cold oil up through a cold bore?
I will run the comp tests and report back, thanks all!

Remember, throttle wide open during a compression test.

I month or so ago, I did the comp test and stupidly forgot to hold the throttle open.
It read about 85 on both sides, cold motor, then put in some oil through the spark plug holes and kicked through again, comp went up to 105 on both
again with throttle closed. Are these figures useless to comment on because throttle closed and motor cold?
would this indicate my rings need replacing?

grandpa, just read your reminder, I WILL do the test today with throttle open, first motor cold then warmed up and report back!

Highdesert, don't get to offended by this comment it is just my opinion,worthless,but 3months ago you considered making a clutch cable to technical and not worth the hassel, yet now you are preparing to rip the heart to pieces on the poor thing, so you have gone from not being able to fit a band aid to open heart surgery :?: I would seriosly try and enlist the help of a skilled enthusiast who is more intrested in the bike than his wallet they do exist, I think. :?: and you may learn something ,I realise you have already done one heart bypass thats been relativly succsesful. :| :|Also I agee with Ludwigs comment, diagnose PROPERLY, its a waste of time spending $500 on the head when $150 worth of rings and gaskets were really needed.

Hi guys,

Not wanting to steer away from whats important, to determine the best approach for what to do with the head or engine, I just have to respond to some of the previous posts.

We here at CNW charge our work based on parts costs and labor. We dont charge higher prices because we think we can get away with it. When somebody makes a comment about 'overhead' and 'higher margins' I am really not sure what they are basing that on. Its clear they certainly dont know. Our over head is no higher than most motorcycle shops around. We are not in a hight rent district, we do not have a huge shop and we dont have a bunch of employees running around. We do outsource a lot of things as we want the absolutely best work possible on our parts and services. We dont believe that you can do everything yourself as well as the people that specialize. The motorcycle industry has very weak margins compared to others and there just isnt much room to work with. It comes back to what I said earlier. We base it on the actual parts used and what it takes to put it togheter time wise.

I absolutely will not take any credit away from Leo Goff as I consider him one of the best in the industry. Hats off to him for the kind of work he has done and is still doing.

What you have to consider when you do look at the product is that you do get what you pay for.

The head service that we offer uses a 450.00 parts package. Thats it....just for the parts, nothing done to the head yet.

Then add:
Disassembly
Media blast twice
Remove guides
Install guides
Fit valves to guides
Cut 3 angle valve seat
Helicoil 3 mounting stud holes (we change the thread size and make studs to fit)
Mill gasket surface
Equalize combustion chambers
Clean and prep head
Build head

Now its clear that I can not do the above labor for 50.00, nor can anybody else if they are in fact in business. So given the parts package and the work we do its very hard to think that somebody can do that for 500.00. This if the use the same parts. If they use the same parts, they pay the same price I do. I am pretty sure of that.

So it really comes down to simple economics. You add the parts and labor up and you come up with a price. Easy.

To make comments about why a certain service cost a certain amount without knowing the details is a waste of everyones time. Its an opinion not based on any facts.

Of course there are several quality shops offering their services out there and people can choose who they want to do the work. The fact that there are choices hopefully makes the good shops even better and weeds out the bad alltogether. This all to benefit the customers in the long run.

Got to go.....got some bikes to build.

Matt