Going rate for a set of crankcases?

Hi guys,
I know an item is worth what the buyer is prepared to cash out, but do you have an opinion on what a good set of Mk3 crankcases is sold for these days?
I've been offered a set of used Mk3 matching crankcases in apparent good condition for $800, which I feel is a bit too much. (Current price with AN is $1415.00).
Good 750 crankcases are usually sold for half that price. What do you think? Does anyone here have a set of matching crankcases surplus to requirements they would sell me?

- Knut

mdt-son said:

Hi guys,
I know an item is worth what the buyer is prepared to cash out, but do you have an opinion on what a good set of Mk3 crankcases is sold for these days?
I've been offered a set of used Mk3 matching crankcases in apparent good condition for $800, which I feel is a bit too much. (Current price with AN is $1415.00).
Good 750 crankcases are usually sold for half that price. What do you think? Does anyone here have a set of matching crankcases surplus to requirements they would sell me?

- Knut

Click to expand...

Knut,

Look here: https://www.ebay.com/itm/3152699104...0ZGUXAIKkMHVJ+pzLp62gxRWM=|tkp:Bk9SR8SX2cvWYw

Bottom end, starting bid $700, good seller I've used before. It's more than you need but it should give an idea on price. You might write him and ask that he part it - he might be willing if it doesn't sell. I don't see MK3 cases come up very often and I don't have any right now.

ebay 'high to low/shipping' option, 'all categories', along with 'buy it now', with the fewest search parameters 'norton case," gives max results (tho irrelevant stuff also) the fastest way,

You can also narrow down 'all categories' to 'motorcycle parts' or something else appropriate. That gives more focus & less irrelevance, but then can miss catching all that may be available.

To focus on specific cases, change 'norton case' to '750 norton case' or '850 norton case'

Going with bidding is usually the cheapest option, but usually means max time/effort.

Stay on https://www.ebay.com and simply search norton mk3 crankcases and you'll find them on page 1.

On https://www.ebay.ca you will also find them on page 1.

On https://www.ebay.co.uk with that search, you won't find the one I pointed to but will find: https://www.ebay.co.uk/itm/13366317...+pDq2CYcbY/Xh1vDP4ATXZRTc=|tkp:Bk9SR5K1j9TWYw for 400 GBP, but it has been repaired.

It's usually good to search multiple ways - so many sellers don't know exactly what they have and often the most clueless sellers have the best deals especailly if you make an offer.

I have no idea if Knut importing to NO from the UK is better or worse than the US or CA.

I paid $900AU for a good low miles set of 850 crank cases back 15+ years ago when looking for a set, I brought from my local British bike shop, I was looking for a while but there were only a few cases around but the ones I looked at had signs of wear and not in good condition with a price of $600/$700 to the ones I ended up buying.
The ones I ended up spending good money for were in top condition, in fact they looked close to new and was willing to pay a high price for a good set and was guaranteed they were perfect, well I have had no problems with the ones I got and have about 40k+ miles on them now.

Ashley

Hi Knut,

Because they are a "one" year model (I say that knowing they were produced until '77) they are rarer than other cases. So when they come up for sale often they are priced higher (same for MK3 cranks).

Back several years ago MK3 cases were the hot setup for Norton race builders because they had the strongest castings. With Maney, and now Molnar, making beautiful and strong cases, that kind of knocked them down a few notches for the racing stuff.
I built my first race bike out of a MK3 bottom end. When I moved to a Maney crank I had to shim each side .060" as MK3 cases are .125" wider at the main bearings than other Commando cases.

We have two MK3s being restored in the shop at the moment and they definitely have their uniqueness in the engine department.

HTH,

-Kenny

In California if the engine number doesn’t match the frame and in this case the gearbox numbers……good luck. We’re looking for any excuse to get these old polluters off the road.

Thanks, guys. I've been on FleeBay for over 20 years, but I'm always open to pick up new tricks. Main challenge when bidding for a used part is to look for defects either overlooked or concealed by the seller. Couple of months ago I bought a Mk3 timing cover from a usually reputed seller which showed up with one fixing point missing (cover had fractured at the rear). This had been concealed in the ad. Fortunately for me, the seller kindly refunded the purchase price - still, an annoying experience. Now I examine every item advertised, thinking "where has the seller hidden the bug".

Ashman, I agree with you. Spending more is a better investment in the long run. Repairing dodgy parts add a lot of grief and expenses, especially if you have to frame out the repair work. I am not sure what to do with the timing cover yet, and I fear the final cost of repair will exceed the cost of a new cover from AN.

As for the set of crankcases offered, the bearing areas looked a bit suspicious, but using an old bearing, the seller convinced me the interference fit is still good, so I went ahead and bought the crankcases.

Greg: The bottom end advertised by evbc has been molested at the drive side, exposing the oil seal circlip. Maybe a shortcut to replacing the oil seal without taking the bottom end apart. Anyway, this scared me off. The set that I bought looks perfect. The second image shows what looks like bearing seat where the outer race has spun. It hasn't - the traces are factory bearing glue.

Cheers, Knut

<Spending more is a better investment in the long run.>

That is the Fast Eddy approach by which I have Come to the Light.
And especially with regards to anything "pre-owned".
Spend more, get more , have less hassles and save time.
Amen.

mdt-son said:

Greg: The bottom end advertised by evbc has been molested at the drive side, exposing the oil seal circlip. Maybe a shortcut to replacing the oil seal without taking the bottom end apart. Anyway, this scared me off. The set that I bought looks perfect. The second image shows what looks like bearing seat where the outer race has spun. It hasn't - the traces are factory bearing glue.

Cheers, Knut

Click to expand...

Shocked - sorry I missed it. Did you tell him? If not, I will. He normally lists anything wrong.

marshg246 said:

Shocked - sorry I missed it. Did you tell him? If not, I will. He normally lists anything wrong.

Click to expand...

Maybe he thought the damage was so obvious, he didn't need to highlight it. Anyway, he knows of the defect now. Offered a discount if I found "horror inside".

- Knut

Buying my replacement crank cases from my local British bike shop I was able to inspect the crank cases before spending my money the owner knew I would folk out the cash as they were in very good condition but everything we buy in Aus is expensive.

mdt-son said:

Hi guys,
I know an item is worth what the buyer is prepared to cash out, but do you have an opinion on what a good set of Mk3 crankcases is sold for these days?
I've been offered a set of used Mk3 matching crankcases in apparent good condition for $800, which I feel is a bit too much. (Current price with AN is $1415.00).
Good 750 crankcases are usually sold for half that price. What do you think? Does anyone here have a set of matching crankcases surplus to requirements they would sell me?

- Knut

Click to expand...

Gents,

I want to go all the way with four sets of Commando crankcases, by preparing 10 mm fit bolts in lieu of the 3/8" bolts. There will be 5 x 10mm bolts similar to the Mk3.
To accomplish this, we will need to drill and ream each of the crankcase halves using a hardened boring plate.

Now, what I am looking for is a drawing which shows the theoretical location of the mounting bolts, either a copy of a factory drawing, or a drawing of CMM measurements recorded by a company or an individual. No worries, this is for my own use only.

If any of you possess such a drawing or sketch, I am happy to pay a fee for the right to use it for my own projects.

Regards,

Knut

What happened to the four sets of cases you mentioned you were going to ream out the bolt locations in? (back in October, your post about 'crankcase bolt locations') see above

Hi dobba99,
It hasn't happened yet due to a sudden remote work commitment which started in november. Planned execution is during the summer months. I have liaised with Andy Molnar for some help.
Thanks for your interest. I will report progress on this task.

- Knut

Holmeslice said:

Hi Knut,

Because they are a "one" year model (I say that knowing they were produced until '77) they are rarer than other cases. So when they come up for sale often they are priced higher (same for MK3 cranks).

Back several years ago MK3 cases were the hot setup for Norton race builders because they had the strongest castings. With Maney, and now Molnar, making beautiful and strong cases, that kind of knocked them down a few notches for the racing stuff.
I built my first race bike out of a MK3 bottom end. When I moved to a Maney crank I had to shim each side .060" as MK3 cases are .125" wider at the main bearings than other Commando cases.

We have two MK3s being restored in the shop at the moment and they definitely have their uniqueness in the engine department.

HTH,

-Kenny

Click to expand...

Thanks for that info Kenny.
I thought I had read or heard that the MK3 cases were the favourite for racing back in the 80s/90s, this confirms that.
I bought some MK3 cases for the 920 hoping that they would have a better chance of handling the extra power.
The extra power on my version of that engine is mostly in the mid and upper mid range. With stock cam and valves it doesn't get revved much above 6k as that is where max power is. I'm hoping that by keeping the rev range there that the engine will hang together. For me, there is no point in building a powerful engine only to have the cases crack after a few thousand miles. Hopefully I haven't done that with this one.
It really pulls in the middle, 100 - 135 kmh on dyno hill vs 100 to 110kmh for the MK3. Im guessing that half of that improvement comes from weight reduction while the other half comes from the 920 engine.

Prices seem to have risen a lot.
In 2018 I paid $700 for Mk3 cases and frame, matching numbers.
Another $140 got the crank from that engine. It was perfect, as were the cases and frame.

Glen

mdt-son said:

Greg: The bottom end advertised by evbc has been molested at the drive side, exposing the oil seal circlip. Maybe a shortcut to replacing the oil seal without taking the bottom end apart.

Click to expand...

Yeah, you can see the drilled holes where a punch was used to remove the main bearing outer race; that happens a lot...

alright, I admit it: to fit 10mm rear crankcase bolts, I used a handheld drill (and probably two drill bits to gradually open out the holes), with Mk3 cases assembled together. Still fine 2k miles later.

grandpaul said:

Yeah, you can see the drilled holes where a punch was used to remove the main bearing outer race; that happens a lot...

Click to expand...

I've seen plenty of pre-MK3s done that way but usually with much smaller holes. It's a shame people don't read! Heat, bang on a piece of wood, out the bearings come!