Looking for New Cases

Status
Not open for further replies.
H

Hungry J0e

Joined
Apr 28, 2008
Messages
191
Country flag
So after opening up my cases to investigate the cause of my low oil pressure on my 850 Mk III, the local shop here found this:

Looking for New Cases


Also discovered that there was no thrust washer on the camshaft, allowing it to eat into the case. Passageway for the oil pickup also had a large gouge going to the outside of the case; likely that the oil pump was sucking air through this passage which could explain the source of low oil pressure.

To reuse this case, will require welding and repair in the area of the photo to hold the stud. Shop recommends replacing the cases as the best solution, repair only if new cases can't be sourced due to the damage in the photo and additionally lots of chisel marks scoring the mating surfaces along both side of the cases.

I occasionally see cases advertised on E-Bay on the order of $300-$500, but usually only distinguished as 850 or 750 cases. I note that Old Britts lists 850 Mk IIIs as separate part numbers from earlier cases... Are they indeed distinct from earlier cases?

Anyone know of a good source or have a set of cases they would be willing to sell for a reasonable amount?

Cheers,

- HJ
 
Damn HJ - more grief on top of the previous stuff - that really sux! How does one assemble an engine / cases with no cam thrust-washer and the other stuff - unbelievable :shock:

i did see a set of 850 MKIII cases on Ebay about 2 weeks ago for $50 with 3 days left, unsure what they finally went for
i'll ask a few people around here and see if they have any

sorry to see this....
 
Joe
indeed the 75 MK3 case's are a one year only with no others interchanging. the crankshaft is also different. sorry to see where this has gone and I just hope GP does as he said and makes it right.
 
bill said:
indeed the 75 MK3 case's are a one year only with no others interchanging. the crankshaft is also different. sorry to see where this has gone and I just hope GP does as he said and makes it right.
Click to expand...

065666 Norton 850 MK III - 1975 CRANKCASE ASSY. (850 MK3) $1,365.90 USD
 
A few more things. the gouge's IF it was on the pickup side it would NOT be the cause of low oil pressure as this is the scavenge side IE return oil from the engine. as you describe it it is from the pick up to the oil pump and the gouge is in this passage than it would have an external oil leak when not running along with trouble keeping the crankcase evacuated of oil. I need more pictures to see what you are saying. The missing thrust washer and chisel marks are also no real surprise from what I have seen.

Hungry J0e said:
So after opening up my cases to investigate the cause of my low oil pressure on my 850 Mk III,

also discovered that there was no thrust washer on the camshaft, allowing it to eat into the case. Passageway for the oil pickup also had a large gouge going to the outside of the case; likely that the oil pump was sucking air through this passage which could explain the source of low oil pressure.

due to the damage in the photo and additionally lots of chisel marks scoring the mating surfaces along both side of the cases.



Cheers,

- HJ
Click to expand...
 
Windy -

Gouges were there from the PO and not associated with the rebuild I think...

Here's a photo of what the shop showed me when talking about the gouge in the oil line. He didn't definitively say this was the source of the problem, only a possibility. Interested in your opinion. Would not be happy to get this beast back together and still have an oil issue.

Looking for New Cases


Cheers,

- HJ
 
it is on the scavenge side so it will NOT have any effect on oil pressure, like I stated if it does not seal it will have trouble evacuating the oil from the sump and could have an external oil leak. looks like your shop needs to look at other possibility's.

Hungry J0e said:
Windy -

Gouges were there from the PO and not associated with the rebuild I think...

Here's a photo of what the shop showed me when talking about the gouge in the oil line. He didn't definitively say this was the source of the problem, only a possibility. Interested in your opinion. Would not be happy to get this beast back together and still have an oil issue.

Looking for New Cases


Cheers,

- HJ
Click to expand...
 
A skilled artisan welder could recoup the things. Young Liveingston in N.Z. was adept at Gas welding Aluminium .

Takes a non half assed approach . Going well back beyond damadge so as to exceed limits of cracks .
Ive seen severly gusseted / bracketed cases ( mod. for raceing ) that resembled a web of braces once done,
presumeably Tig Welded . AIRCRAFT STANDARDS of workmanship required though . More the problem is
finding someone competant and waiting for him to ' fit it in ' so cost isnt prohibitive . Then a good Artisan
AGAIN would hand finish / fit , to zero tolerance on alignments . Wernt hard to find , in the 50s / 60s . :|
 
I'll call the honey hole in town and see if they have any cases. If you want I can weld up your old ones and re machine them to near new. That engine shouldn't have gone back together with those gouges.
 
Contact me off list if you decide to replace the cases as I might have a lead on Mk3 crankcase.

From what I see in the pictures the crack looks to be repairable by welding but you need to find out why it cracked? Was it put together this way? Plan to have someone redeck the top of the cases to even them up.

Modern gasket surface compounds are marvelous about sealing gouges. You may want to consider cleaning the surfaces and screeding a little JB weld in the deeper gouges.

Sorry for your misfortunes. Nobody deserves this.
 
I'm guessin the "honey hole" in Wisconsin is a whole lot different than the "honey hole" in LA (AKA you won't end up on the John's page of the crime blotter) :shock: :?

bwolfie said:
I'll call the honey hole in town and see if they have any cases. If you want I can weld up your old ones and re machine them to near new. That engine shouldn't have gone back together with those gouges.
Click to expand...
 
Hmm, no. Its the shop in town full if undiscovered parts. I got to go in the basement years ago and it was packed with engines and parts.
 
bwolfie said:
Hmm, no. Its the shop in town full if undiscovered parts. I got to go in the basement years ago and it was packed with engines and parts.
Click to expand...

It not one with a drag bike, is it?
 
No, you can call the place I am talking about ans someone WILL pick up the phone! And the room isn't filled with ego.
 
mikegray660 said:
Hey Will
did you find a set of new cases, or did GP replace them/have them welded up? :roll:
Click to expand...

Contacted Jim Comstock at the suggestion of Windy. Based on the pics, Jim thinks he can repair them but will obviously have to have them in hand to know for sure!

Cheers,

- Will
 
Well Santa brought me some good things, so maybe I haven't been such a bad boy.

Jim Comstock was able to repair my cases and they look very fine now. Gouges dressed up as well. While the cases were in the hands of the master, asked him to install one of his case mounted breathers.

Bike is now back together. Fractured case was due to an older type 28 tpi stud being installed on the rebuild. The barrels had to be pulled and rebored, when the local shop reinstalled them they used the 'proper' 24 tpi nut. Thinking they were torquing down on the stud, the stud pulled and fractured the case.

All is good now. Bike was originally sidelined for a broken layshaft bearing as well as poor oil pressure. Gearbox now refurbished along with oil pump, which is now giving much better oil pressure. Glad I installed the Old Britts oil pressure gauge...

FWIW Grandpaul of Born Again Bikes kicked in cash for the repairs. Bike is now spinning like a top and in good shape for our Florida winter season.

Cheers,

- HJ
 
Hungry J0e said:
Well Santa brought me some good things, so maybe I haven't been such a bad boy.

Jim Comstock was able to repair my cases and they look very fine now. While the cases were in the hands of the master, asked him to install one of his case mounted breathers.

Bike is now back together. Fractured case was due to an older type 28 tpi stud being installed on the rebuild. The barrels had to be pulled and rebored, when the local shop reinstalled them they used the 'proper' 24 tpi nut. Thinking they were torquing down on the stud, the stud pulled and fractured the case.

All is good now. Bike was originally sidelined for a broken layshaft bearing as well as poor oil pressure. Gearbox now refurbished along with oil pump, which is now giving much better oil pressure. Glad I installed the Old Britts oil pressure gauge...

FWIW Grandpaul of Born Again Bikes kicked in cash for the repairs. Bike is now spinning like a top and in good shape for our Florida winter season.

Cheers,

- HJ
Click to expand...

It's good to see, Joe, that sometimes we wake up from nightmares...and everything's OK. So glad to see you're all squared away now and enjoying your rewards. Truth in fact that for all the GP shortcomings you and I exprienced, GP did step up and do the right thing and make things right. Gotta hand it to him (tip of the hat GP) since most bike shops would have left us in the dust. BTW, Joe...you, me and Windy need to find a "middle of the state" point to meet someday and spend a weekend day together tearing it up.
 
Nice Will
Glad to hear the bike has been "un-restored-restored" - sure you'll have lots of fun in those brutal florida winter days :mrgreen:
m
 
Status
Not open for further replies.

Similar threads

Tornado
Vintage Brit Bike Repair Channel Asking for Norton Help....
2
Replies
27
Views
1,334
ILLF8ED
ILLF8ED
Old Scratcher
Looking for a Commando engine rebuilder in Nth Qld
Replies
5
Views
418
robs ss
robs ss
S
1972 Combat Interstate Camshaft
Replies
15
Views
1,007
concours
concours
A
That brand new look for engine cases
2 3 4 5
Replies
92
Views
7,158
grandpaul
grandpaul
mean gene
The Queen said off with her head!
2 3 4
Replies
66
Views
4,224
Dan1950
Dan1950
Back
Top