Maney Crankcases

Status
Not open for further replies.
pouchy750

pouchy750

Joined
Aug 20, 2010
Messages
99
Country flag
I had a major internal blow up on my Commando racer last weekend, a conrod seized & locked the engine. See previous posting.

There is a lot of damage inside the engine, but to my amazement, even though the Maney crankcases have gouge damage, they didn't explode, no cracks.

These cases are certainly strong if they can withstand this. I highly recommend them if you are building a fast Commando.

Maney Crankcases


Maney Crankcases


Maney Crankcases
 
"There is a lot of damage inside the engine, but to my amazement, even though the Maney crankcases have gouge damage, they didn't explode, no cracks.

These cases are certainly strong if they can withstand this. I highly recommend them if you are building a fast Commando."

I'd wait until cleaning, checking and measuring were complete before fist pump of victory. For your (wallet's) sake, I hope they are still serviceable. Good luck!
 
So why the seized journal?

Hopefully you know so it will not happen again. I know of one case where the spigot for the oil feed from the oil tank to the pump had some flashing from machining partially blocking the flow. That caused a scuffing of a new set of pistons and near seizure of the Norton race engine.
 
john robert bould said:
track day?
Click to expand...

That is a very profound and thought provoking question "john robert bould". That is right up there next to the world renowned Nobel Prize winning question - "what's this?" :roll:

I submit to you that if "track day" were the root cause of the journal seizure then Norton would never have achieved the rich race history we know today. :D
 
Thank goodness some don't think ruining an expensive engine into failure is a bad thing in the big scope of things. This strong soldier appears to have been sacrificed by big end seizure that cut its legs off not by it failing in its duties.

Maney Crankcases
 
hobot said:
Thank goodness some don't think ruining an expensive engine into failure is a bad thing in the big scope of things. This strong soldier appears to have been sacrificed by big end seizure that cut its legs off not by it failing in its duties.
Click to expand...

Translation: Broken rod.
 
Anyone could come up with "Broken rod", but only a true poet could come up with "This strong soldier appears to have been sacrificed by big end seizure that cut its legs off not by it failing in its duties." More power to Hobot's prose!
 
Duh but why did it break? D/t Norton rods' inherent weakness first ^or^ after something else went wrong first? Would a steel Carillo rod have kept on trucking or would the something else still of let go-siezed up for a show stopper? Did crank get tweaked too?
 
hobot said:
Duh but why did it break? D/t Norton rods' inherent weakness first ^or^ after something else went wrong first? Would a steel Carillo rod have kept on trucking or would the something else still of let go-siezed up for a show stopper? Did crank get tweaked too?
Click to expand...

Good question Steve. Looking at the bits in the bottom of the crankcase. It looks as if the con rod bolt broke on the one side. The other is still attached to what’s remaining of the aluminum con rod. What was the source of the con rod bolts? I think there was a warning about non-standard Andover bolts in the past.
This would be a good time to replace your con rods to the JS Carrillo Norton rods and light weight pistons.
 
Hm I thot I saw all of both bolts still in the cap with the al rod parts still attached. If was a bolt as we have seen in my own and Doug MacRae's, both bolts broke but one reused bolt had about half its dia darkened by oxidation revealing a fracture line working its way across metal grains till the last grain broke the rods back. Bolt is a rod cap fastener, not the connection rod, which suffers by them. Hope JSM rod bolts are up to the job.

What else comes to mind besides 'just' the piston jerk down loads is the crank shaft jump rope shape at hi rpm which tips the journals in the big ends shells to add levering force on on bolts too, till > kapowie?
 
The crank may need crack testing after its sojourn as a jack hammer . :(

Shouldnt , but will take the opertunity , its the LEFT bearing , as in the distant one .
A certain engine always does 4 & 3 first ( & only ) when the oiling goes . Invariably .

Id think a humougous Oil Pump wouldnt be a bad idea , on the olde twins .

Crikey , the PUMP mustve been designed Before the War . Though not the BOER WAR .
 
Oil starvation and crank flex, not the best combination is it? But the maney granade proof case contained it. :!: Wonder if high rpm centrifuged the oil away before getting to the shells.
 
I wonder if the oil seal between the timing cover and the crankcase failed. I usually check to see that oil is returning to the tank when I first start the motor, however if that seal fails oil would still return, and the oil pressure would drop markedly.
 
acotrel said:
I wonder if the oil seal between the timing cover and the crankcase failed. I usually check to see that oil is returning to the tank when I first start the motor, however if that seal fails oil would still return, and the oil pressure would drop markedly.
Click to expand...

Yes, a faulty timing chest oil seal is a good candidate as is a restriction in the oil feed line going to the pump. At high speeds the pump is plenty adequate for the application; even when badly worn. Crank "whip" has nothing to do with this failure.
 
When I was ordering my Maney cases Steve said to me that his dad told him of for making them too strong.... :lol:

Haven't tested mine yet ;-)

Don't want to, I already have Jim's rods and pistons, if something does let go they just might punch through.....
 
Just curious about the Maney cases. On the website it says that the price for them is 969GBP for a pair of cases? Do most people buy 2 sets of cases? Is there a place to buy these on the USA side of the pond? -Or only from Mr. Maney himself? I'm quite confident that I would only need one crankcase :wink: -Fingers crossed.
 
I believe a pair is the same as shoes unless you are 'Jake the peg.
 
Status
Not open for further replies.

Similar threads

B+Bogus
  • Locked
Maney Crankcases
Replies
5
Views
921
B+Bogus
B+Bogus
M
Going rate for a set of crankcases?
Replies
17
Views
1,833
marshg246
marshg246
Fast Eddie
  • Locked
Fitting a magneto to Maney crank cases
2 3 4
Replies
72
Views
8,840
Schwany
Schwany
Onder
  • Locked
Ebay crankcases
Replies
14
Views
1,487
htown16
htown16
H
Mystery early twin crankcases
Replies
1
Views
783
L.A.B.
L.A.B.
Back
Top