Post big bang - Whitsend A10

[charles whitfield]

Here we go guys - After the 'big bang' my mate and I finally took the bottom end apart apart (I had been putting it off frankly)
So as a trouble shared is apparently halved, I will keep you posted on progress.
More diagnostics as we got deeper in, but a bit of background here
- SRM oil end feed conversions about 12,000 - 15,000 miles ago (reputed to last 80,000 miles or so)
- New oil every season - Max 2000 miles per year
- Laid up 5 years
- Recently noticed a knocking but was sure it was clutch related
- Always ride it full on - as I believe it's not a throttle its an on off switch
So:
Cases split - Debris everywhere, but expected
Con rods off - big surprise! Timing side had run metal to metal (SRM say with the oil feed conversion you should get over 80 psi - so how could that happen?) drive side OK, but why?
Then with CHECK YOUR SLUDGE TRAP advice in mind we had a look
Nope - timing side opened up OK (and I didn't realize that a small journal crank has no tube etc in it) but it was clean apart from shavings
Then to the drive side - impact driver out to knock it loosen and then a whack - but no turn, it just pushed it down the hole!!!!
After a load of pain we managed to get it out (see photo of cross threaded/rubbish job plug)
Can I ask for the collective wisdom here - If the drive side plug was not sealing properly and allowing the oil pressure to drop, why did the bearing closest to the pump cop it?
Or, are we way off and is there something else to look for?
NOS conrods here
New pistons on their way
New push rods here
Some more big bills on their way

[charles whitfield]

And here are some more pictures
Before
After
Carnage

[duTch]

 Can't give any ideas just now, but if SRM did the conversion, I would've thought they'd use their hex socket head plugs- unless maybe they didn't exist back then (15k / 2  = 7-8yrs ?)...a bit odd

[RichardL]

Are we really seeing crossthreading there or just the results of beatingnthe crap out of it? Would expect SRM to cross thread anything.

[bsa-bill]

is the "cross thread" not just the result of coming through the centre punch marks, maybe could of had a bit more of them removed ?

[Topdad]

My SRM conversion was done 2002/03 and def had hex plugs fitted they returned the old ones without me asking for 'em so that seems strange. BobH

[metalflake11]

If S.R.M. did it all the casings will be etched with the job number, is this the case? If so ring them and they will tell you exactly what they did, and when. Let me know.

[charles whitfield]

Hi all
Yes, the modified timing side cover is etched P0093 and the oil pump has had SRM etched on the sealing plate- I will give them a call since I need to have the barrels reworked anyway, plus a spacer dropped out that when I split the cases (a specific bit they added) - but I didn't expect it and didn't see where it came from 

So, it most certainly is an SRM job since I sent it to them and then drove a couple of hundred miles to collect it, and remember the payment wince. 

I had had it done since the 'big' ends are small and were already -40. Plus I had scoring on the main oil side journal (bearing had had it when I bought it) - Rather than find a new crank, I went for the conversion.

I appreciate the doubt about the thread strip issue - but as a time served toolmaker, I can assure everyone that it was not the removal - I had dressed the center punch marks away and really did not give it a big belt - it just tipped and moved down the hole a thread or so - There is silicon seal hanging to some of the threads which is odd - I would have expected Loctite?

But for the sake of the debate, what if the plug was sealed OK, where else to look?

This is all a curious issue - but in the end, it's just a matter of metal and money

It WILL run again   

[metalflake11]

Shame you didn't ring them before you stripped it, they might have done an autopsy depending on the circumstances.
Do you run an external filter?

[morris]

Can I ask for the collective wisdom here - If the drive side plug was not sealing properly and allowing the oil pressure to drop, why did the bearing closest to the pump cop it?

Just an idea but I can imagine the timing side bearing giving up because of lack of pressure. Oil has, like any other liquid, to be forced to go where it otherwise wouldn't. So having a significant leak further up the line would mean a significant drop of pressure down the line.
OTOH, if this is the case I think the other bearing must have been close to collapsing also

[charles whitfield]

Well yes, it is a shame - but more learning really   
It must be 13 years or so since I had it done and TBH it never entered my head to give them a call
I am not on a blame hunt, I just want to sort it so that I can run out without worry - the cause is not really clear and I would rather avoid it again   
As for a filter - no, I always changed the oil after 1500 miles max, so hey ho - this time.
I fitted a snazzy magnetic sump trap though three years ago     

[charles whitfield]

Hi Morris
I follow your thoughts and yes, I would suspect so
Just a whacky idea - I live on a Peninsula and set off from the north side clockwise, mainly left hand bends forcing the oil to the drive side!
I should have gone the other way - Damn     

[morris]

Hi Morris
I follow your thoughts and yes, I would suspect so
Just a whacky idea - I live on a Peninsula and set off from the north side clockwise, mainly left hand bends forcing the oil to the drive side!
I should have gone the other way - Damn   

Or mount the engine inclined sideways....

[metalflake11]

They don't have a 'not our fault' attitude, they want to know for their own benefit. After all these years they obviously wouldn't fix it for free, but they might have discounted some parts or the labour. They may still do so.
You've been very unlucky in my opinion.

[WozzA]

Hi Morris
I follow your thoughts and yes, I would suspect so
Just a whacky idea - I live on a Peninsula and set off from the north side clockwise, mainly left hand bends forcing the oil to the drive side!
I should have gone the other way - Damn   

Or mount the engine inclined sideways....

Ahhhh Haaaaa...  BUT if you ride home the same way ALL will equal out...