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Post-Thruxton Post Mortem


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This is just a preliminary report, rather like the pathologist taking fingerprints and body fluid samples!

All ancilliaries removed, ready to hoist out the engine and gearbox.     That included detaching the oil filter and cooler, and the filter adaptor housing had a deposit in it.   Not great, enough to cover a little finger nail, there's probably more in the filter,  but this is what it looks like under the microscope.   The particles are about 1mm wide.   Looks to me like trashed bearing metal.

557119498_PostMortem1depositfromfilterhousing.thumb.png.091e0fded8f749d427312a5f0d505322.png

 

 

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Very little big end left is correct.  No.1 con rod is destroyed.  It must have overheated +++ by the discolouration of the crank, and I doubt if a grind will restore the gouged journal.  No.6 is burnt out, loose on the journal, no shell left.  No.3 has overheated and has a rim of melted bearing, and by the colour, 4 is the same.   2&5 are fine!.

And, thrust washer has come out, the oil baffle plate has been knocked loose, and the coarse filter on the oil pump is full of the same swarf that I found in the filter housing

This engine is an anchor.  Start again.

John

IMG_20210508_183940.jpg

Edited by JohnD
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Hello John

                  That does look nasty!

Are you going to build another 2.5Lt engine or go back to 2Lt?

If you are going back to a 2Lt I have a complete 2Lt Mk2 engine here that is not needed by me!

It is quite a late one but I do not know what it is like inside it was part of Alan's collection

If is is of any use to you it is yours for a reasonable sum.

Roger

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1 hour ago, JohnD said:

Very little big end left is correct.  No.1 con rod is destroyed.  It must have overheated +++ by the discolouration of the crank, and I doubt if a grind will restore the gouged journal.  No.6 is burnt out, loose on the journal, no shell left.  No.3 has overheated and has a rim of melted bearing, and by the colour, 4 is the same.   2&5 are fine!.

And, thrust washer has come out, the oil baffle plate has been knocked loose, and the coarse filter on the oil pump is full of the same swarf that I found in the filter housing

This engine is an anchor.  Start again.

John

IMG_20210508_183940.jpg

Really sorry to see that John. 
 

so did oil supply just stop ?

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Thanks, Roger!

But A/ I need 2.5L, to be even halfway competitive - I've tried 2Ls!   

And B/ I have another 2.5 that I can rebuild, unless the block of this is re-usable - It's bored out so worthwhile considering

And Hamish, suspect your diagnosis correct - haven't looked at the oil pump yet.

John

Edited by JohnD
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Lordy...... that was a only a couple of strokes short of making a new breather.....

The crank is done..... but the block may still be good to go again if it will hold a thrust washer (there are ways around that if the only damage). Even the pistons..... though I reckon #1 will have touched the head.....

I have a couple of cranks I think? 

Were there any stray Max Speeding rods in Alan’s stash Roger? I know he killed a rod from his first set and planned to sell 4 and keep the stray as a spare..... Failing that I have lots of standard rods.

As to the cause..... I note it’s no 1 worst affected. Do you have any external feed or is it last in line for the oil? How about the mains? Looking a bit like a general oiling failure though not sure why the thrust washers came out......

Grim.

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1 hour ago, Nick Jones said:

Were there any stray Max Speeding rods in Alan’s stash Roger? I know he killed a rod from his first set and planned to sell 4 and keep the stray as a spare..... Failing that I have lots of standard rods.

Hello Nick

                 Yes I have one he obviously bought a set of 6 used one and sold a set of four(clever man)

John it is yours and I have remembered I have 2  oil pumps for the sixes (for some daft reason I thought they were the same as the one in Spitty!!!!)

A friend gave me two and I checked and blue printed one and probably pined the cover for best position then found they are different so they are both yours1

The deal would be the usual a donation to your or my favourite charity

Plus I will make you some solid bronze thrust washers if you want (I have a lump of what I think is the right grade for the job) and if you send me the lower bearing cap I will machine it for a thrust washer so you have full circle(same deal!)

We have got to get you back out there before we all get to old!

Roger  

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43 minutes ago, JohnD said:

I have a length of Aeroqip to bridge the main gallery  from  No.6 to No.1  but never fitted it!   

 

Hello John 

                    Alan had done this I have kept it but changed it to a solid copper pipe(belt and braces not that the engine will be worked as hard!)

Roger

ps just remembered I have the non overdrive gearbox from Alan's car going spare as well as I rebuilt the O/D gearbox for touring and longer legs!(If we ever can? )

Roger

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Hello John

                  I have had a rummage and I have found the Max con rod I have found the pumps and I had pinned the end cover for best position and deburred the oil ways and reduced end clearance and rotors are in spec I think and it is a pegged rotor(the other one is not!!!!!!!!!!!)

I have also found a set of Cord Piston rings and they are +0.040"

Plus the non  overdrive gearbox which I will inspect if you are interested in it?

Roger

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Sorry to see this damage. I feel  your pain John. I‘m really  curious about the oil Pump and its drive.

I have an unused  TH2 Kent 295degree camshaft kit I’m going to part with if of any  help. 
 

Martin

 

 

 

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10 hours ago, rogerguzzi said:

Hello Nick

                 Yes I have one he obviously bought a set of 6 used one and sold a set of four(clever man)

John it is yours and I have remembered I have 2  oil pumps for the sixes (for some daft reason I thought they were the same as the one in Spitty!!!!)

A friend gave me two and I checked and blue printed one and probably pined the cover for best position then found they are different so they are both yours1

The deal would be the usual a donation to your or my favourite charity

Plus I will make you some solid bronze thrust washers if you want (I have a lump of what I think is the right grade for the job) and if you send me the lower bearing cap I will machine it for a thrust washer so you have full circle(same deal!)

We have got to get you back out there before we all get to old!

Roger  

GOSH, RogerG!    That is an offer I cannot refuse!    I definitely need one MaxSpeeding rod, and possibly more if others have been burnt.    And this oil pump must have been trying to pump a slurry of oil and bearing swarf.    Thank you!

And I  just wonder if that No.4 main bearing cap is the source of all this grief, so a remachining might be a good idea anyway.     When I first fitted the engine to the car, and went for a start, it seized!   Not actually seized, but would only turn about 60 degrees, with a solid stop both ends.    I found that a thrust washer had spun in the bearing and that there was a chip about 5mm wide in the face of the bearing cap, just where the end of the washer is kept in place.  I had it rewelded and carefully filed it back, flat.  Why that happened I have no idea - the chip was not there when I assembled it!     If that had happened again - a thrust washer was loose in the sump -would that have  caused excess oil loss from the No.4 main bearing, and the subsequent failures?     Please PM me about the parts and we can discuss favourite charities!

For other parts, I have another 2.5L engine that needs a complete rebuild, but that would need all the rebore etc that I did to this one, and of course has OE conrods etc.     I will need another crank and could use that one, but I wonder, does anyone have a 2.5L crank that I might buy?   Straight purchase or charity as with Roger?

Martin, the camshaft I have is a 300 degree Crane, so unless I find that is damaged,  thank you, but no thanks.

John

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Wowsers. That is a right mess. Sadly with racing there is I assume no real warning with an engine being worked so hard, failures I assume (correct me if I am wrong) are more often than not catastrophic. It does not took more than 10 seconds from grenading.

I would offer bits but all my stuff is 2 litre, so apart from a couple of blocks (which you already have) I am of no use to you or you could have had them. 

its a pity but with bearing failures there is so much to replace. Not only damaged parts but oil pumps and cooler matrix and pipework just to make sure all the swarf is gone. 

I hope it all comes together for you John, and with the help of others more skilled on here than me it sounds like you already have the inklings of a plan. Hopefully you will be out there again in no time 

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Nick,   Thank you - but Phil has pointed me to someone selling a box of 2500 engine parts, in Lancaster!    I'll investigate and see if they will do - so much simpler than getting a lump like a crank from you to me!  I'll report back if I need to take you up.

I appreciate very much that the Common Room of Sideways U - or should I say the Dept of Motor Engineering? - is sponsoring me here.    I ought to put a "If you're not SIDEWAYS you ain't trying" sign on the car!  (or should it be Paul's Goldenback?)

OIl pump out - with every sign of having pumped an oil and metal flake slurry!  Grooved base plate and rotors, the shaft is stiff in the body.    There was even a piece of broken cast iron inside the outlet duct, even though the gauze around the intake was intact!

John

 

Edited by JohnD
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I do have a set of pistons on rods standard size flat top from a vitesse  and a domed set on +10 from a GT6 if pistonage is required, although I have no idea what yours is bored to, and they are still attached to rods, although I note you use posh rods.  Hopefully your pistons may be ok, although I suspect one may have decided to visit somewhat higher up the bore and met something else already in that space.

 

 

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The results are back from Pathology, and they are not a pretty sight.   

First, the damage to No.1 big end journal:

771388229_No1bigendjournaldamage.thumb.jpg.470d11565f5da8c626738c9f761d8a1a.jpg

The deepest gouges are about 15 thou deep, which might be recoverable, but the colour of the web doesn't look good.   I fear for its strength:

836629510_No.1webdiscoloured.thumb.jpg.bb7dea3314946938d8d77630586779a9.jpg

So this crank is unusable.

 

No.1 conrod has gone in a big way, lots of shrapnel in the crankcase, but the colour of some of the others., like the crank, make me suspect their strength.   3,4 and 6 are unusable:

1196908592_Conroddamage.thumb.jpg.3713ed76ae6e8fd200d02377e0a14335.jpg

 

3, 4 and 6 have melted their bearing shells, and 3 still has a pretty ring of congealed bearing metal around it.   As you suspected, Nick, the face of No.1 piston has an image of the combustion chamber rim, some of the ring lands are broken and the underside has been shot at.    3,4 and 6 also have lesser imprints, so maybe five pistons are reusable, maybe only two:

 

But239129413_No.1pistondamage.thumb.jpg.2f73f82513119ce271d4738789da1f0b.jpg

But it doen't end there.     The rear thrust washer span and grooved both the No.4 main bearing cap and the block:

563446314_No.4mainbearingcap2.thumb.jpg.3a8cc6d72fd00cf6acf814ae6ad42263.jpg

So unless that can be recut, for a truely enormous thrust washer, the block is unusable.

I didn't take pics, too depressing, but the main bearings were worn to the copper in places, and journals are pitted.   As to diagnosis, it has to be lubrication failure - unless you think otherwise?   I curse myself for not fitting the Aeroquip bypass to equalise pressure between No.6 and No.1 main mearings, because I fear that, as Kastner warned, poor oil flow to the front is the price of high performance.      No.1 big end went, took all the oil flow  and so deprived everywhere else.

The head appears fine, as do the valve and the camshaft and its drive.    I don't remember how much of Steve Austin was left, but I fear that we are not in "We have the technology - we can rebuild him" territory, and if I want my six million dollar engine I will have to start again from zero.   

I have a 'spare' 2.5L engine to start on, and thanks to Phil the Brookster I know of someone in Lancaster who has a  2.5 engine in bits they want to sell!    What are the chances of that!

Onwards and upwards!

John

 

Edited by JohnD
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Number 1 is deffo a candidate for a bit of wood underneath and turning into a mantlepiece ornament. I have some old moto x pistons and bits and bobs that have become windowsill bits. Clearly the boss does not allow them in the house, so they are workshop windowsill bits. 

Well at least you have a plan John and access to an engine and a load of bits, which gives you a starting point. What do you think gave in first? Or have you not got that far? 

 

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:blink::ohmy::pinch::sad:

That’s pretty comprehensive...... one rod isn’t going to be enough...... Reckon there might be two you could use....

Looks like general oiling failure to me. Wondering if something relatively small fell off initially and went through the oil pump (maybe wedged the relief vale open).

The thrust washer thing is odd though, wonder if that is what kicked it all off.....

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