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Zero compression on cylinder 4


Kelv

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No, Kelv, you've done the right thing!   Because your picture has revealed the problem!

See this copy of the parts diagram from the Canley Classics website:

image.thumb.png.072a67b10215a02ebceb1d6263a992f1.png

 

There should be a collar at either end of the rocker shaft, retaining it in place - THEY ARE NOT THERE!

The shaft has been retained, more or less, by the rocker cover.  after you removed it the end rocker could easily slide off, and probably has been doing so in use., but only as far as the cover.    Any witness marks on the inside of the cover?   The rocker has probably been  half hanging off the end of the shaft, on a cant, unable to move and the abnormal leverage hass dislodged the valve guide.   As as said above DO NOT START THE ENGINE!    You need to have the head off now, and have the guide replaced  - "knurling" might ensure that a new guide will stay in place.    

This has to be down to your DPO (Damned Previous Owner) who has left the end collars out, or not retained them with the right pin.  It should be a solid metal "Mills Pin" and the DPO probably used  split pin.

Sorry, but at least you know now!

John 

Edited by JohnD
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NO, NO, NO, Kelv!      Your "mechanic" has no idea, no idea at all!  Except how to bilk you of money      You can buy a reconditioned cylinder head from Canley's for £365, which is a LOT better than the inflated price he wanted.    See: https://www.canleyclassics.com/?catalogue=triumph-herald-1200&diagram=triumph-herald-1200-engine   You could talk to them about the rocker assembly which would be extra, OR they can supply a complete rebuilt engine for £625, still less than the £1000 your so-called 'mechanic' wanted!

See: https://www.canleyclassics.com/?product=rebuilt-engines

John 

(No connection with Canley's, except as a satisfied customer.     Other engine reconditioners are available!)

 

Edited by JohnD
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1 minute ago, DanMi said:

If that valve has fallen into the cylinder, there may well be damage to the piston/bore, head needs to come off to assess but be prepared for more than just a recon cylinder head

Couldnt have fallen in running or there would have been a big bang!

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35 minutes ago, JohnD said:

 You could talk to them about the rocker assembly which would be extra, OR they can supply a complete rebuilt engine for £625, still less than the £1000 your so-called 'mechanic' wanted!

That £625 is for a short engine not a full engine. I do agree though that the price quoted for a cylinder head is very high

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45 minutes ago, johny said:

If he was really ingenious there might be a quick way to do it but youre definitely missing some bits and I take it you probably want a proper job done? Did the valve and rocker come off in your hand (honest guv!) or were you investigating?

I took the rocker cover off. Started the car.

Videoed the rocker in operation.

Switched car off.

Put the cover back on and then attempted to drive the car. After 100 meters the engine produced a loud clattering sounds so I reversed the car back home. 

I took rocker cover off.

Saw the bits lying free. 

 

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49 minutes ago, JohnD said:

NO, NO, NO, Kelv!      Your "mechanic" has no idea, no idea at all!  Except how to bilk you of money      You can buy a reconditioned cylinder head from Canley's for £365, which is a LOT better than the inflated price he wanted.    See: https://www.canleyclassics.com/?catalogue=triumph-herald-1200&diagram=triumph-herald-1200-engine   You could talk to them about the rocker assembly which would be extra, OR they can supply a complete rebuilt engine for £625, still less than the £1000 your so-called 'mechanic' wanted!

See: https://www.canleyclassics.com/?product=rebuilt-engines

John 

(No connection with Canley's, except as a satisfied customer.     Other engine reconditioners are available!)

 

Ok. It's a 1300 engine though, but 1200. I messaged canley classics yesterday but received no reply yet. 

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valve guides should be a light press fit  . often drifted in with a mallet and adrift .

the missing collar has popped the key hole cap off and dropped the valve the head has to come off 

takes 30mins in the sunshine then dog can see the rabbit 

not seen any oversize guides   johns idea of a knurl  or even loctite bearing fit  might help a loose guide 

pete

 

 

 

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1 minute ago, Kelv said:

So if I order a 1300 short engine... Then what do I do? Who will fit it and what will they charge?

a short engine is just the block with crank pistons oil pump and sump, so you would need a 1300 cylinder head, camshaft rockers etc.

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Ok. I'm stressed now and confused. Can somebody take over and organise this repair and I'll throw money at them. I would rather my £1000 go to you than my local mechanic. 

I've got to find a cheap car so I can get to work. I'm a personal assistant to a man with cerebral palsy. My Herald is my only vehicle and was my daily driver. 😔

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dont buy anything till you know just whats required 

you may just need a new valve guide and rocker shaft end cap and pin 

is the loose rocker showing any strange wear damage  ,  

if the dropped valve happend while running you may be in for a major rebuild.  on the other had   you may not 

you must have a good look see  and not guess  

Pete

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2 minutes ago, Pete Lewis said:

dont buy anything till you know just whats required 

you may just need a new valve guide and rocker shaft end cap and pin 

is the loose rocker showing any strange wear damage  ,  

if the dropped valve happend while running you may be in for a major rebuild.  on the other had   you may not 

you must have a good look see  and not guess  

Pete

Cant make out how the valve came free! Oh yes I can - without the end cap the rocker moved along the shaft and pushed on the valve spring cap instead of the valve stem so the collets fell out and the valve was free to fall into the cylinder. It might have then been pushed up by the piston against the valve guide so that got forced out of the head🙁

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Kelv,

remove the head so we can see how much damage there is to the piston.

worst case is it’s been punctured, or the cylinder wall has been damaged.

best case is just getting a replacement head with new valves and rocker shaft.

but until we see inside it’s all guess work.

if you can contact Hugh Glossop and he is prepared to help you are on a winner

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