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TR4 piston oil control ring needs changing


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Good evening: i own a 1964 TR4 that i have had for 40 years this month. The engine is extensively modified (circa 1991) including modified unleaded head, 2290cc, two 45DCOE webers and extractor manifold etc etc. It as you can imagine is quite nippy. Despite oil pressure being around 210psi in all four cylinders I suspect an oil control ring has gone down and needs changing - it is very smokey when warm / hot though remains nippy!

Can anyone recommend a suitable garage near Stoke on Trent that can do the job with the block in situ. Too busy with work myself and have much bigger and more powerful beasties that demand tlc.

Regards

Steve

Edited by Sulzer 12LDA28C
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1 hour ago, Sulzer 12LDA28C said:

Despite oil pressure being around 210psi in all four cylinders

oil pressure being around 210psi ?

 

Sorry I cannot help you with knowing a garage, but wonder if rather than an oil control ring having failed it might instead be a valve guide cracked.?

Cast iron ones are more prone to this than phosphorous bronze of course ..if you happen to know what's fitted. 

What are the plugs like. If one cylinder is oily then it may be the inlet valve whereas if each are clean then it would be an exhaust valve.

Oil control ring failure may be evident in addition blow-by / breather pressures.?

Either way the head would need to come off.  Anyway, just a thought.

Pete

 

Edited by Bfg
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Steve
I think the pressures quoted are cylinder pressures rather than oil. 
I would get a leak down test on each cylinder first. Most garages should be able to manage that. 
as others have said identify which pot is at fault. 
also rule out that the breather from rocker cover to inlet isn’t sucking too much oil. Something that’s worse when hot. 
 

Garage in CONGLETON that did a great job on a head gasket when I first owned my black 3a May help with an in situ investigation and fixes is

mikeanics 01260 297115

He rolling roads my car every year too. 

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Hi Steve,

can you clarify the 210 psi oil pressure. As suggested is this the compression pressure.

After 30 years do not rule out valve guides being worn.

Do not have the sump oil content too high - 1/2 or less is good.  Has the dip stick level changed???

 

Roger

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Try this. Get the engine warm. On the road run up to fairly high rpm in third gear then slow down under engine braking. Floor the accelerator. Do you get a big cloud of smoke?  If so I’d suspect worn valve guides. 

Edited by peejay4A
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  • 6 months later...

Hi: i have had the cylinder head overhauled and the problem was worn valve guides. Refitted a couple of weeks ago and for the first few starts it was still smokey. Persevered and now no smoke at all and performance is all there: lovely job. Pity it was off the road for 12 months.

Since modifying her all those years ago i think she is sitting a bit low all round - from where can i get front road springs to raise her perhaps an inch - might ned to take it to a specailsit who can advise on spring rate / free length etc. Any thoughts please?

Passed its MOT earlier this week - which was nice.

Steve

 

 

 

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Any spacer, known as Packing Piece in the Parts Manual, should sit on top of the spring, not beneath - see P75 in the TR4 Manual. 

This requires the spring to be removed using a proper tool which goes up the inside of the spring.  Never use external spring compressors on a TR, you might not survive the experience - I am not joking, because when they let go, who knows what they will hit and the force built up is terrifying.

Ian Cornish

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