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What is your opinion

 

i have a stage 3 head

which has phosphorus bronze Valve stems fitted

to reduce possible oil burn i thought i might fit oil seals to the inlet guides

however when giving the matter some thought phosphorus bronze

needs oil to work properly so it could be detrimental to the set up ? (oil seal)

 

why use phosphorus against steel ?

 

looking forward to your comments

 

pink

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Hi Pinky,

I thought Phosphour Broze was self lubricating whereas steel is not.

However, not sure what happens to PB when hot.

 

Roger

 

Just googled it and there are a number of unhappy bunnies regarding PB and lack of oil.

Edited by RogerH
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What is your opinion

 

i have a stage 3 head

which has phosphorus bronze Valve stems fitted

to reduce possible oil burn i thought i might fit oil seals to the inlet guides

however when giving the matter some thought phosphorus bronze

needs oil to work properly so it could be detrimental to the set up ? (oil seal)

 

why use phosphorus against steel ?

 

looking forward to your comments

 

pink

 

original ones arent steel they are cast iron. like the rest of the engine.pb guides waste of money.

dont bother buying the moss oil seals, they are just a o ring.

top hat ones from tdi discovery will fit .but i wouldnt fit any type untill youve done several k miles.

and its well run in.theyre supposed to wipe the excess oil of the valve stem but allow some lubrication

if the valve does seize the push rod falls of the rocker and doesnt do any damage.

or at least it didnt on mine.

richard

Edited by rpurchon
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I have PB guides (from Chris Witor) with seals on (inlets only) on my Vitesse. Work fine - no issues. Can't really comment on oil use as the bottom end is very weary......

 

If guides/valves have the correct tolerances and you don't have one of the those infernal external rocker feed pipes, then seals shouldn't really be needed.

 

Oil going down the guides usually manifests as a puff of smoke when the throttle is opened after a period of idling.

 

I've got some manganese bronze guides in the head that's going on my PI and the inlets are machined to take seals. The seals are supposedly engineered to allow small amounts of oil through for lubrication.....

 

Nick

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Good question Pinky, I'm sorting a spare head at the moment and have PB guides, new valves etc. for that.

 

PS Nick...do you have a link for purchasing the seals?

 

Cheers

 

Tony

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Surely if you're having a Stage whatever head created, then the creator is also going to be fitting the guides, valves and springs to match the cam and the actuating gear, along with matching the ports to the manifolds etc etc . . . .

 

Therefore there should be no need to even consider retro fitting oil seals - or anything else for that matter ?

 

Unless of course the head creator has fouled up in a big way - in which case you should be going back to him for a solution ?

 

Cheers,

 

Alec

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I Agree with your comments Alec, there is no problem with the head other than learning or trying to learn more

about the materials used

 

there seems to be several different materials used

 

hi Neil £6 valve?or not Pink? could you exsplain what you are on about, i am an i o w numpty

 

have PB guides (from Chris Witor) with seals on (inlets only) on my Vitesse. Work fine - no issues. Can't really comment on oil use as the bottom end is very weary......

 

If guides/valves have the correct tolerances and you don't have one of the those infernal external rocker feed pipes, then seals shouldn't really be needed.

 

Chris Witor nice bloke, very knowledge, makes them saloon cars fly

Edited by pinky
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Recently rebuilt an engine for a Mk 2 Golf GTi and the standard guides were phosphor bronze and were fitted with seals, they had the added complication that they had to be reamed to size after fitting, fortunately I had a suitable adjustable reamer to be able to do this.

Going way back to my motorcycling days I remember phosphor bronze guides being available for my Triumph but I seem to remember something about the running clearance being greater than the standard cast iron items so some oil burning would be experienced, seals weren't fitted to these engines.

Regards

Graham

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The ones Chris Witor sells have a grove machined into the top of the inlet guide to enable the seal to hold on. The seal is essentially the same as fitted to later Minis.

The O ring type seals are a waste of time - go up and down with the guide but logically can't really seal the guide.

 

The problem is retro fitting seals to existing guides - as unless the seal has some means of being retained on the guide they will be lifted up and down like the o rings are so need to be a tight interference fit or a top hat design. They also have to be slim to fit inside the dual springs.

Someone mentioned Land Rover TDI seals - which year/model would be useful to know.

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the ones i fitted were similar shape to these http://www.ebay.co.uk/itm/Land-Rover-2-5-diesel-Valve-Stem-inlet-seals-x-4-/250992132809?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item3a704c02c9

very tight fit on the guide.probably need a set of 8 to get six on the inlets.

richard

Edited by rpurchon
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Alec I'm not sure that the suppliers think too hard about the mixing of parts.

The tuners often only really consider the needs of race engines - where oil consumption is not a big issue.

 

When fitted to a road car the relatively big clearances used with PB guides can result in significant oil consumption hence the need to consider fitting seals.

 

I would advocate fitting the guides with sealed inlets as sold by Chris Witor (amongst others) and probably would get a groove machined into the exhaust guides but not fit them until a few thousand miles had been covered. I know many don't think that much oil goes down the exhaust guides but my suspicion is that the Bernouli effect may such oil down the exhaust guides too.

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Andy

The ones I linked will only work with the correct length PB guide/springs and should not be used with std spec valves , and the exhaust valves are not an issue hope that makes sense

Edited by ntc
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As mentioned by Andy M above the Witor ones seem to be the same as used on the late A series (A+) P/No. ADU4905. These need the top of the guide machining to accept them, but it's a pretty simple mod (with the guides out obviously!), which I was able to do with a small modelling lathe to match ones previously got from Mr Witor. These can be used with double springs.

 

I'd have happily bought another set of guides from Mr Witor, but they have been out of stock for a while. He did say he was planning another batch but wasn't promising any dates when I spoke to him about 6 weeks ago.

 

Nick

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  • 8 months later...

Reviving this thread for selfish reasons - am anticipating problems with inlet valve stem oil ingress, maybe bigtime. So need a solution that will stop excessive oil from being sucked down the inlet valve stems - standard valves and guides.

The reason is I plan to achieve cylinder deactivation by fitting a valve in the inlet manifold to kill mixture flow to cylinders 4,5 and 6. ( why? see** )

This means the inlet passage will be running for minutes on end with maybe 14psi depression under the valve guide. Will be rather like running downhill on closed throttle for several minutes at 2000-3000rpm. The cloud of blue smoke on reactivating the cylinders could be dramatic and the plugs wont like it.

So what parts do I need to reduce,not kill, oil leaking down standard valves and guides? inlet only.

cheers

Peter

 

( ** Why?: http://www.tr-register.co.uk/forums/index.php?/topic/38941-american-post-mounted-valve-rockers/?hl=deactivation&do=findComment&comment=297547

- building that new valve mechanism is fraught with snags, I've gone off that.)

 

 

Edit. Do those Disco seals work as shrouds that stop oil splashing onto the guide and then being sucked down guides?

Edited by Peter Cobbold
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