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Which 2.5 Litre engines have Valve Stem Seals


Wagger

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My Vitesse has a late 2500TC Engine. Looking at Rimmers, Canleys etc reveals that some 2.5 assemblies have valve stem seals and some do not. Do any of you guys know which models had them? My sons 2500S does have them but has an earlier engine than mine.

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36 minutes ago, NonMember said:

I didn't think any of them did - they were always "must have improvements". My 2500S had them but only because they'd been retrofitted.

Just as I suspected Rob. Some drawings call them 'Collar's, others 'Seals'. Then there are others with nothing shown. I'll have to unassemble one to find out. It will make dribbling penetrating fluid in easier if they are missing. As my car stood for seven years I am pretty sure a valve on number two cylinder is sticking. I hope to take a look this week.

My son and me have a procedure and concoctions for doing this. Won't post it unless it works). Don't wanna take the head off yet as all is so smooth below 2700 rpm. No smoke or leaks of any kind.

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That doesnt surprise me because the oil supply to the six head has always been considered so low that some people have even fitted an oil feed line to it😱 I would have thought that fitting seals to the stems is inviting trouble... 

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9 minutes ago, johny said:

That doesnt surprise me because the oil supply to the six head has always been considered so low that some people have even fitted an oil feed line to it😱 I would have thought that fitting seals to the stems is inviting trouble... 

I agree with that. Might have reduced Hydrocarbons for the US market. Basically, if it ain't broke, don't fix it. No lube in unleaded either. These engines were designed during the Leaded era..

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2 hours ago, Pete Lewis said:

why would a valve stick but only above 2700   thats a bit  Nuts 

look for the simples not the myths and deep wallet ideas 

Pete

It is, probably, the valve not shutting quickly enough. Son had this on his 2500S. Way back in November, this was occurring at a mere 2000 rpm. A ching  noise and popping back through the front carb. It's now happening at higher rpm. Blessed raining today, so cannot work in the drive. Mobility scooter is taking up valuable workspace in the dry. I am dying to take the rocker cover off but don't wanna set the pains off again. It should be obvious if I can watch in running. It was 'Gully' who had a similar problem with a pushrod being responsible for the noise.

At up to 45mph in town it is as 'Sweet as a nut'. Drive shafts and prop all quiet, no smoke, no overheating and no leaks. Just have this one mystery to fix now, so won't post any more on it til I've had the rocker box off.

Do not worry, I won't be spending massive amounts on this. The whole car plus what I have bought since last July is under £4k.

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1 hour ago, NonMember said:

Worth inspecting the valve springs. It may be that the one on that valve is cracked and therefore not producing the right return force.

Yes Rob. It has to be something like that. Spring, rocker or cam follower. I am tempting fate with my blasted sciatica but the sun is out now. If I run it with the rocker cover off, I may be able to film and record the noise, then do a slow motion playback. It needs a reliable third party on the throttle pedal though watching the rev counter and me.

I've seen this on an 'A' series where the pushrod was slightly bent, rotating and makng a cyclic sound. The tappet clearance was not constant, due to the rotation and the valve only jammed for about three firing cycles. Mark space ratio of splutter not for 75% of the time and splutter for the other 25%. That one had me going for a while.

 

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OK Guys, you have to promise not to laugh.

Removed rocker cover, checked all tappets and compared all valve spring pressures with a lever. Noted that It only has single valve springs and no seals. Ran engine and observed rockers and pushrods. All well. Pushrods turning without eccentricity. Rev'd up and the noise started at 2700rpm. Loads of oil where it should be, and over my glasses. Almost lost temper so gave it a real boot and a load of fabric appeared flaying around in the fan. Switched off to investigate.

The fan belt was delaminating. Peeled off a turn and ran again. All ok. It then took me half an hour to find the new belt. All now fitted and running ok but needs some adjustment as there is a flat spot between 2700 and 3300 rpm. Have to downshift, get through it then change up to cruise.

It is strange when these noises happen. One can think the worst, like 'Its the thrust bearings being chucked around in the sump' so I always lift the right foot off and de-clutch when I hear something that could be nasty. Having my tuned bike engines seize taught me that.

Sat on the left wheel do do most of it. Now awaiting pain, and your leg pulling.

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11 hours ago, Pete Lewis said:

we have had guys on here in the past fitted bronze guides only to find they seize 

I’ve done two heads now with bronze guides and seals. No seized or sticking valves yet. One has done about 60k….. I’ve also put seals on standard CI guides and they haven’t seized either, though to be fair they were that baggy that seizure would have been amazing…..

Always nice to find simple (cheap!) causes for what you feared was a complex (expensive) problem 🙂

Nick

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Wagger,

On the "plus" side, you are now assured that all under the rocker cover is operating as it should!.👍 Silverlining in every (oily?) cloud.

I found a top Chiropracter, some years ago he "cured" the sciatica, 3 sessions, even relief after the first session. Good one`s however are hard to find. Most of the better one`s are American Trained. I was a complete sceptic, but in the 80`s I had big trouble with my neck, crawling around inside steam boilers does not help, A work collegue of the wife at Westland`s, recomended her. The relief after the first session more than worth the fee!.

Pete

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2 hours ago, PeteH said:

crawling around inside steam boilers does not help,

Pete, 

Had a sudden flashback of being a Midshipman in HMS BULWARK 50 years and doing the clean inside an Admiralty Three Drum boiler, wore blue overalls not white but as for any other kit.  "That will remind the young gentlemen...."!

Dick

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12 hours ago, Nick Jones said:

I’ve done two heads now with bronze guides and seals. No seized or sticking valves yet. One has done about 60k….. I’ve also put seals on standard CI guides and they haven’t seized either, though to be fair they were that baggy that seizure would have been amazing…..

Always nice to find simple (cheap!) causes for what you feared was a complex (expensive) problem 🙂

Nick

Hi Nick. I used to tune Triumph motorcycle engines. I have fitted bronze and cast iron guides. The cast iron ones never seized as they do nor compress. However, some did work loose in alloy heads due to expansion rate differences,

The bronze ones would seize as they compressed when inserted, so we reamed them out after fitting. They always wore out faster than the cast iron ones. I really do not have an opinion either way. However, I now use 0.5% two stroke oil in the fuel as a UCL. Two strokes don't oil up plugs. I wonder why? It's cheaper than UCL or lead replacement stuff.

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