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Triumph - That was a year that was..


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In the meantime I've been pulling together a list of parts, and also a list of engineering services I might require to recondition this engine. 

That may seem not so difficult ...you think !   Perhaps I'm going about it the wrong way, but most suppliers & engineering companies do not freely offer such a list. Whether a deliberate policy or not., it does make comparison rather difficult.  I guess the average customer chooses a supplier and basically works through their website, or calls them up for prices and to order. 

Personally speaking I don't have a prince's budget ..so like my grocery shopping - I need to compare prices.  Furthermore I'd rather like to know what I need and the brand I'll be buying (as an indication of the quality i might expect) before I buy.   After all, whose not been there before ?  Where you've bought a bundle of stuff and then find you need a few more ' little bits'.  Aside from the hassle and delay ..just as you were ready to put things together again, the postage on those small items is always disproportionate to their value. 

So, unreasonable as I might be - I'd like a list, either printed out so I can scribble across it, or else one which is compatible with the Microsoft programs on my computer.   TR Revington were generous enough to help me out with such a list and their prices. That was in picture .jpg  format which would have been fine to print out,  but tbh I'd much prefer a spreadsheet.  Online I translated their two page .jpg to .txt and then I formatted that.  I had to individually select text and change those from upper to title case (because my dyslexia struggles with everything being in upper case Ariel font).  I then copied that into Excel and corrected the cell spacing, changed the order of the words in many listings - so items might be appropriately grouped together, and finally I coded and sorted that into listings - such as ; fastenings, gasket, engine block, camshaft & timing, cylinder head, and such forth.  I also added columns to include VAT and to multiply number required by the price. 

I systematically pulled in other parts listing from other suppliers and engineering company's  ..which I'd taken over the telephone and hastily written on the back of envelopes or across a journalist's note pad.  Naturally, the terminology used was different, as was the methodology in listing, so they were changed.  Hey ho.!  

The following list is work-in-progress, and is just the parts list with the engineering services. So far, there are figures from one engine re-builder and two Triumph parts suppliers (differentiated by colour of text).  It was a fair amount of work, but now at last - I'm beginning to see what might be need  ..and how much it all adds up to.  Also I can begin to prices compare side by side.  Now that I have the bulk of the list, adding any other item or prices will be easy.

My next edit will be from Moss's excellent on-line buying website, referring to the exploded diagrams to hopefully pick up on any minor bits which are otherwise missing.  It's a very good resource and I'm sure why Moss have been so successful in business. Of course it doesn't copy easily into a spreadsheet !  Their customers just scroll down the pages and tick the boxes ..and then pay by card. For many I guess it's just too time consuming to compare prices, so Moss wins the whole order.  

Talking about which I found similar with the engine re-builders. The price of their parts and engineering services are on the whole carried across from their previous job's prices, plus a little ..just in case.  In fairness, the engine re-builder don't have the time to chase around for the best prices anyway.  One company in effect said '"this is out (total) price for a 4-cylinder TR engine rebuild  ..bar any infrequent issue. We don't have the manpower to provide quotes with a breakdown."   Another instance of this, from another engine re-builder, was the price for pistons & liners @ £522.  These were 89mm dia but I had found them on offer for £255, for 87mm dia, from one of the suppliers.  Had I accepted his quote and given him my engine to rebuild then I doubt if I'd have seen that £267 difference knocked off the bill.  This was a biggie but the little items all add up too, which is why I'm obliged to shop around. 

Most obviously missing from my own list - is the prices for valves and valve seats. It seems as if these are usually priced as a whole by the engineering service ..and their price includes the valves and seats.  That of course tells me nothing about the brand / quality of parts being used, nor does it tell me if all are being replaced or only the exhaust valves (for unleaded).  And does that including new valve guides ?  I guess knowing this will take further conversation &/or is otherwise taken on trust ..according to the reputation of the company involved.  It's all rather hit n' miss though.  

I'll let you know in a couple of weeks what the breakdown is and of course the total.  



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Yesterday was a bit of a wash out. It revolved around a set of  TR4 fibreglass wings. . .

The basket-case TR4A  I’m still hoping buy in America,  has GRP wings supplied & fitted in 1965 by SAH.  These had slightly wider flared arches to accommodate the magnesium alloy wheels, likewise supplied by that company.  In subsequent years ; one rear wing had been smashed and a replacement (without the wider flare) had been found but never fitted. And those wheels have been sold off and replaced with a set of Mustang alloys, also of wide profile but styled rather like a minilite.  

I’m happy to have fibreglass wings on my car, not least because I want a driver which is less precious to drive as a daily or in a spirited way ..and also because I also value the weight savings in each corner of the car.  I used to build kit-cars with fibreglass panels ..so GRP doesn’t worry me.  However the wide minilite style alloy wheels would (imo) look better on a TR6 or 8.  For the TR4  I’d be happier with the original skinny steel wheels. 

There was a scruffy but otherwise good set of standard TR4 wheels on ebay ..but they were up in Barnsley, Yorkshire.  So, before I bought them, I asked around on this 'ere forum to see if anyone might convey them south for me. Very kindly a chap living in Barnsley, Simon, said his parents lived in Lincolnshire and that he could bring them that far when he visited.  And another equally generous gentleman, Keith, said he worked up in Lincolnshire a couple of days a week, and otherwise lived just 10 miles from myself here in Suffolk. And he too would gladly bring them down for me.  Excellent !

..with that arranged I bought the wheels and let the parties get together for the exchange and conveyance. Simon collected the wheels from the seller, but since then (8 months ago) the conveyance didn’t managed to happen. Communication issues, illness, a change of job for Keith, and so forth.  So I said ; no problem I’ll drive up and collect them myself from Lincolnshire.


Then recently, a set of fibreglass TR4 wings also came up for sale on ebay, which I thought would be useful as repair panels ..because those on my car were mismatched and quite probably damaged after all these years. The seller was in Lincolnshire, but that was less of an issue because I need to get up there to collect the wheels anyway.  I ‘won’ the set of four panels for £41.  Great. I was happy with that.

However, it turned out the wheels are still up in Barnsley, and Simon is very poorly ill and not driving. I had thought the wheels were left at his parents.  Expletive - This wasn’t going to plan.!  It’s not economical for me to drive all the way up to Barnsley for a £50 set of scruffy steel wheels. And so unless other arrangement might be made they can be scrapped.


I really ought to collect the grp panels.  Never mind I thought “look on the bright side.”  I’d not been to Lincolnshire since the 1980’s when I exhibited the kit cars at Newark, and so this ought be a pleasant drive in the Norfolk and Lincolnshire countryside. Sunday was forecast to be beautiful sunny day, so on Saturday I dropped the seller a note to ask for a collection address and if  it would be OK.  Unfortunately I didn’t get a reply until midday Sunday ..which was then too late.  And the address was another 25 minutes further away,  so now some 3½ hours drive away.

Still the weather forecast was dry for yesterday (Monday), so I rescheduled to drive up then.  That was a mistake. Here in Suffolk we sort of joke about “Norfolk time” being slower than anywhere else. Lincolnshire drivers appear similarly inclined. And the road network north from the A14, at Newmarket, to Lincolnshire is founded in the agricultural 1950’s.  Of course nowadays the amount of  traffic and the number of  HUGE lorries are quite contemporary. 

And then there’s a flood basin around the ‘Six-Mile Road’.  Apparently it’s there to protect Cambridge.  The flood gates had been opened and the flood plain was.. flooded.   It was only a ten mile diversion (..either way) but in that stream of traffic, at that pace .. wasn’t part of my idea of a pleasant drive in the countryside.  And of course ; those panels weren’t worth the additional cost of £50 in diesel.

Hey Ho !


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Today I had a parcel arrive through the post.. upon opening it seemed as if the mice had nested in it..  :unsure:


Thankfully no furry critters scampered out ..and once the packaging was swept up I was left with a very nice looking . . 


TR3 flywheel, with resurfaced clutch face and new starter ring. :) 

This weighs in, on my vintage bathroom scales,  at (about) 8-3/4 kg.  So what's that ¬ 19 - 20lb  +/- couple pound.  B)  That's said to be about 10 lb lighter than the standard TR4A one.

In fact it's actually very similar in weight to the flywheel which was sold to me with the engine (below left) but which is wrong one . . .


^ unknown flywheel (above & below) left.  TR3 flywheel (above & below) right.


The starter ring supplied with the TR3 one is a slightly small diameter than that of the unknown one.  And as you can see the mounting hole pcd is very different.  The unknown is about 2-1/4" whereas the  pcd on the TR3 flywheel and my TR4A's crankshaft are both about 3-1/4".   The bolt-holes match but the dowel size is different dia. (but same place) so that flywheel needs to be drilled a little.   I understand the TR3 one will also need to be drilled for the diaphragm clutch, but otherwise I hope it and the starter ring are good for the TR4A.

I'm guessing the unknown flywheel is off a six cylinder.  But can anyone definitively identify it please ?


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Out of interest, this is David Vizard's take on lighter flywheels. .


The standard flywheel is, on the 6-cylinder engines, good for giving a smooth tickover, but for a tuned motor it is unnecessarily heavy.

The four cylinder engines also have a heavy flywheel. For these engines, you can have one of two different flywheels depending on the type of clutch fitted, the one being heavier by far than the other. To lighten the flywheel, it is simply mounted in a large lathe and machined as shown for the relevant flywheel in Fig.46.

Practically any machine shop has a lathe large enough to tackle such a job, so there should be no problem getting it done. It must be pointed out that a lighter flywheel neither increases the power nor makes the car faster. It does, however, allow the car to accelerate faster because of the reduced mass which the engine has to speed up.

To clarify the point a little, let us look at a simple example in assuming we have reduced the effective weight of a fly-wheel by 10 lb.  

While the car is in bottom gear the engine rpm to driving wheel rpm is 16 :1  ie. the engine turns 16 revs to the wheel’s one rev.  The 10 lb. flywheel weight reduction is equivalent (in acceleration) to reducing the weight of the car by 160 lb. that is 16 x 10 lbs.

When we change to second gear which, which is about 12 :1 overall ratio, the gain, because of the lighter flywheel, will be 12 x10 lbs which is 120 lbs. By the time we get to top gear, the effect of the lighter flywheel will only be about the same as lightening the whole car by 4 x10 lbs. or 40 lbs.  With the exception of one of the TR4 flywheels the effective weight saving (in its machining) will not-be as great as 10 lbs.  A more likely figure is between 6-8 lbs., but this is enough to make a noticeable difference.

By way of a bonus, the lighter flywheel also enables snappy gear changing when going down the box.


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This thread is shaping up nicely. You're already scouring the country for spares and parts for a car which is still at least three months and about 7000 miles away. 

Now you're looking into proper old school tuning, as recommended by no less than Dave Vizard!

'tis a thread full of win, keep going!

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^ Thanks all,  I do appreciate your support.   B)


For a couple of hours this afternoon, I started into what will be the first of many dirty jobs . .


^ scrub a dub dub






^ The combustion chambers of cylinders 3 and 4. The latter being the one which had been full of flaky rust.  Assuming the exhaust seats (..and the valves ?)  are replaced when going unleaded, then I think only #4 inlet valve need be swapped out for one which is not pitted with rust. Perhaps I can find a good used one to save a few quid.

And although the pitting in this combustion chamber will result in that cylinder have a very slightly different swirl,  volume and therefore compression ratio - I'm guessing it'll not make a huge difference for a standard road car.  I'll have the cylinder head pressure tested, but I wonder what will the engineering company need from me (aside from the head itself) to do this ? 

Might I also ask - should I use a chemical rust treatment inside the water jacket & thermostat housing.  And then, after the head has been pressure tested - what's best to paint it with.?  I have POR15  ..but haven't checked to see if that's suitable for this application and the temperatures involved.  The same question will apply to when I pull the cylinder sleeves out and wish to treat the block's water jacket.  

Thanks, Pete.  

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25 minutes ago, Bfg said:

And then, after the head has been pressure tested - what's best to paint it with.?  I have POR15  ..but haven't checked to see if that's suitable for this application and the temperatures involved.  The same question will apply to when I pull the cylinder sleeves out and wish to treat the block's water jacket.  

Thanks, Pete.  

POR15 is for protecting chassis members. I wouldn't use it on a head.

Google engine paint, or just use matt black barbecue paint.

Same for the block.

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^ POR15 I have leftover from sealing motorcycle petrol tanks.   And you realise I'm asking about paint inside the water jacket, not the outside of the engine.?

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Did any other engine maker use inserted aluminium pushrod tubes in the head? 

No idea about the flywheel, but I am reminded that I have somewhere a photo of a broken crankshaft from Uncle John's TR2, which happened long after it's track career was finished. Presumably the TR2 and TR4 engines are similar?

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19 hours ago, Bfg said:

  And you realise I'm asking about paint inside the water jacket, not the outside of the engine.?

No, that wasn't clear from your post.

Why would you want to paint there? It will just flake off and block the waterways.

Antifreeze/coolant additive stops the corrosion in the cooling system.

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^ Don't know about other engines and their pushrod tubes. Those on the Triumph 4A are swaged in and its been suggested that sometimes they can leak  ..in which case - use a suitable sized ball punch to tighten the swaging up a little tighter. Judging by the oil residue on the engine before I cleaned it - this engine doesn't have that issue. 

TR2 and TR4 are very similar and parts are interchangeable. The TR2 had a smaller capacity (83mm dia pistons with 1991cc capacity) and the latter had greater bore and therefore greater capacity (86mm dia pistons and 2138cc).  But the TR2 was a smaller and lighter car and so in many respects quicker. Otherwise it comes down to ancillaries being updated through the years.  Good engines if you like torque rather than revs. 


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This afternoon I continued cleaning ' stuff '.  One thing I was concern about was the wear in the oil pump. .


^ this is the oil pump and strainer before I took it off so that I might clean inside. 


^   And the (external) oil filter - after a first clean, while still fitted to the block. But then put aside in a work tray.


^ After a good scrub, and with the gauze strainer removed I thought it prudent to mark which way around the pump's cap was fitted.  Centre punch was hardly visible on the cast iron surface so I just opened those out with a 3mm drill, not at all very deep. 

Yeah OK., in retrospect ;  the base of the pump points which way the cap goes !  Sometimes I just can't see the obvious for all the crud. 

moving on . . .


^ four 1/2" AF hex head screws secure the cap. Inside there's just the spindle and rotor.


^ cleaned up sufficiently to handle and measure ..and man were they filthy !  oil pump parts and drive in the left hand tray and the oil filter housing and can in the right.

- - -

The oil pump is visually assessed to ensure there's no scoring or otherwise damaged bits, and then checked for wear with four measurements. 

The first measurement is to place a straight edge diagonally across the case (not on the screw holes but next to those on each diagonal), and then to measure from that straight edge to the top surface face of the rotor and spindle, with feeler gauges.  This should not exceed 0.004" (Haynes manual says 0.005").   Incidentally, a new pump is within tolerance with 0.0025" end float.  Mine was at 0.004" on one side and 0.005" on the other. This can be corrected by ensuring the cap is perfectly smooth and then taking the top edge of the housing down.  I recently did this on my Norton Commando's oil pump, rubbing the surface down on emery paper laid on a flat surface. I took that down to a little less than 0.001" clearance.   

The second measurement (below) is between the tip of the spindle's vane to the rotor.  I did this four times ..to check each tip.


^ the maximum acceptable clearance (wear) is 0.010". Each of mine were 8-1/2 to 10 thou. ..so not brilliant and only just within tolerance. I then turned the rotor over in the housing and this reduced by 0.001".    I would be interested to know what this tolerances were when new.?  

The third measurement, I don't see in the book but is mentioned in 'dimensions and tolerances', and that's the clearance of the spindle shaft within the body, which should be 0.001" - 0.003".   It's not easy to measure accurately in the spindle versus the pump body's hole  ..but the spindle can be rocked a little while doing the (above) spindle tip to rotor measurement.  This one rocked by a difference of about 0.0015"  as best I might measure it.  ie., plus or minus 3/4 thou at the top of the spindle vane.  I'll take that as being well within tolerance.  Again according to the specs, a new pump might have 0.003" clearance between the spindle and the bore it sits in.!

And then the fourth measurement is between the rotor and the pump housing (below) ..


^ this should not exceed 0.010" (Haynes manual says 0.008").  Mine was 0.005" so comfortably within tolerance.  Oddly a new pump is within tolerance if this is 0.0075"

I'm now faced with that contemporary chestnut of,  sticking with the O.E. but part worn pump, or to buy a replacement quality after-market part ?    I must admit.., with the tolerances possible (according to the Triumph workshop manual) within a new pump - I can't see much benefit in buying a replacement ..unless I could go to the store and measure it for size (before purchase) - and then I might buy a new spindle and rotor.  But I don't suppose that would be wholly agreeable.?

So be it.  I'm quite sure after I reduce the end float of this pump to 0.001" or less,  and then only ever used SAE40 or 50 weight engine oil and a good oil filter - this pump would give good pressure for many a year.   Also it's not difficult to remove and refurbish it ..any other time the sump is off.  



p.s.  Is it just me, or does the following from one of our best known international suppliers, not instill confidence. ?


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3 hours ago, Bfg said:

I'm quite sure after I reduce the end float of this pump to 0.001" or less,  and then only ever used SAE40 or 50 weight engine oil and a good oil filter - this pump would give good pressure for many a year.   Also it's not difficult to remove and refurbish it ..any other time the sump is off.  


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For the old Sunbeam motorcycles I ride - I prefer to use Morris Oils of a straight SAE40w. I have tried 20/50w but they are then discernibly noisier, and I relate rattles to not being good.  As I now do not ride when temperatures drop to very low single figures  I can't see the advantage of using a winter weight engine oil, in our now milder temperate climate. My inclination is to use that same oil in this engine.

But, might I ask what are the forum's thoughts on engine oil, for a long stroke 4-cylinder engine  ..for normal road use . ? 

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Postie's arrived :)


Three piece clutch kit : TR4A-5-250.  GCK6004X.  £99 (inc VAT and post) was the best value I spotted this week., from Midland Sport & Classics (..and on ebay).


^ assuming I use this TR3 flywheel, it'll give the engineering company something to do - to very accurately re-drill for the diaphragm clutch cover and to balance it. 

Me mum's old bathroom scales are not very accurate, but indicate together they weigh in at about 26.5 lb (12kg).  However with a smaller clutch the rim of this flywheel might be well chamfered, to loose weight off the peripheral.  


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Sorry to intrude on your thread, but a friend today asked if I knew where he could source a pair of doors for an early TR2 (I think they are the long doors). Any idea of a source?

I would stick to 20W/50 as that is what I use in all my old motors, including the 30s Royces.

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19 hours ago, Bfg said:

I'm now faced with that contemporary chestnut of,  sticking with the O.E. but part worn pump, or to buy a replacement quality after-market part ?

If the original pump is within spec, I'd use that all the way. New classic car parts are very variable in quality unfortunately. Modern cars are supplied by high quality parts from the big brands. However the classic car market seems to use the worst manufacturing companies. I guess in a combination of both cost and the fact the volumes are low, so the big manufacturers aren't interested.


18 hours ago, somewhatfoolish said:

Why would you actively chose to forgo 60 years of progress in oil technology?

Because the engine and it's design isn't 60 years newer? Thus it's spec will be what the engine manufacturer gave back in the day. 

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1 hour ago, Saabnut said:

Sorry to intrude on your thread, but a friend today asked if I knew where he could source a pair of doors for an early TR2 (I think they are the long doors). Any idea of a source?

I would stick to 20W/50 as that is what I use in all my old motors, including the 30s Royces.

If you let me know whether they are long doors then I'll ask around.  The TR group I go to isn't meeting this last Thursday of the month, but I can make a telephone call or two. Otherwise I suggest he drops the ebay sellers a note. Many of them have stocks of stuff but only sell a few items at a time, so there's no point in waiting for a listing to come up as that sort of stuff disappears to trade contacts.  

I be surprised to hear of any 1930's cars originally specifying a multigrade oil.  But possibly their build quality allows you to get away with using a lighter oil.   

Thanks, Pete.

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3 hours ago, SiC said:
22 hours ago, somewhatfoolish said:

Why would you actively chose to forgo 60 years of progress in oil technology?

Because the engine and it's design isn't 60 years newer? Thus it's spec will be what the engine manufacturer gave back in the day. 

Of course even mineral oils have progressed over the past 60 years.!  

I'm sure you are well aware that these old engines rely on plain bearings and brass bushes and, perhaps with the exception of the highest quality and highest performance brands, were never built to particularly close tolerances. With the shafts designed to float on a film of pressurised oil within those bearings, I am reluctant to use too light a viscosity.  I do use 20/50 on the Sunbeam motorcycles ..as a flushing oil when first start the running-in process ..when the tolerances are at their tightest.  But the fact of the matter is that I have not yet replaced every single bearing, bush and pump in any engine ..so although within tolerance - some clearances are already a little looser than new. Hence the use of a more viscous oil. 

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Communication failure; I meant why would you use monograde, but you clearly are not intending that. 20w50 is exactly what I would use in it.


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yesterday afternoon was less productive.





I see a stamp on the top of this which says 25D.  Is that correct for the 4A ?   The number stamped on the side is 40822A


Distributor is not really salvageable, and even the cap has two chips out of it.


From my newly acquired Moss catalogue . . .


^  cunning little catalogue can be misleading huh ! It would be easy to read TR4A in the bottom line as being the latest.. but alas that was for the rarely optioned 83mm pistons ..to take the engine capacity below 2 ltrs - which would qualify it for different race class and/or in some countries for different insurance and tax class.

:unsure: I'll have to watch out for that.

So I have no idea what the distributor I was sold with this engine was from ..with its Lucas number 40822A ! ?


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Good Afternoon Europe ..and all other former colonies :rolleyes:

..and today's first special request is from Mr. Peter W.  of Pinner ..down there in an overcast Middlesex, who writes in for us to play a piece by that classic composer ; Distributor Shimming  . . .  It seems that Peter has been practicing this little ditty himself on his bass size hole punch

We are of course very glad to oblige. .  So, from the sheet music by Haynes, we will begin with the chorus .  . .



darn.. determine this, calculate that  - it's really not very clear is it. 

In the Standard-Triumph workshop manual, their examples confused me more., and the description makes no mention of (nor allowance for ) the gasket between the pedestal and block. This is in the parts book, but is described as a 'washer, joint, between pedestal and block'  ..so I assume it should be there (..I know never assume !)   But surely, unless this gasket is allowed for, its thickness would add to the end-float being set, and then the total end float would be quite massive and non-sensible.  This manual instead talks of  "requires packing"  ..but doesn't explain further. 

And there-in lies the confusion - the language.  To a simple-minded engineering type, like me ; a "gasket" is is a compressible membrane used to help seal between joint surfaces. And "packing" is either carrying a weapon, or rather more frequently with my lifestyle ; something a parcel has internally to prevent the contents from moving about &/or is wrapped around the outside to protect the item from getting bashed.  Whereas a "shim" is a flat, non-compressible spacer with a thickness made to a tight tolerance. 

To lil 'ol me they are very different things.  Moss catalogue describe it as a gasket/shim ..which is like saying to a pilot "over and out"   :P

And as someone who bought a scrapper engine and then ancillary 'bits' to go on it ..three of which (..so far) have proven to be the incorrect part,  and otherwise expecting there to be a gasket between any ancillary and the block  ..I was kinda lost :blink:

I ventured on nevertheless

..for this engine ;


^ Haynes paragraph 4.  A washer with a 1/2" (13mm) inside hole, to fit over the oil pump / distributor drive shaft.  I measured this one's thickness to be 0.0415 ( 41-1/2 thou " ). Its outside diameter isn't important but the washer does need to be clean and flat ( I deburred this one on emery paper).  


^ 5. Note the machine face on the engine block has been thoroughly cleaned. Likewise the machine face on the underside of the distributor pedestal which clamps to it.


^ 6 & 7.  Fit the distributor pedestal in place (without a gasket) and with those two nuts lightly pinched up - the temporary washer holds the pedestal away from the gasket face of the cylinder block. This is the gap to be measured. On this engine that gap measured  0.033".  

8. compare the thickness of the temporary washer with the measured gap. The difference represents the end float,  so ;  0.0415 --  0.033" = 0.0085" end float

It should be between 0.003 - 0.007"

"measure the thickness of a new gasket"    but, but, but  I don't have one !  ..I'm here trying to determine what thickness I'll need to buy.


Hey ho,  I'll do things my way ..and disregard all of the above !


^  With the pedestal bolted in place, with no ; gasket / shim / spacer / fag packet / toilet paper / nor anything else - I simply measured down the hole - the end-float of the distributor / oil pump shaft. ie., the amount of movement of that shaft between the brass bush it sits in and the underside face of the pedestal.  

Although the digital vernier may not be nearly as easy to use as a depth gauge in this sort of situation - it's what I have ..and with care is accurate enough. I used a spring between the vernier's jaws ..to keep its bottom end prod pushed against the top face of the shaft's gear, zeroed the digital read-out, and held the instrument steadily in place while pushing* upwards on the bottom end of that same shaft ..to see / measure how much free-play there was. The extent of up and down movement, pushing against the spring on the vernier, is the end float. (full stop !). 

This measured 0.005 - 0.006", so within the 0.003 - 007" permissible tolerance.  It's good. No shim is require.  And no gasket will be fitted, I'll just use a decent jointing compound.

* the oil pump is not fitted at the moment.

Now why couldn't Haynes or the Standard-Triumph manual just say  " measure the end-float movement with a depth gauge, and if tighter than 0.003"  add a shim under the pedestal to increase it.  And if the end-float is greater than 0.007"  then shim between the engine block and the underside of the flange on the shaft's brass bush ..to decrease it."   It's just one sentence ...and there's no piddling around with finding or making a 1/2" ID washer, feeler gauges in the gap, nor any calculations.

Btw ; inserting shims to between the block and the brass bush is best practice, because if they were placed on top - very thin shims could possibly buckle in the rotating shaft, , whereas underneath there is no rotation - It is more work but much safer.  

Hope that's of interest,  whatever your car ..or taste in music.!


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Finishing up from last week, and just because I want to shelve them for the time being - so need to know they work and are the right part before doing that ; I cleaned up the fuel pump and starter motor.


Apart from AC cast into the top I see no part number.   Moss catalogue state the same part for all the 4-cylinder model TR's so I'm hoping it is the right item.


^ it scrubbed up pretty well but there's still a fair amount of petrol staining, particularly in the top corners which is reluctant to come off.  It would probably shift easy enough if I got the de-carb out, but I'm not too worried about that as I don't want a pristine car.


The important thing is that it appears to work well, although by now I guess the rubberised parts inside might be due for replacement. 

So that, and the starter motor - which works when a battery is connected, and I've subsequently cleaned of the gritty grease in & around the bendix, can be boxed and put away.  I also removed the surface rust off the casing and squirted some zinc.    



^ The Lucas M418G part number checks out as being correct starter for the TR3A - 4A. 

I guess that's it for a few days now, as I've just had a couple of molars extracted, and it's very soon to be Christmas Eve.  So for tonight I'll bid you all

Wonderful Seasons Greetings

..and I'll catch up with you soon.



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^ Thanks Dave,  mouth is sore with ulcers which come and go, seemingly moving around in the night, and the gum is tender but healing in it's own good time.  


Getting parts in to get on with this engine didn't quite go to plan..  I was keen to get some of the machining started, which I cannot do without having the parts for them to dimensionally match to.  So I'd hoped to get an order in to the TR Shop just before Christmas, for some of the bigger items like the piston and liners, for courier delivery inbetween Christmas and New year.   Unfortunately they were closed when I called on the Monday.  I sent them an email with what I wanted but nobody replied for a card payment.

Hey ho., I proceeded with trying to pull together a parts list of smaller items I'd also need. My friend Rich called one day, and in conversation advised me that said shop was open between Christmas and now, so I called them again to discuss a few bit and get prices. I got answers to my questions but they asked me to send them an email list for the prices. I did that but haven't yet got a reply.   Then another friend, Chris suddenly decided to visit me for a couple of days, giving 24 hours notice, so although it was great to see him - I lost four days of getting this engine stripped and into the machine shop. Now we wait until after the holidays, as the order for parts has still not been taken.  All in all that's a little frustrating.

While not being able to do much, I did do a quick drain down test. . 


Aside from turning the engine over, when I freed it from being seized, I haven't touched these valves. But just out of interest I wanted to see how well (or not) the valves were seating after years of standing / rusting.  Here I've simply filled the inlet and exhaust ports with parts cleaner.  Gravity does the rest.The above was after 45 minutes and #1 cylinder exhaust port is already an inch or two emptier than the others.


^ two hours later the fluid level in #1 cylinder exhaust port has dropped / drained a few inches. The others have seeped a little but not a lot, which is pleasantly surprising considering the pile of rust found inside #4 cylinder.  

Each of the exhaust valve seats will be replaced as they are converted for unleaded petrol ..and so will be re-cut and lapped in.  But unless the valve guides also need replacing, this little test tells me - the inlet valves just need a little hand re-bedding in. That's nice.

- - -

While my buddy Chris was here we inverted the engine on the motorcycle lift so I might remove the big end cap and thrust washers..   So here you go.  Father Christmas when not on duty, with beard trimmed again and out of his long red coat  . . . 


  ^  I know.. I'm not a photogenic person .. and then look even dumber in real life ! 

TR engine block inverted on the motorcycle lift / work bench (with its conveniently adjustable height, and narrow width - so I might work from either side). The wire is just there for safety / to prevent the engine from toppling when undoing things like the main bearing bolts.

Why not have it on the engine stand ?  Well, when I removed the cyl.head  I lost use of two of the mounting bolts (where the manifold studs go) for the engine stand to be mounted from the side.  And I couldn't mount the stand from the bell housing flange and still access to the bolts to the crankshaft scroll seal.  So this work bench works better all round. 


Back to the tasks in hand..


^ Removal of the middle main bearing cap is needed to get the thrust washers out. The lower (underside) halves of these thrust bearings have tabs on them (arrowed) which locate in the slot machined into either side of the middle main bearing cap.. They are there to prevent the thrust bearings / shims from turning with the crank.


The other (upper) half of these bearings / shims have no tab - so, with just the one cap off - they can be pushed / rotated around the main bear journal and easily removed / replaced ..with the crankshaft still in place.

Thrust bearings limit the amount end-float of the crankshaft, which generally isn't going anywhere ..until the clutch is disengaged. The clutch release bearing is pushing against the clutch spring(s) ..either conventional or diaphragm,  and that force is transferred via the pivots to the clutch cover ..which is bolted to the flywheel ..which in turn is bolted to the end of the crankshaft.   The clutch release mechanism is within the gearbox bell-housing, and so it is the force applied through this that pushes the whole floating / rotating assembly, including the crankshaft, forwards.  And that wears the rear thrust bearing ..because the oil (normally in this bearing) is squeezed out by the crankshaft pushing forward against the main bearing's seat & cap.

The significance of crankshaft end float ?  Well, an important factor here is in the alignment of the timing chain sprockets, especially as the two are relatively closely spaced and using a duplex chain. Logically,  because the crankshaft moves forward, and the rear thrust bearing wears soonest - the crankshaft sprocket might be statically aligned (perhaps 0.002 - 0.004") rearwards than the sprocket on the camshaft. 


So, the thrust bearings / shims are consumables which wear.  Replacements are available in different thicknesses, to accurately set the crankshaft end-float. The books say the end float needs to be 0.004 - 0.006"  (Haynes manual). The Standard-Triumph workshop manual gives a little more information insomuch as this end float ; 0.004 - 0.006" (desirable), but the wear limit,  ie. end float, is within tolerance with anything upto ; 0.015"   ..and that manufacturing tolerance may be anything between 0.0048" - 0.0117".    The sods.,  so four to six thou-of-an-inch is correct but Triumphs might have been made with almost twelve thou end float ..and that was fine.!  

Way back when < here >  I measured this engine's crankshaft end float to be 0.011",  so it is within tolerance.   

However as the engine is already stripped down and it's now easy to do - I'd like it correct.  So my next question was ; what thickness replacement thrust bearings do I need to buy ?    I couldn't find the answer in Haynes nor the Triumph workshop manual, but thankfully Moss catalogue helps us out.  p.19 item 85  tells us that the thickness of these bearings / shims  (standard) are 0.0925" thick.   With this information I could measure and determine the difference / wear of mine as ; 0.001" of the forward thrust bearings, and 0.0025" wear of the rear ones.  So if i were to replace these with new standard thickness bearings the end float would be 0.011 - 0.001 - 0.0025 = 0.0075"  ..that's still too much (but probably as this engine was originally assembled).

And if I were to replace these with the next thickness  which is 0.005" additional thickness (for the pair) then I'd have 0.011 - 0.001 - 0.0025 = 0.0075" - 0.005" = 0.0025"  ..which is too tight. 

So what I'll need to do is to re-use the lesser worn of the old ones, and just one new thrust bearing (which is 0.0025" thicker than standard)  ie. 0.011 - 0.001 -(0.0025 - 0.0025) = 0.005" end float.   That'll work.

Next job is to inspect the main bearings..



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