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Triumph - That was a year that was..

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. . also delivered yesterday.


^  194.2g including its hardened rubber, the four steel spacer tubes, and 3 out of 4 steel washers.  If I recall, the original tropical fan blade was 910g, so I'm happy with this plastic one and its refined aerofoil blade shapes. 


Positioning is different to the original in respect that the new would mount onto the end of the extension piece, whereas the the original blades sat further back towards the engine.  Not having a car here, I don't know if the 20mm difference will position it too close to the radiator ?  If so, then someone has suggested using the shorter extension piece off the TR6.


Different number of blades but very similar in diameter.  The perspective from it being in front of the original fan makes it look bigger in comparison, but its radius / each blade length may be perhaps 1/4" (6mm) more.


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Question .. regarding crankshaft balancing. 

I've spoken to the machine shop recommended to me ;  J.D. Robertson, in Colchester, about this and they say they only ever balance the crankshaft in isolation, and with the flywheel  ..and they don't even need to know the weight of the con-rods, big ends, pistons, etc.   This was a surprise to me because I understood their mass, balance, length and the crank throw was an important part of the dynamics.  I had assumed these factors along with the compression ratio and perhaps other aspects like intended RPM target, and camshaft would have been entered into the computer program of their balancing machine.  

Perhaps someone here may advise me what is usual for 'fast road use' ( ie., sports cars), and what do the racing fraternity do ?  ..And whether I'd be wasting my money to have this specialist work done  ..assuming of course I could find someone to do it, and could afford their services !   Or should I just be content with Robertson checking and perhaps slightly altering the balance of the crank after the big ends have been re-ground.

. . .

Later I was given the number of another engineering company who happen to be not too far away from me ;  Coltec Racing, just the other side of Woodbridge  ..as I was hoping to find someone to do this aspect of the job.  

I spoke to Richard Coles about this, who was very friendly and helpful, and he says that ; with a straight four or six engines, where equal numbers of pistons are going up as coming down, then there is not the need to account for the weights of conrods big-ends, crank throw, etc, etc.  He assures me that's already accounted for in the crank's original design. 

In short, it would seem as I'm worrying about nothing.  I would be right if we were talking about balancing the crankshaft on my parallel-twin-cylinder motorcycle engines, where both push-rods are always on the same crank throw. Then the con-rod's weight do need to be factored in ..but not for a four cylinder car engine.

Robertson's in Colchester can do the crankshaft, with flywheel + clutch cover, so it's only the pulley which is not suitable for their machine.  Perhaps it's time I just cut my losses and buy a narrow belt conversion and an electric fan, and then that pulley's weight is negligible

Best regards,  Pete. 

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Hi,  it's been a few days since I last posted so I thought I'd do a bit of catching up.

I had a slight delay before the new old stock inlet valves arrived, and then aside from everyday distractions in life,  my efforts were to try and get my act together ..regarding what the engineering machine shop was to do. 


Standard-Triumph new-old-stock Inlet valves, valve guides and timing chain tensioners. One tensioner is very slightly thinner steel than the other, and also has sharp bottom corners so may have been from a different model, but both are new and from the same source.  Yes there are two sets here because.. ever hopeful that one day I might get the car with its engine.,  I will then need these same parts for that.

With those coming in on Monday,  I took everything across to the machine shop J.D Robertsons, Colchester, on Tuesday.  it was the same very nice gentleman on the desk, that I'd spoken to on the phone several times before, so he had a pretty good idea what was coming in.   As it happens a gentleman brought in the cylinder head for a 1955 Massey Ferguson tractor while I was there, so I had the rare opportunity to compare them side by side.  Talk about low compression ! phew the combustion chamber was recessed into the head by something like 45mm, whereas my TR4A head was recessed only about 15mm. That was a low port head which is designed to run on paraffin.  Aside from it's extra depth it was quite familiar though.. a few changes to the water jacket holes including one which ran front to back underneath the inlet and exhaust ports.   oh and those ports were half moon shape rather than round.   All in all a pleasure to see and chat with the owner.  The gent in the machine shop seemed equally as interested and so there was no hassling to get on with things.   It's very nice to deal with such old school gentlemen.

My own engine's cylinder head is in for ;

  • pressure testing
  • checking the machined gasket faces are flat,
  • new unleaded exhaust valve seats,
  • re-cutting or replacing the inlet valve seats,
  • if required replacing the valve guides, and
  • replacing the core plug while cleaning out inside the water jacket.   

The crankshaft is in for ;

  • regrind the big end journals to suit the +0.010" shells (supplied assembled in the con-rod for their measurement)
  • check to ensure the main journals are within tolerance
  • to remove the core bungs and clean out the oil galleries inside.
  • for balancing.

And so then we had the flywheel(s)..  The one I'd bought from a TR3 and one Rich C-R  lent me from a TR4 (..this had been lightened and is still drilled for the coil-spring 9" clutch).   Before I took them across I compared them . . .


TR4 is on the left is heavily greased rather than rusty, and the clean / lighter coloured TR3 flywheel is on the right.  The TR4 has a bolt on starter gear-ring and so the recess for that is noticeably deeper-in from the perimeter.

What cannot be seen here is that the overall diameter of the TR3 flywheel is about 8mm greater, so a lot of metal will have to be removed to get the TR4 bolt-on ring to fit it. That's OK because I'm happy to save more weight from around the perimeter.


From the engine side.,  the greased / brown flywheel has been lightened considerably. It was a similar dished shape to the TR3 one but someone has machined it flat to within a few mm of where the starter's gear-ring bolts on.  According to my ancient bathroom scales, with the gear ring it weighs in at 9kg (21lb).  The TR3 flywheel, as seen is I believe original aside from it's clutch side face has been skimmed back to flat. That weighs in at 7-1/4kg (15lb). 


The clutch side ; lookes very similar but the dowel positions are different and of a different size.  I believe they are both drilled to take the 9" coil spring clutch. It's barely discernible from the photos but you might just make out the dowels and bolt holes are closer to the edge on the TR4 one ..because it is the aforementioned 8mm smaller in diameter (approx 280 versus 288mm).  As I say Rich's flywheel has been packed away in dark brown heavy grease, it is not rusty.

The dowel pin which goes into the end of the crankshaft is different, as you may see on the shiny TR3 one, only the pilot holes have not been drilled all the way through.


The diaphragm clutch sitting on the TR3 flywheel illustrates the difference in overall diameter and the PCD of the clutch mounting holes & dowels.

For those interested in doing a similar thing, here is my brief  ..written out as much for me as to discuss with the engineering company . . .


1.  Flywheel : I am furnishing x2 flywheels (used) x1 bolt-on type gear ring (new), x1 diaphragm clutch cover (new), x4 bolts and x2 lock washers (each new, for fastening the flywheel to the crankshaft). And x1 page copied from workshop manual regarding fitting to the starter gear.

The hollowed out / 15lb flywheel  is from a TR3, and the one I wish to use.  The other, flat faced one,  is an already lightened one from a friend’s TR4A.  This is only for use as a pattern to help determine offsets and drillings - so no machining work is to be done on this part.

I would like the TR3 flywheel’s perimeter to be appropriately turned to fit the starter gear ring provided and also to drilled and tapped for x6 suitably sized bolts. Triumph of this period predominantly used UNC or UNF bolts.  Personally I do not mind what the thread is, only that they are high-tensile bolts and with low profile heads.

The gear ring is a slight interference fit, necessitating modest heat to the ring for its fitting.  The teeth of the gear ring are shaped on one side, and the starter motor Bendix gear is drawn forward ..from the gearbox / clutch side of the flywheel to engage.

I would also like this flywheel to be drilled for the Borg & Beck diaphragm clutch cover supplied. Again I don’t mind what the threads are but again the bolts must be of high tensile specification.  The location dowels will also need to be moved to suit this clutch cover. 

The mating face which fits to the crankshaft and flywheel needs to be checked for flatness, size, and run-out. Again the dowel hole needs to be altered to fit that on the crankshaft. A page (p.1.123) copied from the workshop manual is supplied. It tells me that clutch-friction-face run-out should not exceed 0.003”.  

The TR3 flywheel is approximately 8mm greater in overall diameter than the TR4A one, and the diaphragm clutch is 8-½” dia.  so smaller than the TR3’s  9” coil-spring clutch. I would like the excess metal removed to ensure ample clearance for the starter gear and to save weight.

And where practical,  I’d like further excess weight trimmed off.  Please see the illustration, copied from Triumph’s official publication “Tuning Triumphs with engines exceeding 1300cc” which illustrates where it may safely be removed.  Personally I would aim to leave 3mm of land either side of the gear ring, but please remove as much as you feel comfortable with.

Finally, the crankshaft, flywheel together with the clutch cover will need to be re-balanced

Thank You.


The red line indicates where (I think) Rich's TR4 flywheel has been lightened. I have read that the original weight was 31lb, with starter gear-ring, so this has removed about 8lb in weight.


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By coincidence, on the TR Register forum there was a thread regarding someone using a hi-torque starter motor on a TR3, using a super-lightweight flywheel. The question then was which way around should its gear ring be fitted.? 

That in turn made me unsure of myself and the instructions I gave to the engineering machine shop. 

For the TR4 / 4A  the Haynes manual says fit with the "front of the teeth facing the flywheel register".  That is unclear to me.  I might, at best, only presume the "front of the teeth"  is that with the chamfer,  but even then I'm not familiar with what a "flywheel register" is.   Unfortunately the Standard-Triumph TR4 / 4A workshop manual appears to make no specific mention of which way around the gear-ring is fitted,  nor do the drawings show the teeth chamfer,  but a photo on p.1-123 (fig.46)  does show them on the gear-ring's teeth facing rearward.  The TR4 flywheel (I borrowed) didn't have its gear-ring fitted, so I can't use that to confirm. 

NB. The type of clutch being irrelevant to the starter & gear ring.

My own logic does tend to suggest ; the chamfer side of the ring-gear teeth faces the direction the starter-gear engages from.  So.., 

  • The early car's bomb-type starter gear pinion (this is used with the 91-tooth heat-shrunk-on ring-gear) moves rearwards ..to engage with the gear-ring from the engine side. Therefore the teeth's chamfer are to face towards the flywheel's crankshaft mounting (ie., away from the clutch cover).
  • The TR3A / TR4 / 4A  bendix-type starter motor pinion (which is only used with the 90-tooth bolt-on ring-gear) comes forward ..to engage with the gear-ring from the clutch cover / gearbox side. Therefore its teeth chamfers face towards the clutch cover. 



 OK here's we go again. .


^ This is a bendix type starter motor used on the later 4-cyl. TR engines.


The point which is so obvious that I was missing it ..is that the chamfer / bevels on the gear-ring are there to both help engage and disengage. 

As you can see in the above photo, the starter's gear pinion also has bevels on its teeth to help engage it  ..so even if the starter ring was on back to front it would generally work.  But the very important function of those bevels on the gear ring is to ensure that the starter motor disengages when the engine starts.  

Consider for a moment, the ratio between the starter's gear and the flywheel's gear ring is (..lets say) 1 :10.  So the starter motor turns at 1000rpm,  and because of that gear ratio - turns the engine over at 100 rpm to start it.  (That may not seem a lot but I can assure you it's very much more than a motorcycle kick-starter ..however many cylinder or powerful the engine is).  

Now what happens when you've blipped the throttle and the engine starts ?   The engine fires, starts and engine revs spin up to 2000rpm.  So if the starter motor is still engaged that would be spinning at ;  2000 rpm x gear-ratio of 10:1  = 20,000rpm !     Those ring-gear chamfers / bevels are there to protect the starter motor by encouraging the gears to disengage as soon as the fire kicks into life. 

Clearly that's a pretty important thing to happen, so the chamfers/ bevels need to face the bevels on the starter motor's pinion.   

And as the early cars and the later ones had a different starter motor, and the hi-torque may come in either configuration, and then there's probably some which have been mix n' matched - then the sure fire answer is to look at the starter motor to see which side of the starter's gear pinon the lightweight spring is.  (see illustration above).


Out of interest would it not be usual practice to replace the gear ring for new when you fit a new starter (or bendix gear / pinion assembly ) ..so the wear of one was not detrimental to the other.?


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I haven't pulled the rockers off the shaft yet to examine the bushes, but I have tried to rock them (side to side) to feel for play. Only the inlet port rocker for #2 cylinder seems to have excess play.  I'll strip them off to check them this coming week.  In the meantime I'd be glad for any advice on the rocker arms themselves


again #2 cylinder rocker arms are in the worse condition . . .


^ in a close-up photo they look worse than they feel. 

Without caps on the valve stems, the stem of the valve presents a localised load.  I asked the machine shop I'm using and they said that they do not have the facilities to re-harden surface if they were to grind these smooth. They recommend hand dressing them ..to take of any high ridge, but otherwise making do with them.   What are the thoughts of this forum ? 

- - -

Very little tangible progress this past week.  I did get the camshaft wrapped and sent of to Newman Camshafts.  I want to ask them what they make of the broken surface condition of the lobe tips ..as discussed previously, and whether it was practical to / worth regrinding that camshaft.?  Their Ph1 camshaft has been recommended and is intended for good degrees of torque rather than a high revs.  So that's what I'll go for.

Otherwise I also got the water pump sent off to EP services, in Wolverhampton to be checked and if necessary rebuilt. 


^ It cleaned up and looks to be in good shape, but was locked up when I bought this engine.  The belt-pulley is a press-on type rather than bolt on, so I thought I'd just pass the matter over to their capable hands.  I've asked them about converting to a narrow belt and they are going to advise me as to what they can do. 

- - -

For sake of pulling together my experience with this engine ..all in one thread, and for the sake of anyone doing the same in the future - I (below) copy a reply to Mark, who has just imported a TR4A from the US  < here on the TR Register forum >  ..  The reply was in regard to his rebuilding the carburettors, and I spoke of my intent to out-source some tasks to a few specialist companies . . .


Mark, I'm glad to be of some guidance.  I am a novice to car engines so I have to take things pragmatically if  I am to learn with least mistakes. There are some chaps on here who are great with their advice and have been really generous in sharing their experience and contacts..

I bought a pair of carburettors with this engine, but I haven't touched them yet.  My friend Rich and others have suggested a few specialist which I will probably try. 


One of the first was Glen Watson t/a  GW Carbs in Bicknacre, Essex - 07803 593126.   I haven’t spoken to him yet, but Rich tells me that he will refurbish the carburettors & linkages, returning them to as new condition for about £400. 

Well, I could tackle this task myself, and probably save a chunk of money to boot.  But if someone is geared up specifically to do them, to thoroughly clean inside n' out, and will return them with good adjustment and pretty much guaranteed to work ..straight out of the box so to speak - then that will save me shopping for rebuild kits, getting exactly the right parts (of decent quality),  possibly a couple of trips to the machine shop,  and a few weeks of work myself ..that I might better use for other doing other jobs (..of which I have plenty !).  So perhaps £400 isn’t too much ? ..in the big picture of getting the car running smoothly and reliably as soon as possible.


Another, contact was Martin Jay - Distributor Doctor - 01984 629540.  I spoke to him a couple of days ago (seemed a very nice chap) because the distributor supplied with my car was incorrect to the TR’s.  (see page 88 in the Moss catalogue for the correct numbers) and it was also rusted up inside.  I have managed to source a replacement ..but that one is off the TR4, which again is not quite the same as for the 4A.  It is also without a cap.  Martin can correct the specification to be 4A as he rebuilds it, and includes the cap - so it's ready to just bolt on, set the timing and go.  His price is currently £195 + VAT to rebuild my own distributor, or plus another £50 + VAT to supply one outright. 

Again it’s a lump of money ..and I don’t have much to splash around, but I’m thinking - if I'm spend a thousand or two on the engine itself, am careful in its rebuild, and then the distributor and carburettors are in first class order - I ought then to have a really good and reliable engine.  Final decision has not been made yet ..but that’s the thinking.  

A third contact was ; EP Services, Wolverhampton, West Midlands - 01902 452914, who specialise in rebuilding water pumps. Again I have spoken to them recently, and they are very helpful. They will charge £45+ VAT on exchange.  My car’s water pump has a interference-fit pulley on it, rather than a nut on the front which is more easily removed & refitted, and although I could probably do the job myself for less, it probably isn’t worth the small amount I’d save.  These chaps replace what’s needed to give a 5-year guarantee. So their parts must be good. And for about £60 (with postage) I feel that’s good value..


Yes, these costs do add up very quickly, but they also shortcut a considerable amount of time.  They'll save a lot of my time in learning, and any concerns about decent quality parts, and getting the job done absolutely right.  Personally I’m tending to think - I’d rather like my project happening and be done ..before I’m too old.   

These are decision anyone doing a major restoration is faced with.  To have the satisfaction of doing it ourselves or just get it done n’ dusted  ..while we get on with saving money in doing other tasks.?    Food for thought perhaps.  Only you can make those choices according to your own time and financial pressures.


- - -

And then, yesterday I wrote to Raymond, the seller of 'Chance' the TR4A I'm trying to buy in Arkansas.

Back in May last year, we came to an agreement of price, and what was to be included (I didn't want his TR6 engine nor the Mx5 seats) and what was necessary to prepare for shipping.  I offered to pay extra, for him to build (or have built) a cradle up from the bumper irons and to fit the 'spare' chassis on that.  The car was rolling but had been stripped out of interior, exterior trim, ancillaries, engine, gearbox and diff., but these things were still with the car, even if the engine was totally in bits.  ie., I was buying a basket case. 

The agreement was ;  the heavy mechanical lumps were to be loosely refitted into the car and everything else was to be boxed up inside ..this was for convenience of handling one rolling, steering 'car' overland to Huston and into a shipping container.  Cutting to the chase - the agreement was that the car would be ready to ship by the beginning of September.   However, Raymond, his family and their community have had a series of disasters, including a flood, hurricanes, accidents and illness.   All in all the family had a pretty difficult year ..so I tried to be patient.  And I bought another engine to get on with .. moving towards my having a half decent TR4 to tour in. 

From the beginning of May to nearing the end of January is quite a long time when you're waiting for something, but the real issue was - that Raymond was communicating less and less each month.  No money had been transferred so it wasn't a matter of having been ripped off, it was just that it looked as if this was never going to happen. Excuses, however real and valid - are still excuses. 5 or 10 minutes occasionally to keep me updated should be too much to ask.   So I wrote a stern but polite letter yesterday evening to express my profound disappointment, saying that he was making a fool of me,  and that I wished him and family well.  In short, a kindly but rather sad Goodbye.  It was time for me to look elsewhere.    


>  Twelve hours later, received at 5:49am our time, which would be just before midnight in Arkansas,  I received a very nice letter from his wife Kathy (who had not written before) to apologise and to explain that Raymond was working 60-70 hr weeks in his own job and in helping with her commercial cleaning business, which on top of the catalogue of disasters this past year has him "beyond exhausted".

She went on to say.. "If however you are no longer interested, we would fully understand. After all of the delays, I wouldn't blame you at all.  If you choose to go ahead with purchasing the car and are willing to wait until the end of March, please let us know as soon as possible so that we may go ahead with getting it prepared."


Even though I know this car needs a huge amount of work, I still have a good feeling about 'Chance'.  And in my mind's eye - it is the car I see us touring in 

I must admit I've never known anyone waiting the best part of a year to buy an old car ..which is not rare, is in bits, which they haven't seen, and don't even have very good photos of.  Admittedly, it's not expensive (by today's prices),  but with overland transport to Huston, and then shipping across to England, and then import tax and registration ..it's not cheap either.  

I have just replied that I would still like to buy the car, and agree to wait until the end of March before it's ready to ship.

What is with men ..that might account for such irrational thought and actions ! ?


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Good afternoon all,

Just thought I'd add a quick pictorial sequence of what's been happening the past couple of days in (..and out) of the garage. . .


^ Water pump housing, much as it came off.


^ Clean up but not quite finished yet


^ cleaning up the push-rods.  I cleaned one by one so as to keep them in the same order as they came out of the engine. and then I polish them on the mop. The one being held is half polished to show the difference.   

Why ?  Well, at the last TR club meeting (again tonight at The Alma, near Colchester), a gent brought in a push-rod in two parts ..as if it had separated in the middle, twisted slightly and been pushed back together again.  I cannot quite imagine how it had happened, but I felt the necessity to carefully examine mine ..to ensure that non had any sign of stress nor had any nick in it - that might propagate to a failure.  Polishing these parts helps me see any surface imperfections very much easier.   Of course one has to be very careful when doing this job because the polishing mop tends to toss anything aside that is not being held very carefully. 


^ pretty ..but more importantly exposed to very close examination.


^ I finally got around to pulling the pin and cleaning out the shish kebab.  The shaft is badly worn so I'll look for a replacement.  Again every part is kept in strict order of assembly, for when it goes back together again everything will be in its original position. 



^ engine on the stand again.  You can see the inside of the water jacket, sans liners, and amazingly (to me) it still hadn't dried out in the corners. Considering the horrid rusty mess that came out of it I'm pleased at how well it looked ..but I needed to do a bit more yet

This is the first time I've mounted the engine-block from its bell-housing end.  Must admit I'm not impressed with the balance I achieved, as it was top heavy and so awkward to rotate.   However it did mean this still heavy engine case was easier to move about on my own ..away from the overhead winch.


^ With the (Makita) pressure wash on it's most viscous fine jet setting I wanted to blast out any remaining rust flakes and to for the water pressure to delve right into the casting's pitting and deep corners.

P1330586s.jpg.c2891d05e94640eb28cc2dac6ed177ec.jpg     s-l640.jpg

I then scrubbed it with a household degreaser (Sgrassatore) for pots and pans that I was introduced to by my dear friend Barbara ..living in Slovenia.  A few years ago, she and her family helped me clean up (ready for restoration) a '74 Citroen Ami-Super,  and she used this stuff to clean off underseal from the inside of that car's wings (they were also bolt on / removable).  I was so impressed that I bought a couple of bottles back to England with me, and when they were used up I then bought 5-ltrs via e-bay and had it shipped from Italy.!    In the photo above I had used a pot cleaning brush, with stiff plastic bristles, to work it into the corners. I used a pipe cleaner into any of the larger drillings. And I used an old wood chisel to loosen a few more encrusted rust lumps in the corners of the water jacket, and then used a rotary wire brush in my cordless drill to really work it in and scrub it all a bit more.   I spent a good two hours trying to get this clean.


The cavities where the cam followers go and the underside insides (where oil normally is) is painted from the factory. I didn't want to loose nor damage that finish so I only scrubbed in there with the plastic bristle pot cleaner and degreaser - Not with the chisel or wire brush.  I did thoroughly blast it with the power wash though ..including into each of the oil galleries between the main bearings and the camshaft bearing, and along the oil gallery which runs the length of the LHS of the engine (pulling each of its bungs and blasting in inside.)  


And then the block came back into the garage and was placed alongside the coal burning stove, and with my dehumidifier blowing up its skirt.

I proceeded to dry the metal with a clean t-shirt and paper towels.


^ underside inside - the original factory paint (used to seal any pores and to lock any remaining sand from its casting) remains intact and in excellent condition. As far as I can see non was blasted of by the power wash (which I used as aggressively as I could).


^  the water jacket is about as clean as it's going to be (save just a little more work with the wire brush). The machined faces where the figure-eight sleeve gaskets go are in good shape,  and the heavy build up of sludge in the cavities above the cam followers is now cleaned out.  I think some of that came back and hit me in the face judging by the look that greeted me when I later looked in a mirror !  Each of the drillings for the studs had been jet-blasted into or through so I'm guessing they'll be mainly clean too.

That was it. The stove was stoked up to burn for another six hours, and I laid a dry clean t-shirt over the top of the engine and left the dehumidifier on a high setting all night to blow through and thoroughly dry inside all the crevices and drillings. 

Another job done and now most of the engine parts are clean enough to handle.


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On 1/26/2020 at 3:58 PM, Bfg said:

.What is with men ..that might account for such irrational thought and actions ! ?


You’re certainly not alone in taking this course of action. Sometimes you just need to trust your instinct and roll with it.

Life tends to sort things out and brings its own karma.

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A chap on the TR forum made a point of mentioning how the water jacket drain hole his engine had been blocked with rusty crud.   This was mine .  . .


^  Arrow indicates the spot where, drilled from the outside - the water jacket's drain tap is ..which was likewise hard-packed with rusty crud.  Obviously the photo is before I chiselled it out ..shamefully misusing a small screwdriver to do so :wacko:

- - -

Next..  very likely controversial but.. I've decided to paint my engine block inside the water jacket ( and out). 


" I have read the arguments against painting inside the water jacket.. and that antifreeze has anti corrosive properties so there's no need to do so ..but having seen the crud that was in there (see photo below) the thought of putting it back together with raw cast-iron inside there was just too difficult to bear..  

I spent most of a day looking on-line, and was frustrated that no-one in this sunny Suffolk backwater called Ipswich seemed to stock anything but VHT rattle-can paint.   So it's my own engine and I'm prepared to use it as a guinea pig.  And I've used POR-15 petrol tank sealant, which is what I had left over from coating / sealing petrol tanks on my vintage motorcycles ..so I know it sticks incredibly well to rough surfaces and raw metal that's not perfectly clear of rust.  I also know it has excellent resistance to many strong chemicals. So my major concern was - how well would it stand up to engine temperatures.?  

I contacted POR-15 and was told it's only rated up to 100 degrees c.   However, short of experimenting with other / unknown products, I decided to test a sample piece. Actually, this was a length of 1/2" flat bar that I had used as a mixing stick .. and which had deliberately been left outside in all weathers for the past six months.  That was a test to see how well it might protect the chassis.

I used the oven in my tiny coal-burning stove and placed the painted and weathered bar in there. It's temperature tends to range from 100 to 190 degrees c. depending on how low or high I have the stove burning.  When I put the piece in there it was c. 140 degrees.   I laid it flat to the floor of the oven (hottest place in this particular oven because the fire box is immediately below it) and left it for an hour.  I pulled it out and was happy with a simple scratch test. I put the sample back in the oven as I worked for another couple of hours.   I stoked the fire before bed and left the air-intake vent cracked open, so the fire would burn hot (575 degrees is usual in the firebox itself).  The following morning,  the paint on the sample was still fine.  I have to admit that my sample had weathered outside from being originally the grey aluminium colour you see (above) to being gold  ..and that amount of heat had caused it to turn more of a darker antique gold colour.  Although that indicates a change - I'm still giving it a try.   I've also painted inside the water pump housing (which will have most turbulence)  and I will do the same with inside of the thermostat housing.I can easily lift this off to inspect inside.  If I see evidence of flaking then I can of course strip the engine down and remove it again. That will cost me in time and a gasket set,  however compared to the rust that was in there  (below) I can't see paint as being much of an issue, unless it comes off as a sheet rather than as flakes. .

Note:  I'll not be painting the liners themselves, so heat dissipation through those to the coolant / water will be unaffected.  Nor have I painted in any place inside where there's engine oil, so they'll be no risk of paint getting in the oil ways, pump or bearings. The inside / machine spaces of the cast-iron block was of course originally painted by the factory ..and it remains in excellent condition ..despite I feel it being a very much harsher environment.


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Not a whole lot of progress to report ..but a smattering of jobs interspersed with everyday life from the past couple of weeks.

As mentioned above, the camshaft was sent to Newman Cams - to see if they might be able to identify why cam lobes had chunks missing.  I spoke to Ken Newman and he thought the wear on the leading edge of the lobe was excessive for the overall wear that was otherwise apparent and suggested the springs may be too stiff.  I've now had those sent to him (by the machine shop as they were still with the cylinder head) and hope to speak further on the matter. 

Btw. the waiting time on the Newman Ph1 camshaft is six weeks, or thereabouts, as they are presently awaiting another consignment of blanks.

JD Robertson, Colchester - the machine shop I'm using, hadn't done anything as of mid last week, as the chap who is to do the work went in for a cataract operation.  Unfortunate timing on my part.

The water pump was sent off to Paul King at E.P Services and is now rebuilt and parceled up to send back to me. He's also changed the pulley for me. Further news about that soon.   "Tune in.. Same time, same channel".

The carburettors were sent to Glen Watson of GW Carbs  for total refurbishment.  They were in a bit of state, not bad but very much needing careful disassembly and cleaning . . .


Topside doesn't look so terrible but you can see the underside is pretty filthy.  The fuel inlet pipe is bent and both carb's sliders are locked in place. I suspect these are tarred up with stale fuel residue.  Why might I suspect that ?  well ..


^ literally the consistency of treacle. But I wasn't going to taste it to see if there were any other similarities !


^ judging by the oil distribution it confirms the timing cover was seeping oil and the fan has distributed that to the underside of the forward carb.

Altogether with the manifolds and control rods - these are a pretty big lump to post, but I found a plastic storage crate to packed them in, and used cardboard wrapped over the top to close it off.  A parcel I had received some time ago had blocks of expanded polystyrene as packing. This was recycled to secure the carbs very tightly  All up weight wasn't very much and MyHermes couriers delivered them safely.  I think their insurance cost as much as the courier service.  

. . .

I've also been going through parts lift sent to me by Bob Smith ..there are numerous other little bits in need ..like a replacement rocker shaft, manifold studs, head stud washers and all those sorts of things.  It was a surprising time consuming task, checking and cross checking numbers required and part numbers, but hopefully Bob has most of what I need for the engine's reassembly.  

While in the 'admin' mode I've also pulled together a spreadsheet of where my money has been going.. It adds up to quite a bill.!   I'll present that as this engine rebuild nears completion. 


^ I didn't need to measure the wear on the rocker arm bushes to see if they might needed replacing.!   Funny wear pattern though.  These and indentation (..more than wear) of the contact pad (where contacted by the valve stem) again implies too stiff valve spring or perhaps as likely the spring coil-binding (the spring be fully squeezed down and yet still being loaded by the lift of the camshaft lobes).

. . .

Aside from that I've done a bit more cleaning up and repainting  . .


^ I cleaned up the cam chain / timing cover and went around straightening where the localised fastenings bent / dished the metal around the bolt holes. Here you can see I'm using a craft knife blade as a short straight edge to see if the cover is locally flat.  Non were (..the blade rocked on the indentation).  The metal on these covers is surprisingly thick though, compared to the motorcycle ones I'm used to. Those are possibly half as thick as this. ..now they really get bent !


^ The flange around the sump was nice and straight, as if it had been even torqued down in the factory and never since has been off.  Perhaps it hadn't ..after all most owners wouldn't drop the sump to change the oil, and the prior owner of this engine doesn't even seem to have changed the oil.!


There were a few minor dings in the metal, just as likely to have happened when this engine was taken out and put aside by the gent I bought it off.  I knocked those out as best I might (there's limited access to get inside because of the baffle plate). But otherwise it was a matter of thoroughly degreasing the outside and using various wire brush / abrasive wheel attachments to clean off all the paint and as much of the rust as I could.


Again I'm using POR-15 as the protective coating (outsides only).  

All in all I'm pleased with how well they've straightened and cleaned up.  

Earlier today I was trying to buy 5/16" oval washers, which are used on MG timing cases, but so far I've not found them at a sensible price. Hey ho., I can always cut some penny washers down (which is what I use on my Sunbeam engines). 

So that's about it for now as a progress update. Hopefully soon I'll be sharing photos of parts as they come back from the machine shop &/or specialists.

Have a good evening,


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On 1/26/2020 at 3:55 PM, Bfg said:


^ This is a bendix type starter motor used on the later 4-cyl. TR engines.


The point which is so obvious that I was missing it ..is that the chamfer / bevels on the gear-ring are there to both help engage and disengage. 

As you can see in the above photo, the starter's gear pinion also has bevels on its teeth to help engage it  ..so even if the starter ring was on back to front it would generally work.  But the very important function of those bevels on the gear ring is to ensure that the starter motor disengages when the engine starts.  

Consider for a moment, the ratio between the starter's gear and the flywheel's gear ring is (..lets say) 1 :10.  So the starter motor turns at 1000rpm,  and because of that gear ratio - turns the engine over at 100 rpm to start it.  (That may not seem a lot but I can assure you it's very much more than a motorcycle kick-starter ..however many cylinder or powerful the engine is).  

Now what happens when you've blipped the throttle and the engine starts ?   The engine fires, starts and engine revs spin up to 2000rpm.  So if the starter motor is still engaged that would be spinning at ;  2000 rpm x gear-ratio of 10:1  = 20,000rpm !     Those ring-gear chamfers / bevels are there to protect the starter motor by encouraging the gears to disengage as soon as the fire kicks into life. 

Clearly that's a pretty important thing to happen, so the chamfers/ bevels need to face the bevels on the starter motor's pinion.   



Out of interest would it not be usual practice to replace the gear ring for new when you fit a new starter (or bendix gear / pinion assembly ) ..so the wear of one was not detrimental to the other.?


Surely it is the helix under the pinion that extracts the pinion from engagement, as the torque upon it reverses when the engine fires?

I never heard of a Bendix type starter motor staying engaged but recall being shown a burst pre-engaged (but not disengaged because the solenoid jammed) starter from a VW van. Made quite a screaming sound before the bang apparently.

On those FWD Triumphs, you can watch the Bendix, pinion and ring in action, as it is all visible on the wrong end of the crankshaft. Makes a hell of a racket too, even when not worn-out, the gear ring does ring like a gong.



As for those rockers with the chewed up pads - what about getting them stellite welded and ground back to size?

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13 hours ago, Asimo said:

Surely it is the helix under the pinion that extracts the pinion from engagement, as the torque upon it reverses when the engine fires?

^  you are right about the helix gear acting to both engage and disengage the starter's pinion to and from the flywheel's gear ring.  When the starter switch / motor is first engaged.. the (static) inertia of the deliberately heavy pinion gear prevents it from accelerating immediately or as fast as the starter motor's shaft, so it slides around and therefore along the helix (spiral) groove in that shaft, until its teeth engage with those on the flywheel's gear ring.. and then the engine is also turned.   When the engine fires / starts / runs ; the pinion is then spinned (by the flywheel gear) faster than the starter motor's shaft, so the tendency is then for the pinion to be slip the other way around the shaft and back down the helix groove in it  ..so the gear ring is disengaged.  

Of course each part of these sliding motions are subject to friction and time lapse.  So although the tendency is for the pinion to reverse back down the helix ..friction, particularly between the pinion gear and a square-cut ring gear, works against clean disengagement.  Whereas the gear teeth ..with tapers on one side - act like a ratchet. Turn one way and it engages, turn the other way and it is push aside to disengage.

I've heard starter motors not disengage immediately (admitted on neglected cars where rust and crud is likely to have been detrimental to anything like teutonic-like efficiency), and more commonly have heard a starter being inadvertently being switched when the engine was already running. Then the glancing blow of the tapered angle of the gear teeth prevent actual engagement.  As you say they can make quite a racket !

That fwd Triumph layout looks so odd with the starter gear exposed   :unsure:

14 hours ago, Asimo said:

As for those rockers with the chewed up pads - what about getting them stellite welded and ground back to size?

I asked the engineering company I have the crank and cyl. head with ..and they don't do rebuilding, hardening type work.  And as the price of replacement rocker arms is still relatively cheap then I'd hazard a guess it's not economic to have these Triumph ones done.   A friend suggested.  They're not good, but they're not too bad either.  Use them for another 50,000 miles ..and even then they're easy to swap out with the engine in situ..   Valid point I thought  ..so I'll take the high ridges off these and use them as they are for now.  Perhaps I'll find some NOS ones at a Triumph club show or spares day.

Pete .

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..delivery today from Paul King of EP Services, Wolverhampton who recondition the water pumps.

It used to look like this . .


       and now looks like this  (Below, bottom Left). . .


..aside from recondition everything inside the pump, EP very kindly swapped out the pulley for a narrow v-belt one.  It's apparently off a Jaguar XJS, which had been a double pulley until their local machine shop turned it down.

Unexpectedly Paul also found an aluminium narrow v-belt pulley blank (no holes in it) with the right offset for me, and it passed over to his friendly machine shop to be modified to fit the TR4 crankshaft.  Needless to say Paul has been very generous in his time and trouble on my behalf, but he says he enjoyed the challenge.!  

I have yet to source an alternator for this engine but I guess I can find one also with a narrow-v-belt pulley on it. Adjusting it offset might be fun but hey ho.. I'm all up for a bit of joviality.!     


I don't have the engine parts, so I can't check the alignment of each pulley, but that on the water pump has some room for adjustment and the alternator brackets will have to be made anyway, so I recon things ought to work out at the end of the day. 

The cost ?   ..well let's just say it was a substantial saving over 'the usual suspects' prices for a narrow belt conversion.  That said, I'm sure the Triumph suppliers would be more convenient to buy as a complete package.  If it wasn't for Paul's helping me - it probably wouldn't have happened. 

Give me a month or two to get the engine bits back together and to reassemble it then I'll tell you how well it all worked out.

Next, I need to find someone with a lathe ..to make a replacement of the fan extension piece for me,  in some material lighter than forged steel !


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. . yesterday afternoon, out in the garage was flipping cold ..but I did a little more dismantling and cleaning.. I turned my attentions to the thermostat's housing.  .


^ as it came off.  Btw the aluminium washer under the temp sender was doing absolutely nothing, as the inside end of this unit seats in a cup (like an plumbing olive) and so that washer was loose. 


^ the temperature sender was a right sod to get out.  Penetrating oil and the right-size spanner (courtesy of Austin of England) didn't work, nor did applying heat to the surrounding case.  Even clamping the hex head in the vice and using extension bars didn't want to play magic roundabout.  The more effort I applied the more the brass hex-head slipped.  In the end the darn thing crushed. After that I'd was resigning myself to the likelihood of it shearing off completely and I'd have to drill it out or find a replacement housing ..But it finally shifted. It felt like it had sheared but nope it broke its lock ..even then it did not give in to the struggle.   Determined little "wotsit" !


^ reckon that needs replacing !

Thereafter it was just a matter of dismantling and cleaning up each component.


^ One odd bolt ?  anyway I cleaned up the gasket faces on a flat of emery paper too.

I liked how the bronze-age Waxstat came apart for cleaning.  It's possibly shot but I don't know the critical parts of how it works (again m' motorcycles don't have such sophistication !) so I'll simply push it back together again and drop it in a mug of hot water to see if it does anything.  I assume, when heated the wax expands inside the capsule and the consequential movement along the central pin opens the coolant's waterway.  I'm just not sure if the (presumably rubber) seals on this are any good. 

Mind you, looking in the Moss catalogue, they're only  £4  ..so I'll get a replacement anyway (if only as a spare). 

This one was rated at 82-degrees c. which (according to Moss) is for 'standard' climate.  So, unless y'all advise otherwise I'll get the same. 

And that's all the practical work I got done ..huh ! <_<


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