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Hi Pete

Im almost mirroring what you are doing regarding engine build I see you have new little end bearings to fit not sure if your aware and I hope Im not poking my nose in, these should be done by your machine shop as they need to reamed centrally  

Chris 

 

 

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Pete - DON'T give up with owning a TR - there are other cars out there - just put the word out on here and elsewhere and I'm sure something will come up Chin up  Cheers Rich

Or these people? http://www.leacyclassics.com/parts/classicmini/engine-components/2k7440.html Roger

. Carrying on from TR4 -v- Tr4A engine, and my purchasing a 'spare'  < here >  ..so that I might get on and have an engine ready by the time the Chance is actually bought and shipped,  we h

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Thanks Chris,  I don't have the correct size reamers so I will indeed have to give them to the machine shop to do.   Please feel free to make any such suggestions - because there are many instances when I simply don't have the experience of such things.  Unlike the TR's, my Sunbeam motorcycles have short but chunky aluminium con-rods and there are no bushes nor direct oil feed to the little ends, and yet I never known excessive wear in them.   Strange considering the age of these bikes.  

How are you getting on with your motor ?

Pete

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Hi Pete

Im waiting for the crank and con rods to return from the machine shop so I can start the re build. spent ages cleaning block, doing liner heights ,ring gaps and pedestal free play, changing camshaft bearings whilst waiting now twiddling thumbs so to speak

Chris

 

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. .

I hear you..  Likewise I'm waiting on the machine shop (..since January 21st  !). But because I'll still be waiting on Newman Cams - I haven't been chasing them.  So Chris, you're some way ahead of me ..because I don't have the cylinder head (it's in having new valve seats) - I haven't been able to get on and pre-torque that (..as Mick recommends) to then set the sleeve heights. 

I ought to just say "never mind" ..as I have another 10 years of other projects to get on with in the meantime, but I pent up the frustration of not being able to get on with this task (and my schedule of work throughout the year now being screwed with) ..and that has dumped big time on my motivation. So now I'm regretting setting off along this route (..getting a TR  at all).  :wacko:

With the chap in the US  it's been one thing after another.  Similarly with this engine rebuild.  And now it's coming into the wrong time of year for me to do it..  The plan / my attempt was to get parts bought and into the machine shop before the New Year (..but I'm working to too tight a budget - so had to shop around and wait for prices, and leading up to Christmas was the wrong time of year to get much sense out of a retail business, so no parts) after which the machine shop said it would be 2 - 3 weeks.  Aside from a few really decent private sellers and the services of Paul King at E.P. Services (re. water pump), things just haven't fallen into place.  By the end of this month the engine should have been reassembled.   Best laid plans and all that.!  :lol:

Now it's probably best to fling the whole thing into the back of the garage and come back to it next year.  As you might gather - I'm pretty peeved off with the whole thing.  If I could - I'd cut my losses and get out of it,  but I'm financially committed (or perhaps I ' should be committed ' ..if you get my drift). 

Hey ho., tomorrow's another day.   Pete.  

.

Edited by Bfg
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18 minutes ago, trchris said:

 Hi Pete

I feel the same at times  , its frustrating waiting I know, but it will be worth it, especially when your body arrives it will give you a big boost keep the good posts going

Chris

Enjoy the out of body experience while you can. 
 

 

:ph34r:

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chin up Pete

                        really like your posts so far ,The parts hopefully not far away.

Sometimes it's good to have a break but mothballing it to the back of the garage can be fatal.

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Hello Pete,

This is a Loooong thread, and I apologize if I’ve missed the bit to do with you buying a TR from the US.
When I first started to read it I thought….

“Hmmm… Interesting, but I’ve just done an engine rebuild, so I won’t bother following it.”

I kept looking in from time to time and I realized that this is the PERFECT way to describe an engine rebuild. Anyone can go on YouTube and see it all going on, but you don’t get the IMMEDIATE feedback that you do here. You are writing it all in detail, in real time, and people give their comments as it happens. (Some comments right, some comments wrong, but it all helps understand the process.)

I’ve been impressed, and think there should be a section like this dedicated to in depth rebuilds of engines/gearboxes/ and back axles.

But you say:

“…With the chap in the US it’s been one thing after another…”

I can only say “I hope you have not paid for it yet.”

You mentioned that the last communication you had about it was from his wife...

Hmmm.....Maybe it’s just me being cynical…

Charlie.

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I had problems with a guy in the US when I bought my car over there in 2006.  Made even more challenging because he had my money.

In the end I sent a fax (I didn't have an email address I could use), asking if it would help if we called the whole deal off and I came over there and collected my money back.  At which point things started to move.

Rgds Ian

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  • 2 weeks later...

Finally I got my Triumph engine parts back from the machine shop.  But to be honest - I'm of mixed emotions ..because things were not exactly as I had expected. . . 

P1340070s.jpg.bbe6d36f0a9882dabc720cf6fd279ae8.jpg

Cylinder head ; now has been pressure tested and the core plugs replaced.  It now has hardened exhaust seats, re-cut inlet valve seats, NOS valves (all of them),  NOS valve guides,  and the cylinder-head gasket face has been skimmed.

Good news is that it's now good to go (..I hope),  unfortunate news is that the original valve guides were a better fit than these.  I thought those from #3 cylinder, and possibly one of those in #4, were a little loose and so might need replacing - but instead they went ahead and changed them all ..and now the all valves feel as loose in the guides as those to #3 cylinder were.! 

As you see I haven't yet unwrapped the cling film - so I also haven't visually checked the valve seats or the job done. I guess next week I''ll do this and also refit the valve springs so that I might do a drain-down test ..just to ensure the valves are well bedded in.

Aside from replacing all the valve guides, I also didn't ask them to, nor want them to skim the gasket face.  I simply asked them to check it for trueness and to advise.  I have no reason to suspect the old gasket had any issues so if it ain't broke - don't try to fix things.  I don't know how much has been skimmed off but I had no desire to increase the compression ratio.   I'm not overly happy. 

 

P1340074s.jpg.d8a4386502878c05236a675422662c5c.jpg

Crankshaft ; journals reground to 0.010",   oil-way drilling plugs removed and cleaned out inside, and crankshaft assembly has been balanced..  But.........  I specifically didn't want the main bearing to be reground. (only the big-ends).  The mains didn't need it ..and I so bought original manufacturer NOS main bearing shells of a standard size  ...Which Now Don't Fraking Well Fit !    That has me well and truly 'upset'.   

Balancing . . .

P1340075s.jpg.0bdfffb516f85305e639781b4ba65afe.jpg

Having seen the job done on Mike's TR4 (Brenda )'s crankshaft - which necessitated his having to buy a replacement ..because his had been previously 'balanced' so badly and was beyond retrieving - I now see this in mine.   I fail to see how so much needed to be removed from the balancing Triumph had originally done ?   It gets worse on the other end . . .

P1340076s2.thumb.jpg.d7db172538ea13eae6a514df62318d18.jpg

^ blue arrows indicate original balancing notches,  the two red arrows indicate where these corners has now been angle-ground away.  The one has actually cut into the ground side face of the journal.  Again, I fail to see how so much needed to be removed from the balancing Triumph had originally done ?  

P1340077a.jpg.7aadfda8bcc2e80de8e1265d47ba903d.jpg

I am of a mindset that they have done the same damage as Mike's crankshaft endured..  I fear this crankshaft ..which ought still to be on its standard size main bearings, and first regrind on the big ends - is now scrap. I may be wrong but I really don't think so. To be sure - I now need to take it to another company to have it checked.  

 

P1340078s.jpg.1f677c18955156c47aee0c751086c0a0.jpg

Flywheel (right) is good (I think) and I am pleased. As requested - they turned the outer edge of the TR3 flywheel ..to reduce its overall diameter and to take the bolt-on TR4A starter gear ring. I'm told its metal was very hard indeed.  With its starter ring, this is now 17lb in weight. As the standard spec was 31lb - I'm very happy with that weight saving.  The flywheel seen here on the left is an already lightened TR4 one (which I borrowed for dimensions) which weighs in at 19lb. The gear ring weighs 3lb so altogether = 22lb.  I would have been happy with that but it was not mine ..which is why I bought the TR3 one and had it reworked. 

P1340081s.jpg.85ba0bcad218a007eb85c1bf44a05b69.jpg

The TR4 flywheel (left) is drilled for the 6-spring type clutch,  my TR3 one has now been drilled for the diaphragm clutch.  It was balanced independently and with the crankshaft.  

Overall the bill with VAT was £40 less than anticipated (all in all very close to £520 total), but until I know that crankshaft has not been ruined I'm left worrying.  I also need to check dimensions and to find myself a set of +0.010 main bearing shells, so the final bill will end up more.

Oh., and I need to drive back to the machine shop because they still have my con-rods and big end shells. My mistake as much as there's I should have remembered.   There was no work to be done on them (I had weight matched them myself) but I supplied them so they might measure for themselves the exact big-end journal size required.

That's all for tonight. 

Pete.

Edited by Bfg
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Morning Pete, sorry to read this about your parts that you have just received back from the machine shop after all the hard work you have put in cleaning and measuring so methodically, I hope your crankshaft is balanced correctly, I know it will cost you but myself I would like a second opinion. I do not think it looks as bad as my one but it will be a big job if you fit it and it’s not correct when you get it in your car eventually. Not a lot I can say really mate but keep your chin up and continue with the blogs.

Mike. Redrose Group (Brenda)

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Thank you Mike,

I've just searched your posts to find photos of your own crankshaft *.  Me being me I forgot they were in this thread !   I am cloth-brained at times :blink:   ..but I did find your and Carol's birthday greetings from September which I'd not seen before.  Thank you.  

* Those photos of Brenda's old / now replaced crankshaft are < here >

I need to take my 'other' car into the garage on Monday (engine went into limp mode on the way back from the engineering shop, and now a warning light is telling me something is not happy),  but yes - thereafter I hope to get these engine parts across to another engine specialist here in Suffolk for their assessment.  I can't really afford the additional cost, but equally I cannot take the knock to my state of mind which would be inevitable if I had to pull it all apart again,  ..although from your own experience - it seems it has to be a long way out of balance before it's a matter of major concern ..or enough to stop you driving and enjoying Brenda.    B)

 

Iain and Michael,  I'll report on the verdict / opinion of this other engine specialist, and only if I'm mistaken (..which I very much hope I am) and damage has been done - then I'll name the business.  Otherwise it would be grossly unfair to name n' shame ..and then find out that they have actually done a good job.  I'm sure you understand. 

Pete

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On 12/19/2019 at 11:48 PM, Bfg said:

and then only ever used SAE40 or 50 weight engine oil and a good oil filter

Pete,

This question comes from a total ignoramus with no background in mechanical engineering and very poor science, and who therefore  reads reports like yours just to improve his understanding. Why choose a single grade as opposed to a multigrade? Is it to get more protection ie. viscosity? (I am not bothered if I reveal my ignorance. I just aim to reduce it, ever so slightly.)

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.

In a utopian world there should never be shame in wishing to learn.   B)

Instinctively from a toddler age we ask ..to learn.  And without an adult admitting (to themselves) their lack of understanding - they cannot self-teach.   I'm always looking up things and constantly learning - I love it.  Imo, the internet is truly a wonderful resource. The task then is to sort the wheat from the chaff of hearsay opinions.

Multi-grade versus mono-grade engine oils - My understanding is that multi-grades are compounded to be the assigned viscosity when cold.  And then as they get hot (sometimes very hot indeed) there is a molecular change and instead of thinning as they get hot - they stay much the same thickness / viscosity.  This means the oil is not too thick to pump through tight clearances (like bushes) when it is cold ..but then as the oil gets very hot it doesn't go all watery - and therefore it retains the thickness of film coating to lubricate surfaces.  Lighter oil, when cold, also offers less resistance to quickly turning and starting the engine. The sooner the engine fires up - the sooner the engine oil is being pumped to pressure and at the designed pace around the whole engine.

That sounds great..  but used in the wrong engine design - is to ignore the reality that mechanical tolerances also change as individual components and then the engine block heats up.  No two assemblies are the same, but some - for example, a spindle in a housing may thermally expand more (as it heats up) than the housing itself ..so the clearance between the two actually gets tighter.  This can happen when the housing has better flow cooling or a greater surface area, or heat dissipating material than the spindle.  Piston slap of a cold engine, which goes quieter as it warms up, is perhaps the most easily recognisable example of this - but it can also apply to valve stems in their guides, to camshafts in their bushes, and to numerous other parts - particularly in engines where plain bearings / shells / bushes are prevalent.

Furthermore, if parts within an oil pump are loose fitting ..through sloppy machining or wear - then thicker oil will more quickly build up its pressure,  whereas thinner oil tends to squeeze passed the pump's lobes, around the lobe ends, &/or out through the shaft.  Nor does the less-viscous oil help when the tolerances are already 'ample' in other engine parts. Then you may want the thicker oil film to provide its lubrication from the very first kick into motion. 

Another scenario, especially on older engines, is the matter of engine oil draining away while the engine is not being run.  My infrequently used Norton Commando didn't like multi-grade engine oils because its oil tank was remote (positioned high up under the saddle) and its lesser viscosity would drain back from the tank ..and flood the crankcase,  even when it was cold.  Mono-grade oils conversely thickened up as they cooled, so when left standing - the oil had less of a tendency to drain away.  My 650cc Triumph Bonneville similarly had a tank mounted just under their seat, but in 1970 Triumph changed the design to be oil-within-the-frame ..which was deliberately situated low down ..to prevent drain-back and for the c. of g.   Go figure.. the revised design was not understood so never well thought of by the pundits, which to this day is still reflected in the respective bike's values.

A similar situation to the Norton is experienced with my Sunbeam motorcycles ..which has a wet sump but also has generous oil galleries in its overhead camshaft and rocker assembly.  Multi-grade oils tend to run back down into the sump. So if a bike isn't used in a while - the almost always multi-grade oil drains down ..giving a false impression that the oil level on the dipstick is correct, and then taking crucial moments to build up oil pressure, to re-fill those galleries, and only then to squirt oil onto the camshaft (..this being at the very end of the oil route).  

Thick engine oil is also a very good acoustic damper. So again, because multi-grade engine oil is generally thinner than mono-grade oil (unless the latter is really very hot) - it  makes the engine noisier. 

Hopefully you'll realise that any engine design was done in conjunction with the oils to be used.  We owners ought to be aware of these things if/when we choose to overrule the specifications.  But just sometimes - such characteristics can be used to advantage.  For example I like to use a good multi-grade oil with element filtration in my Sunbeam motorcycles while I run a newly rebuilt engine in.   ie., when every bearing is tight and the engine oil is hotter than normal. 

Anyway, I hope this has given you some of the pro-and cons, and otherwise food for thought. 

Pete.

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On 3/20/2020 at 8:25 PM, Bfg said:

I specifically didn't want the main bearing to be reground. (only the big-ends).  The mains didn't need it ..and I so bought original manufacturer NOS main bearing shells of a standard size 

The official workshop manual says ; Main Journal Dia.:  2.4790  - 2.4795".  Today measured the front journal at 2.4675"  = which according to my maths is not the 0.010" increment,  but rather is a 0.012" difference. 

Admittedly my measuring with digital vernier calipers is not so accurate, but my previous pressed-tight measurement recorded a 0.013 - 0.014" difference !  ..so I might only hope that my calipers / each of my measurements are way out.  Again I'll have another engineering company check them for me,  but the fear is that this machine operator removed 0.010" from whatever he measured the original part-worn journal size was ..rather than referring to workshop manual. 

I provided the con-rods with shells only for the big ends to be reground to.  But the mains were not meant to have been reground so the machine shop never had the engine block, caps, or bearings to measure or work from. 

I loathe the prospect of dragging this through the courts but just in case - does anyone know of a lawyer who is very good with cases like these.?

Pete.

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On 3/21/2020 at 3:18 PM, Bfg said:

.

In a utopian world there should never be shame in wishing to learn.   B)

Instinctively from a toddler age we ask ..to learn.  And without an adult admitting (to themselves) their lack of understanding - they cannot self-teach.   I'm always looking up things and constantly learning - I love it.  Imo, the internet is truly a wonderful resource. The task then is to sort the wheat from the chaff of hearsay opinions.

Multi-grade versus mono-grade engine oils - My understanding is that multi-grades are compounded to be the assigned viscosity when cold.  And then as they get hot (sometimes very hot indeed) there is a molecular change and instead of thinning as they get hot - they stay much the same thickness / viscosity.  This means the oil is not too thick to pump through tight clearances (like bushes) when it is cold ..but then as the oil gets very hot it doesn't go all watery - and therefore it retains the thickness of film coating to lubricate surfaces.  Lighter oil, when cold, also offers less resistance to quickly turning and starting the engine. The sooner the engine fires up - the sooner the engine oil is being pumped to pressure and at the designed pace around the whole engine.

That sounds great..  but used in the wrong engine design - is to ignore the reality that mechanical tolerances also change as individual components and then the engine block heats up.  No two assemblies are the same, but some - for example, a spindle in a housing may thermally expand more (as it heats up) than the housing itself ..so the clearance between the two actually gets tighter.  This can happen when the housing has better flow cooling or a greater surface area, or heat dissipating material than the spindle.  Piston slap of a cold engine, which goes quieter as it warms up, is perhaps the most easily recognisable example of this - but it can also apply to valve stems in their guides, to camshafts in their bushes, and to numerous other parts - particularly in engines where plain bearings / shells / bushes are prevalent.

Furthermore, if parts within an oil pump are loose fitting ..through sloppy machining or wear - then thicker oil will more quickly build up its pressure,  whereas thinner oil tends to squeeze passed the pump's lobes, around the lobe ends, &/or out through the shaft.  Nor does the less-viscous oil help when the tolerances are already 'ample' in other engine parts. Then you may want the thicker oil film to provide its lubrication from the very first kick into motion. 

Another scenario, especially on older engines, is the matter of engine oil draining away while the engine is not being run.  My infrequently used Norton Commando didn't like multi-grade engine oils because its oil tank was remote (positioned high up under the saddle) and its lesser viscosity would drain back from the tank ..and flood the crankcase,  even when it was cold.  Mono-grade oils conversely thickened up as they cooled, so when left standing - the oil had less of a tendency to drain away.  My 650cc Triumph Bonneville similarly had a tank mounted just under their seat, but in 1970 Triumph changed the design to be oil-within-the-frame ..which was deliberately situated low down ..to prevent drain-back and for the c. of g.   Go figure.. the revised design was not understood so never well thought of by the pundits, which to this day is still reflected in the respective bike's values.

A similar situation to the Norton is experienced with my Sunbeam motorcycles ..which has a wet sump but also has generous oil galleries in its overhead camshaft and rocker assembly.  Multi-grade oils tend to run back down into the sump. So if a bike isn't used in a while - the almost always multi-grade oil drains down ..giving a false impression that the oil level on the dipstick is correct, and then taking crucial moments to build up oil pressure, to re-fill those galleries, and only then to squirt oil onto the camshaft (..this being at the very end of the oil route).  

Thick engine oil is also a very good acoustic damper. So again, because multi-grade engine oil is generally thinner than mono-grade oil (unless the latter is really very hot) - it  makes the engine noisier. 

Hopefully you'll realise that any engine design was done in conjunction with the oils to be used.  We owners ought to be aware of these things if/when we choose to overrule the specifications.  But just sometimes - such characteristics can be used to advantage.  For example I like to use a good multi-grade oil with element filtration in my Sunbeam motorcycles while I run a newly rebuilt engine in.   ie., when every bearing is tight and the engine oil is hotter than normal. 

Anyway, I hope this has given you some of the pro-and cons, and otherwise food for thought. 

Pete.

Yes it has! I may, however, reveal further ignorance. What I conclude is that while multigrade is very suitable to modern petrol engines, there are good reasons to opt for a 40 grade oil for a four cylinder TR, in light of its design relative to what oils were available in the 1950s. Opting for a monograde means opting for a quieter engine and one which is not subject to the ill effects of excessive drainage, regardless of how often the TR is used.

I would also like to add my congratulations to those acknowledging the value of detailed -- and very clear -- explanation.

Sir Ernest Gowers, civil servant and author of The Complete Plain Words (1954), -- latest edition, 2014 -- would have been very impressed. But not as much as I am.

Edited by David Brancaleone
Accuracy. Surname mispelt. Pub date missinge
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I have attended a couple of the seminars given by the oil companies (Penrite, & Duckhams) at past International meetings.

They both said that the original single grade oils were originally made without any detergent added, & were used on (pre-war) cars which were not fitted with the modern type of oil filter, instead there was a gauze covering the sump, which would strain out any "lumps".

Smaller particles of "crud" would tend to migrate to corners inside the block, & stay there, doing no harm.

Later, when engines were fitted with oil filters, it was advantageous to add detergent to the oil, so to "pick up" these finer particles, & then dump them in the filter.   This coincided with the development of mutigrade oils, & so we now have the choice of "straight" oils with no detergent for cars without oil filters, or mutigrade oils for cars with oil filters.

At both seminars I asked the question "why can't you make a mutigrade oil without detergent for use in older cars" neither rep could answer that question !   They just don't do it.

So for a TR, there is no problem with mutigrade oils, provided you choose the right one, i.e. lots of ZDDP, & at least a 20W50 grade, not thinner.

Also (I gather) no point using synthetic.

BOb.

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I recommend you read this book. It explains everything very clearly and in great detail.  You will see why monogrades can only be a compromise. As a result I use a 'classic' multigrade 20-60 in both my TR and my 1930 M type (which has been converted for a proper filter as per Bob's comment above).

A monograde which gives good pressure when hot is too thick to flow properly during starting from cold and hence gives less lubrication. A monograde which flows well when cold becomes too thin when hot.

 

oil.jpg

Edited by RobH
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7 hours ago, Lebro said:

original single grade oils were originally made without any detergent

Bobs comments on detergents is very valid.  Nowadays many mono-grade oils use various degrees of detergent (usually moderate or mild ) to keep 'bits'  (particularly combustion byproducts) in oil suspension long enough to be carried through to an element-type filter.  

Non-detergent oils are still available - which are supplied for prewar designs where the ' filters' consist of a gauze mesh (often loose enough weave for even small insects to get through ! ) combined with centrifugal crankshaft galleries and an oil-settling design of sump.  My Sunbeam motorcycles, although post war,  were designed like this. So I modify my own bikes to use an element filter (.. same as specified for a 1980's Skoda)  so I might take advantage of detergent oils.

Btw., Oil filters which are washable - I tend to think of as being the equivalent to gauze, rather than the disposable element type which are really so fine that they cannot be effectively washed out. 

The 4 potter Triumph TR engine has both the gauze pick-up essentially to prevent broken bits of steel or careless globs of gasket sealant from getting to the pump, but then an element oil filter to pick out the finer contaminants. 

14 hours ago, David Brancaleone said:

What I conclude is that while multigrade is very suitable to modern petrol engines, there are good reasons to opt for a 40 grade oil for a four cylinder TR, in light of its design relative to what oils were available in the 1950s. Opting for a monograde means opting for a quieter engine and one which is not subject to the ill effects of excessive drainage, regardless of how often the TR is used.

In the old days  (..yes, even I remember them !)  engine oils were sold for winter use or for summer use  ..so straight 20 for winter might be changed to straight-40 when the weather warmed up, and then back again near the end of Autumn.  This doubly served good purpose, because a conscientious owner would also change his engine-oil twice a year ! But as so many owners became lax in their maintenance schedules - multi-grade oils were like a God-send. 

Engine designers took advantage of the lower viscosity to specify finer replaceable element oil-filters. The lighter-weight oil didn't however float heavy parts so well, so there was a massive move (1970's) towards ever lighter engine parts - which in turn led to the trend for shorter stroke, higher revving engines with six gears (..1980's sewing machines). To achieve the faster engine speeds (rpm)..  less internal friction was needed so plain bearings gave way to bearing races - which require more splash than high pressure floating lubrication. However ball and roller races point-crush the oil,  so oil molecules needed to be linked together by way of additives. Unfortunately some of those &/or the detergents were found to chemically attack (eat away) certain metals (such as bronze) which was used (for bushes and gears) in old engine designs.

Physically smaller engines meant less engine oil was needed (still more compact and less weight) but being splashed around and without settlement tanks - the oil suffered from aeration (not good for pumping),  so they were then modified to be wetter (to better flow back together again).  And with such compact car designs a revolution in engine 'oil systems' occurred whereby the importance of internal oil cooling (localised heat dissipation from very hot spots) moved to be on parity with an oil's lubrication qualities. 

Those molecular links (which generally define synthetic oils) have especially slippery properties.  Absolutely great for reducing friction  ..but not good for older engine designed to wear (bed-in / run-in) from newly rebuilt.  I have never tried it., but I have read that synthetic oils can prevent piston rings and plain bearings from bedding-in correctly.      

Bottom line..  over the past 50 years - engine design and oil development were hand in hand,  and as you suggest ; a modern high-performance multi-grade oil designed for the high pressure loading, speeds and temperatures of turbo components - isn't necessarily the best thing for a slow but torquey 1950's design of engine.   But perhaps the equally important thing to watch out for is the oil additives ..and what they might do to brass / bronze and/or to rubber parts like seals within our engines.  Mineral oils seem to be an absolute-must during running in + a few thousand miles.  However (thereafter), a fellow Sunbeam rider says he uses synthetic oils in his bike and has only seen positive effects. 

 

SAE ratings :

The later TR4A workshop manual tells me, for the British Isles - that either straight 20w  or  SAE10w/30 from Shell was recommended, as was straight 20  or  SAE20/50 from Duckhams  (..other brands available from all good stores ;) ).   For overseas countries, generally over 20 deg c. it became straight 40 from both companies, dropping to straight 30 where temperatures of  0 - 20 deg c. were more the norm  ..with 20w/40 recommended for both markets from Shell.

Nowadays though (..and there are exceptions) very few British Isle owners who drive them in such sub-zero temperatures, let alone leave their TR parked outside overnight in such conditions.  So, aside from the occasional week of "big freeze",  I'd suggest we now live in a warmer climate than when the manual was written.

This graph illustrates how multi-grades work. .

839046601_Engineoilviscosityvtemperature01.jpg.3c41aadfeadbdf2dc623ccce2536dac5.jpgcourtesy of mechanics.stackexchange.com <here>

And as the author correctly says -   "All oils reduce in viscosity as the temperature goes up. The 10W-30 just means you have grade 10 viscosity when cold, and grade 30 viscosity when hot. Grade 10 oil when cold is still thicker than grade 30 oil when hot.  The viscosity of a multi-grade oil still varies with temperature, but the slope representing the change is lessened."

Put these things together and perhaps what I'm thinking is something like .. Penrite Engine Oil - Classic Medium 25W-70.   

As copied from Holden's website < here >  it says ;

" Penrite Classic Medium is a premium mineral, 25W-70, high zinc, low detergent engine oil designed specifically for engines manufactured between 1950 and 1989. This SAE 25W-70 grade oil can be used to replace SAE 40, with better results than using a 20W50. Classic Medium features a double layer of engine wear protection with high zinc and increased operating temperature viscosity, over older style multigrade oils or where SAE 40 monograde oil was specified by the manufacturer. It controls oil consumption and maintains oil pressure in older engines."

This on the face of it appears to gives us 

  1. a good quality mineral oil
  2. high zinc
  3. low detergent (just enough perhaps to keep a restored engine clean inside)
  4. a winter weight which is still good for 0  to  -10 deg c. 
  5. not too thin - so it ought to still quickly build up oil pressure.
  6. but not so thick when cold to significantly slow the engine's cranking.
  7. at normal engine temp, a weight equivalent to SAE40. ie., summer weight
  8. but not too thin when the engine gets really hot.  ie., when stuck in traffic.  
  9. at a price which is not at all outrageous for a respected brand.

What do you / others think ?

Pete.

Edited by Bfg
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Agree, I used the Penrite oil while on offer from the TRR, for the same reason I now am using Duckhams 20W50, but Penrite is probably the better of the two.

Bob.

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If the engine has been rebuilt and deposits removed at that time a high detergent oil should be ok.

20 50 or 20 60 should be fine.

Thinner than a 20 might result in leaks and low oil pressure related to the larger clearances the TR. 

Modern car engines are built with tighter tolerances and regulation of temperature so can use thinner oils.

However our engines are not that old and have modern filtration so using the exact type of oil and in particular non detergent monogrades that were what were available back in the day would be a retrograde step. 

 

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3 hours ago, Andy Moltu said:

If the engine has been rebuilt and deposits removed at that time a high detergent oil should be ok.

Again from what I've read, and I have no experience to the contrary - low detergent engine oils do not soften / dissolve / clean deposits off the inside of old engines.  This might be likened to a mild detergent (for vulnerable fabrics / clothes dyes) used in your clothes washing machine - where its soapy-ness simply stops dirt re-sticking to other fibres ..after the hot water, tumbling and agitation lifts them out. Then the dirt is in fluid-suspension until its filtered (or in a wash machine changed).  

Personally,  I would be very wary of using a high detergent oil in an older engine because - if it does soften / dissolve / clean deposits off the inside of oil ways or in hidden galleries ..and that comes off in flakes - they might cock sideways and cause a blockage    ..But then I'm not having each of my engine parts chemically dipped to remove every last deposit.   

I have had to scrap badly pitted worm-gear wheels, made in bronze (..and very expensive to buy nowadays !) from the rear-drive of a post-war Sunbeam motorcycle ..because a prior owner used EP gear oil in it (standard spec is straight 90 mineral oil).   But perhaps EP gear oil has different chemicals which caused that.?   Still, I was warned that some high-detergent engine oils can be damaging / corrosive to certain metals such as the bronze bushes and gears (speedo-drive gear for example) used in older engines. I don't know this for a fact, but I do tend to heed such warnings. 

Pete.

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I use Penrite 20/60 and very pleased with it. It also has the correct levels of that stuff we need for flat tappet  engines.....dare not mention the four letters! 
Iain

Edited by iain
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