The Carryfast engine design discussion

zb_anorak · 12 November 2020 20:30

Carryfast:

[zb]
anorak:

Carryfast:
… you can’t get 246 psi BMEP from a TL12.

Is that because there is no such thing? What if you polish the rocker cover? Will a genie come out of the exhaust manifold?

Carryfast:
It is too stupid to know exactly HOW that torque was produced by the engine whether by cylinder pressure or piston area or leverage.

That is exactly what you are doing, by declaring that one engine, of similar capacity to another, but with a shorter stroke, will blow its head off, if both engines have the torque output increased. By saying that the TL12 will batter its bearings and destroy its head gasket, if it had been developed to produce a similar torque to the later Eagle engines, you are using the variable (BMEP/stroke). If you had other information, such as cyl pressure vs. crank angle for both engines, your declaration might have carried some weight, but you can only cite the parameter of which you deny the existence. That is the centre point of the stupidity.

It’s only the TL12 that needs its BMEP/Specific torque increased.
The Eagle is already there at 1,216 ft that’s close enough to 100 lbft per litre to provide 246 psi BMEP.
Oh wait you’re in denial that that amount of specific torque output = 246 psi BMEP because you don’t accept the formula specific torque x 2.464.
So you need 43% more specific torque with a 7% leverage deficit.
Also a 2.5% piston area deficit v the Eagle’s leverage advantage.
Tell us how you’re going to make that torque reuirement.
The required extra cylinder pressure is going to wreck your head fastenings.
The required extra force required on the con rod is going to wreck your end bearings.
There is no stroke or piston area variable in the BMEP calculation.It’s is just based on specific torque at the flywheel regardless of how its produced.

Which makes BMEP an oxymoron in itself in creating the erroneous premise that more specific torque/BMEP by definition means more ‘cylinder pressure’.Which the two variables of piston area and leverage prove is bs.
Not to mention numerous documented statements confirming BMEP doesn’t mean cylinder pressure as I posted.It’s a non existent abstract hypothetical comparator that’s all.Might as well use the specific torque figure that it’s based on.

BMEP couldn’t possibly be a measure of cylinder pressures no matter how much those with your erroneous ideas try to say it is.
It’s a measure of specific torque.Which is made up of the combination of cylinder pressure, piston area and leverage.Leverage having the advantage of multiplying the effort of both of the former and you’ve got a 7% deficit of it.

I’m still waiting for your answer to the question can you make an F1 engine produce its around same 200 psi BMEP but at 1,200 rpm.If not why not.

You have nothing to back up the assertion that the engine will wreck its head bolts or bearings, other than torque, capacity and stroke. If the parameters you are citing cause force on the parts you mention, you need to arrange them in the expression F∝T/V.s, or F=P.A. Simplifying every piece of bolleaux you say comes back to that. You have nothing else but those parameters, so you are citing BMEP, in ignorance, while denying it has any actual physical use LOL. If you were not completely oblivious to very basic algebra, you would realise how foolish your waffle is.

Colour- I like it. Good idea, Mr. 551.

carryfast · 12 November 2020 21:17

[zb]
anorak:
You have nothing to back up the assertion that the engine will wreck its head bolts or bearings, other than torque, capacity and stroke. If the parameters you are citing cause force on the parts you mention, you need to arrange them in the expression F∝T/V.s, or F=P.A. Simplifying every piece of bolleaux you say comes back to that. You have nothing else but those parameters, so you are citing BMEP, in ignorance, while denying it has any actual physical use LOL. If you were not completely oblivious to very basic algebra, you would realise how foolish your waffle is.

You’re the one who said that BMEP = cylinder pressures which it doesn’t.
It = specific torque.
You also based your stress estimates on the bs figure of 2 x BMEP.Where did that come from.
You also denied specific torque x 2.464 = the BMEP figure.
I’m not citing BMEP in ignorance.You clearly are.
You need to tell us how you’re going to make up a 43% specific torque deficit with a 7% leverage deficit without that putting excessive stress on your end bearings and head fastenings.
Here’s a clue 2 x BMEP wont get close to the cylinder pressures nor the force on the con rod to get there you’ll need let alone when that force is applied to the much smaller end bearing and head fastenings areas.
As it stands you couldn’t even give us a proper cylinder pressure figure, at that torque output, with all the algebra in the world at your disposal.

Algebra as I said garbage in garbage out.

dave_docwra · 12 November 2020 22:08

cav551:
So this below is what? make believe ? Well it can’t be can it, because there is leverage involved ? You’d better make that an extra, extra large bag of super size gobstoppers.
x-engineer.org/automotive-engin … ue-engine/

Thats a great display & I can sort of get the gist of it, but like someone else on here it is also way above my pay scale to fully understand.

carryfast · 12 November 2020 22:48

dave docwra:

cav551:
So this below is what? make believe ? Well it can’t be can it, because there is leverage involved ? You’d better make that an extra, extra large bag of super size gobstoppers.
x-engineer.org/automotive-engin … ue-engine/

Thats a great display & I can sort of get the gist of it, but like someone else on here it is also way above my pay scale to fully understand.

Yes the gearbox acts as an auxiliary lever multiplying the engine torque.Who would have thought it.
The clue is in the title ‘FROM’ engine torque.
You know the engine torque made by the pressure of the expansion of the ignited compressed charge in the cylinder acting on the piston area both then multiplied by the leverage
of the stroke measurement.
The more torque made by the engine the less gear reduction you’ll need so the faster your wheels can turn.
The less leverage in stroke, the more cylinder pressure and/or piston area and resulting forces on the end bearings and head fasteners you’ll need to make the equivalent torque by the engine.
But you knew that.

zb_anorak · 13 November 2020 01:22

Carryfast:

You’re the one who said that BMEP = cylinder pressures which it doesn’t.

It = specific torque.

You also based your stress estimates on the bs figure of 2 x BMEP.Where did that come from.

You also denied specific torque x 2.464 = the BMEP figure.

I’m not citing BMEP in ignorance.You clearly are.

You need to tell us how you’re going to make up a 43% specific torque deficit with a 7% leverage deficit without that putting excessive stress on your end bearings and head fastenings.
Here’s a clue 2 x BMEP wont get close to the cylinder pressures nor the force on the con rod to get there you’ll need let alone when that force is applied to the much smaller end bearing and head fastenings areas.

As it stands you couldn’t even give us a proper cylinder pressure figure, at that torque output, with all the algebra in the world at your disposal.

Algebra as I said garbage in garbage out.

Not me. Everyone.
So it is.
No I did not.
The equation is in every textbook. 4π is the constant, for four stroke engines. Torque in Nm, capacity in litres.
Get someone to read my previous post, and explain it to you.
All together now.
Until you provide actual measured values for cylinder pressures, you’re basing your piffle on nothing at all, apart from BMEP.

If you can’t see that you’re actually denigrating your own daft ideas, you should take evening classes in GCSE maths. If you didn’t know, a good grade in A level maths is required for admission onto a Mechanical Engineering degree course. You’d better start now. In total, it takes about 10 years of theory, before you are allowed to make one detail alteration to a drawing. In Germany, where engineers are considered to be the professional equal of surgeons and lawyers, you would actually be banned from working at all, without the correct education. The Germans do some great work, don’t they? The OM400 series was, arguably, the greatest commercial vehicle engine of the last century.

carryfast · 13 November 2020 03:11

[zb]
anorak:

Carryfast:

You’re the one who said that BMEP = cylinder pressures which it doesn’t.

It = specific torque.

You also based your stress estimates on the bs figure of 2 x BMEP.Where did that come from.

You also denied specific torque x 2.464 = the BMEP figure.

I’m not citing BMEP in ignorance.You clearly are.

You need to tell us how you’re going to make up a 43% specific torque deficit with a 7% leverage deficit without that putting excessive stress on your end bearings and head fastenings.
Here’s a clue 2 x BMEP wont get close to the cylinder pressures nor the force on the con rod to get there you’ll need let alone when that force is applied to the much smaller end bearing and head fastenings areas.

As it stands you couldn’t even give us a proper cylinder pressure figure, at that torque output, with all the algebra in the world at your disposal.

Algebra as I said garbage in garbage out.

Not me. Everyone.

So it is.

No I did not.

The equation is in every textbook. 4π is the constant, for four stroke engines. Torque in Nm, capacity in litres.

Get someone to read my previous post, and explain it to you.

All together now.

Until you provide actual measured values for cylinder pressures, you’re basing your piffle on nothing at all, apart from BMEP.

If you can’t see that you’re actually denigrating your own daft ideas, you should take evening classes in GCSE maths. If you didn’t know, a good grade in A level maths is required for admission onto a Mechanical Engineering degree course. You’d better start now. In total, it takes about 10 years of theory, before you are allowed to make one detail alteration to a drawing. In Germany, where engineers are considered to be the professional equal of surgeons and lawyers, you would actually be banned from working at all, without the correct education. The Germans do some great work, don’t they? The OM400 series was, arguably, the greatest commercial vehicle engine of the last century.

1 contradicts 2.It’s either cylinder pressure or it’s specific torque which is it.How is something that is the product of cylinder pressure, piston area and leverage supposedly a measure of cylinder pressure.

3 What was your reference to 2 x BMEP supposedly about if it wasn’t a laughable reference by you to a supposed cylinder pressure figure erroneosly extrapolated from BMEP.You know because BMEP dosn’t refer to cylinder pressures at all because it can’t possibly do so.So are you saying that BMEP is a measure of cylinder pressures.
Or is it just another way of expressing specific torque as I’ve argued over the previous pages.It can’t possibly be both nor the former.

4 In what way does your supposed 4 Pi bollox trump specific torque in lbft x 2.464.Are you saying that 100 lbft per litre = 246 psi BMEP or not.If not give us your figure for it.

So now you’re saying that the relevant cylinder pressure isn’t 2 x BMEP nor could it be just as I said.Yes or no.

I don’t need to provide measured values as I said we just ain’t going to find them.
But proper maths says that the peak cylinder pressures as applied to the head fastenings and the forces acting on the con rod are massive.You know like 43% more torque required with a 7% leverage deficit and 2.5 % piston area deficit v leverage.
The only/best way of settling this disagreement is by finding a mug who’ll be prepared to subject a surviving TL12 to being boosted to 1,216 lbft at 1,200 rpm then see if it breaks.Good luck with that.Although even that wouldn’t tell us if it would have made it through it’s warranty period.

As for the OM remind me what was the difference between the 402 v 422.

ramone · 13 November 2020 05:40

Carryfast:

ramone:
Well if the RR Roadtrain and the TL12 Roadtrain were both putting out 270 bhp it would be difficult to tell, well maybe the driver of the TL12 could has he passed the RR up the hill but all this as already been said you just ignore it. The TL12 was a very good engine giving few problems in service.
How long would this aforementioned torque wrench be would it be of a standard length or a 8 to 10 mm longer one that would give 900% more leverage and the rest would be history

Which part of the Eagle was putting out more than 273 hp at 1,200 rpm didn’t you understand.
Good luck with 7% less leverage when you need to apply 1,216 lbft.
The rest was history for the TL12 from 1983 the only surprising thing being why bother with it at all.Unless you want the firm to fail.

So the 265 RR was putting out more than 273 hp , that is the closest match eagle to the TL12 , have a look at road tests between the 265 or the 290L compared with the TL12 and see the results and how much difference that 8mm makes

carryfast · 13 November 2020 13:01

ramone:

Carryfast:

ramone:
Well if the RR Roadtrain and the TL12 Roadtrain were both putting out 270 bhp it would be difficult to tell, well maybe the driver of the TL12 could has he passed the RR up the hill but all this as already been said you just ignore it. The TL12 was a very good engine giving few problems in service.
How long would this aforementioned torque wrench be would it be of a standard length or a 8 to 10 mm longer one that would give 900% more leverage and the rest would be history

Which part of the Eagle was putting out more than 273 hp at 1,200 rpm didn’t you understand.
Good luck with 7% less leverage when you need to apply 1,216 lbft.
The rest was history for the TL12 from 1983 the only surprising thing being why bother with it at all.Unless you want the firm to fail.

So the 265 RR was putting out more than 273 hp , that is the closest match eagle to the TL12 , have a look at road tests between the 265 or the 290L compared with the TL12 and see the results and how much difference that 8mm makes

Up to 400 hp at 1,950 was actually the difference that 10 mm or 7% made without bankrupting the warranty department budget.
Why do we have to stay with the 265.

290 RR v TL12 which road test would put the TL12 ahead at 38t unless it was rigged as part of the ‘plan’.Oh wait the TL12 was ditched as soon as 38t arrived on the scene.I wonder why.
Not enough cash to bolt an intercooler to it.Yeah right.
Feel free to post this mythical road test.

ramone · 13 November 2020 13:23

Carryfast:

ramone:

Carryfast:

ramone:
Well if the RR Roadtrain and the TL12 Roadtrain were both putting out 270 bhp it would be difficult to tell, well maybe the driver of the TL12 could has he passed the RR up the hill but all this as already been said you just ignore it. The TL12 was a very good engine giving few problems in service.
How long would this aforementioned torque wrench be would it be of a standard length or a 8 to 10 mm longer one that would give 900% more leverage and the rest would be history

Which part of the Eagle was putting out more than 273 hp at 1,200 rpm didn’t you understand.
Good luck with 7% less leverage when you need to apply 1,216 lbft.
The rest was history for the TL12 from 1983 the only surprising thing being why bother with it at all.Unless you want the firm to fail.

So the 265 RR was putting out more than 273 hp , that is the closest match eagle to the TL12 , have a look at road tests between the 265 or the 290L compared with the TL12 and see the results and how much difference that 8mm makes

Up to 400 hp at 1,950 was actually the difference that 10 mm or 7% made without bankrupting the warranty department budget.
Why do we have to stay with the 265.

290 RR v TL12 which road test would put the TL12 ahead at 38t unless it was rigged as part of the ‘plan’.Oh wait the TL12 was ditched as soon as 38t arrived on the scene.I wonder why.
Not enough cash to bolt an intercooler to it.Yeah right.
Feel free to post this mythical road test.

Which RR engine was nearest to the 273 bhp TL12 was it the 290 or 265? The E290 was the nearest rival and it had to be driven very carefully to match the TL12 which wouldnt happen with a fleet of drivers , so come on which RR engine was nearest bhp wise to the TL12 then you can compare the leverage and see what difference there is in performance

zb_anorak · 13 November 2020 14:40

Carryfast:

ramone:

Carryfast:

ramone:
Well if the RR Roadtrain and the TL12 Roadtrain were both putting out 270 bhp it would be difficult to tell, well maybe the driver of the TL12 could has he passed the RR up the hill but all this as already been said you just ignore it. The TL12 was a very good engine giving few problems in service.
How long would this aforementioned torque wrench be would it be of a standard length or a 8 to 10 mm longer one that would give 900% more leverage and the rest would be history

Which part of the Eagle was putting out more than 273 hp at 1,200 rpm didn’t you understand.
Good luck with 7% less leverage when you need to apply 1,216 lbft.
The rest was history for the TL12 from 1983 the only surprising thing being why bother with it at all.Unless you want the firm to fail.

So the 265 RR was putting out more than 273 hp , that is the closest match eagle to the TL12 , have a look at road tests between the 265 or the 290L compared with the TL12 and see the results and how much difference that 8mm makes

Up to 400 hp at 1,950 was actually the difference that 10 mm or 7% made without bankrupting the warranty department budget.
Why do we have to stay with the 265.

290 RR v TL12 which road test would put the TL12 ahead at 38t unless it was rigged as part of the ‘plan’.Oh wait the TL12 was ditched as soon as 38t arrived on the scene.I wonder why.
Not enough cash to bolt an intercooler to it.Yeah right.
Feel free to post this mythical road test.

You have nothing to back up the argument that the TL12 would not have suited further development, other than the variable F=P.A, where P = BMEP and A is the bore area, which is 7% larger on the TL12, than is was on the Eagle Diesel. Nothing.

You are gradually retreating into a corner of mangled repetition. Calling the real engineers “nerds” marks you out as a frustrated brush attendant.

zb_anorak · 13 November 2020 14:47

There is no such thing as pressure! The force comes from somewhere else!

It comes from the torque and the capacity and the stroke, but don’t mention how, because that variable does not exist!! Grrr…

carryfast · 13 November 2020 18:59

ramone:

Carryfast:
Why do we have to stay with the 265.

290 RR v TL12 which road test would put the TL12 ahead at 38t unless it was rigged as part of the ‘plan’.Oh wait the TL12 was ditched as soon as 38t arrived on the scene.I wonder why.
Not enough cash to bolt an intercooler to it.Yeah right.
Feel free to post this mythical road test.

Which RR engine was nearest to the 273 bhp TL12 was it the 290 or 265? The E290 was the nearest rival and it had to be driven very carefully to match the TL12 which wouldnt happen with a fleet of drivers , so come on which RR engine was nearest bhp wise to the TL12 then you can compare the leverage and see what difference there is in performance

Your bias is laughable.Anything which can beat the TL12 must be ignored.
Yes I know the 14 litre E290 was derated to the point of counter productivety.Which makes the case for the TL12 how.
The 265 RR was also just a de rated option.You know like for use in 6 wheeler rigids.Trust me the thing pulled like a train even at that rating and weight.
Why would anyone want the 265 in a 38 tonner.The difference is that the RR could handle more much more unlike the TL12.
You think that the buying choice had to be limited to only what the TL12 could handle.
So exactly what’s your problem with the 290 Rolls which unlike the ‘E290’ actually produced 290.
Oh wait your obsolete piece of AEC junk can’t match it so we have to ignore it.
That’s exactly what Edwardes ( deliberately ) did in 1979.The rest is history.

carryfast · 13 November 2020 19:16

[zb]
anorak:
There is no such thing as pressure! The force comes from somewhere else!
0
It comes from the torque and the capacity and the stroke, but don’t mention how, because that variable does not exist!! Grrr…

Where did I say that the variable of cylinder pressure doesn’t exist in the torque equation that’s how turbocharging actually works.We’re talking about SPECIFIC TORQUE not CAPACITY.The Eagle is actually a smaller ‘capacity’ motor than the TL12.

You’re the one who’s trying to pretend that the variable of leverage doesn’t exist and BMEP is all about cylinder pressure to the point of stating that BMEP is a measure of cylinder pressure when it’s anything but.

My case is that trying to substitute leverage with more cylinder pressure and piston area to make the equivalent torque comes at a cost in head fastening and end bearing stress.

The TL12 was already clearly at its limit in that regard.Which is why we saw a 400 hp Eagle at lower engine speed as opposed to the 273 hp TL12.

You think that chucking more money at it would have solved that problem.Yeah right with end bearings and head fastenings made out of unobtainium.

cav551 · 13 November 2020 22:21

Carryfast:

ramone:

Carryfast:
Why do we have to stay with the 265.

290 RR v TL12 which road test would put the TL12 ahead at 38t unless it was rigged as part of the ‘plan’.Oh wait the TL12 was ditched as soon as 38t arrived on the scene.I wonder why.
Not enough cash to bolt an intercooler to it.Yeah right.
Feel free to post this mythical road test.

Which RR engine was nearest to the 273 bhp TL12 was it the 290 or 265? The E290 was the nearest rival and it had to be driven very carefully to match the TL12 which wouldnt happen with a fleet of drivers , so come on which RR engine was nearest bhp wise to the TL12 then you can compare the leverage and see what difference there is in performance

Your bias is laughable.Anything which can beat the TL12 must be ignored.
Yes I know the 14 litre E290 was derated to the point of counter productivety.Which makes the case for the TL12 how.
The 265 RR was also just a de rated option.You know like for use in 6 wheeler rigids.Trust me the thing pulled like a train even at that rating and weight.
Why would anyone want the 265 in a 38 tonner.The difference is that the RR could handle more much more unlike the TL12.
You think that the buying choice had to be limited to only what the TL12 could handle.
So exactly what’s your problem with the 290 Rolls which unlike the ‘E290’ actually produced 290.
Oh wait your obsolete piece of AEC junk can’t match it so we have to ignore it.
That’s exactly what Edwardes ( deliberately ) did in 1979.The rest is history.

What is the name of the parallel universe you live in please? …the one where time moves backwards.

So the 265L Rolls from the late 1970s was a derated version of the 800 Rolls series 2000 from the 1990s?

The ■■■■■■■ E290 Big Cam 1 of 1978 was a derated what? 525, from however many years later?

Development of the Rolls Perkins 2000 was stopped because it was not going to be able to meet the next stage of exhaust emission regulations.

But seeing as you are so clever and KNOW what the ultimate output limit of the TL12 is, then you’ll be able to tells us all categorically what the ultimate output limit of the 743 Cu in Rolls design would have been as well for it as a ‘mechanical’ engine. You know, how you are going to achieve the output figures you claim, not xyv times 2 point whatever; actual figures for compression ratio, expansion ratio, boost pressure, injection timing, valve timing, anything else physical? but you have to prove with figures that those are possible remember. The answer I suggest is that you don’t ■■■■■■■ KNOW just like you don’t KNOW what could have been achieved with the TL12 or how that might have been brought about by engineers who knew their product intimately. Keep in mind that engine design at a practical level is as much an art as it is a science.

So now is your moment, just like in the wedding ceremony: put up or forever ■■■■ gobstoppers.

Remember you are trying to avoid this:

epi-eng.com/piston_engine_te … stakes.htm

carryfast · 13 November 2020 23:09

cav551:

Carryfast:
Your bias is laughable.Anything which can beat the TL12 must be ignored.
Yes I know the 14 litre E290 was derated to the point of counter productivety.Which makes the case for the TL12 how.
The 265 RR was also just a de rated option.You know like for use in 6 wheeler rigids.Trust me the thing pulled like a train even at that rating and weight.
Why would anyone want the 265 in a 38 tonner.The difference is that the RR could handle more much more unlike the TL12.
You think that the buying choice had to be limited to only what the TL12 could handle.
So exactly what’s your problem with the 290 Rolls which unlike the ‘E290’ actually produced 290.
Oh wait your obsolete piece of AEC junk can’t match it so we have to ignore it.
That’s exactly what Edwardes ( deliberately ) did in 1979.The rest is history.

What is the name of the parallel universe you live in please? …the one where time moves backwards.

So the 265L Rolls from the late 1970s was a derated version of the 800 Rolls series 2000 from the 1990s?

The ■■■■■■■ E290 Big Cam 1 of 1978 was a derated what? 525, from however many years later?

Development of the Rolls Perkins 2000 was stopped because it was not going to be able to meet the next stage of exhaust emission regulations.

But seeing as you are so clever and KNOW what the ultimate output limit of the TL12 is, then you’ll be able to tells us all categorically what the ultimate output limit of the 743 Cu in Rolls design would have been as well for it as a ‘mechanical’ engine. You know, how you are going to achieve the output figures you claim, not xyv times 2 point whatever; actual figures for compression ratio, expansion ratio, boost pressure, injection timing, valve timing, anything else physical? but you have to prove with figures that those are possible remember. The answer I suggest is that you don’t [zb] KNOW just like you don’t KNOW what could have been achieved with the TL12 or how that might have been brought about by engineers who knew their product intimately. Keep in mind that engine design at a practical level is as much an art as it is a science.

So now is your moment, just like in the wedding ceremony: put up or forever ■■■■ gobstoppers.

Remember you are trying to avoid this:

epi-eng.com/piston_engine_te … stakes.htm

The 265 of the late 70’s-early 1980’s was a derated option of 290-340.Ultimately putting out more than 1,000 lbft by 1982.

The ■■■■■■■ E’290’ wasn’t even actually putting out ‘290’ unlike the Rolls 290.

The ■■■■■■■ was though a derated option of a range which went up to 400 and even 475 in turbo compound form.No short stroke help for your case there either.With the addition of more piston area reducing cylinder pressures at the equivalent rating.Followed by the later ISX with a lower bore stroke ratio.

We know what the Eagle ultimately achieved.
You and Anorak are doing all the shouting that you could achieve the same with 7% less leverage.So why don’t you give us the figures of what that meant when the resulting extra cylinder pressures and force on the con rod you need to make up for that deficit was translated into psi on the end bearings and head fastenings.
Let me guess you want to argue that it isn’t actually 43% more specific torque required with 7% less torque multiplication in the form of leverage and 2.5 % less piston area v leverage.The TL12 was just coincidentally knocked on the head at 273 hp and less than 900 lbft torque when 38t gross was allowed.

All it supposedly needed was a bit more boost and an intercooler bolted to it to match the Eagle.But Leyland couldn’t afford the ‘upgrade’.All the production machinery was worn out anyway.Yeah right.

So what did Edwardes and his government handlers do in 1979.Let’s flog off RR.Instead of bringing it in house to power the new Roadtrain with a proper 290 engine that had, an eventually proven, potential 400 in it and well over 300 when the TL12 was put out of its misery.

If clever means that I knew that the Eagle had the potential of 400 hp in it within a mile of driving the 265, at a realistic gross for that output, the first time in the early 1980’s, then I’ll give that accolade to its designers.
While stupid doesn’t get much more stupid than flogging off RR and crippling the Roadtrain with the TL12.

carryfast · 13 November 2020 23:24

cav551:
Remember you are trying to avoid this:

epi-eng.com/piston_engine_te … stakes.htm

Which is relevant to the RR Eagle v TL12 comparison how.

ramone · 14 November 2020 10:58

Carryfast:

ramone:

Carryfast:
Why do we have to stay with the 265.

290 RR v TL12 which road test would put the TL12 ahead at 38t unless it was rigged as part of the ‘plan’.Oh wait the TL12 was ditched as soon as 38t arrived on the scene.I wonder why.
Not enough cash to bolt an intercooler to it.Yeah right.
Feel free to post this mythical road test.

Which RR engine was nearest to the 273 bhp TL12 was it the 290 or 265? The E290 was the nearest rival and it had to be driven very carefully to match the TL12 which wouldnt happen with a fleet of drivers , so come on which RR engine was nearest bhp wise to the TL12 then you can compare the leverage and see what difference there is in performance

Your bias is laughable.Anything which can beat the TL12 must be ignored.
Yes I know the 14 litre E290 was derated to the point of counter productivety.Which makes the case for the TL12 how.
The 265 RR was also just a de rated option.You know like for use in 6 wheeler rigids.Trust me the thing pulled like a train even at that rating and weight.
Why would anyone want the 265 in a 38 tonner.The difference is that the RR could handle more much more unlike the TL12.
You think that the buying choice had to be limited to only what the TL12 could handle.
So exactly what’s your problem with the 290 Rolls which unlike the ‘E290’ actually produced 290.
Oh wait your obsolete piece of AEC junk can’t match it so we have to ignore it.
That’s exactly what Edwardes ( deliberately ) did in 1979.The rest is history.

So when comparing engines surely you would look at the nearest outputs to compare. If you were looking for a new unit now and you wanted a 460 hp engine would you be comparing say a Merc 450 with a Daf 520 and then slate the Mercs performance and say it was crap ( it is incidentally) You would go out and compare like for like.
The TL12 was hastily developed from the 760 and hit the roads in72 and at 273 hp it was and proved a good reliable and economic engine. At the time Rolls were still producing the 220/280 troublesome thirsty leaky engines. It was another 5 years before they introduced the 265/290 Eagle and things move on and remind us who redesigned the Rolls, the man who designed the TL12 . The TL12 was never touched in development terms for almost its total production life until just before the Roadtrain launch when they introduced the Flexitorque . Like i keep repeating , there was no money to develop the engine even though people much more informed and more experienced than yourself mentioned a 320 hp engine had been produced . You can scoff and make up ■■■■ all the time but those are the facts. The two things that killed the TL12 were the lack of funds to further develop it and more funds to replace the completely worn out machinery used to build it. THE MONEY WASNT THERE. Ideally Leyland should have left AEC to developing the engine into a modern power unit for the Roadtrain but THE MONEY WASNT THERE. The propriety engine route didnt work and as history proves no European manufacturers use them now.
You have compared the TL12 to the bigger ■■■■■■■ Rolls Daf and even ridiculously the F12 , put the comparisons like for like . If you still want to go down that road put the Rolls 265 or 290 against the F12 385 , and see how the comparisons add up. You talk ■■■■

carryfast · 14 November 2020 12:38

ramone:

Carryfast:
Your bias is laughable.Anything which can beat the TL12 must be ignored.
Yes I know the 14 litre E290 was derated to the point of counter productivety.Which makes the case for the TL12 how.
The 265 RR was also just a de rated option.You know like for use in 6 wheeler rigids.Trust me the thing pulled like a train even at that rating and weight.
Why would anyone want the 265 in a 38 tonner.The difference is that the RR could handle more much more unlike the TL12.
You think that the buying choice had to be limited to only what the TL12 could handle.
So exactly what’s your problem with the 290 Rolls which unlike the ‘E290’ actually produced 290.
Oh wait your obsolete piece of AEC junk can’t match it so we have to ignore it.
That’s exactly what Edwardes ( deliberately ) did in 1979.The rest is history.

So when comparing engines surely you would look at the nearest outputs to compare. If you were looking for a new unit now and you wanted a 460 hp engine would you be comparing say a Merc 450 with a Daf 520 and then slate the Mercs performance and say it was crap ( it is incidentally) You would go out and compare like for like.
The TL12 was hastily developed from the 760 and hit the roads in72 and at 273 hp it was and proved a good reliable and economic engine. At the time Rolls were still producing the 220/280 troublesome thirsty leaky engines. It was another 5 years before they introduced the 265/290 Eagle and things move on and remind us who redesigned the Rolls, the man who designed the TL12 . The TL12 was never touched in development terms for almost its total production life until just before the Roadtrain launch when they introduced the Flexitorque . Like i keep repeating , there was no money to develop the engine even though people much more informed and more experienced than yourself mentioned a 320 hp engine had been produced . You can scoff and make up [zb] all the time but those are the facts. The two things that killed the TL12 were the lack of funds to further develop it and more funds to replace the completely worn out machinery used to build it. THE MONEY WASNT THERE. Ideally Leyland should have left AEC to developing the engine into a modern power unit for the Roadtrain but THE MONEY WASNT THERE. The propriety engine route didnt work and as history proves no European manufacturers use them now.
You have compared the TL12 to the bigger ■■■■■■■ Rolls Daf and even ridiculously the F12 , put the comparisons like for like . If you still want to go down that road put the Rolls 265 or 290 against the F12 385 , and see how the comparisons add up. You talk [zb]

When ‘comparing’ engines we use BMEP ( specific torque ).

Your idea of comparing engines is to just ignore any rating of any engine that beats your piece of AEC junk.So why the double standards in ignoring customers who wanted 290 + ?.Why only those who were satisfied with the TL12’s output.

The Eagle and the TD120 were both smaller capacity motors than the TL12.
Why would anyone who wanted 290+ ignore the higher rated Eagle options and make the choice only between 265 RR and TL12 just to suit your silly fan boy arguments.

So put the Volvo TD120 against the 400 Eagle.Your point being what.Where is the TL12 in that comparison.

The only total zb being talked here is from those backing Edwardes’ and the government’s case for putting the TL12 in the Roadtrain instead of the 290 RR with the option of 340 + to follow within 2 years.You know bs arguments like the TL12 can only make less than 900 lbft and 273hp so why should anyone want anything more than that and why should we offer anything more.

The money was ‘there’ because no money was needed to change hands to bring RR on board as Leyland’s in house engine supplier.

While the fact is you ain’t going to get 100 lbft per litre from the TL12 without unsustainable warranty claims regardless of how much money was thrown at it.That’s why it had to be knocked on the head when 38t arrived.
If AEC had stayed with the bore stroke ratios laid down by the 173 or 590 for the 760/TL12 history would have been very different in that regard.

The only logical conclusion being an agenda of sabotage because that type of stupid just doesn’t happen.

zb_anorak · 14 November 2020 14:04

Carryfast:
The ■■■■■■■ E’290’ wasn’t even actually putting out ‘290’ unlike the Rolls 290.

RR quoted gross bhp, like all of the other proprietary suppliers. How could they quote net bhp, when the installed power output depended on the installation? The Scammell brochure shows the power output of the RR305 version to be 300ps DIN, which is about 295bhp.

The torque figure for the 290L RR engine was 880 lbft gross. What was the number for the TL12 Flexitorque?

zb_anorak · 14 November 2020 17:33

Carryfast:
While the fact is you ain’t going to get 100 lbft per litre from the TL12 without unsustainable warranty claims…

You would not have the first clue how to calculate warranty claims projections. You laughed at the idea of fatigue failures earlier. If you came out with this sort of talk in the pub, in an area of the world which does design engineering, complete strangers would tell you to shut your mouth. I’ve actually seen this happen, on the train. There were some young men talking magazine talk about motor engineering. An older man leaned over them, introduced himself as a middle manager in an engineering department at Canley, and told them to stop it. The entire carriage, which was full of production line workers and administrative staff on their way home from work, burst into a round of applause.