Yes - all correct. The “M” SMG looked ridiculous when you saw all the stuff laid out. A high school shop kid should’ve seen it was stupid. When they failed, and they did, you had to take the car apart to fix it. Our Italian set up was infinitely simpler, and as far as I can see, worked the same. I guess used in Alfas, where it also didn’t work well, and MAYBE Ferraris. Due to OBD emissions issues when you convert them it is also hard to get them to pass a download emissions check as they throw codes. Does BMW help you with this? You’re joking, right?
I’m a retired licensed, registered mechanical engineer, long time member of the ASME and SAE. This is statement is simply jaw dropping for its lack of any basis in engineering or physics. Please stop.
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So, you can back that up with some basis in engineering or physics? Like why an engine with overlapping power strokes needs a 30-pound flywheel?
Of course I can. But I’m not doing it to appease your ego.
Can you back it up by providing even ONE example of a production car with no flywheel, as I asked? Or are ALL automotive engineers incompetent?
Regards,
Ray L.
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You can’t build a car with no flywheel unless you can figure out some way to live without a clutch. But it is my contention that the only point of a flywheel on any engine with 8 or more cylinders is to provide a drive surface for a clutch. And for optimum performance, you’d want that clutch mounting surface to be as light as possible, for the same reason you’d want every other rotating object in the drivetrain to be as light as possible.
And several of us are telling you that is simply not correct. It is an energy store, that is used both to smooth the engine rotation, and to provide extra inertia to make it easier to get the car off the line without stalling, and ease shifting.
Regards,
Ray L.
You can get the Jaguar V12 off the line without stalling without even using the clutch. Just put it in gear and hit the starter. A flywheel is not needed at all for this. And it doesn’t smooth the engine rotation a whit, it just slows its accels. Just because you have a 30-pound flywheel doesn’t mean it’s a good idea.
Somebody with their tranny out should bolt on a flexplate from an A/T and start the engine up. Tell us how it runs.
You’re a point that has no point. Almost any car can be started in gear using the starter. That says absolutely nothing about driveability. The issue is feathering the clutch to get the car off the line without stalling the engine. Have you ever driven a Jag with a very light aluminum flywheel? I have. Many time. I’ve always hated it.
Getting off the line without stalling requires revving the engine higher than normal, very careful modulation of the clutch, and often slipping it for longer. With the stock flywheel, a complete klutz can get it off the line quickly and easily.
Again, you seem to be assuming you are right, and all automotive engineers are idiots. Does that not make you consider that you might just be wrong? Why don’t all high-performance cars then have VERY light flywheels?
Regards,
Ray L.
I knew if I waited long enough that there’d be a point in this thread where I’d get dragged into it…
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If you had that much trouble with an aluminum flywheel, something other than the aluminum flywheel was the problem. Perhaps a racing clutch, perhaps hot cams, something. An aluminum flywheel shouldn’t make a noticeable difference to clutch operation, other than the engine revs easier.
Does this calculation, which seems to be in error by a factor of roughly 1000, reflect the same arithmetic skills you are using when pontificating about flywheel mass, Kirbert? 
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Something I haven’t seen mentioned yet. Flywheels are also important in ensuring the crankshaft stays healthy.
It’s interesting, to me anyway, to see how much energy the SAE devotes to flywheel research.
https://saemobilus.sae.org/search/?
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So, to summarise your line of reasoning:
You make a wild assertion that someone refutes.
You respond by stating that almost every word of refutation is incorrect
When asked to point out any errors of fact you quote an accurate statement, confirm its accuracy, and then simply declare a personal irrational opposing opinion that it should not be true.
That’s it? That’s your best shot at proving ‘almost every word’ of my accurate call-out was BS? I guess to stay accurate I need to rephrase that ‘line of reasoning’ description. ‘Load of old cobblers’ is more factual (and keeps it civil). I’m not sure which word applies more: chutzpah or meshuggeneh.
The irony is that in your response quoted above, many of the words that follow “Just as an example of being wrong:” are indeed bonkers, but not the ones I wrote.
Still, you know a lot about turbines, I assume.
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My fundamental beef with some forum folks is rarely the quantitative or qualitative point they are making, although in this thread our favourite turbine wallah has confused opinion and fact. It happens a lot on forums but it’s pretty rare amongst listers posting in their supposed area of professional expertise.
My problem is when people devalue the efforts of others without knowing pivotal factors involved in the decisions made at the time.
Pretty much anyone who has been asked to lead a team effort, or even been consulted on their own account to solve a problem, knows it is vital to gather data before coming up with a plan. I have seen this happen many times in sales contexts, where technical or sales people give a fantastic schpiel and find out too late that the available budget or time is 50% of what their proposal would require.
In the case of Jaguar flywheels, we can assume that selling smooth, refined cars was a key Jaguar business objective. The use of selective matched engine components and extensive NVH enhancements, substantial flywheels etc. were vital tools in creating that ‘wow’ moment they wanted every roadtest customer to experience. I have no more insight than anyone else, but it is sad to read repeated derogatory opinions of people’s efforts when even a moment’s consideration and a speck of humility would lead a fair-minded person to hold back on the ‘POS’ and ‘stupid’ insults.
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Yes, I read the synopses, or summaries if you prefer, of many of the SAE articles you can access from the cite I posted. Concern for NVH is a prominent concern, repeated in study after study. .
My 1200 Datsun, with a 305-degree duration cam, and associated race mods, used a 10" Tilton flywheel and multi-disc clutch.
Boy howdy…!!!
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I see what you did there! LOL! A little physics humor!
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I had Datsun Z cars in college, and I was in search of a Datsun 1600 or 2000 roadster when I stumbled across my first XK120.
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The lack of which… guided me towards geology.
I didn’t hafta do math: I just had to identify and pick up heavy rocks.
