In pursuit of engine excellence 1920/30's.
Discussion
I've always been a motorsport-orientated petrolhead but most of the pre-war stuff has been of little interest to me over the years. My main focus has always been on the 60/70's era because that it when I developed spots, graduated from short to long trousers and discovered Brut 33.
Maybe its an age thing but recently I've been focussing on the pre-war era. Great books such as DSJ's AFN (Frazer Nash) story and Quentin Spurring's 2 volumes on the pre-war decades at Le Mans.
What has struck me is the avalanche of (engine) technological advances that were being forged during the 20/30's. OHC (often twin), forced induction, alloy blocks, hemi heads, fancy multi carb set ups, 4V per cylinder, desmodromic valves etc etc.
OK this was largely competition car technology & some of it carried over post-war in the more exotic offerings but your average mass produced car laboured on post war with a pushrod, 2V per cylinder head, cast iron boat anchor until things livened up in the 1980's.
Purely down to economics ?
Maybe its an age thing but recently I've been focussing on the pre-war era. Great books such as DSJ's AFN (Frazer Nash) story and Quentin Spurring's 2 volumes on the pre-war decades at Le Mans.
What has struck me is the avalanche of (engine) technological advances that were being forged during the 20/30's. OHC (often twin), forced induction, alloy blocks, hemi heads, fancy multi carb set ups, 4V per cylinder, desmodromic valves etc etc.
OK this was largely competition car technology & some of it carried over post-war in the more exotic offerings but your average mass produced car laboured on post war with a pushrod, 2V per cylinder head, cast iron boat anchor until things livened up in the 1980's.
Purely down to economics ?
moffspeed said:
Purely down to economics ?
Possibly.Align technological innovation to Kondratiev Waves (K-Waves) and your timescale fits with the 40-60 year cycles proposed in this theory.
Basically, new technology is introduced (in this case, the car). Development takes place rapidly over the next couple of decades, after which it starts to stagnate a little. Then something comes along that kickstarts it all over again. In your 1980s example that could be the advent of efficient fuel injection, economic prosperity encouraging widespread car ownership or the increase in models offered by manufacturers to fill (or indeed create) a niche market.
Rinse and repeat: 40 years on from the early 1980s we now have the explosion of EVs (pun fully intended), driverless cars etc.
moffspeed said:
Purely down to economics ?
Also, War.You'll have some advances made during WW1 which are picked up by civilian engineering in the 20s.
I believe the Germans in that period were getting around their Versailles Treaty restrictions by using motorsport as a testbed for technologies that could also be useful for military purposes.
Alfa Romeo and Lancia carried a certain amount of race tech into their mass produced cars from the 1950's onwards. In the UK, Jaguar had some good engine offerings post-war. On the other hand, pre-war beauties like Riley, which had some gorgeous vehicles, the 1930's Kestrel 14/6 with straight six alloy overhead cams and pre-selector gearboxes for example, I think were amalgamated into BMC, and so cast iron and mallets it was going forward into mass production unfortunately. Even Issigonis with the post war Morris Minor (Mosquito project) designed in a new flat 4 engine and independant suspension all round, but of course, the pre-war wheezy side valve from the Morris 8 and cart springs were to hand for Lord Nuffield, who hated the "poached egg" design anyway.
Truckosaurus said:
moffspeed said:
Purely down to economics ?
Also, War.You'll have some advances made during WW1 which are picked up by civilian engineering in the 20s.
I believe the Germans in that period were getting around their Versailles Treaty restrictions by using motorsport as a testbed for technologies that could also be useful for military purposes.
the first cars were exploring everything Loads of things didnt work, some did. Over time these were refined and developed.#
It was very hard to produce engines (well, anything) to a decent tolerance. Oils weren't very good, spark plugs were poor, bad fuel too.
I remember years ago reading an article from when Crosthwaite and Gardner rebuilt the pre-war Auto Unions GP cars (when the Iron curtain fell and people conned their owners into selling them and made a mint. But hey, Capitalism!!)
They coudnt get the head to seal- if they tightened it down enough to make the seal, it would crask. So they sent off a piece of the original alloy to British steel for analysis.
The report can back identifying the metal and said something like "suggested uses: garden furniture"!!
It was very hard to produce engines (well, anything) to a decent tolerance. Oils weren't very good, spark plugs were poor, bad fuel too.
I remember years ago reading an article from when Crosthwaite and Gardner rebuilt the pre-war Auto Unions GP cars (when the Iron curtain fell and people conned their owners into selling them and made a mint. But hey, Capitalism!!)
They coudnt get the head to seal- if they tightened it down enough to make the seal, it would crask. So they sent off a piece of the original alloy to British steel for analysis.
The report can back identifying the metal and said something like "suggested uses: garden furniture"!!
williamp said:
the first cars were exploring everything Loads of things didnt work, some did. Over time these were refined and developed.#
It was very hard to produce engines (well, anything) to a decent tolerance. Oils weren't very good, spark plugs were poor, bad fuel too.
I remember years ago reading an article from when Crosthwaite and Gardner rebuilt the pre-war Auto Unions GP cars (when the Iron curtain fell and people conned their owners into selling them and made a mint. But hey, Capitalism!!)
They coudnt get the head to seal- if they tightened it down enough to make the seal, it would crask. So they sent off a piece of the original alloy to British steel for analysis.
The report can back identifying the metal and said something like "suggested uses: garden furniture"!!
That's a little unfair. If there was any prospect that the cars would be worth tens of millons now, the likes of Colin Crabbe and the Karassiks would have found themselves competing with a lot more bidders. Their efforts to retrieve and rebuild, and race (!), these cars are thoroughly commendable. Crabbe and Neil Corner used to race these things in club meetings at British racetracks. Now, they're on a fIt was very hard to produce engines (well, anything) to a decent tolerance. Oils weren't very good, spark plugs were poor, bad fuel too.
I remember years ago reading an article from when Crosthwaite and Gardner rebuilt the pre-war Auto Unions GP cars (when the Iron curtain fell and people conned their owners into selling them and made a mint. But hey, Capitalism!!)
They coudnt get the head to seal- if they tightened it down enough to make the seal, it would crask. So they sent off a piece of the original alloy to British steel for analysis.
The report can back identifying the metal and said something like "suggested uses: garden furniture"!!
king plinth at Goodwood. (The cars, not the people.)[quote=williamp]the first cars were exploring everything Loads of things didnt work, some did. Over time these were refined and developed.#
It was very hard to produce engines (well, anything) to a decent tolerance. Oils weren't very good, spark plugs were poor, bad fuel too.
Yes, agree with that. It applied to all the ancillaries & tyres in particular.
Suddenly cars were running at 100mph + at Le Mans and although the track surface improved year on year the tyre technology wasn’t there to cope with the challenge of such high speeds.
Witness 1931 at LM where the Bugattis were throwing tyre treads every hour or so. One team car crashed on the Mulsanne as a result of tyre failure & the other Bugs were withdrawn from the race. Meanwhile the monstrous Mercedes SSK was shredding its Englebert tyres even faster but a mid race change of tyre supplier (thank you Mr Dunlop) allowed it to salvage 2nd place.
Technology moves on but half a century later Sauber would withdraw their LM entries as a result of tyre failures…..
It was very hard to produce engines (well, anything) to a decent tolerance. Oils weren't very good, spark plugs were poor, bad fuel too.
Yes, agree with that. It applied to all the ancillaries & tyres in particular.
Suddenly cars were running at 100mph + at Le Mans and although the track surface improved year on year the tyre technology wasn’t there to cope with the challenge of such high speeds.
Witness 1931 at LM where the Bugattis were throwing tyre treads every hour or so. One team car crashed on the Mulsanne as a result of tyre failure & the other Bugs were withdrawn from the race. Meanwhile the monstrous Mercedes SSK was shredding its Englebert tyres even faster but a mid race change of tyre supplier (thank you Mr Dunlop) allowed it to salvage 2nd place.
Technology moves on but half a century later Sauber would withdraw their LM entries as a result of tyre failures…..
OP- have a read of The Secret Horsepower Race by Calum Douglas. It’s about ww2 aircraft engines but lots of the info will be right up your street. It’s written in a very readable style by a Formula 1 engineer.
Loads of info about why fuel injection wasn’t adopted much earlier, the use of better fuels being limited by spark plug technology and loads of other stuff that isn’t immediately obvious. Well worth a read.
Loads of info about why fuel injection wasn’t adopted much earlier, the use of better fuels being limited by spark plug technology and loads of other stuff that isn’t immediately obvious. Well worth a read.
As others have noted there were a lot of "secondary bottlenecks" such as material technologies (to produce strong, light, rigid components), oil quality, progresses in fluid dynamics, availability of high-octane fuels, etc, etc and without these issues resolved (or without them being soluble in mass production) the value of the obvious "Top Trumps" tech (ohc, 4v, etc) was marginal.
The Talbot in my garage is a good example; iron block, 2V, pushrod, "bathtub" heads, single carb but with specific output (93hp from 2.3lt) it's about as efficient as could have been hoped-for in 1930 without needing trick fuel, moonshot materials or introducing the cost, complexity and refinement issues that went with forced induction. Throwing extra valves, ohcs and multiple carbs would probably yield little or no more power - there are plenty of lower-output 30s cars *with* all that gubbins!
The Talbot in my garage is a good example; iron block, 2V, pushrod, "bathtub" heads, single carb but with specific output (93hp from 2.3lt) it's about as efficient as could have been hoped-for in 1930 without needing trick fuel, moonshot materials or introducing the cost, complexity and refinement issues that went with forced induction. Throwing extra valves, ohcs and multiple carbs would probably yield little or no more power - there are plenty of lower-output 30s cars *with* all that gubbins!
Also bear in mind that taxation of cars used to promote long stroke engines.
Which were also perhaps better for everyday use on poor roads with limited numbers of gear ratios?
The old type mainshaft/layshaft gearbox wasn't doing much in top gear, which is quiet and efficient as well as less demand on metallurgy of gears.
As with the 'classics with disappointing performance' thread, car makers knew their market.
Buyers did not always want the fastest, they wanted easy to drive cars which were cheap on tax and insurance, and would survive on poor maintenance and poor oil.
Not that many generations ago, 'performance' engines were fairly easy to blow up or wear out in a short time.
We've become used to engines giving over 100bhp/litre and lasting 100,000 miles on routine maintenance, when I were a lad, your sportier British bikes generally needed serious work before 15,000 miles, so your BSA Gold Flash was a more sensible purchase than a Gold Star for many.
Also higher performance engines are more sensitive to errors in mixture and timing, you had to spend a lot of time or money keeping nice engines properly fettled. Even my 60s cars used to need frequent points and carb adjustment, I can recall setting timing with a dial gauge when there's nothing to strobe. My Dad used to have pre-war and immediate post-war bike maintenance books, it looked a lot harder than the 70s!
Which were also perhaps better for everyday use on poor roads with limited numbers of gear ratios?
The old type mainshaft/layshaft gearbox wasn't doing much in top gear, which is quiet and efficient as well as less demand on metallurgy of gears.
As with the 'classics with disappointing performance' thread, car makers knew their market.
Buyers did not always want the fastest, they wanted easy to drive cars which were cheap on tax and insurance, and would survive on poor maintenance and poor oil.
Not that many generations ago, 'performance' engines were fairly easy to blow up or wear out in a short time.
We've become used to engines giving over 100bhp/litre and lasting 100,000 miles on routine maintenance, when I were a lad, your sportier British bikes generally needed serious work before 15,000 miles, so your BSA Gold Flash was a more sensible purchase than a Gold Star for many.
Also higher performance engines are more sensitive to errors in mixture and timing, you had to spend a lot of time or money keeping nice engines properly fettled. Even my 60s cars used to need frequent points and carb adjustment, I can recall setting timing with a dial gauge when there's nothing to strobe. My Dad used to have pre-war and immediate post-war bike maintenance books, it looked a lot harder than the 70s!
OutInTheShed said:
Also bear in mind that taxation of cars used to promote long stroke engines.
Which were also perhaps better for everyday use on poor roads with limited numbers of gear ratios?
The old type mainshaft/layshaft gearbox wasn't doing much in top gear, which is quiet and efficient as well as less demand on metallurgy of gears.
The point on driving characteristics and the tax-HP (based on bore diam, hence long stroke designs being common) system is well made. Consumers and designers put a lot of emphasis on a car being able to drive around in top gear, only needing 1-3 for steep hills, spirited acceleration and dead-stops; and over-square designs worked for that. Which were also perhaps better for everyday use on poor roads with limited numbers of gear ratios?
The old type mainshaft/layshaft gearbox wasn't doing much in top gear, which is quiet and efficient as well as less demand on metallurgy of gears.
Which comes back to the utility of many Top Trumps technologies. If your engine is heavily over-square and completely out of ideas at 4,500rpm, what end does a head/valve-gear with huge flow potential serve? This is especially true in an era where the subtleties of timing, swirl, flame spread, etc, etc (which in combination served massive ends in terms of not just power but combining power with driveability) just weren't well understood.
Racing rules have an influence too, cc is an arbitrary limit, in some contexts, if you want more power, just get a bigger engine!
A lot of the 'top trumps ' concepts were out there in aero and marine engines a very long time ago, 4 valve heads, overhead cams, injection etc, lots of people tried them in cars too soon and failed to make any money. At the end of the day it's about selling cars and bikes at a profit. Too many failures of too-high tech doesn't win commercially in a mass market.
A lot of the 'top trumps ' concepts were out there in aero and marine engines a very long time ago, 4 valve heads, overhead cams, injection etc, lots of people tried them in cars too soon and failed to make any money. At the end of the day it's about selling cars and bikes at a profit. Too many failures of too-high tech doesn't win commercially in a mass market.
AmyRichardson said:
Which comes back to the utility of many Top Trumps technologies. If your engine is heavily over-square and completely out of ideas at 4,500rpm, what end does a head/valve-gear with huge flow potential serve? This is especially true in an era where the subtleties of timing, swirl, flame spread, etc, etc (which in combination served massive ends in terms of not just power but combining power with driveability) just weren't well understood.
Perhaps I'm not reading this correctly but do you mean undersquare rather than oversquare? An oversquare engine will rev happily as the bore is larger than the stroke. OutInTheShed said:
Racing rules have an influence too, cc is an arbitrary limit, in some contexts, if you want more power, just get a bigger engine!
A lot of the 'top trumps ' concepts were out there in aero and marine engines a very long time ago, 4 valve heads, overhead cams, injection etc, lots of people tried them in cars too soon and failed to make any money. At the end of the day it's about selling cars and bikes at a profit. Too many failures of too-high tech doesn't win commercially in a mass market.
Yes the pace of progress was dazzling in those pre-war years.A lot of the 'top trumps ' concepts were out there in aero and marine engines a very long time ago, 4 valve heads, overhead cams, injection etc, lots of people tried them in cars too soon and failed to make any money. At the end of the day it's about selling cars and bikes at a profit. Too many failures of too-high tech doesn't win commercially in a mass market.
Focussing on Le Mans the square-rigged design typified by the Bentleys in the 1920's persisted into the early 1930's but by 1937 most of the field were looking at not only efficient engines but also aero. A couple of examples as run by Adler & Bugatti.
Airflow under the car was also being considered with some competition cars running full-length under-trays. I guess it took us another 4 decades or so to join the dots up on that one...
rovermorris999 said:
AmyRichardson said:
Which comes back to the utility of many Top Trumps technologies. If your engine is heavily over-square and completely out of ideas at 4,500rpm, what end does a head/valve-gear with huge flow potential serve? This is especially true in an era where the subtleties of timing, swirl, flame spread, etc, etc (which in combination served massive ends in terms of not just power but combining power with driveability) just weren't well understood.
Perhaps I'm not reading this correctly but do you mean undersquare rather than oversquare? An oversquare engine will rev happily as the bore is larger than the stroke. Forums | Classic Cars and Yesterday's Heroes | Top of Page | What's New | My Stuff