88 replies to this topic

[David Birchall]

This discussion caused me to go out to the garage with a tape measure.

Bentley 3.5 crankshaft length 31 inches approx

Aston DB2 (2.6litre) '' 33 inches ''

Alfa Romeo 2600 '' 32 inches ''

Of these the Alfa has the shortest stroke and can rev to 8000rpm but has a critical vibration period at 7000.

The Aston with stock crank is safe to 6000 maybe. Mine has a special billet crank and is safe to 7500.

The Bentley has a billet crank as standard but with a long stroke, weird vibration damper design is limited to 4500 absolutely.

[VAR1016]

This discussion caused me to go out to the garage with a tape measure.

Bentley 3.5 crankshaft length 31 inches approx

Aston DB2 (2.6litre) '' 33 inches ''

Alfa Romeo 2600 '' 32 inches ''

Of these the Alfa has the shortest stroke and can rev to 8000rpm but has a critical vibration period at 7000.

The Aston with stock crank is safe to 6000 maybe. Mine has a special billet crank and is safe to 7500.

The Bentley has a billet crank as standard but with a long stroke, weird vibration damper design is limited to 4500 absolutely.

Well, you have a most interesting garage I must say! Now who's got a LG45 Lagonda and Alvis 4.3 crank they can measure??

I recall that the A-M crank was the one with the dreaded "cheeses" wasn't it?

Paul

Edited by VAR1016, 07 May 2010 - 15:50.

[David Birchall]

I have made some phone calls and have a couple more measurements. I think Terry Walker must be thinking of the earlier RR engine-as used in the Ghost and Phantom 1&2. That had two blocks of three and was enormously long but then again, it was over 7 litres. I am waiting for a friend with a 1913 Ghost to return my call.

Lagonda LG 45 36 inches

Bentley 4 1/4 (1950) 34 inches This is the later engine that was eventually opened up to 4.9 as mentioned by Terry.

Isn't this fun?

[VAR1016]

I have made some phone calls and have a couple more measurements. I think Terry Walker must be thinking of the earlier RR engine-as used in the Ghost and Phantom 1&2. That had two blocks of three and was enormously long but then again, it was over 7 litres. I am waiting for a friend with a 1913 Ghost to return my call.

Lagonda LG 45 36 inches

Bentley 4 1/4 (1950) 34 inches This is the later engine that was eventually opened up to 4.9 as mentioned by Terry.

Isn't this fun?

Fun indeed - yes!

I once saw a Ghost crankshaft - at Serdi's in Uxbridge - to me, used to my V4 Lancias, it looked as though it came out of a ship!

Interesting that the post war 4 1/4 crank is longer; how could this be if it is in the same block/crankcase assembly? And 36" for the Lagonda; the 3 1/2 is starting to look quite dinky! Pity I haven't an XK Jag here to measure up.

I am willing to bet though that a Talbot 110 would be the shortest!

Paul

Edited by VAR1016, 07 May 2010 - 17:57.

[David Birchall]

A friend has a Talbot 105 but I am not sure he has access to it right now.

The postwar Bentley/Rolls engine has no connection to the prewar design-I believe it derived from a military engine Rolls built during WW2.

Still waiting to hear from the Ghost owner...

[elansprint72]

"The Technical Facts of the Vintage Bentley", otherwise known as "the Gen book", has surprisingly little information on crankshafts, other than to say that the 6.5 ltr and 8 ltr shafts are interchangeable.

[VAR1016]

"The Technical Facts of the Vintage Bentley", otherwise known as "the Gen book", has surprisingly little information on crankshafts, other than to say that the 6.5 ltr and 8 ltr shafts are interchangeable.

Interesting to have that confirmed. As I remember, the 6.5-litre's bore and stroke were 100 x 140 (same as the four-and-a-half) and the bore was increased to 110mm for the 8-litre.

Paul

[David Birchall]

Another piece of trivia: We hear about the "heavy crank" and "light crank" Bentley 4 1/2s. I owned two Vauxhall 23/60s-the lower part of the engine is essentially identical to the 30/98and the same dimensions as the Benley-and upon weighing a crank one day found that it was heavier than the Bentley "heavy" crank. Vauxhalls are not known for destroying cranks but they do rev quite nicely.

[VAR1016]

Another piece of trivia: We hear about the "heavy crank" and "light crank" Bentley 4 1/2s. I owned two Vauxhall 23/60s-the lower part of the engine is essentially identical to the 30/98and the same dimensions as the Benley-and upon weighing a crank one day found that it was heavier than the Bentley "heavy" crank. Vauxhalls are not known for destroying cranks but they do rev quite nicely.

I have wondered about the "heavy crank" business. The heavy version came I understand, from the "blower" model. Was it just a case that close to the end, Bentley's found that they had a stock of "blower" cranks lying about and decided to use them? I think it was Cecil Clutton who wrote concerning the heavy crank, that "the engine proved unequal to rotating this enormous mass of metal." Strange: if the 23/60 could rotate it then surely the 4 1/2 could?

[David Birchall]

I received a reply from my Ghost friend --crankshaft length 42 inches!

[VAR1016]

I received a reply from my Ghost friend --crankshaft length 42 inches!

Ha ha! Size isn't everything is it?

I suppose that maximum revs on a Ghost were probably <2500, so perhaps problems never arose.

I would certainly love to drive one, naturally one of those lovely sporting ones from 1914 or thereabouts. There was once an historic car rally at Crystal Palace, late sixties/early seventies I suppose, and with my father I spoke with a nice chap who had a beautiful pre WWI Ghost with the sort of coachwork that was so attractive and sporting. I asked what it was like to drive on the road, and he said: "Lovely and so relaxing: in the Ferrari, one is always catching people up..."

Paul

Edited by VAR1016, 07 May 2010 - 21:47.

[David Birchall]

We have a Ghost of that type locally-very elegant and light. London-Edinburgh I think they call it.
Since you have mentioned the Talbot 110 I looked in Anthony Blight's book and found the following-The Talbot crank is approx 1 1/2 inches shorter than a Jag XK crank but most importantly, the reciprocating weight of the Talbot parts is only 2/3 that of the Jag.

[Terry Walker]

The postwar 4.25 Bentley engine was an automotive adaption of the military B60 engine, which was all cast iron. The Bentley version had an alloy head and twin SUs and other mods. But the bore and stroke, and bore spacing, were identical to the prewar 4.25 litre R-R and Bentley engines. Sort of full circle: the military B-series was developed in the late 30s by "ruggedizing" and simplifying the car engine, making it much tougher for heavy use, and then after the war it was adapted yet again for passenger car use.

R-R got a long run out of their machine tools by keeping the same crankshaft stroke, and bore spacing, from 1922 to 1959!

And you're right about one iron block of six pots between the alloy crankcase and alloy head in the prewar engines, not two blocks of three. My memory wobbled.

[VAR1016]

We have a Ghost of that type locally-very elegant and light. London-Edinburgh I think they call it.
Since you have mentioned the Talbot 110 I looked in Anthony Blight's book and found the following-The Talbot crank is approx 1 1/2 inches shorter than a Jag XK crank but most importantly, the reciprocating weight of the Talbot parts is only 2/3 that of the Jag.

Yes "London-Edinburgh"; beautiful. And thanks for the confirmation of the shortness of the Talbot crank; there was some correspondence about this in Motorsport donkey's years ago, if I am correct involving Roesch himself, and I remember that Roesch liked large diameter but narrow bearings - to keep the crank short - and he also believed in reducing internal frictional losses and obviously, reciprocating weight. I could go even further off-topic, but that would be too naughty...

[VAR1016]

The postwar 4.25 Bentley engine was an automotive adaption of the military B60 engine, which was all cast iron. The Bentley version had an alloy head and twin SUs and other mods. But the bore and stroke, and bore spacing, were identical to the prewar 4.25 litre R-R and Bentley engines. Sort of full circle: the military B-series was developed in the late 30s by "ruggedizing" and simplifying the car engine, making it much tougher for heavy use, and then after the war it was adapted yet again for passenger car use.

R-R got a long run out of their machine tools by keeping the same crankshaft stroke, and bore spacing, from 1922 to 1959!

And you're right about one iron block of six pots between the alloy crankcase and alloy head in the prewar engines, not two blocks of three. My memory wobbled.

Thanks. Yes, R-R certainly got value there - as you say 1922 - 1959 was quite a run. And your "full circle" point is well made!

Meanwhile slightly back on topic, a lap of Le Mans in a Turbo R. Here at the garage (in France) we have a Turbo R and a Turbo S (and an Arnage in fact), but this Turbo R appears to be quite rapid

This I think is the same car. I wonder if he does any real racing?

Paul

[Terry Walker]

Way OT now, but: London-Edinburgh Ghost, at RREC Rally 2004:

[Jesper O. Hansen]

One of the more intreeguing entries not to make it to Le Mans is one you can find on some of the more complete Le Mans 24h results sites around. In 1952 a Bentley Continental Registration number OLG490, so obvious a very specific car, was entered by the organising club ACO itself, but listed as "Did not arrive". Of further interest it was to be driven by no less than the founding father of the race itself Charles Faroux, who would have been 79 years of age by the time of the race!

Jesper

Edited by Jesper O. Hansen, 08 May 2010 - 08:21.

[VAR1016]

Way OT now, but: London-Edinburgh Ghost, at RREC Rally 2004:

Thanks Terry; they're lovely aren't they?

[VAR1016]

One of the more intreeguing entries not to make it to Le Mans is one you can find on some of the more complete Le Mans 24h results sites around. In 1952 a Bentley Continental Registration number OLG490, so obvious a very specific car, was entered by the organising club ACO itself, but listed as "Did not arrive". Of further interest it was to be driven by no less than the founding father of the race itself Charles Faroux, who would have been 79 years of age by the time of the race!

Jesper

Fascinating, Jesper. It would be great to know the story behind this wouldn't it? Wiki tells me that he was Course Director at Le Mans up to 1956, at which time he was 84. He died in 1957.

When I read the name "Faroux" I'm more inclined to think of 120HP Panhards, enormous FIATs, Mercedes and Richard Brasiers!

[elansprint72]

Interesting to have that confirmed. As I remember, the 6.5-litre's bore and stroke were 100 x 140 (same as the four-and-a-half) and the bore was increased to 110mm for the 8-litre.

Paul

Apologies for not adding another "fact" (I sensed that this was, predominantly, a post-WO thread) "The heavy 4.5 crankshaft has the supercharger driving spigot cut off".

[VAR1016]

Apologies for not adding another "fact" (I sensed that this was, predominantly, a post-WO thread) "The heavy 4.5 crankshaft has the supercharger driving spigot cut off".

Yes I think it was supposed to be a post-WO thread

I must say that I like the relaxed meanderings that are possible on this forum and also on the Technical Forum; one learns all sorts of interesting and sometimes arcane, things!

[Bjorn Kjer]

While trying to help the Bentley Drivers Club on transporters , it does seem that they were driven to the races , both pre and after war time.

I will however point to post 36 , part 2 of my post , which may have drowned a bit in all the informations :

In about 1945 a 6,5l. Bentley was converted into a station wagon , and used by the HRG team at the SPA 24 hours in 1948 as a team car. Now this is both a Bentley and a HRG question , but.......any ideas ?

[MarkBisset]

 

TNFer Tony John’s (and buddies) ‘Vintage Bentleys in Australia’ tells me Keith Gender’s 3-litre Bentley, chassis #943 is a ‘Standard Colonial’ model built in 1925, delivered to the Colonies in 1928.

 

Here he is racing it on the Woodside road circuit in the Adelaide Hills, perhaps during the Labour Day 1947 meeting 

 

Photo: John Medley Collection

Edited by MarkBisset, 24 April 2022 - 04:36.

[cooper997]

Mark, correct. South Australia Labour Day Monday October 13, 1947. He's listed in Event 7 - 30 mile Handicap (10 laps) 3.20pm.

 

 

Stephen

[MarkBisset]

Thanks Stevo,

I managed to circulate around Victor, Lobe and Nuri in my Adelaide three year sojourn but never did the easiest one to access of the lot! 
Must put a few shots up, I see there is an old Woodside thread.

 

m

[Lee Nicolle]

Thanks Stevo,

I managed to circulate around Victor, Lobe and Nuri in my Adelaide three year sojourn but never did the easiest one to access of the lot! 
Must put a few shots up, I see there is an old Woodside thread.

 

m

I never knew of a Woodside track. The other three yes.

[Charlieman]

 

TNFer Tony John’s (and buddies) ‘Vintage Bentleys in Australia’ tells me Keith Gender’s 3-litre Bentley, chassis #943 is a ‘Standard Colonial’ model built in 1925, delivered to the Colonies in 1928.

Standard Colonial? Higher ride height and beefier springs, like other colonial models, or did Bentley add something more? 

[MarkBisset]

Hi Charlieman,

 

Vintage Bentleys in Oz - writing about 1924 - says “Bentley’s concession to their overseas market was the introduction of a ‘Colonial’ model, with 880 rather than 820 tyres for increased ground clearance and a lower back axle ratio.”

 

I suspect, to your point, nothing different for Australia.

 

m

 

 

Fred Brodribb was both a Bentley competitor and the major importer to Australia until The Depression (Vintage Bentleys in Australia)

Edited by MarkBisset, 25 April 2022 - 22:19.

[Ray Bell]

One of the delights of Woodside is the sign in the children's playground along what used to be the main straight...

 

This was the main road out to Kayannie and Mount Torrens corners and through Charleston on the Lobethal circuit (Onkaparinga Valley Road), it crossed the railway at an angle and near that railway crossing was a playground:

 

 

The sign used to read (I have no idea if it's still there...) that the playground had been built with moneys from the motor racing, and maintained on the proceeds of the leftovers invested for the purpose. As at 1977 the people at the council told me that still held true.

 

On the map there you'll see the Amy Gillett bikeway. This follows the line of the railway, but not where it crosses the road. Obviously the safety of cyclists led to that being a perpendicular crossing.

 

Unfortunately, these blokes...

 

 

...aren't likely to be coming out of Riverview Road and racing towards the cyclists any more.

[Michael Ferner]

Large Tablet with a Maybach - sounds like an order in a restaurant!

[MarkBisset]

 

Interesting story re use of funds raised Ray.

 

This start shot (?) is of the same pair - Jones and Whiteford - at the same October 1951 meeting. The building in the background (top left) is the same one as in the first, Bentley, shot above. What corner does that make it? 
 

(David Zeunert Collection)

Edited by MarkBisset, 26 April 2022 - 19:20.

[Ray Bell]

This is the start, on this occasion in Riverview Road...

 

Whiteford actually passed Jones before the first corner, so the pic I posted might be just a few seconds after this one.

 

Note particularly, however, that this was Australia's first race ever run to Formula One regulations. Note that there are no smaller cars in the event, they ran in F2, while later the fields were combined and Whiteford ran off the road while trying to catch Jones.

 

As for the Bentley, I have two options here. Or three. It's either the turn off the Onkaparinga Valley Road into Nairne Road, or it's the sharp turn Nairne Road makes at the corner with Tolmer Road and William Street. However, as that house is not there, and at the latter corner a very different house of that era exists, and because Nairne Road doesn't continue across the Onkaparinga Valley Road and there are business premises there where the spectators are standing in this picture, I rather suspect that the photo comes from somewhere else.

[john medley]

I didnt write down my observations back then-- but I walked both sites back then. My memory tells me the first pic (with the Bentley) was taken at Woodside circuit's NW 90 degree corner ( at the top of  the hill out of Woodside), the other near what had been a wartime military camp, with that army ? hut in the background. The two buildings depicted are not one and the same, and the building behind the Bentley was still there when I looked perhaps 20-30 years ago( Nairne Road sounds familiar).

[Catalina Park]

The house in the background of the Bentley photo is in William street. It's still there.

[Ray Bell]

You're right, Michael, I didn't take Street View far enough up William Street...

 

John, the army base provided the paddock area for the races, there's a driveway into it right behind where the cars are starting the race.

[MarkBisset]

 

 

Thanks for all of that guys, so annoyed I didn’t have a reccy-mission when I had the chance.

 

The only other ‘locational’ shot I’ve got is this State Library of SA one of Whiteford’s Bess ahead of the Jackson and Martin T-Specials during the Woodside Handicap during the October 1949 meeting.

 

It doesn’t appear to be the same corner as the Whiteford/Jones cornering shot 

[Ray Bell]

I think you'll find that it is, Mark...

 

And do you like the way Doug is studying the cameraman?

[Michael Ferner]

I think he's checking the mirror...?

 

 

Edited by Michael Ferner, 27 April 2022 - 13:07.

[Ray Bell]

Could be, but I don't think so...

 

The other point about the location is that the railway tracks are visible on the entry to the corner. Definitely the Riverview Road-Onkaparinga Valley Road intersection.