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Why were there no supercharged Grand Prix cars 1966 to 1976?


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#51 Charlieman

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Posted 25 March 2019 - 10:52

Changing the subject ever so slightly something that has always puzzled me was the Flat 16 Climax engine. Why would a down to earth English Midlands company like Coventry Climax build such a complicated unit knowing that it almost certainly would never be raced? Makes no sense to me unless they knew something, had some plan which would have made sense but disappeared with the Climax withdrawal.

My understanding is that Coventry Climax intended the racing and road car engine division to be a profit generating business. Right at the start, Coventry Climax ordered parts for 100 FWA engines so they had confidence that they had something better than other manufacturers. The four cylinder engines were expensive but a better prospect than the alternatives. The 1.5 litre V8 engines were very expensive but every top team ordered them -- or the V8 BRMs. Sir Alfred Owen had told BRM that they had to make money selling services, chassis and engines several years previously. We can assume that the V8 engine businesses were profitable for both BRM and Coventry Climax. 

 

When Jaguar shut down Coventry Climax's racing engine division, the "spares" were purchased by Bob King. According to the book on Royale cars history, the parts included the usual spares, unmachined components and major assemblies. Coventry Climax were down to earth but had invested a lot in running a professional business.

 

Why build a flat 16 1.5 litre engine? I can understand how the project might have kicked off. Unlike others, Coventry Climax had a history of delivering designs and the flat 16 had been peer reviewed by people with experience and history. Had a rethink and redesign been completed, the engine might have been more desirable and more expensive than the V8. But that is just what-iffery. It is more of a mystery to me how the project continued after Jaguar's acquisition. However I don't think we can blame it for Coventry Climax's withdrawal from motor sport; the racing division just didn't fit in with Jaguar's plans.



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#52 RogerFrench

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Posted 25 March 2019 - 17:03

I'd imagine the 2:1 equivalence was a temptation to build blown 1.5s. The 3.33:1 of the previous formula hadn't tempted anyone (pace DB) to make a serious effort.

#53 Henri Greuter

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Posted 25 March 2019 - 17:59

I'd imagine the 2:1 equivalence was a temptation to build blown 1.5s. The 3.33:1 of the previous formula hadn't tempted anyone (pace DB) to make a serious effort.

 

Even easier....

 

It was `offered` to the then current builders of the superseeded 1.5 liters as an option to put blowers on thier existing hardware, of course a bit modified to cope with the higher outputs, higher temperatures etc. But it simply would have taken way too much efforts to `blow` a Coventry Climax or BRM V8. As already pointed out, lots of knowledge about blown engines was kind of lost in the past decade(s) and of little relevance since in the last decades of supercharged engines they ran on those exotic fuel blends that were forbidden by now. There was so much that had to be learned all over again.

 

Just for fun to mention, the late 20's supercharged Miller 91 Straight eights (1.5 liter) have been documentated to run primarily on gasoline fuels but with awful amounts of Tetra-Ethyl-Lead (in short `Lead`) to allow higher compression ratios and prevent `knocking`.

It is said that when Leon Duray set the track records at Indy in 1928 that, despite his reputation on developping alcohol based fuels, he set the records on gasoline with unreal amounts of `Lead` for fuel. The joke I heard about it was that he used so much `Lead` that his exhaust pipe almost was like a machinegun of `shooting` lead, be it not as bullets but in atomics....



#54 Wuzak

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Posted 04 April 2019 - 01:17

Would water injection have been legal in 1966? This would have certainly gone a long way toward helping the power output. From memory water injection was also used in WW2 aircraft, but don't quote me.

 

Yes, many WWII were equipped with water injection, termed Anti-Detonation injection (ADI) in the US. 

 

Typically ADI used a blend of water and methanol, usually about a 50/50 ratio.

 

Germans used water/methanol injection extensively with the MW50 system. This improved low down performance (increased boost reduced full throttle height/critical altitude)..

 

The other performance enhancing injection system used in Germany was the GM-1 nitrous oxide injection. This was used for more altitude power.

 

The British also nirous oxide injection experimentally, in a squadron on Mosquitoes in order to catch V-1 flying bombs.

 

I don't believe any British production engines used ADI during the war, certainly not the Rolls-Royce Merlin and Griffon, although it was used experimentally. The Packard V-1650-9 version of the Merlin did use ADi, and was introduced in the P-51H in 1945.

 

Most US radials had ADI versions, notably the R-2800. The Allison V-1710 also used ADI in some versions, particularly the 2 stage versions, most of which did not have an intercooler or aftercooler.



#55 Wuzak

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Posted 04 April 2019 - 01:39

WW2 plane engines used air to air and air to coolant variants. Both s/c and turbo which the Yanks preferred.


The US Army Air Corps/Force preferred the turbocharger, the US Navy preferred the supercharger.

 

Turbocharged engines all had intercoolers, but no aftercooler.

 

US engines mostly had air to air intercoolers, and no aftercooler, except for some versions of the 2 stage Allison V-1710 which used a liquid cooled aftercooler.

 

2 stage Merlins and Griffons used an liquid:air aftercooler. But they also had a measure of intercooling, with the coolant being circulated in a water jacket around the supercharger housing.

 

 

Though that was of course to give the engines atmospheric ability, eg ground level and 30000 feet the same available power.


Correct. The turbocharger provided little or no boost to the engine, the aim being to make the engine think that it was at sea level.

 

As well as short term, take off power for heavily laden bombers.


The turbochargers weren't providing boost at take-off.

 

I read recently that 617 Lancasters with the 10 ton bomb weighed about the same as the bomb.And accounts of the period had 617 Lancs extremely modified both in the frame and engines.


617's Lancasters all had single stage, 2 speed supercharged engines, the Rolls-Royce Merlin.

These provided about 1,600hp for take-off.

The Lancaster B.I (Special) used to carry the Grand Slam bomb had the top and nose turrets removed, as well as the bomb bay doors. A normal Lancaster had an empty weight of about 37,000lb, so it was a bit heavier than the bomb.

It was said that the wings had an extreme bend when carrying the bomb, and would jump several thousand feet higher when it was released.

 

Though with those bombs hanging out the bottom needed the power to get off the ground and defeat the drag at altitude.


The Lancaster, for most variants, had a limited operational ceiling, about 21,000ft - 22,000ft, depending on loading.



#56 Glengavel

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Posted 04 April 2019 - 06:16

Several thousand would be one hell of a jump!

Grand Slams were so expensive that aircraft were ordered to return if conditions meant they were unable to bomb the target. That must have been enormously entertaining for the aircrew.

#57 GreenMachine

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Posted 04 April 2019 - 06:58

Not quite sure when the B1(Special) designation started, but the Dams raid Lancs had the nose turrets for flak suppression - flying straight and level, low altitude, with two big lights shining on the water, they needed all the help they could get to deal with the defences on and around the dam walls.  One of the reasons Gibson got his VC was that he made his own bomb run solo, but then accompanied the later aircraft to draw some of the flak.   

 

The nose turrets were later removed for the Grand Slams, as not needed (they were released at altitude) and for weight reduction.  Those aircraft only had tail turrets.



#58 PayasYouRace

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Posted 04 April 2019 - 08:53

For UK military aircraft, a detail in parenthesis after the Mark number indicates a role fit. So they would just call them (Special) to indicate that they were standard Mk.1 airframes with bits removed as needed. It also indicates that they could be converted back to standard B Mk.1 spec if necessary.

A new Mark number indicates more than a modification but a change at factory level.

#59 Wuzak

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Posted 04 April 2019 - 10:14

Not quite sure when the B1(Special) designation started, but the Dams raid Lancs had the nose turrets for flak suppression - flying straight and level, low altitude, with two big lights shining on the water, they needed all the help they could get to deal with the defences on and around the dam walls.  One of the reasons Gibson got his VC was that he made his own bomb run solo, but then accompanied the later aircraft to draw some of the flak.   

 

The nose turrets were later removed for the Grand Slams, as not needed (they were released at altitude) and for weight reduction.  Those aircraft only had tail turrets.

 

The Dams raid Lancasters were B.III (Special), aka Type 464 Provisioning Lancaster.

 

The difference between the B.III and the B.I was that it used the Packard built Merlin, which used an American injection type carburetor.

 

The mid upper turret and bomb bay doors were deleted, and the hydraulic pump that was for driving the turret was used to drive the hydraulic motor for the Upkeep bouncing bomb. The bomb bay was faired in.

 

The Upkeep bomb was 9,250lb, or 4.2 metric tonnes.

 

The normal maximum bomb load for the Lancaster was 14,000lb.

 

Other large weapons the Lancaster used were the 12,000lb Tallboy (used initially by 617 and then 9 squadrons, developed before the Grand Slam and used more often), the 12,000lb High Capacity and the 8,000lb High Capacity blockbuster bombs. These latter 2 bombs were modular, the 8,000lb version being made in 2 sections and the 12,000lb in 3.

 

The HC bombs were basically steel tubes filled with explosive. 

 

The 4,000lb HC bomb was a normal fitment to Lancasters in area raids.

 

The 8,000lb HC, 12,000lb HC and Tallboy bombs required the fitment of bulged bomb bay doors, and did not require the removal of any turrets, though sometimes they were.



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#60 Charlieman

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Posted 28 April 2019 - 15:12

What were people saying about supercharged and turbocharged engines at the time? I'm reading Colin Campbell's book "Design of Racing Sports Cars", dated February 1973.

 

Campbell's assessment of supercharged engines is pretty much as described here. Regarding turbos, he noted the BMW 2002 project but the book unfortunately predates the appearance of Porsche's Carrera 911 RSR. Campbell correctly predicted that the 2.1 litre turbo sports car engine would work -- he suggested output of 520 bhp, 247 bhp/litre.

 

Campbell estimated the USAC Offy turbo at 700 bhp (270 bhp/litre) and the Ford turbo at 725 bhp (280 bhp/litre). 



#61 Henri Greuter

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Posted 28 April 2019 - 19:09

What were people saying about supercharged and turbocharged engines at the time? I'm reading Colin Campbell's book "Design of Racing Sports Cars", dated February 1973.

 

Campbell's assessment of supercharged engines is pretty much as described here. Regarding turbos, he noted the BMW 2002 project but the book unfortunately predates the appearance of Porsche's Carrera 911 RSR. Campbell correctly predicted that the 2.1 litre turbo sports car engine would work -- he suggested output of 520 bhp, 247 bhp/litre.

 

Campbell estimated the USAC Offy turbo at 700 bhp (270 bhp/litre) and the Ford turbo at 725 bhp (280 bhp/litre). 

 

 

The latter two American Indy engines were more powerful than that in '72.....



#62 Charlieman

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Posted 29 April 2019 - 06:47

The latter two American Indy engines were more powerful than that in '72.....

Campbell noted that 850 bhp had been reported on the dyno and might have been used for qualifying, but that the lower figures were more realistic for race boost.



#63 Pat Clarke

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Posted 29 April 2019 - 09:21

 

The HC bombs were basically steel tubes filled with explosive. 

 

I recall reading somewhere that these bombs were made from old, shot-out battleship gun barrels.

 

Pat



#64 Vitesse2

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Posted 29 April 2019 - 09:53

I recall reading somewhere that these bombs were made from old, shot-out battleship gun barrels.

 

Pat

I think someone was pulling your chain, Pat. The RAF dropped nearly 90,000 of the 4000-pounders alone.



#65 Pat Clarke

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Posted 29 April 2019 - 10:56

Wrong war Vitesse :-)

 

As I said, I vaguely remembered something but in the swirling melange that is my memories these days, I wouldn't bet on anything.

 

But, I was only half wrong...   https://www.wearethe...owitzer-barrels

 

Pat