45 replies to this topic

[arttidesco]

Here are a few McLaren M7 questions arising from the Jo Bonnier thread :-

Ah, but the plot now thickens. I've been back through the contemporary race reports in Autosport. At the 1969 International Trophy Simon Taylor carefully explained the genesis of the M7C, and that the chassis plate on it read 'M7A/004'. However, at the very next race (Spanish GP) the Autosport race statistics refer to the car as 'M7C-1', and continue to use that designation for the rest of the car's GP career. There must have been a good reason for this ...

What I don't understand why McLarens would have advance paperwork for MT7C-1 and then race the car as M7A-004

Thanks for the chassis number clarification Tim

Still not sure where McLaren put the fuel prior to the side tanks being added by SRO ?

It would be interesting to know what became of M7A/004 / M7C-1 after it's days as part of the Eccurie Bonnier team?

Or why M7A-3 became known (in some places) as an M7B?

Thanking you in anticipation :-)

[Nigel Beresford]

M7B began life as M7A-3, and was then fitted with the pannier fuel tanks at the beginning of 1969 because Bruce had a theory that this gave better handling, based on the similar configuration of the CanAm cars. This car was raced by Bruce McLaren at the South African GP and RoC before being sold to Colin Crabbe and driven by Vic Elford.

One off M7C then built using full depth monocoque (i.e upper half of tub was aluminium skin (like the M10A) rather than glass fibre (like the M7A), and this was Bruce's car for the balance of the 1969 season from the International Trophy onwards. The car was then sold on to John Surtees. (source, Eoin Young's "McLaren! The Man, the Cars & the Team") and then on to Jo Bonnier. This chassis was restored at Penske Cars in the mid 2000's and is now in "Monaco Thursday" biplane spec in the McLaren collection.

Incidentally, the upper half of the M7B tub was also integrated aluminium, rather than separate GRP, so it was indeed halfway between the M7A and M7C.

Thanks

Nigel

Edited by Nigel Beresford, 20 September 2010 - 19:44.

[arttidesco]

Nigel thanks for your clarification, would this be the 'Monaco Thursday' biplane spec of the McLaren collection now sitting in the Donington collection per chance ?

If so I believe the F1 chassis, for which Peter Connew designed the external fuel tank mods, while working for John Surtees in 1970, now has the engine McLaren 'lent' to him for his own Connew PC1 project in 1972, sitting in the back !

Edited by arttidesco, 20 September 2010 - 20:22.

[Nigel Beresford]

Nigel thanks for your clarification, would this be the 'Monaco Thursday' biplane spec of the McLaren collection now sitting in the Donington collection per chance ?

If so I believe the F1 chassis, for which Peter Connew designed the external fuel tank mods, while working for John Surtees in 1970, now has the engine McLaren 'lent' to him for his own Connew PC1 project in 1972, sitting in the back !

RJ,

Yes, the car at Donington is the car which McLaren commissioned Penske Cars to undertake restoration work on. When we got the car it didn't have the Connew panniers. Hope this helps.

Thanks

Nigel

[arttidesco]

RJ,

Yes, the car at Donington is the car which McLaren commissioned Penske Cars to undertake restoration work on. When we got the car it didn't have the Connew panniers. Hope this helps.

Thanks

Nigel

Thanks Nigel, strange circularity of people and parts revolving around the M7C then :-)

The 'Monaco Thursday' biplane looks immaculate, do I take it you are talking about the restoration being done at the Penske shop in Poole Dorset, UK ?

Would you happen to remember what the engine number was ?

Barry Boor only remembered that the engine was 'in a McLaren at Donington' when I recently contacted him.

I look forward to seeing the M7C at Donington sometime.

[mfd]

Thanks Nigel, strange circularity of people and parts revolving around the M7C then :-)

The 'Monaco Thursday' biplane looks immaculate, do I take it you are talking about the restoration being done at the Penske shop in Poole Dorset, UK ?

Would you happen to remember what the engine number was ?

Barry Boor only remembered that the engine was 'in a McLaren at Donington' when I recently contacted him.

I look forward to seeing the M7C at Donington sometime.

I'm not 100% sure it's still at Donington...here along the M8D from Woking at the FoS
http://www.sportscar...-can-am-car.jpg
Just that recently a friend was allowed to do some measuring and it was at Woking

[arttidesco]

I'm not 100% sure it's still at Donington...here along the M8D from Woking at the FoS
http://www.sportscar...-can-am-car.jpg
Just that recently a friend was allowed to do some measuring and it was at Woking

Maybe one day I'll get an opportunity to make an 'appointment' to see M7C in its deservedly busy schedule

[Nigel Beresford]

Thanks Nigel, strange circularity of people and parts revolving around the M7C then :-)

The 'Monaco Thursday' biplane looks immaculate, do I take it you are talking about the restoration being done at the Penske shop in Poole Dorset, UK ?

Would you happen to remember what the engine number was ?

Barry Boor only remembered that the engine was 'in a McLaren at Donington' when I recently contacted him.

I look forward to seeing the M7C at Donington sometime.

We did a couple of cars at Poole, including an M15 as well. I can't remember much of what was done to the M7C, because I was rather more occupied with our contemporary racing activities, and this project was handled by "Car Build" and "Fabrication" rather than the DO. I do remember that we made the front wing.

I have a pic of it somewhere - I'll dig it out.

[arttidesco]

We did a couple of cars at Poole, including an M15 as well. I can't remember much of what was done to the M7C, because I was rather more occupied with our contemporary racing activities, and this project was handled by "Car Build" and "Fabrication" rather than the DO. I do remember that we made the front wing.

I have a pic of it somewhere - I'll dig it out.

Sounds like happy days Nigel :-)

Look forward to seeing any pics you might have :-)

[mfd]

Look forward to seeing any pics you might have :-)

http://www.flickr.co...in/photostream/

[arttidesco]

http://www.flickr.co...in/photostream/

Breathtaking thanks mike

[arttidesco]

I was thumbing through Anthony Pritchards Directory of Formula One cars just now, could I be correct in thinking that John Surtees had Peter Connew draw up the M7C fuel tank panniers at the beginning of 1970 in order to comply with the new for 1970 requirement to have fuel tanks fitted with rubber fuel bags ?

[Tim Murray]

Now that's interesting. I'd been idly musing that perhaps the extra tank capacity was required because 1970 DFVs were more powerful and thus thirstier than before. If M7C's tank capacity was then reduced by the need to fit rubber bag tanks, it all begins to add up (or does it?).

Edited by Tim Murray, 23 September 2010 - 11:53.

[mfd]

Now that's interesting. I'd been idly musing that perhaps the extra tank capacity was required because 1970 DFVs were more powerful and thus thirstier than before. If M7C's tank capacity was then reduced by the need to fit rubber bag tanks, it all begins to add up (or does it?).

I'm not sure if this helps, but if you look at the M14A introduced in 1970, there's not a bulge or pannier in sight.

Edited by mfd, 23 September 2010 - 13:16.

[arttidesco]

I'm not sure if this helps, but if you look at the M14A introduced in 1970, there's not a bulge or pannier in sight.

Could that be because the M14A was designed to be constructed with the mandated rubber fuel bags from the outset ?

Was fixing pannier tanks to the M7C a cheaper/easier/faster way for John to meet the rubber fuel bag requirement, for an interim car until the TS7 came on stream ?

Anthony Pritchard suggests Matra used similar strategy in 1970 to upgrade their MS80 chassis to MS120 spec.

[mfd]

Could that be because the M14A was designed to be constructed with the mandated rubber fuel bags from the outset ? Was fixing pannier tanks a cheaper/easier/faster way for John to meet the rubber fuel bag requirement, for an interim car until the TS7 came on stream ?

Not sure about that, but Gethin drove an apparently unmodified M7A at the RoC - although this might have been because that event was over a shorter distance.

[arttidesco]

Not sure about that, but Gethin drove an apparently unmodified M7A at the RoC - although this might have been because that event was over a shorter distance.

Might Peter & the McLaren team have got away with a 1969 spec fuel tank in a non championship event to ?

Edited by arttidesco, 23 September 2010 - 14:39.

[mfd]

Might Peter & the McLaren team have got away with a 1969 spec fuel tank in a non championship event too ?

That's exactly what I was thinking, but then there was no bulging tanks on the M7D Alfa in Spain, so I doubt it's the solution. Possibly the M7C tanks were that way for another reason, could just be to do with CoG ? Remarkably similar to the BRM P153...
Just discovered on the cover of Pritchard's book about the 1969 seaon, there is a photo of Bruce McLaren in car #6 (USA & Mexico) with the bulging tanks. Technically he non-started in both, so possibly not too many photos around.

Edited by mfd, 23 September 2010 - 15:31.

[arttidesco]

I only have Anthony's Directory '66 - '86 with Alboreto and Berger on the f/c and Amon on the b/c !

[Nigel Beresford]

'68 Autocourse cites "FPT" as McLaren's fuel bag suppliers. You are correct that the Matra didn't run bags (according to the same book), but certainly F1 McLarens did from the word go (ref 1966 Autocourse). I recall Marstons being used in the 70s.

Nigel

Edited by Nigel Beresford, 23 September 2010 - 16:21.

[arttidesco]

That's exactly what I was thinking, but then there was no bulging tanks on the M7D Alfa in Spain, so I doubt it's the solution.

I don't believe there ever was an M7D, the Alfa car was an M14D, the M14A was 'based on' the M7C, which its self was based on the M10A F5000 chassis.

The M14 had bigger tanks, (?) to accomodate the rubber fuel bags (?), which acording to Anthony necessitated a narrower cockpit, than the M7C.

So I suspect Surtees ditched the original M7C tanks, ie simply did not use them because he couldn't get the rubber bags in and simply added pannier tanks as a stop gap til mid season ?

[mfd]

I only have Anthony's Directory '66 - '86 with Alboreto and Berger on the f/c and Amon on the b/c !

Yes sorry, mine is the annual produced in period

[Nigel Beresford]

I don't believe there ever was an M7D, the Alfa car was an M14D, the M14A was 'based on' the M7C, which its self was based on the M10A F5000 chassis.

The M14 had bigger tanks, (?) to accomodate the rubber fuel bags (?), which acording to Anthony necessitated a narrower cockpit, than the M7C.

So I suspect Surtees ditched the original M7C tanks, ie simply did not use them because he couldn't get the rubber bags in and simply added pannier tanks as a stop gap til mid season ?

Yes, there was an M7D, raced on several occasions by Andrea de Adamich in 1970 and Nanni Galli at Monza.

As stated before, it wasn't a problem for the M7 cars to accommodate fuel bags - they were designed to use them from the word go. As mentioned before there was a lot of experimentation done at the time moving fuel around because of Bruce & Denny's experience with the Can Am car, which handled better than the F1 car. This, of course, doesn't explain Surtees' changes.

Nigel

Edited by Nigel Beresford, 23 September 2010 - 16:32.

[arttidesco]

Yes sorry, mine is the annual produced in period

Yours is probably worth a veritable 'fortune' compared to mine which cost a whacking £9.95 24 years ago

[mfd]

So I suspect Surtees...simply added pannier tanks as a stop gap til mid season ?

but the flared tanks were there before Surtees bought the car, as the photo on my Pritchard book proves.

[Nigel Beresford]

but the flared tanks were there before Surtees bought the car, as the photo on my Pritchard book proves.

Looking at the 1969 Autocourse, it's possible to see RHS add-on tanks on both McLarens at the start of the race in Monza. Other photos from the same meeting show the cars running without these tanks in practice. To me this would indicate that they were only fitted because of worries about making the race distance. I also have pictures of McLaren's M7C with the side tank at Silverstone during the race.

Thanks
Nigel

[arttidesco]

Thanks Nigel and Mike so the mystery of the M7C pannier tanks appears to be resolved in so much as they were designed to be removable from the outset and had been used prior to the introduction of the rubber fuel cell requirement and Big John getting the car in 1970.

I just found this pic of Bruce at Montjuic in 1969 which would seem to confirm that theory but raises another question ?

Look closely at the pic I just found and you'll notice that Bruce is running an asymmetric car, he only has one pannier tank on his right hand side !

Can you discern if that was the case in your Pritchard pic Mike, and your Autocourse Monza pic Nigel ?

[mfd]

Looking at the 1969 Autocourse, it's possible to see RHS add-on tanks on both McLarens at the start of the race in Monza. Other photos from the same meeting show the cars running without these tanks in practice. To me this would indicate that they were only fitted because of worries about making the race distance. I also have pictures of McLaren's M7C with the side tank at Silverstone during the race.

Yes I'd spotted the same thing Nigel. Monza both the M7A & the M7C had a tank on one side, neither resembling the later curvy tanks on both sides of the M7C. I've definately got the photo of car #6 (either from the USA or Mexico) with the curvy tank sides, so I'd guess it would make sense they were there for Canada as well, but I lack photos of that race to confirm it.
There's got to be some reason for the change to that car, which reading contemporary reports hasn't so far informed. I've checked the Doug Nye McLaren book, Automobile Year, Autocourse, Motor Racing Year and the aforementioned Pritchard Annual so far. Unfortunately I don't have Autosport, MN or Road & Track for those races.

[arttidesco]

Yes, there was an M7D, raced on several occasions by Andrea de Adamich in 1970 and Nanni Galli at Monza.


Nigel

Looked again in Anthony's Directory 1966 - 86 and there is no mention of the M7D but there is on Wiki ? Correction accepted with thanks !

[mfd]

Thanks Nigel and Mike so the mystery of the M7C pannier tanks appears to be resolved in so much as they were designed to be removable from the outset and had been used prior to the introduction of the rubber fuel cell requirement and Big John getting the car in 1970.

I've just blown my "last few races theory"! So much so, I'm tempted to delete my previous post.
The photo I have on the book cover with the bulging tank (similar to the Surtees version) is definately Silverstone GP - the big clue is the word L U C A S on a hoarding
I've also noticed that both the M7A & the C ran with a single side tank at Zandvoort, yet the Bruce version was just like the curvy Silverstone one.
I wonder if it's as simple as this? Surtees wanted the spare extra tank but in the interest of symmetry, weight distribution CoG etc asked for a mirror imaged one to be made...

[Nigel Beresford]

I've just blown my "last few races theory"! So much so, I'm tempted to delete my previous post.
The photo I have on the book cover with the bulging tank (similar to the Surtees version) is definately Silverstone GP - the big clue is the word L U C A S on a hoarding
I've also noticed that both the M7A & the C ran with a single side tank at Zandvoort, yet the Bruce version was just like the curvy Silverstone one.
I wonder if it's as simple as this? Surtees wanted the spare extra tank but in the interest of symmetry, weight distribution CoG etc asked for a mirror imaged one to be made...

Unfortunately my dad is no longer alive, otherwise I'd be able to get a first person account of the whys and wherefores of the side tanks. Just to underline, the M7 series cars, like all McLaren F1 cars ever made from '66, were designed to use fuel bladders - it's not the case that the capacity was compromised by having to put bladders in to an existing car. Personally I'd favour the theory that engine development drove fuel consumption beyond what the car was initially designed for.

Nigel

[mfd]

Personally I'd favour the theory that engine development drove fuel consumption beyond what the car was initially designed for.

I think this is the key Nigel. I do have a photo from 1970 where the M7D also had an extra tank - across the board more bhp in those days used more fuel.
I've also read the positioning of the M14 front suspension was rearranged to allow more fuel capacity along the sides of that particular (slimline) tub

[Tim Murray]

Unfortunately I don't have Autosport, MN or Road & Track for those races.

The only relevant photo I can find for these races in Autosport is of McLaren in Canada. Here's a detail from it showing the tank:

The photo I have on the book cover with the bulging tank (similar to the Surtees version) is definately Silverstone GP - the big clue is the word L U C A S on a hoarding

There's a photo of McLaren in the Autosport report in which the bulging side tank can just be seen through the front suspension, and it looks rather different to the one used in Canada. It seems to me that McLaren were continually experimenting with various different designs of side tank, both on M7C and the M7As, and they all seem to be detachable. Could it be that the Surtees mods made the tanks permanent fixtures to the chassis?

[arttidesco]

The only relevant photo I can find for these races in Autosport is of McLaren in Canada. Here's a detail from it showing the tank:




There's a photo of McLaren in the Autosport report in which the bulging side tank can just be seen through the front suspension, and it looks rather different to the one used in Canada. It seems to me that McLaren were continually experimenting with various different designs of side tank, both on M7C and the M7As, and they all seem to be detachable. Could it be that the Surtees mods made the tanks permanent fixtures to the chassis?

Thanks for the pic Tim that strap on tank looks particularly detachable.

As noted by Nigel earlier in the thread the Surtees pannier tank mods to his M7C were of course only permanent until they were removed prior to the car turning up at Penske for restoration

Correction rereading AP's '66 - '86 section on the M14A & M14D mention is made of an Alfa powered M7A (non M10 based chassis ?) which I have now noted was known as M7D.

[Tim Murray]

As noted by Nigel earlier in the thread the Surtees pannier tank mods to his M7C were of course only permanent until they were removed prior to the car turning up at Penske for restoration

True - let's call them semi-permanent, then. As Nigel pointed out, McLaren could whip their tank on between practice and race at Monza 1969. I suspect that the Surtees tanks were less easy to remove/refit.

[arttidesco]

Doh! The penny has just dropped, now that the fuel bladder theory is discounted thanks to Nigel, if the M7C was based on the M10 F5000 chassis that might explain the need for the extra fuel tank, since I imagine an F5000 car would have smaller tanks for generally shorter races, perhaps marginal enough to go all the way in some F1 races when fitted with a DFV but not at all the F1 races ?

[arttidesco]

True - let's call them semi-permanent, then. As Nigel pointed out, McLaren could whip their tank on between practice and race at Monza 1969. I suspect that the Surtees tanks were less easy to remove/refit.

Agreed :-)

[mfd]

I suspect that the Surtees tanks were less easy to remove/refit.

Indeed Tim, I have a photo that clearly shows they were riveted in place.
and @ Arti/Ralph - I think you could be up a blind alley with the M10 reference.

[Roger Clark]

The original M7A carried its fuel in the sides of the monocoque, behind the driver's seat and in a scuttle tank. THe scuttle tank was undesirable as it led to a higher centre of gravity but was not needed for the majority of races. The temporary tanks seen on the cars in 1968 and 69 were probably an attempt to provide greater capacity without the handicap of the scuttle tank. The revised front suspension of the M14 ( the lower radius arm ran forward from the wheel) meant that an internal bulkhead wasn't needed so greater capacity could be provided within the monocoque.

[Nigel Beresford]

The original M7A carried its fuel in the sides of the monocoque, behind the driver's seat and in a scuttle tank. THe scuttle tank was undesirable as it led to a higher centre of gravity but was not needed for the majority of races. The temporary tanks seen on the cars in 1968 and 69 were probably an attempt to provide greater capacity without the handicap of the scuttle tank. The revised front suspension of the M14 ( the lower radius arm ran forward from the wheel) meant that an internal bulkhead wasn't needed so greater capacity could be provided within the monocoque.

Absolutely - I think you've summarised it perfectly. I have been looking for a pic of the scuttle tank for a couple of days to illustrate that point.

[mfd]

The revised front suspension of the M14 ( the lower radius arm ran forward from the wheel) meant that an internal bulkhead wasn't needed so greater capacity could be provided within the monocoque.

As I had mentioned in my P32, but your words much better

Edited by mfd, 24 September 2010 - 13:47.

[arttidesco]

The original M7A carried its fuel in the sides of the monocoque, behind the driver's seat and in a scuttle tank. THe scuttle tank was undesirable as it led to a higher centre of gravity but was not needed for the majority of races. The temporary tanks seen on the cars in 1968 and 69 were probably an attempt to provide greater capacity without the handicap of the scuttle tank. The revised front suspension of the M14 ( the lower radius arm ran forward from the wheel) meant that an internal bulkhead wasn't needed so greater capacity could be provided within the monocoque.

Thanks Roger, I now have a clear understanding of the rational behind the pannier tanks, nothing to do with fuel cells or capacity everything to do with the 'balance' of the car, something no one else seems to have experimented with on an apparent race to race basis, I suppose testing between races was not such a big part of F1 programmes back then not least because Bruce amongst many others had a fairly hectic trans atlantic schedule with his Can Am commitments.

[Roger Clark]

Don't forget also that in 1969 the Matra MS80 showed the benefit of carrying the fuel close to the centre of gravity. The MS80's influence can be seen in Surtees' M7, the BRM P153, the Tyrrell 001 and, later, the McLaren M19.

[arttidesco]

Don't forget also that in 1969 the Matra MS80 showed the benefit of carrying the fuel close to the centre of gravity. The MS80's influence can be seen in Surtees' M7, the BRM P153, the Tyrrell 001 and, later, the McLaren M19.

Indeed would you know if the March 701 would be included in the list of vehicles carrying fuel close to the centre of gravity or were it's side pods purely aerodynamic ?

[PeterElleray]

interesting then that when the surtees ts7 appeared at the british gp it was about as slim as possible and never ran with additional tanks through the rest of 1970 ( the race distances were generally shorter from 1971 on, with a 200 mile cap). several of those late season races were the ones that had traditionally required extra capacity and indeed rodriguez ran out of fuel on his way to winning the us gp that year in his p153 brm.

also interesting to look at the shape of the connew's side tanks alongside the surtees m7...

peter

Edited by PeterElleray, 24 September 2010 - 20:02.

[arttidesco]

interesting then that when the surtees ts7 appeared at the british gp it was about as slim as possible and never ran with additional tanks through the rest of 1970.

also interesting to look at the shape of the connew's side tanks alongside the surtees m7...

peter

As you suggest a significant difference of approach between the M7C, TS7 and Connew.