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BRM Lotus twin-cam engine


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#1 CDCJ

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Posted 12 October 2006 - 14:39

Hi all,
I'm very interested in a history of some tuning Lotus TC engine at that time(60's).
This time, I'd like to ask you about Lotus TC engine tuned by BRM.
The engine must be first appear in 1964 for Racing Lotus Cortina or Racing Lotus Elan 26R.
(In 1963, Racing Lotus Cortina or Racing Lotus Elan(26R) have used be COSWORTH one.)
We can see some photos of the engine from period magazine. The engine has original Lotus TC cam cover with their engine plate.
However it's always B/W photos. So my first question is the color.
Do you know a color of Lotus TC cam cover for BRM? Somebody said it was painted BRM orange or BRM green. Please let me know if you know about it.
I know COSWORTH one was standard Lotus TC color(blue:hanmertone finish) with their engine plate. Then the color was changed to
Red(hanmertone finish) with their engine plate.

Well I have a BRM Lotus TC cam cover, please have a look the photo.
Posted Image

Next my question is When the cam cover appear and which car for?
I think the cam cover never used for Racing Lotus Cortina MK1 or 26R maybe.
also BRM Elan too. Please tell me.

Kind regards,
Hiro :lol:

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#2 Stephen W

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Posted 12 October 2006 - 15:49

The above picture looks like it is correct with respect to colour. I don't think BRM slapped any orange on it!

:wave:

#3 Dallas84

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Posted 14 October 2006 - 10:46

I think the BRM badged twin cam was available in the 26R in various stages of stages of tune and Miek Spence was involved in the marketing

#4 RTH

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Posted 14 October 2006 - 10:58

I certainly saw a BRM engined Elan in the early 70s and the cam cover was painted dark green.

#5 hipperson

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Posted 14 October 2006 - 15:43

When Dad bought our Lotus Cortina TC new in 1965 the standard cam cover (105bhp) was blue,the Special Equipment (115bhp) was red and the BRM 130bhp (?) and was dark green.

#6 hipperson

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Posted 14 October 2006 - 15:47

I see 'Racing Fabrications' on that cam cover....that company near Bury St Edmunds is run by an old friend of mine George Wadsworth. Call him he knows everything about twin cams....had his apprenticeship with Brian Hart in Harlow.

#7 Peter Morley

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Posted 14 October 2006 - 18:02

Originally posted by hipperson
I see 'Racing Fabrications' on that cam cover....that company near Bury St Edmunds is run by an old friend of mine George Wadsworth. Call him he knows everything about twin cams....had his apprenticeship with Brian Hart in Harlow.


'Reg Holdsworth' is far and away the best twin-cam engine builder I've come across, a Racing Fabrications badge on the engine is a very good sign.

#8 Pedro 917

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Posted 14 October 2006 - 18:16

I took these pictures of a Lotus 47 Europe at the Brussels Retro Fair last year :

Posted Image Posted Image Posted Image Posted Image

#9 CDCJ

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Posted 17 October 2006 - 14:53

Hi all,
Thank you for the informations.
I think one of Lotus TC cam cover with BRM plate (BRM tuned) painted orange.
Because my friend has restored ex-Team Lotus works 1965 Lotus Cortina MK1 sir2(JTW) which Jim Clark drove one. Mr.Bob Dance who former Jim Clark mechanic adviced him, "the Lotus TC engine was BRM tuned one and the cam cover not BRM (made: which I posted the photo) Lotus TC cam cover. It's standard Lotus TC cam cover with BRM plate and it's painted orange".

The other my friend who he was editor of car magazine at that time.
In 1965, a proper Lotus dealer imported 26R here in Japan.
The engine was was BRM tuned one and the cam cover not BRM (made: which I posted the photo) Lotus TC cam cover. It's standard Lotus TC cam cover with BRM plate and it's painted dark green".

I think both correct. However why they used different colour? for Cortina painted orange, for 26R painted dark green?

Other my interest is BRM Elan(Mike spence Elan, made in 1967) ,
The engine was was BRM tuned one and the cam cover must be not BRM (made: which I posted the photo) Lotus TC cam cover. I've seen one here it's standard Lotus TC cam cover(silver, no paint) with BRM plate. But the plate different one. It's forMike Spence. Do you have any other informayion?

So next my big question is when did the BRM (made: which I posted the photo) appered on the market? which car start used the com cover?
Maybe after 1967, from 47GT?

Kind regards,
Hiro :lol:

#10 elansprint72

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Posted 28 January 2009 - 19:53

Period road tests of the Mike Spence "BRM" Elans show ordinary Lotus cover with the BRM plate, as previously posted. These BRM pattern covers are currently available from Tony Thompson Racing.

#11 a1topdog

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Posted 29 January 2009 - 13:30

Originally posted by hipperson
When Dad bought our Lotus Cortina TC new in 1965 the standard cam cover (105bhp) was blue,the Special Equipment (115bhp) was red and the BRM 130bhp (?) and was dark green.


As far as I am aware the Special Equipment (115bhp) cover was always green (various shades) , and the cosworth built engines had the Red cam cover.

#12 llmaurice

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Posted 29 January 2009 - 15:37

The twin cam was of course used in F3 from '71-'73 as a 1600 and a few went on to the later 2.0l series overbored .
Vegantune were most active and I'm fairly sure that some Motors were BRM too.

#13 fyrth

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Posted 29 January 2009 - 17:50

John Reid also built a few at Holbay for the restricted F3 formula of the early 1970's.

Posted Image

#14 SJ Lambert

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Posted 01 June 2011 - 02:32

I know COSWORTH one was standard Lotus TC color(blue:hanmertone finish) with their engine plate. Then the color was changed to
Red(hanmertone finish) with their engine plate.

Hiro :lol:



G'day Hiro

Off topic vis-a-vis the BRM questions I know but as far as the Cosworth covers are concerned - I think with the in house Cosworth Twin Cam engines the cam cover colours were actually the other way around. Without being sure, I think Cosworth tuned ones started off with red tops then went to blue tops when they moved to St James Mill Road, Northampton. The complete original engine that we have is blue topped with a Cosworth Racing Engine plate from St James Mill Road at least.

I think I've seen period pictures of the Covers in red with the softer, earlier, rounder curvature at the front where the timing chain and sprockets are accomodated......

Cheers

James

#15 David McKinney

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Posted 01 June 2011 - 05:05

Without being sure, I think Cosworth tuned ones started off with red tops then went to blue tops when they moved to St James Mill Road, Northampton.

The first ones I saw - late 1963 - were definitely blue
Were the red ones Holbays maybe?


#16 SJ Lambert

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Posted 01 June 2011 - 08:46

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I can't reference this cover - it has an early Cosworth plate and is on an early head - ours is a later head and cover - of course this one may have non original coloured paint on the cover...............

#17 SJ Lambert

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Posted 01 June 2011 - 08:49

That's what left of the original paint on ours.......

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#18 simonlewisbooks

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Posted 01 June 2011 - 08:49

I can't see this has been mentioned previously - BRM also did a small number of twin cam engines for use in the Chrysler Avenger rally car of the mid 70s . This was prior to the introduction of the Chrysler/Talbot Sunbeam and later Lotus Sunbeam, so I'm guessing 1975-76?. I don't know if it was ever used by the works team or was a cancelled project that never officially saw the light of day. I have heard it said there were less than 20 units in existence, although that may have been hot-air.

A friend of mine rallied one in the early 90s(now with his brother and just doing classic car events) . It was a bit of a 'weapon' although the engine itself wasn't putting out the same levels of performance as a similar sized BDA (he had one of those in an Mk2 Escort shortly afterwards so could compare them directly). The BRM unit had been rescued from a scrap yard!

It's always been a bit of a mystery engine to me

Anyone know any more?

Edited by simonlewisbooks, 01 June 2011 - 09:42.


#19 SJ Lambert

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Posted 01 June 2011 - 10:11

Sorry Simon - I'm no help whatsoever with the Chrysler Avenger engines.

This engine is in a Brabham - Dad would have taken this shot at Longford in around 1964. Whenever taken, it shows an early head with the crescents in the spark plug wells. Maybe early Cosworth ones were only blue??? The cover post #16 has obviously been repainted......



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#20 RS2000

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Posted 01 June 2011 - 20:04

The works did run the BRM twincam Avenger in the "home" International Rallies (around 75/76 as posted), with "Brazillian block" 2 litre engine.

"Works" Chrysler rally driver Colin Malkin drove it first then, after a bit of diagreement with Des O'Dell as to whether the car or driver was at fault, Chris Sclater was brought in - which then proved it was the car...

It was, I think, first homologated in Gp2 under the Appendix J version that allowed homologation of alternative heads (that gave us the equally unsuccessful Holbay 16v Pinto Escort and the Opel Kadet C GTE 16v). By 76 it was running under the FIA concession that allowed cars to the ultimate Gp2 1975 spec to continue to compete for a further 2 years but in the Gp4 category (Gp2 having been quite severely restricted for 76). The works BDA Escorts of course ran similarly in Gp4 in 76 and 77 prior to the creative homologation of the non-existent "Escort RS" into Gp4 with all the bits by then banned in Gp2 - but essentially the same car as thre original Gp2 BDA.

Chysler then concentrated on the even more creatively-homologated Brazillian block 2 litre Gp1 Avenger with success.

#21 RS2000

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Posted 01 June 2011 - 20:14

The works Avenger TC appears briefly in this 76 classic, driven by Chris Sclater.

http://ssa.nls.uk/film.cfm?fid=6699

Edited by RS2000, 01 June 2011 - 20:15.


#22 RCH

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Posted 01 June 2011 - 23:24

The works did run the BRM twincam Avenger in the "home" International Rallies (around 75/76 as posted), with "Brazillian block" 2 litre engine.


Chysler then concentrated on the even more creatively-homologated Brazillian block 2 litre Gp1 Avenger with success.


I may be wrong but didn't the BRM Avenger only actually run as a 1600? I've a feeling there was an attempt to match the head to a Brazilian block but it wasn't used because they realised by then that the idea just couldn't match a BDA. I've a feeling it had a far too narrow power band to work as a rally car engine. Incidentally no one has mentioned it was actually a 16-valve design.

Rootes/Chrysler were always very good at "creative homologation" as witnessed by the Brazilian block but I've a feeling there was something in the rules that made them believe they had to stick to 1600cc.

#23 RS2000

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Posted 02 June 2011 - 20:22

I may be wrong but didn't the BRM Avenger only actually run as a 1600? I've a feeling there was an attempt to match the head to a Brazilian block but it wasn't used because they realised by then that the idea just couldn't match a BDA. I've a feeling it had a far too narrow power band to work as a rally car engine. Incidentally no one has mentioned it was actually a 16-valve design.
Rootes/Chrysler were always very good at "creative homologation" as witnessed by the Brazilian block but I've a feeling there was something in the rules that made them believe they had to stick to 1600cc.


No, they seriously saw it as a "works Escort beater" initially (well, competitior at least...). I don't have the Scottish entry list for 76, although I did the event, but the 76 Welsh lists it as 1910cc (which I think was the exact capacity of the later "Brazillian" engines in Gp1 too, although they were usually referred to as 2 litres) and the 76 RAC has it in the 2000cc class. ( I moved us to the Gp4 class on the 76 RAC to avoid some quick Gp2 cars and I recall the Corollas were the only works 1600s in Gp4).
I think there were two cars. RHP551M appeared on one, although I think that plate was later also used on a (Mopar?) Gp1 car?
I'm not sure but I think they had already got Gp1 homologation on at least the earlier Brazillian block (1800cc?) so Gp2 was automatic. They were Gp2 cars running in Gp4 under FIA concession, not Gp4 cars in their own right (something even the Escort experts constantly struggle with, bandying around the term "Gp4" as if it defined all Mk2 BDA Escorts).
I think they gave up for 77 (and it would have been severely restricted by the 76 onwards Gp2 regs after 77, when the FIA 2 year concession ended - they couldn't have tried for new Gp4 homologation of the full spec car in the way Ford did, as no one would have taken it seriously in the way Ford claimed 400 full spec cars existed).

Edited by RS2000, 02 June 2011 - 20:24.


#24 elansprint72

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Posted 02 June 2011 - 22:15



I am currently going through the due diligence process with a 69 Elan which has come my way. From conversations with someone who was at Mike Spence at the time it seems that most, if not all, of the BRM Elans (and we are only talking about a dozen, at most) emerged with "normal" LOTUS cam-covers. If you know anything about Lotus, you will realise that the "correct" colour is whatever pot of paint was open on that particular day. Mike Spence were the only producers of Lotus/BRM cars but there were several other suppliers of BRM Lotus TC motors.

This shot shows the top of the engine of my most recent Elan; it went to Mike Spence when fairly new for a BRM upgrade; I suspect that the cam cover was from Mike Spence Developments, who were building F3 motors at that time (after Mike died). Gawd only knows what components are located South of this fancy piece of kit. :rolleyes:

It has been a fascinating journey so far, trying to get to the bottom of the BRM/TC conundrum, lots of folks have "learned" opinions, as already demonstrated here; hopefully I'll have more horse's mouth info in the next couple of weeks. :)

Posted Image

Edited by elansprint72, 05 December 2011 - 10:50.


#25 David Birchall

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Posted 02 June 2011 - 23:04

You lucky sod! :)

Thought y'all would like this:
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Edited by David Birchall, 02 June 2011 - 23:20.


#26 Julian Roberts

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Posted 03 June 2011 - 07:32

This shot shows the top of the engine of my most recent Elan; it went to Mike Spence when fairly new for a BRM upgrade; I suspect that the cam cover was from Mike Spence Developments, who were building F3 motors at that time (after Mike died). Gawd only knows what components are located South of this fancy piece of kit. :rolleyes:

Posted Image



I really like that photo, I just gazed at it for a couple of minutes, taking it all in. :wave:

#27 simonlewisbooks

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Posted 03 June 2011 - 08:54

I'm not sure where Cosworth comes into relevance with this thread and also; I'm reasonably sure that BRM was out of business by the time the Avenger came along; although someone else may well have picked up their tab... DCN would know.


BRM were still running in 1977 - although many would say 'running' was an optimistic use of English. Staggering would perhaps be more suitable!


#28 SJ Lambert

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Posted 03 June 2011 - 10:04

I'm not sure where Cosworth comes into relevance with this thread and also; I'm reasonably sure that BRM was out of business by the time the Avenger came along; although someone else may well have picked up their tab...

I am currently going through the due diligence process with a 69 Elan which has come my way. From conversations with someone who was at Mike Spence at the time it seems that most, if not all, of the BRM Elans (and we are only talking about a dozen, at most) emerged with "normal" LOTUS cam-covers. If you know anything about Lotus, you will realise that the "correct" colour is whatever pot of paint was open on that particular day.......................


I just seized on the aside in the opening post as I thought it was an interesting tangent related to the BRM questions - after all, weren't early BRM covers those same "Lotus" down each bank covers with a BRM plate where the "Cosworth" plate is on the ones I've posted?


Miles Wilkins, in his book, goes into some considerable detail from memory on cam cover colour for correct spec engine/car combos - am happy to put up in broad brush stroke terms what he says if anyone's interested...... ? I think there was more more of a method than random pots at dawn......

I didn't think it was worth starting another thread to discuss colour of the Cosworth tuned variants as Hiro mentioned the likely suspects, red and blue, at the outset. Wilkins is silent on the competition/Cosworth colours, as he deals with road cars alone in his cam cover colour dissertation. I haven't seen anywhere else either what colour the Cosworth ones were. I know that in 1968 at least one Aussie constructor had Cosworth ones on hand with blue covers (the same as the 1966 vintage one of ours that is pictured above in post #17 in an unrestored state). So that gets us blue ones topping off Cosworth donks on perhaps a constant or at least on and off basis from 63 according to David through to around 68 (there's a chance that pics of 'em in 68 that I have are of old stock at that stage, but I doubt that the stock was too old.....)

Cheers

James

#29 Hamish Robson

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Posted 03 June 2011 - 10:59

Period road tests of the Mike Spence "BRM" Elans show ordinary Lotus cover with the BRM plate, as previously posted. These BRM pattern covers are currently available from Tony Thompson Racing.


Tony has the castings machined here at RT Quaife Engineering :wave:

#30 RCH

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Posted 03 June 2011 - 12:15

No, they seriously saw it as a "works Escort beater" initially (well, competitior at least...). I don't have the Scottish entry list for 76, although I did the event, but the 76 Welsh lists it as 1910cc (which I think was the exact capacity of the later "Brazillian" engines in Gp1 too, although they were usually referred to as 2 litres) and the 76 RAC has it in the 2000cc class. ( I moved us to the Gp4 class on the 76 RAC to avoid some quick Gp2 cars and I recall the Corollas were the only works 1600s in Gp4).
I think there were two cars. RHP551M appeared on one, although I think that plate was later also used on a (Mopar?) Gp1 car?
I'm not sure but I think they had already got Gp1 homologation on at least the earlier Brazillian block (1800cc?) so Gp2 was automatic. They were Gp2 cars running in Gp4 under FIA concession, not Gp4 cars in their own right (something even the Escort experts constantly struggle with, bandying around the term "Gp4" as if it defined all Mk2 BDA Escorts).
I think they gave up for 77 (and it would have been severely restricted by the 76 onwards Gp2 regs after 77, when the FIA 2 year concession ended - they couldn't have tried for new Gp4 homologation of the full spec car in the way Ford did, as no one would have taken it seriously in the way Ford claimed 400 full spec cars existed).


Everywhere I look it says 2-litre so I don't know where I got the 1600 idea from.

Gp4 seems to have become a generic term for ALL rally Mk II Escorts even those with Vauxhall "Red Top" engines!

Going completely OT but on the subject of "thoughtful" homologation I was told a story about the Gp. 3 homologation of the Hillman Rally Imp. When the FIA inspectors were due to visit to ensure that 500 cars had been made all Rootes actually had were about 200 kits of the non-standard bits. They got together about 250 normal Imps (Chamois as well presumably, since they shared the homologation) and every apprentice they could find. They were given the job of fitting "appropriate" chassis number plates to the cars and a few of the cars were fitted with the "Rally" parts. They were then arranged for inspection so that the modified cars were the only ones that were easy to get at. When the inspectors were satisfied that they had seen half of the production cars they were whisked away for a long, slap up lunch. The apprentices were then called in to change the chassis numbers and move the cars around a bit to provide the other 250. Afterwards the Imps just went back to being normal Imps and the kits were sent out to dealers who had the job of building the actual Rally Imps when a customer ordered one.

#31 RS2000

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Posted 03 June 2011 - 21:35

In "Rootes Maestros", Graham Robson refers to it as a 1600. I've also a feeling I've heard of an engine still around that is 1600. Maybe the first ones were 1600. Certainly the works rally engines were listed as 2000 (or rather 1900 and a bit).

On the subject of real "TCs", I'm pretty sure the the works (Mk1 Lotus Cortina) BRM-built rally engines had normal TC cam covers, not BRM. I can't believe Chapman would have had anything else on the (BRM-built) Cortina race engines either.

#32 David Birchall

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Posted 03 June 2011 - 21:54

There is also no mention of a different valve cover in the Lotus parts list, dated June 1965, that I posted yesterday.

#33 SJ Lambert

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Posted 03 June 2011 - 22:52

This one, a contemporary shot, of what looks to be a magnificently preserved original example, looks to be thoroughly representative of the type.

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#34 ed holly

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Posted 04 June 2011 - 06:05

James,

Re: - Your post above showing the photo your Dad took at Longford in 1964.

Here are a series of photos of the same engine bay - the last one I took 10 minutes ago !!

The car from the colour of the bodywork was Frank Gardner's BT6 (FJ-9-63) entered by Alec Mildren Racing but according to correspondence from Frank, not Alec's until after the conclusion of the Tasman series as the car was still owned by Brabham's until then, being the works car as it was the Formula Junior driven by Denny in 63 then fitted with the Lotus Cosworth twincam by Frank himself, the first car to be so fitted by the factory.

I believe the head is still the same as delivered by Cosworth to Brabham's in 63 as it is stamped that way underneath. It still makes fabulous HP which has taken it to many Group M wins in the last few years, and in Nick mcDonald's hands still holds the outright M record at PI where he went from last to first or second in a Handicap M and O race with it.

The first photo shows the car at Mildren's with Glen Abbey and Alec - comes from a contemporary magazine of the period.

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The next shot shows the car in Roly Levis's hands in NZ

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The last shot is about 10 feet away from where I am typing this .. !!

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Never noticed until now that someone has removed the Lotus embossing at some stage. Probably when they removed the guaze oil breather from the back of the left hand cover and welded that over. Thankfully the cut-off remnants of th oil breather were not discarded and came with the spare I got with the car.

Now we have a 47 year span of a Cosworth plate !!

Would love a copy of the original photo ....


#35 SJ Lambert

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Posted 04 June 2011 - 06:34

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OK Ed, you win, only got 45 years on this one!!!

Will send you that Longford shot, keep an eye out for 1966 shots of this one, Phil Hotchkiss's Elfin Mono, MC 6653 - ran at Warwick Farm (practice, not race in Oct 66) and Mallala before that, Katoomba early 67 and then to NY.

Do those plug leads look familar???

James

#36 ed holly

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Posted 04 June 2011 - 06:51

James,

It looks very cold in NY.

Maybe Cosworth supplied the leads - they've lasted well on the Mono that's for sure ... better than the paint they used !!

Sent you a PM

Ed

#37 SJ Lambert

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Posted 04 June 2011 - 11:05

Miles Wilkins reckons the best race motors were an amalgam of BRM and Cosworth components. He says that BRMs cylinder heads flowed better and that Cosworth's bottom ends were lighter. Rods I can readily accept, but I'd be very interested in being able to compare crankshafts - I'd have thought that there may have been very little, if any, difference between them. I'm not even sure that they'd have been produced under different rooves, in that Laystall were grinding cranks for plenty of engine firms back then, including Cosworth. Did BRM make their own, have Laystall make 'em, or use someone else?

It would be quite something to be able to compare a crankshaft from each firm........

Wilkins reckons that Jim Clark and co. in the Team Lotus Cortinas did use these hybrid BRM/Cosworth Lotus units - do we have anyone out there with shots from Team Lotus Cortina racing workshop days??

Pistons were different - Wilkins says BRM used Mahle (David's sheet confirms same) - I'd also be interested to get the specifics on BRM camshaft profiles.......

Edited by SJ Lambert, 04 June 2011 - 21:10.


#38 David Birchall

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Posted 04 June 2011 - 14:45

I have always understood that the BRM crank was much heavier than the Cosworth/Laystall unit. The racing Elan I presently own has BRM cams and may have a BRM crank but it will be a few weeks before I take it apart to find out! (Water in the oil).

#39 Peter Darley

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Posted 04 June 2011 - 15:50

[quote name='SJ Lambert' date='Jun 4 2011, 12:05' post='5078187']


Wilkins reckons that Jim Clark and co. in the Team Lotus Cortinas did use these hybrid BRM/Cosworth Lotus units - do we have anyone out there with shots from Team Lotus Cortina racing workshop days??




Go to the Coterie Press website and into their Library. There are some of my photos showing the twink in and out of the engine bay.




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#40 David Birchall

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Posted 04 June 2011 - 16:50

BRM spec sheet--Vegantune and Brian Hart to follow later:

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Edited by David Birchall, 04 June 2011 - 16:52.


#41 elansprint72

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Posted 04 June 2011 - 21:32

James,

Re: - Your post above showing the photo your Dad took at Longford in 1964.

Here are a series of photos of the same engine bay - the last one I took 10 minutes ago !!

The car from the colour of the bodywork was Frank Gardner's BT6 (FJ-9-63) entered by Alec Mildren Racing but according to correspondence from Frank, not Alec's until after the conclusion of the Tasman series as the car was still owned by Brabham's until then, being the works car as it was the Formula Junior driven by Denny in 63 then fitted with the Lotus Cosworth twincam by Frank himself, the first car to be so fitted by the factory.

I believe the head is still the same as delivered by Cosworth to Brabham's in 63 as it is stamped that way underneath. It still makes fabulous HP which has taken it to many Group M wins in the last few years, and in Nick mcDonald's hands still holds the outright M record at PI where he went from last to first or second in a Handicap M and O race with it.

The first photo shows the car at Mildren's with Glen Abbey and Alec - comes from a contemporary magazine of the period.

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The next shot shows the car in Roly Levis's hands in NZ

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The last shot is about 10 feet away from where I am typing this .. !!

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Never noticed until now that someone has removed the Lotus embossing at some stage. Probably when they removed the guaze oil breather from the back of the left hand cover and welded that over. Thankfully the cut-off remnants of th oil breather were not discarded and came with the spare I got with the car.

Now we have a 47 year span of a Cosworth plate !!

Would love a copy of the original photo ....


Ed,
Are you sure that is the same cam-cover? Not only the LOTUS script that has been removed, the oil-filler boss has gone too, that is a big job and it would have been much easier to get another cover and slap it on. Dry-sump covers were available and that looks like what you have now. Don't ask me how I know about trying to weld up old cast-ally parts!

Great thread, good to have some folks who know their stuff here. :up:

Incidentally, went for a rip in my Sprint today; first real blast since the trip to Le Mans Classic last year; engine re-build seems good, annoying electrical gremlins have surfaced, could be something to do with the mouse-shit in the engine bay! :rolleyes:



#42 ed holly

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Posted 05 June 2011 - 01:03

Peter,

Yes positive same cam-cover. Not only is the Cosworth plate authentic, but as you can see the oil breather has indeed been welded over. If you look closely at the rear of the cover you will see a square headed plug on the LH side and the oil breather on the RH side - all matches perfectly whenever a photo was taken.

Thankfully this oil breather tower has been kept for posterity and came with the car's spares. NOTE that it is a breather with a wire guaze inside, it was not an oil filler, something pretty unusual and maybe pretty rare and only from the early Cosworth prepared engines?

As the rules changed and we all required catch tanks from engine openings it would have spelt the end of this arrangement and someone has removed it with an angle grinder, and I guess at the same time thought it would be a good idea to remove the LOTUS signs as well.

As you can see it was still there in Roly's time with the car, my guess is that it was removed in recent times when Ian McDonald restored it late 90s - must ask him if he remembers next time I talk to him.

Its the little details like this that make these cars so interesting, not just the driving of them to me. That's why I had these photos and they form part of the 300 page history file I have put together on the car in my ownership of it.

This is the cutoff piece

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this is where it used to live

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Ed

#43 David Birchall

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Posted 05 June 2011 - 03:13

Vegantune spec sheet-no date but must be about 1970:

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Edited by David Birchall, 05 June 2011 - 03:16.


#44 David Birchall

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Posted 05 June 2011 - 03:22

Brian Hart 416B spec sheet--my favourite and a giant killer:

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#45 elansprint72

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Posted 05 June 2011 - 15:42

Ed,
Hats off to the welder! Must have been well clamped down, these covers are not the most stable pieces of kit and can distort quite a lot. Great that you kept the cut-off bits too. What exactly is inside that breather? I can see the "expamet" gauze, anything else?

Edited by elansprint72, 05 June 2011 - 21:36.


#46 SJ Lambert

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Posted 05 June 2011 - 20:50

Thanks for those spec sheets David.

Anyone ever seen steel cam caps on one of these motors??

#47 ed holly

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Posted 05 June 2011 - 22:21

Hats off to the welder! Must have been well clamped down, these covers are not the most stable pieces of kit and can distort quite a lot. Great that you kept the cut-off bits too. What exactly is inside that breather? I can see the "expamet" gauze, anything else?


Peter, difficult to say what has been done even now after I have had a closer look .... my guess is that it was bored out and a thin steel sleeve pressed in, then inside this again an alloy hollow cylinder capturing the mesh guaze pressed in. Whatever it is - not much of it is magnetic - so the steel sleeve is only long enough to stablilize the alloy cylinder part.

One thing that is for sure though is that it was on the engine that Frank Gardner installed at MRD at the end of the 63 season before the car came out here for the 64 Tasman series.

Ed

#48 Paul Hamilton

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Posted 05 June 2011 - 22:29

Thanks for those spec sheets David.

Anyone ever seen steel cam caps on one of these motors??


Except for the alloy block version the Hart 416B engines used the later 701M block with its larger main bearing caps in standard form and I have never heard of that leading to any problem. These days a set of those caps from a discarded later model block can be fitted to any older Ford engine making steel caps unnecessary.

#49 David Birchall

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Posted 05 June 2011 - 23:39

Paul, I think he is asking about the camshaft bearing caps--I seem to recall seeing steel caps-I cannot now remember if my 416B had them-certainly everything else was very special.

#50 Paul Hamilton

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Posted 06 June 2011 - 01:37

Paul, I think he is asking about the camshaft bearing caps--I seem to recall seeing steel caps-I cannot now remember if my 416B had them-certainly everything else was very special.


Sorry, I misread James' reference to cam caps but I have never seen a twin cam engine with anything other than the standard cam bearings and caps except for the recent reproduction heads which eliminate the cam bearing shells altogether. Certainly the Hart 416B engines used standard caps and bearings. They were (and are!!) a gem of an engine if maintained properly but developed a reputation in some circles for unreliability.

That reputation was, in my view, undeserved and generally resulted from either user abuse or poor quality initial assembly. Brian Hart did seem to have some quality control problems at times as several of the engines which came down to oz in the early 70's had problems from the outset. We quickly learnt that it was best to pull the engines apart before using them and carefully check them through. The valve timing and lift were pretty radical and clearances and dimensions in the cylinder head, valves, valve springs etc. were critical.