Jump to content


BRM Lotus twin-cam engine

  • Please log in to reply
59 replies to this topic

#51 SJ Lambert

SJ Lambert
  • Member

  • 2,378 posts
  • Joined: March 09

Posted 06 June 2011 - 12:27

Yes, Wilkins on page 51 of his Lotus Twin Cam Engine book says, almost in the same breath as when he mentions the hybrid BRM/Cosworth units that Cosworth had, inter alia, steel cam caps in their engines - hence the moniker "all steel" twin cam. Without wanting to cast aspersions if you're out there Miles, I'm not aware of any Cosworth Lotus Twin Cam racing engines, or any racing Lotus Twin Cam heads by anyone in the period through to 68 (or after) that had steel cam caps.

Of course anything is possible, but I can't really see the need for them.....

I'm not saying that there are none out there, just that I'd be surprised if there is/was...........


#52 SJ Lambert

SJ Lambert
  • Member

  • 2,378 posts
  • Joined: March 09

Posted 06 June 2011 - 13:40

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.

Thanks for the tip Peter - found a couple but got an error when trying to select individual shots from the "thumbnail" broadsheets.............

#53 Nick Wa

Nick Wa
  • Member

  • 165 posts
  • Joined: June 07

Posted 06 June 2011 - 14:06

As there seems to be several variations of colour being put forward here is it possible that everybody is correct to some degree.
I wonder if when a customer ordered a new engine from the various tuners an engine with a distinctive coloured cam cover was supplied but if the customer sent his own engine for modification the original cam cover was retained.

As can be seen on SJ Lambert's engine.

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

Edited by Nick Wa, 06 June 2011 - 14:13.

#54 Peter Darley

Peter Darley
  • Member

  • 274 posts
  • Joined: September 06

Posted 06 June 2011 - 17:06

Thanks for the tip Peter - found a couple but got an error when trying to select individual shots from the "thumbnail" broadsheets.............

Coterie are checking out the problem

#55 CDCJ

  • Member

  • 43 posts
  • Joined: September 06

Posted 12 June 2011 - 13:17

Hi James and all,
Today I just doing net surfing and I've seen "The Nostalgia Forum" after a long time.
I'm big surprise my first topic(dated 12th October 2006) still alive!
Unbelievable! But I'm very happy some people interested in 60's tuning company especially For/Lotus base engine.
I love 60's Lotus especially Cortina MK1. So I'm study and collecting the relating stuff include 60's tuning company.
Anyway I forgot my first thread(Can I see the first thread?) but I'd like to try to put my comment.

Regarding COSWORTH Twin Cam engines the cam cover colours
My reference was Lotus 26R which is one of five imported 26R here in Japan in 60’s direct from Lotus.
The first 26R(Production:Dec.1964) imported Feb.1965 and a few raced here in 1965 then stored until now!
Definitely the 26R must be most original 26R in the world.
Yes! It's still have original parts and original paint include engine.
The engine has early COSWORTH plate(this mean London address. good point James!),
the cam cover colour is Red(It is metallic rather than hanmertone finish). The engine built Oct.1964.

However I've seen a video Cortina at Sebring 1964.
We can see first works lotus Cortina include engine room and clearly show the cam cover colour is blue with early
COSWORTH plate of course. The engine must be built before Feb.1963.
Probably one of the first COSWORTH tuning unit. Now it's became my reference.

FYI: I know and I've seen the engine and the car which the photo from James.
It has early COSWORTH plate and plane red colour. The engine built Feb.1964 for ex-works Lotus Cortina.
The Cortina restored many years ago. probably the colour is not original. But nice colour and the details.

I know 3 type of original COSWORTH plates. It has all different header.
Another one is "Manufactured for the Ford Motor Company Ltd. by" at Nothampton address.
I also have "Racing engine by" same as photo. It exist black plate and silver plate.
I've seen many times silver one on FVA or their later engine.
So I think "Racing engine by" type is last type from late 60's.

That's all today. I will post other information about BRM, Mike Spence and other.

Thank you very much for your interest.
Hiro :)

Edited by CDCJ, 12 June 2011 - 13:20.

#56 SJ Lambert

SJ Lambert
  • Member

  • 2,378 posts
  • Joined: March 09

Posted 02 July 2011 - 00:02

G'day again Hiro. Your first post has been restored and can be seen on page one of this thread. It does seem as though the various cover and plates from the sixties for BRM and Cosworth variants have been given a good summary through this thread. Have you seen any other covers with the breather where the filler usually is as pictured on Ed Holly's Brabham? It seems to be a fairly rare set up......

Perhaps Ed can restore it or maybe instal the breather into another donor cover for historic display purposes if he gets a chance - what do you reckon Ed?



#57 CDCJ

  • Member

  • 43 posts
  • Joined: September 06

Posted 03 July 2011 - 01:57

Hi James and all,

I have seen many Lotus TC cam covers.
But I’ve never seen the breather set up, include early Cosworth prepared engines.
It’s based ordinary Lotus TC cam cover, maybe Brabham or ex-owner processed it?

Today’s information about Mike Spence Ltd Lotus TC engine.
I think basically the engines has been modified for Mike Spence Ltd by BRM.
I know 2 type of their engine plates .
#1 Silver type BRM+Mike Spence Ltd (post #33 photo?)
BRM name and address with Mike Spence Ltd information.
#2 Black type Mike Spence Ltd only (post #24 photo)
Mike Spence Ltd address and information only.
The both types looks like same type and colour scheme as BRM plates.
(Yes, I know there were many type of BRM plates at that time, even today repro one too!)

The post #33 photo looks like BRM Elan engine and it has the BRM+Mike Spence Ltd engine plate?
However the colour(green:hanmertone finish) for SE spec engine.
Is this original BRM Elan engine colour?
I’ve seen two Lotus TC cam covers with BRM+Mike Spence Ltd engine plate.
The first one is silver(no paint) and second one is BRM green(It was over splayed on hanmertone finish blue!)
The both engine type number is 125, 1967 year made and low unit number.
Does any one know an article include road test or photos of BRM Elan at that time?

The post #24 photo looks very nice indeed!
BRM cam cover + black type plate. My interest is the engine number.
It’s type 125 and 1967 year made 038? unit and CPL1 cam spec? I think.
I believed type 125 for BRM Elan engine. However BRM Elan was not made more than 17.
So my reference become type 125 means modified Lotus TC engine for Mike Spence Ltd by BRM.
also BRM use their cam cover from 1967! and BRM orange colour too.
However I still have question, How did they use their colour BRM green or BRM orange properly ???

Do you know any other engine number about Mike Spence Ltd engines?
I have a document of BRM engine test certification. The customer is Mike Spence Ltd!
The engine for Formula Ford in 1969. The engine number start from 0745.

That's all today.
Thank you for your interest.
Hiro :)
P.S I have NOS Black type Mike Spence Ltd engine plate. I'm pleased to swap for other relating rare items.

#58 ed holly

ed holly
  • Member

  • 298 posts
  • Joined: June 04

Posted 03 July 2011 - 10:42


The breather on the Cosworth plated twincam cover in the picture above is genuine Cosworth. The engine it was on - was installed ex Cosworth into the works Brabham BT6 (FJ-9-63) by none other than Frank Gardner, after the car had finished it's 1963 season's Formula Junior duties in the hands of Denny Hulme. The last meeting it did in that form was 28th September.

In a letter I have, Frank says that this car was the first factory Brabham fitted with a Lotus Ford Cosworth twincam and the car was shipped to Australia for the Australian legs of the 1964 Tasman series for Frank to drive and to be taken over by Mildren Racing at the end of the series, all of which occured. The car would have been shipped in October (or very early November) 1963 to be here in time. It's first meeting on Australian soil was Australia Day 26th January at the Blue Mountain's venue of Catalina. 2 weeks later it ran in the AGP at Sandown.

Fortuitiously, the photo of Alec Mildren and Glen Abbey shows the car from the engine end - in very early 1964. Alec was the team owner and Glen their fabulous mechanic. There is no way that anyone would have modified the cover from as it was received from Cosworth - simply there was no need. Also the thickness of the metal casting around it shows it was never tampered with. For whatever reason, this cover was direct from Cosworth, and as there was no need to have a filler cap with a dry sump, it appears that in this instance this is what they came up with to make use of the hole.

Thankfully, who ever cut it off, threw it in the "spares" box and it stayed with the car over the years.

Maybe someone out there might have another cover the same?


Ed :)

Edited by ed holly, 03 July 2011 - 10:45.

#59 CDCJ

  • Member

  • 43 posts
  • Joined: September 06

Posted 09 July 2011 - 16:17

Hi Ed,

Thank you for the information.
Your engine must be Cosworth MK12(standard cast iron rods and crank) or MK13(steel rods and crank).
Probably Cosworth MK12 or MK13 dry sump engine has the breather set up.
Do you have the engine number? The serial number of these engines will start with 12 or 13.
and the engine has early COSWORTH plate(London address) right?
My interest is Cosworth MK15 or MKS15 wet sump engine for Cortina and Elan. I’ve never seen the breather set up.
Anyway the early Cosworth dry and wet sump engine(1963) has blue painted cam cover!

Hiro :D
P.S I also have early Cosworth engine plate for swap.


#60 SJ Lambert

SJ Lambert
  • Member

  • 2,378 posts
  • Joined: March 09

Posted 14 November 2011 - 06:35

Hi all, what's the best way to reproduce the Hammerite/Hammertone Cam Cover Blue and the Cosworth Engine Block Red as used on some of these motors?



Edited by SJ Lambert, 05 December 2011 - 12:33.