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JohnD

Coventry Climax Racing Engine 1960-1965

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In my course researches, I came across a paper thus entitled, published by SAE, and written by the legendary Walter Hassan.     He originally worked for Bentley and was Wolf Barnato's chief mechanic.  He went to Jaguar where he was instrumental in the XK engine, and then Coventry Engines, where he took his design for a lightweight fire pump engine from four cylinders to V8 and then flat 16 versions.   Walter Thomas Frederick Hassan, OBE,  died in 1996.

HARRY%2BMUNDY%2BAND%2BWALTER%2BHASSAN.jpg

Walter Hassan (R) with Harry Mundy (ERA, BRM, Coventry and Jaguar designer) and the flat-16 engine.

   His paper proved to be very difficult to access, as old SAE papers often are, but the College Library came to my assistance and  obtained a copy from the British Library.    It proved to be a fascinating read, for several reasons.    First, he details in 26 pages the development of an iconic race engine from its four cylinder origins through V8 to a flat-16 cylinder (!) apogee.    

The section on his use of  both Lucas electronic ignition and  PI on these engines, alone was of interest to a Triumph user.   The early PI metering unit was cogged belt driven,  and was said to completely suppress fuel vaporisation, thanks to the high pressure used (we knew that!), despite being mounted in the centre of the Vee.   The pump, not described in detail but I assume the same as we are used to,  "caused some trouble, due to overheating"!    It had to be moved in front of the radiator, "despite the lengthy fuel pipes required".

The M/u was controlled by a mechanical linkage from the slide(!) throttle  to a lever bearing a cam that set one of the limits of the shuttle movement.    A version of this was rediscovered by Kas Kastner, and described in his books.   The rotor, I was surprised to read, was "twin-bored"for two, not the one shuttle we are accustomed to, to provide the fuel flow required at max revs.   Another difference was that this M/u included it's own oil pump, but that later models did not, after "the development of materials suitable for high speed running in petrol".    No explanation, another Lucas secret!    Another problem they had was persistent blocking of the M/u's internal fuel filters, the contamination coming from the habit of refuelling race cars from open churns. They lost races fro two years before working this out!  No wonder we are still obliged to use very fine filters on our systems, despite very clean fuel and fuel delivery today.

Hassan found that, although with this linkage fuel delivery should be directly proprotional to air consumption, in fact at maximum torque and due to the ram effect, the volumetric efficiency was greater than theoretically possible!   Tuning the M/u for slight richness at max.torque meant that it was excessively rich either side of that, inhibiting power output.       So they ran in slightly de-tuned condition that lost 3% of maximum power, but still won races and world championships, showing "the relatve unimportance of maximum power compared with middle range torque."!     Today we know that Lucas Pi runs rich at less than full power, so we are usng lessons from Hassan in the '60s.

I've not only learnt more about Pi but more about engine design than I have ever learnt before from a few pages!  If anyone would like to read it, I'll see if I can scan it and post it here as a PDF, as that may reproduce better than scanning a photocopy and then printing it.

John

 

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I'm about to complete my BSc in Motorsport Engineering, at Myerscough College, University of Central Lancashire.

You have PM, MPB

John

Edited by JohnD

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I have PMs from several who would like to read this paper, but I can't send it via PM.  Will they send me their email addresses, please, so that I can send them a copy?

Thanks,

John

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I have four requests with email addresses to go on the mailing list, but none from my first requesters.

Save me doing this many times and send me your email address, please!

John

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Richy and Steve?

Your addresses, please?

It occurs to me, gentlemen, that if I send this to you as a group, you will all be able to read each others email addresses.   I hope that you all are happy with that?    

JOhn

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2 hours ago, JohnD said:

It occurs to me, gentlemen, that if I send this to you as a group, you will all be able to read each others email addresses.   I hope that you all are happy with that?    

JOhn

John, personally I am happy with this, however may I suggest a solution?

If you look on your email client/software/whatever you use, at the top (sometimes hidden, look for an arrow to expand more options) you will have a field labelled "BCC", or "Blind Carbon Copy". Enter all the email addresses in here, instead of the "To" field. Then all the email addresses are hidden from the recipients.

Cheers,

Phil

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9 hours ago, JohnD said:

Richy and Steve?

Your addresses, please?

It occurs to me, gentlemen, that if I send this to you as a group, you will all be able to read each others email addresses.   I hope that you all are happy with that?    

JOhn

no problem for me but as others have suggested use BCC.

cheers

mike

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Thank you for that advice!   Which I will use - email addresses are the last bastion of privacy!

I've only been using computers for forty years........

John

PS But I'm still short of a few who ahve asked for copies.

Edited by JohnD

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