Engine Number 31??!!

Researching the history of 1559 has been a fascinating exercise.

There had been much speculation over the years regarding a Lotus Elite with a factory-fitted Twin Cam engine, and a number of Lotus experts doubted its existence.

The only Twin Cam powered Elite that was never in question, was David Lazenby’s “company car” (#2001) which he converted to twin cam power in July of 1967 — four years after Elite production ended. This car was described in  a 1968 ‘Car’ magazine article by Nick Brittan. Return of the Elite!  The ’68 Twin Cam Elite‘ . 

In the article, Brittan mentions an earlier twin cam conversion to an Elite, which he says didn’t work well and was abandoned. It is the existence of this first twin cam that has been debated for 50 years.

The Mysterious Engine Number

The original factory records, listing chassis numbers and engine numbers were lost. However Warren King, who worked in the accounts office at the Lotus factory, had been keeping a separate, handwritten list of this information along with sales invoices as each car was shipped. 

Dennis Ortenburger published scans of this handwritten list in his book The Lotus Elite: Racing car for the road, and that list has since become the de facto authority for Elite chassis and engine numbers.

In that list, there is one Elite that stands out as an anomaly. #1559.

Every car in the Warren King list was either fitted with a Climax engine (with serial numbers in the thousands) or was shipped without an engine. i.e. “CBU only”.

But #1559 is shown with an engine number of 31.  Ever since this list was published in 1977, the 31 was assumed to have been a mistake.

Chassis and Engine number listing showing 1559 with engine no. 31

Elite #1559 is fitted with a Lotus twin cam engine, but the engine number is LP326.  So what does engine number 31 signify?

What happened

When #1559 was being prepared for delivery, Warren King (or an associate) would have recorded the numbers from the engine and CBU. However this was the first twin cam Elite they had seen, and when they went to find the engine number they probably weren’t sure where to look.

Yes – there is an engine number stamped in this boss

Although the number LP326 was stamped in the normal location for a Ford block (the right-hand engine mount boss) it was so faint as to be essentially invisible. 

However it is also likely that they would have looked for the engine number where they would normally find it on a Climax Engine — on the forward right hand side of the block, which is where they found the ’31’.

Furthermore, being the first twin cam to be seen in an Elite, an engine number of 31 would not have been that surprising.

Why wasn’t this discovered sooner?

Subsequent owners of 1559 knew enough about twin cams to know where to find the engine number.  Using a flash light, one can just make out the LP326 stamped into the engine boss.  The number is also stamped into the back of the cylinder head where it can be seen with a mirror, but the folks filling out the invoice list probably didn’t know this.

But most significantly, the 31 stamped on the side of the block was obscured by the carburetors, and was only discovered when the carbs were removed for restoration.