Head Identification

[1963 S1]

Does anyone have information about the Weber head identification numbers, the period produced, nuances about the various early production units? The head and block are believed to be original to the Series 1 Elan, Unit Number 3190, Chassis Number 0209. Thank you.

Head Number: LP581 (installed, a 'mirror' image)

Engine Number: LP584

[rgh0]

Early twincams like yours had the engine number on the head and block as shown . It looks like your has had a head or block swap for a similar period number unit or more likely Lotus just stuffed up and did not install the right head on the right engine block or made a mistake stamping one of them after assembly.

Lotus dropped the engine number stamping on the head around 1967 and heads after that either have no number on the rear face or a 4 digit number of the format "letter, letter, number, number". The exact meaning of this code is not clear and I have never been able to fully decode but it is probably a year letter plus month or batch code letter and then sequence number within that month or batch.

As usual with Lotus there are many other variations such as engine number on the bottom face not the rear face. or a date code. Engine shops also have a tendency to stamp a job number on the rear face when rebuilding a head which further confuses the situation.

cheers
Rohan.

[trw99]

As Rohan has intimated, this looks like a production line error.

The factory records list your Engine No as LP584. I have no record of an Elan being fitted with 581. Due to the similarities in number, I suspect that the 1 on the head should more rightly read 4.

During September /October 1963, when your car was invoiced, Lotus were ramping up Elan 1600 production. I dare say several anomalies exist on cars of the period!

Tim

[1963 S1]

Thank you Rohan. As usual, your input is very detailed and helpful. I appreciate the support you provide to us forum members. Likely an assembly matter rather than a post-dispatch head exchange.

Thank you Tim. Yes, many anomalies have been documented/eluded to on this forum; so not a surprise to have this present on Unit 3190.