Engine Numbers enquiry

[richardcox_lotus]

The John Bolster book referred to is probably "The Lotus Elan and Europa" ISBN 0 900549 48 3,
The version I have is printed 1980. Martin Colvill probably remembered it as his garage is on the front cover !

It's not bad actually, but I think the Robinson & Ross one may be more useful.

Paddy - I doff my cap !

Rgds
Richard

[elans3]

(Paddy)
"This isn't quite true - the earlier Lotus engines (all "rope-seal" engines and the early "lip-seal" engines) did not have the "L". They were the same blocks as came from Ford's mainstream production line, athough selected for Lotus based on production tolerances. Later, the blocks changed to the 681F block, and then then 701M block, part way during the S3 and early +2 production. These 681F and 701M were the ones with the L.
So if it doesn't have the L it might be an original early Lotus engine, or a later non-Lotus block"


The Robinshaw and Ross book is incorrect in this aspect, I have a 3020-6015 L block sat on my bench at the moment, and it has the L cast into it.
I've known the engine for 25 years, it came out of an early S3 belonging to afriend of mine, its an early LF 12000 number, and my friend owned the car from new.

Don't know how many were like this, but just to put the record straight,
Cheers
elans3

[rgh0]

Your 3020 number is stamped not cast ?

I have a block like this it was the orginaly one in my early S4 - looking at the details of the block it is actually a 681F block with the 681F groound off and 3020 stamped.

The L appeared on the blocks i believe when Ford stopped making 1500 blocks for themselves which was aroiund 67 sometime ( except for their replacement engine program) so it was easy to distinguish them from the 1600 blocks in the foundry and machine shop.


Dimensionally the blocks are identical inclusding bore casting thickness despite the myths about the L blocks being thicker

I am sure with the Lotus usual dedication to clean production line changeovers it took a couple of years for non L block casting to finally be all used up so I am sure l blocks filtered their way into cars from S3 on for a couple of years

You find old L blocks in cortinas due to Ford using them for replacement engine supply post 67

cheers
Rohan

[elans3]

Hi Rohan, yes the 681 is ground off and the 3020 is stamped. The Elan it came from was a very late S3, registered late '67, and I agree with you that there must be a good few of these around,
Regds
elans3