Engine block mystery

[Jentwistle3]

Let me preface this post by saying that I have read all the posts here about engine block identification, Buckland's book, and the Lotus Cortina website. None of these have given me the answer to this question, nor has a reasonably thorough purusal of the web, so I'm coming to the forum in the hopes that someone will have seen one of these and can solve the mystery! It doesn't really matter all that much as, unless there is a terminal issue when I unbutton it, I'm going with what I have, which is:

1965 Elan S2, cylinder head with tappet sleeves on the exhaust side only, four bolt crank. It was supposedly rebuilt prior to purchase but compression is 90 in #2 and it is blowing copious amounts of oil out of same so clearly something is wrong and out it has come. This is what I found on the block regarding casting marks:

Clearly someone has scrubbed off all but the "L"

In all of my research I have not found a Ford casting number that ends in "L".

Other casting marks are:

Does the date code indicate a decade anywhere? Is this october 64 or 74 or ??.

I believe this is simply the core or mold number

No Lotus "L" under the motor mount, but someone has obligingly stamped in the correct engine number!

And now this. I can't make heads nor tails of this. Has anyone seen it before?

Am I simply blind (something my lovely wife accuses me of all the time) or is this some type of aftermarket cylinder block? Any help would be appreciated.

When I get around to tearing it apart my first measurement will be of the deck height, as the motor mounts were bodged up because the dpo couldn't get it to fit properly. Another mystery awaits!

[Chancer]

Last one looks like the period scripted FoMoCo logo (Ford Motor Company) that was often marked on parts and packaging.

I think that I can recall seeing it on engine blocks and also sometimes EnFo in the same location and script but its a long and distant memory now.

[SJ Lambert]

4K20 = cast on 20th Oct 1964.

L after the ground off (likely was ) "6015 120E" is a new one on me!

[rgh0]

120E blocks as used in the early Elans have been made with the L in the engine mount in some cases. Maybe Ford at some stage added them at the end of the casting number rather than in the engine mount?

Lots of undocumented detail variation in engine castings numbers - yours is a new one

cheers
Rohan

[types26/36]

I have seen several blocks with the "L" at the end of the casting number but I have never been able to figure out what the casting number was before it was ground off.
I have pictures of casting numbers of blocks that was around at the time but have not found one that ended with the L digit. I doubt it was a 120E 6015 as I have never seen a 120E block with an "E or L" at the end, even the 116E 6015 does not have an "L" at the end.

[casalunge]

Your stamped in engine number is correct for an early Lotus block.
You would not expect to find a large L under the offside engine mount on an early car, these came much later.
What identifies it as a Lotus Block is the LB stamped after the first part of the engine number.
If you look at the machined face at the front of the block behind the timing chain covers you should also find LB stamped there in the top left hand corner.
Regarding identification overall if you provide Andy Graham the Lotus Factory archivist with you VIN plate details etc he will be able to confirm whether this is the original engine for your car and more or less date it for you.

[casalunge]

Your stamped in engine number is correct for an early Lotus block.
You would not expect to find a large L under the offside engine mount on an early car, these came much later.
What identifies it as a Lotus Block is the LB stamped after the first part of the engine number.
If you look at the machined face at the front of the block behind the timing chain covers you should also find LB stamped there in the top left hand corner.
Regarding identification overall if you provide Andy Graham the Lotus Factory archivist with you VIN plate details etc he will be able to confirm whether this is the original engine for your car and more or less date it for you.

[trw99]

Engine No LP2706 left the factory fitted to 26/4333, a Series 2 Elan on 8th January 1965

Tim

[rgh0]

Grinding off all or part the casting number appears to have been an early Lotus only thing, at least I have never seen reference to standard Ford blocks having the numbers ground off like you see in Early Lotus twincams. Who did it (Ford?, the engine assemblers? or Lotus themselves?) and why appears to be an unresolved mystery. The fact that the L at the end was left and that no blocks appear to have been used by Ford themselves with the full engine casting number in place and the L, suggests that the block was made specifically for Lotus and that the L may be to signify that in the same way it was used in later blocks also. Not all blocks have the L but given Lotus' chaotic ordering Ford may have made the specific blocks in the way shown for a short time only.

From the part photos of the castings with the "L" the block itself appears to be a 120E 6015 casting

cheers
Rohan

[Jentwistle3]

Thanks everyone! I love this forum, it makes Elan ownership a lot more fun.

[Jentwistle3]

Engine No LP2706 left the factory fitted to 26/4333, a Series 2 Elan on 8th January 1965

Tim

That is my car, thanks Tim!

[redcarandco]

Dear gentlemen your science in engine block numeration makes me crazy (I am serious even if it sounds not) Sorry for my broken english ...I have this to submit to all of you ...What I can say is that this one was in a 23 B and all (absolutely all) threads are elicoiled and block is linered to 83.55 mm and but I doubt of holbay provenance because I have had severals not so marked....but mains are steel but perfect imitation of cast iron ones and no L nowhere..... I am not able to show them they are at magnaflux testing ...... best regards and have fun....Roger P.S. It seems that the marks stamped in block has been done by a drunken sailor........

[redcarandco]

When I say no L it means on block of course not on mains.....

[rgh0]

Interesting block

I think it is actually a later block, probably 120E assuming it has a screw in oil pick up, that has been stamped with the Holbay the 116E code and LP numbers at some stage.

The 116E blocks had only one web at the rear right bell housing flange the later 120E blocks had two which is what it looks like in your photo. Since its out of a race car someone probably blew up the original block and put in a new block but kept the original numbering

The "L" appears on a few 120E blocks but did not appear consistently until around 67/ 68 with the 681F block. The block casting numbers were usually / often ground off by Lotus so sometimes hard to tell exactly which block casting was used.

116E block

120E Block

cheers
Rohan

[redcarandco]

Many thanks rohan I did suspect something like an engine swap ...but I had the candor to think seing the old fashion (fomoco) insert that the block was older than one with angular logo...and once again you are right it has a screwed pick up... Yet One thing troubles me if you look at foundry date it seems to have been done in 1964 so did ford fabricated 116 and 120 blocks in same period? Was it true that Holbay made their proper blocks melting the qualities of several different foundries to improve their own block??????very best regards
Roger