Twincam Engine - Connecting Rods

[zrxmd]

Hi everybody,

This is the first time that I use a discussion forum. I need your help, I'm rebuilding my Twincam engine for my Elan S2 and I read in a book that the early Lotus Elan Twincam engines were equiped with fragile connecting rod. After that, they changed them for the new "C" type connecting rods. How can I identify witch connecting rod my engine have?.

Thank you

Marcel

P.S. Sorry about my english !!!

[Dag-Henning]

Unless yr engine is a very, very early ( -63) untouched item, you need not wory. If your rods are marked 125E , - which I guess they are -, you are safe...
That is, if you behave and keep the rotor with the limiter.......
Dag

[Dag-Henning]

- a short one to follow ; Buy yourself new rod-bolts, - a cheap insurance.....
Dag

[zrxmd]

Hi Dag,

Thank you to reply to my request.

I've checked my connecting rods and the only mark written on the rods is "SDF 9A" on one side and "L front" on the other. My Elan is a S2, but we could say it's a "S1-1/2", it's an early S2. The first Lotus Elan S2 had chassis number 26/3901 and mine is 26/3997. Do you have any information about my connecting rods?

Thanks again

Marcel

[types26/36]

I dont think 125E rods were fitted until the very last of the 4 bolt crank engines (mk1 engine) and I think it was about the time the S3 was introduced that they changed
I dont think your car would have had them, I have S2 26/3944 and that had the early rods (since modified)
If 125E is not cast into them they must be the early ones.
Brian.

[Petter Hval]

Hi Marcel
According to Miles Wilkins: " In the unlikely eventthat you come
across L-type rods, they should be replaced immediately by the
C-type, regardless of their condition". The standard C-rod bigend
bolts shuld be replased with grade 12.9, 13/4 by 3/8 " UNF HT
socket cap screws. If yu don`t have Wilkins book? BUY IT NOW!!!

Regards
Petter

[Dag-Henning]

"SDF 9A" does not sound very "Ford-like" to me....Maybe you have later steel-rods ?? The early ones that Lotus fitted was the original Ford items and should have 113E on them .
Petter's advice on the bolts is very good ! Use "off shelf" socket-bolts in 12.9 quality. Cheap and strong!
Can you take a picture of yr rods and post them on this forum ?? ( - sorry, but I am new here......)
Dag

[zrxmd]

Hi Dag,

Thanks for your help,

I've posted a picture of my connecting rod in the gallery photo. The rods are original, I'm the second owner of this Lotus Elan S2 1964 and it never has been restored so far (including the engine).

Marcel

[types26/36]

" The early ones that Lotus fitted was the original Ford items and should have 113E on them .Dag

I dont think it was 113E as I remember a "113E" was a 1200 Anglia, I think it was 116E or 120E which were 1500 engines.
Brian

[gjz30075]

Definitely the early rods. I had a LoCort that had rods like that. Changed out the rod bolts and kept to a 6500 redline and all was well. That said, since you have the motor apart, certainly try to obtain a set of 125E rods, especially if you plan on any mods.

Greg Z
'72 Sprint

[1964 S1]

Are you planning any mods?

[Dag-Henning]

" The early ones that Lotus fitted was the original Ford items and should have 113E on them .Dag

I dont think it was 113E as I remember a "113E" was a 1200 Anglia, I think it was 116E or 120E which were 1500 engines.
Brian

You are absolutely right Brian, - they should read "116E" ! Sorry!
From the pic, they look like the old rods to me.....- and should be changed for something with 3/8" bolts according to all the gurus.....

Dag

[zrxmd]

Hi everyone,

Thanks to all of you, your help is really appreciated. I want to restore my car as it was in 1964 (including the engine), but you confirm that I need to change the connecting rods for the 120E.

Thank you again

Marcel

[Dag-Henning]

- the 125E!
Dag

[zrxmd]

YES!!! ... 125E

Thanks Dag