Twin Cam Engine Details needed

[Certified Lotus]

I just purchased this twin cam engine and after reviewing about an hours worth of posts I'm still not sure of the details of this engine. Some of you seem to be well versed in the history of twin cam engines, your help would be greatly appreciated!

[Plus 2]

Duplicated

[Plus 2]

Haha.......well engines and transmissions are not at all my subject but I would like to tag onto the post and learn a bit as with nearly 60 views and no responses yet it must be the weekend.

What I will say from my limited engine experience it is an original L block as I can see the L on the RHS albeit I believe some blocks slipped through without if the casting was found suitable.

If the cam cover is original then that has to put it at around 69/70's as the Stromberg carb cable boss is there yet it is a Weber head much after that we went to the 130bhp spec that had the ribbed camcover and much before that the cam cover had the Lotus embossed on each side of the casting. There are many cases as is my car where Weber heads were seen with the Stromberg camcover and bonnet bulge around the 69/70's.

Sometimes year idents on cast blocks can be deceiving as the castings were left for months to 'de stress'

It is painted in Ford tractor grey by the look of it which also I think is the correct original block colour, and the front plate water pump casting hose outlet looks in really good shape.

I am sure the numbers will 'tell all' to the experts and even give you the car it was originally fitted to leaving the factory but looks like you have got an excellent find as Weber heads alone are well sort after.

Hopefully I might be awarded the odd point for a non engine guy.......

Regards

Steve

[gjz30075]

trw99 on this site can tell you from what car this is from based on the number on the mounting boss. There's also a date code on the block in the form of a number/letter/number(s), which is Ford's way of saying year/month/day of month.

What are your plans for it?

From looking at the butt end of the crank, is it 4 bolt or 6 bolt?

Greg Z

[types26/36]

I have a block that is approx 60 units after that engine and believe it came from a MK2 Cortina Lotus, as the engine has a LF prefix I think it unlikely it came from an Elan which are generally an LP prefix which I believe was LOTUS-PRODUCTION while I believe the LF prefix was for LOTUS-FORD.
Again I am not sure but think the block would probably be a 681F as it is to late to be a 120E and too early to be a 701M.
Lotus used to grind off the casting number and stamp 3020E in its place which was Fords designation for a MK2 Cortina Lotus although these "ground off" engines were also fitted in Elans.
The 6015 is just Fords number for a block.
I would guess it is Special Equipment (115-118 HP) spec but you would need to check which cams are fitted (denoted by the number of rings in the front of the camshaft's next to the sprocket)

[rgh0]

[quote="types26/36"].
Again I am not sure but think the block would probably be a 681F as it is to late to be a 120E and too early to be a 701M.
Lotus used to grind off the casting number and stamp 3020E in its place which was Fords designation for a MK2 Cortina Lotus although these "ground off" engines were also fitted in Elans.
quote]

The ground off numbers are a mystery as to what they were- The remaining cast digits are E 6015. So you would assume it is a 120E block. However it probably has a six bolt crank and press in oil pick up which makes it similar to the 681F blocks. I have a similar block ( the original out of my 1968 S4 ) with the numbers ground off and 3020 stamped followed by the cast E 6015. The block also has the rear oil dipstick position available in the casting as used by Escorts introduced in 1968. Somewhere in the transition from the 120E to the 681F there was something going on with the casting numbers and the grinding off of them that is not explained anywhere

cheers
Rohan

[Certified Lotus]

Thanks guys! I bought this engine as a spare due to how difficult they are to acquire. I'm going to have it rebuilt and then decide if I should put it in my '64 Elan S1 right away or wait for another time. The piston rings on my current engine need replacing (white smoke) and having a ready to install spare allows a fair amount of flexibility.

I'll probably get comments about the extravagance of buying a spare engine. It's something I have done a number of times during British car ownership.

Knowing the details of this engine are very helpful. This is a great community and I greatly appreciate the knowledge and insights you provide.

Best, Glen

[rgh0]

Buying a complete spare engine is the best thing to do if you appreciate driving your car and don't want it off the road for 6 months during a major engine overhaul. Certainly not extravagance in my mind

cheers
Rohan

[Certified Lotus]

Thanks for the positive comment Rohan. I learned my lesson the hard way a number of years ago waiting for engine parts and then shop time to build a new engine. Lost a whole summer of driving. I swore that would never happen again. Besides, even if I never use it, the value of these engines isn't going down

[trw99]

Glen, I have had a good look through my records and been unable to find either an Elan or +2 with that engine number. It was most likely fitted to a LoCort, I suspect.

Most Elans and +2s with engine numbers in the 11### series were fitted to cars in the spring and summer of 1968.

You could ask Andy Graham at Lotus if he can track down the car the engine originally came from.

Tim

[Certified Lotus]

Tim, thanks for looking in your records for me. All I know is that this engine was in a Lotus 7 for a while and when the owner switched to an original engine for the 7 this twin cam went up for sale. So this may be an assembly of different parts (head and block). Here in the states a used weber head in good condition goes for about $3K so finding a complete used engine for not much more is a bargain.

As I have the original engine for my Elan S1, this engine will be my spare until I pull the engine that is in my car. According to the records I have for my S1, the last engine overhaul was done in 1983 (new bearings, larger valves, overbore, new pistons, rods & rings and cams to create a sprint engine).

I'm on a steep learning curve with this car, having come from a 2007 Exige S. All my memories of owning British sports cars in my youth (and the countless hours in the garage repairing them) are coming back. The difference this time is I can afford the parts, I have all the tools (after 40 years of collecting them) and I have a new Audi sitting next to it that is my real transportation.