Elan S2 engine block and cylinder head identification

[Tobermory]

Hi Everyone
Hoping someone might help me learn a bit more about the block and head of my TC. The motor is from an Elan that has been in Canada for all its life, I assume. It was converted to a race car in the late 70's and has likely gone through a few changes along the way.

I have some of the numbers that are cast or stamped into both parts but they don't mean much to me. A stamped 3020 was added ahead of the cast E6015 on the left side of the block while LP12037LBA is stamped above the right engine mount which in turn has an L in the middle of it. The head has CX71 stamped on the back where it connects to the block while directly under that, on the block, is stamped JD196. See pics I have included.

Another question I have concerns the VeganTune cam cover. Does this belong with this motor or was it just added along the way? Is there a way to be able to tel? l It has an engine ID #1139 on the plate that is visible.

Any insight into the age and origin of any of these parts would be much appreciated. Like I say this has been a race car for a while and many things may have changed along the way...



Thanks

Dugald

[trw99]

According to my records Engine No H12037B was fitted to an Elan +2, invoiced in July 1968. However, confusingly the 3020E casting no. was used on the Lotus Cortina MkII. It is, I suppose, a possibility that there were two blocks marked up with the same Engine No (12037), but if that was the case it is the first such duplication I have come across.

CX71 (2 x letters followed by 2 x numbers) is a four digit code used by Lotus, or possibly the William Mills foundry, the meaning of which has never been deciphered. The one on my 1972 Elan BV head is GP72, for example.

JD196 on the block is a mystery to me. Rohan may know?

Vegantune certainly made a fair number of twin cam heads, as well as some engines, including a fuel injected version. Whether they made as many as 1,139 I do not know. They may well have started their engine numbering system at 1000. Anyone know?

The only way I would know of ascertaining if your head is a genuine Vegantune one is by your measurement of your head and engine against reference to the known dimensions listed by Vegantune. I have scans of two of their catalogues with specifications in them. They are too large to attach to a post in the forum, so please send me a PM with your email address and I shall gladly send them to you.

Tim

[rgh0]

The head and block appear to be both from the late 60's based on the numbering. I have seen the 3020 stamping on both Cortina and Elan blocks from the era so I dont think they were unique to Mk 11 Cortinas. The CX71 code on the head I can best decipher as around c= year 1969 x=batch number 71= head number in the batch. Whether the head and block originally were on the same car is impossible to tell but they of the same period

Vegantune were building competition engines back then and so this may be one of those with this cam cover. It would be understandable that such an engine could end up in a S2 Elan that was converted to a race car in the 70's.

The number stamped on the block under the head number looks to me like the sort of thing an engine rebuilder would do to make an engine they had worked on. Potentially it may have been put their by Vegantune when they built it as a compeition engine

Pulling the egine apart may reveal more details of its origins but given its been a race engine much of the original internals will probably have been replaced, potentially multiple times.

Tim

I would be very interested in any details you have on Vegantune engines

cheers
Rohan

[Tobermory]

Thanks Tim & Rohan - very interesting.
Will be interested to see the info on Vegantune - I sent you a PM Tim.

Is it possible to say, based on the production date of July 1968, whether this is a 120E block? I understand from Bryan Moorecroft’s article on Ford cylinder blocks that this would be the most likely candidate. FYI It currently has 83.5 mm pistons.

The head has the large 1.625 valves. Is it safe to assume it did not start life that way based on the production date?

Dugald

[Craven]

Couple of points you may like to look at, a characteristic of Vegantune camshafts is a smooth turned finish between the cam lobes you should be able to see this through oil filler hole. In the pic, area on the block where the casting date is shown. 1st Character = Year within decade. 2nd Character = Month,
A=Jan NoI used. 3rd Ch = Day.
If your is 1968 Block most likely a 681

cast date.jpg (81.28 KiB) Viewed 847 times

[Tobermory]

Thanks Craven

My date tag says 7L17. 1967 Nov 17?
Have I got that right?
Not far off from 1968..

My Vegantune cylinder head cover has no oil filler hole…. Designed to go with a dry sump I assume. Also I know that the cams have been changed. Any other tell tale signs that would identify the head as a Vegantune?

[rgh0]

Does the block have the screw in oil pick up tube or the press in pick up tube ?

cheers
Rohan

[Tobermory]

Rohan
Are we talking about this? See pic
Looks like press-in to me

[mbell]

The first picture on this first post shows the corner of what is likely an none standard oil pump for a dry sump setup. You can also see what is possibly a oil pickup pipe.

[Craven]

Correct for casting date but remember it would have taken a while before being fitted by Lotus.
Not totally sure but 3020 came in with MK2 Cortina in March 1967. Not only used in the Cortina.

[Tobermory]

Yes the engine is dry sumped and that is a pickup from the pan.

Craven - it sounds like there is not a definitive answer as to the origin of the block…
I guess that is not entirely surprising given how many changes there were with blocks at Lotus over the years….

[rgh0]

There should be the original oil pickup connection point in the bottom of the block under the oil pump mounting. This is not used for dry sump modified engines. The 120E blocks had a screwed fitting the 681F blocks had a press in fitting

cheers
Rohan

[2cams70]

This block is most likely a 2731E block restamped “3020E” after being bored by Ford to the larger Lotus bore size.

The 2731E block was the last production of blocks for the 1500cc pre-crossflow engine. Does it have a push in oil pickup tube and lip type rear seal? If so it’s almost certainly a bored out 2731E block. The block date stamp aligns with the crossover period between the pre crossflow and crossflow engines which is when this change took place

Later 681F and 701M Lotus blocks will have provision for a rear dipstick location. The 2731E does not.

The last of the 1500 pre crossflow engines had lip type rear seals.

[Tobermory]

I don't claim to know much about this subject - hence the call for help - but were the 2731 blocks not marked 2731 6015 without the E ( as per Bryan Moorecroft's article) - mine has the cast E.

He also says "they were the last of the NON-L blocks" while mine is a L Block? Thoughts?
With the oil pan in place of course I can't see the oil pickup unfortunately. will check the rear seal...

[Craven]

It’s a mine field who really knows ? only 3 engine types list in parts book.
A026E0708 UP TO eng no LP7463
B026E0708 FROM eng no LP74634 to LP7799
C026E0708 FROM eng no LP7800