LOtus Elan S4 - Engine questions

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I have recently bought a 1970 SE4 originally sold 2/11/1970 as a FHC with twin Strombergs which has at some point morphed into a DHC Big Valve and dellortos.

Engine numbers are 3020E 6015 on the block & stamped on the shelf, LP 12495 LBA, which I understand is a bit strange ??.

The mains caps are round type. The Cap shells are part worn through the White metal to the copper underneath. Would it be better to change to the sturdier square type?? and I guess the shell wear suggests I should be looking at a new oil pump & oil pressure relief valve spring. All advice welcome

[nmauduit]

I have recently bought a 1970 SE4 originally sold 2/11/1970 as a FHC with twin Strombergs which has at some point morphed into a DHC Big Valve and dellortos.

Engine numbers are 3020E 6015 on the block & stamped on the shelf, LP 12495 LBA, which I understand is a bit strange ??.

The mains caps are round type. The Cap shells are part worn through the White metal to the copper underneath. Would it be better to change to the sturdier square type?? and I guess the shell wear suggests I should be looking at a new oil pump & oil pressure relief valve spring. All advice welcome

If it were mine I would upgrade to the later style square caps - though be aware that this requires a line bore machining (100-150 pounds ?) - conversely you may also fit steel caps (about 100 pounds a set from what I recall). Care of using quality bolts/studs is also recommended, so an other budget to plan there (esp. rods bolts).
Shell wear may not be a direct symptom of an oil pump issue, but I would change the oil pump in any case.

Generally speaking, starting with a well rebuild fresh big valve engine is a good approach for fully enjoying your elan.

[RogerFrench]

The shell wear also suggests you should be measuring your crankshaft bearings for ovality and taper. May need a regrind.

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Gents many thanks for your responses. As the pistons have around 0.030" play as best as I can measure with feelers a re-bore et al is a certainty.

Along with that naturally comes a Crank regrind. With 0.010" shells fitted at present still plenty of meat to take.

I will for sure go the Square caps route , with a line bore.

What's a house re-mortgage between friends anyway.

By the way I am now a fully paid up member of the "want to get at something? take at least 3 things off first" Chapman club. Figuring how to work on on an Elan is the nearest thing to chess I have ever experienced on a car.

[The Veg]

By the way I am now a fully paid up member of the "want to get at something? take at least 3 things off first" Chapman club. Figuring how to work on on an Elan is the nearest thing to chess I have ever experienced on a car.

It's still much easier than working on an Esprit.

[denicholls2]

By the way I am now a fully paid up member of the "want to get at something? take at least 3 things off first" Chapman club. Figuring how to work on on an Elan is the nearest thing to chess I have ever experienced on a car.

When you're done with the Lotus, get yourself an Audi A6 Avant. Replacing the exhaust system requires disassembly of a considerable amount of the driveline to gain access via a "one flat per flip" hand wrenching job. I find it hard to believe there is a more difficult car to work on. Not many more expensive either, Lotuses don't come close.

[Elanintheforest]

Hi Bob and welcome. Your engine, number LP 12495 LBA, isn't original to the car, although I think you had already guessed that! It's from mid 1968, and my guess was it was originally from a mk2 Lotus Cortina when they were very cheap in the 1970s. It was common practise to replace a tired engine with one from a crashed or rotted out Cortina, but of course it may just have been swapped to convert the car to Webers in the first instance.

Mark

[trw99]

LP12495 was in fact first fitted to an Elan. As Mark surmised it was invoiced by the factory in June 1968. It falls within the batch of cars at the switchover from S3 to S4, and may have been a SS, though that has little bearing on the engine dynamics.

3020E 6015 are the block casting numbers.

Tim

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Thank you all for the help well impressed by this website