positive/negative ground, engine type & some other q's

[ill_will]

I have been doing a bit of work on my non-runner. One thing I am unsure about is whether it is positive or negative ground. It had no battery in, nor are the terminals marked (nor would I trust them if they were given the quality of some of the electrical installation...)

It is a S3 S/E FHC baby Elan, chassis number around 36/73** off the top of my head.

I've read through numerous posts on the conversion, and it seems like one of the big clues is the alternator/generator.

Now, it looks to me like an alternator, but having never seen a generator, could someone advise on how to tell the difference please? I've taken the radiator out so could get some photos later today if necessary.

On a positve note, I whipped the plugs out and cam cover off, oiled the bores and cam lobes last weekend, left it sitting for a week. With the plugs out it turns easily by hand - very encouraging! Have got the carbs off for a good cleaning and want to get some of the instrumentation up and running so I can turn the engine over and check the oil pressure and whether it's supplying the cams.

Having not got a workshop manual yet, I have identified what I think is the water temp sender and pipe (coiled pipe from heater connection thing above the ex. manifold.) and the oil pressure sender (above the oil filter.) Do these need any electrical connections to function, or do they come in different varieties and thus depend on type? Will try and get a photo of both later.

One final question - any pointers for where the block number is? clues for type so far are: big valve, red crinkle cam cover (painted over in black) twin DCOE webers, screw on oil filter, lucas distributor. Any ideas?

thanks for your time!

will

[Jason1]

Hi Will

See pics attached.

Hope this helps

[neilsjuke]

Check the rev counter .

[ppnelan]

Check the rev counter

It should state whether it is positive or negative earth.

The original dual oil pressure/water temperature gauge is not electrically operated. The water temperature is measured via the capillary tube you spotted, with a brass 'bulb' screwed into the head. This tube is part of the gauge and should not be detached from it. The oil pressure is conveyed to the gauge through a small-bore pipe from a union on the block above the oil filter.
A little way back from this union, just above the engine mounting, is a horizontal-ish face on the block which should have the engine number stamped on. They are often difficult to see due to minimal stamping & layers of paint...

Best of luck

Matthew

[RotoFlexible]

Check the rev counter

It should state whether it is positive or negative earth.

But, don't necessarily believe it if it says "Positive earth". It could have been converted. Mine was, years ago, but the face still says "Positive earth" (unless Nisonger changed it when they rebuilt it recently - can't say that I've noticed one way or the other).

If you have a dynamo (generator), you can't tell by looking whether it is positive or negative earth. It can actually be changed from one to the other by an arcane polarizing technique. I think an alternator is always negative earth, but I could be wrong. The Elan dynamo has that unmistakable late-age-of-steam look, as in the photo.

[garyeanderson]

One final question - any pointers for where the block number is? clues for type so far are: big valve, red crinkle cam cover (painted over in black) twin DCOE webers, screw on oil filter, lucas distributor. Any ideas?

thanks for your time!

will

engine number is on the horizontal pad above the engine mount of the left side, look down between the carbs

Lotus grading of the Ford block

Lotus Ground off the Ford part number sometimes, photo of an Mid production Elan S2 block that was not re-stamped

[billwill]

As mentioned, you can't be sure whether it has already been converted to negative earth.

If it is a dynamo, see if you can spin it in the correct direction and see if it generates plus or minus volts relative to Earth; that will tell you what it was last polarised to do.

Regardless of what it used to be, unless you are a total purist, convert it to negative earth as part of the re-build.

See:

http://www.lotus-cortina.com/electric/convert.htm

[1964 S1]

Hello ill will, (what an odd id.)
Follow billwill's advice.
Also, beware of using the term baby Elan here.
Eric

[billwill]

Indeed.

Now this IS a baby Elan (made by Corgi)

[ill_will]

Thanks for all the tips.

As I suspected, it is definitely an alternator. I turned the motor over for a couple of seconds on the starter (plugs out) but the oil gauge didn't appear to move, so I'll prime the pump with vaseline and try again. Until I get pressure I obviously don't want to turn it much.

If I assume because of the alternator that it's negative earth, am I right in thinking the starter should be turning the crank clockwise (viewed from the front?)

Re. the 'baby' (mis)nomer: I was distinguishing between type, but I guess the 36 is a bit of a give away... Nice Corgi, by the way, never seen one with a separate chassis before!

Re. the block number: I managed to locate some numbers by the engine mount, but as Matthew said, it's incredibly hard to read. Cleaning with petrol and a paintbrush as best as I can, I'd say it says N28502. I'll check those other locations too.

Thanks everyone!

will