Mystery engine number?

[nebogipfel]

Gentlemen,

I have Little'un apart to try to stem some of the oil leaks and have just noticed the engine number doesn't appear to conform to the usual conventions.

It is a 701M 6015 casting (with "L") and the engine number stamped in the usual place reads 6SM 550.

Just wondered if this rings any bells with anyone?

Thanks

[garyeanderson]

Hi John

Foird made replacement engines after the 2731 that they used used in the 1967 Cortina 1500, after that point (starting in late 1967) they made 1300 and 1600 height blocks for there crossflow engines. The 1500 height block was not used in Ford production after that point so it was a Lotus only and they had some blocks the did not meet the standards that Lotus specified so these were sold as "replacement" blocks for the pre-crossflow and also built up into complete pre-crossflow engines for there industrial engine division too. When the 701 block was introduced in 1970 the same thing went on and 701 blocks that were not sold to Lotus for what ever reason (bore thickness) were sold for replacement and folks seem to think they all look alike so many have been bored .060 inch over to standard twin cam bores (3.25 inch) and they work just fine but may not take the additional .030 (3.280 inch) that one of the LB engines will. As usual someone may find an error or three but thats the gist of it or how I have read it. Richard has posted an article a few time on the various Ford blocks and what they are.

Gary

Maybe this explanes it better than I can or tried

http://lotus-cortina.com/library/block/blocks.htm

[nebogipfel]

Thanks for the answer and the link Gary but it was the stamped on engine number I was particularly curious about (the 6SM 550)

[elansprint71]

Beats me what is going on.

[bcmc33]

What does the registation document say the engine number is?

However, it is probably not the original engine.

[nebogipfel]

What does the registation document say the engine number is?

However, it is probably not the original engine.

Haven't got it to hand Brian but it's a conventional LP **** number so nothing like the number stamped on the mounting boss.

Almost certainly not the original block ..

[rgh0]

Hi John

.....701 blocks that were not sold to Lotus for what ever reason (bore thickness) were sold for replacement and folks seem to think they all look alike so many have been bored .060 inch over to standard twin cam bores (3.25 inch) and they work just fine but may not take the additional .030 (3.280 inch) that one of the LB engines will.

Gary
The bore wall thickness stuff between different blocks ford 6015 - casting numbers and T numbers and L and non L blocks is a myth
I can find no statistical difference between the bores wall thickness used in Lotus of any casting numbers and those not used in Lotus. They are all as likely or less likely to be able to be bored beyond the Lotus twink standard 82.5mm

The only meaninful number is the lotus grading stamping LA LAA LBB that was done on some blocks. Even this was dodgy as it was not done with a full ultrasonic survey but with a couple of spot checks

cheers
Rohan

[garyeanderson]

Hi Rohan

I don't know why or what is or was different. All I know is that they did do some sort of inspection however minor it was or wasn't. I am clueless but they did and it cost them time to do it. That says it cost money, and money was not spent at Ford or certainly not at lotus for no reason. I respect your opinion and your ability to cut to the chase but I still feel that there was a difference. I do agree that T numbers is just bullsh1t and that it is the core box casting number, all of the cast iron ford parts have it and it makes little sense to have it other than to track a batch of castings that came from a particular set of casting core box pieces. I don't know how many times a set of core parts can be use with out deteriorating but these core pieces get damaged after X number of parts and need to be refurbished and that is my gut feeling for T numbers.

Gary

[Peter +2]

Thanks for the answer and the link Gary but it was the stamped on engine number I was particularly curious about (the 6SM 550)

John,

Waking up this old post, did you ever get to find any information on your engine number?

I have 6SM 835 so would be interested to know what you may have gleaned.

Thanks

Peter

[2cams70]

That engine block may have been originally purchased as a bored to size (i.e 82.5mm) spare part from either Ford or Lotus. From what I can gather the 701M "L" blocks bored to the standard pre crossflow size (81mm) and intended to be used in standard pushrod engines were not graded with the LA, LB markings.

Blocks purchased through spare parts were not stamped with engine numbers. That engine number may have been stamped by the local registration authorities to enable the original car fitted with that block to be registered. It doesn't seem to conform to anything I've seen from Ford.

Here in Australia it was common for the later crossflow engines to have the original engine number stamping erased during engine reconditioning. Ford Australia thoughtfully decided to place the stamping on a small pad that was part of the cylinder block deck facing so of course when the block deck was machined during reconditioning the engine number disappeared!!

It happened to me on one occasion and the registration authorities stamped a number according to their standard - something along the lines "V12345" if I recall correctly with the "V" standing for Victoria the state the number was issued in. They refused to register the car otherwise and it is illegal to transfer the engine number from one block to another.

[512BB]

'Waking up this old post, did you ever get to find any information on your engine number?

I have 6SM 835 so would be interested to know what you may have gleaned.'

I think you will be waiting a long time for an answer Peter, as Nebi does not post here any longer. He sold his Elan to a friend of his, who also used to post here, can't recall his name, but has not contributed for some time.

I was out for a drive in Suffolk one sunny Sunday, and spied a yellow Elan in a small village car park, no one in it. So I parked up next to it and waited. After a short while, a fellow appeared with a grin on his face, said he thought he was seeing double. And that was Nebi, aka John. Lovely chap, shame he left.

Leslie

[Peter +2]

2cams70

Many thanks for the extra information which seems to support my understanding that the car has had a new block following a major engine failure in its early life. The engine is currently being disassembled and the block has standard bores again supporting my understanding that this block is probably newer than the age of the car.

Many thanks.

Leslie

Many thanks for the update on Nebi.

Much appreciated

Peter