Re: Engine identification
Posted: Mon Jul 09, 2012 8:37 am
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512BB wrote:The pics that Paddy posted for me, thanks Pad, show a 681F L block, with SQUARE main caps, as it came from the factory. Quite unusual no? I would think that this block was one that was cast in around 1970, as Ford were going over to the 701M L block for Lotus, but the case casting number has not been changed yet.
Leslie
EdHolly wrote:Just spent the day stripping a 120E long engine with an L cast in at the appropriate place.
This engine came from my Lotus Elite series 1 which had had an engine transplant in the USA back in the dark ages. I pulled the engine out some 14 years ago in late 1998 and put it aside when I built and installed a Climax.
A few years ago I was moving the engine and it was then I realised the engine was built around an L block a T3.
As I now have 3 cars with twincams, 2 Brabhams and a series 1 Elan, I thought I would start the process of building a spare around this block, starting with stripping it bare. I always imagined that seeing the Elite was a Lotus they had sourced a Lotus engine and put a non-crossflow head on it. Well, first disappointment was ordinary pistons, no eyebrows. Next disppointment was 116E crankshaft and rods. Next disappointment was bore size 81 mm. Next and last disappointment was only about 3mm meat measureable in the rear wall of the rear cylinder, not enough to get 82.5 even.
So it would appear occassionally a block cast with an L was realised to have too thin a wall thickness to use as a Lotus and it was sent down the normal assemby line as a normal production block and only bored to 81mm
Almost 50 years later we learn a little more - anyone else ever found an L block with only 81mm ?
Going to list it on E-bay as might be useful to someone from an originality point of view - but it will have to be sleeved. I have searched all over it but cannot find an engine number on it. It still has 120E-6015 embossed on the side.
Ed
SJ Lambert wrote: I think 701Ms have it as well,
James
rgh0 wrote:The block of mine in the photos is I think the orginal block from my 68 S4 Elan 36/8555 assembled in August 68 but with so many engine changes over the years I have lost track. I would have to check the engine number to be certain. its date fits with it being the orginal block
The thing I dont understand around this block is that the E is cast and the 3020 stamped unlike Piss-ants's version where the E is also stamped. I had believed that the 1500 ford blocks only had an cast F in this location ahead of the 6015 as in 681 F around this time or no letter as in 2731. The E suggests it was a 120E block but the press in oil pick up says its not.
So what was the casting number that was ground off ? --- Did Ford have a Lotus specific casting variant around this time that had some unpublished casting number that they ground off to produce the stamped 3020 plus cast E6015 combination?
regards
Rohan