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    Getting off lightly
    CAR: 1970 Lamborghini Espada
    OWNER: Harry Metcalfe

    / #1970-Lamborghini-Espada / #1970 / #Lamborghini-Espada / #Lamborghini

    With the Espada’s engine out and on the bench (see last month’s), it’s time to delve inside and finally discover why it had an unsustainable appetite for coolant and why its crankcase was breathing so heavily.

    First job is to remove the cylinder heads. These have a habit of being sticky on a #Lamborghini-V12 of this vintage but we’re in luck because, when this engine was last rebuilt in the mid-’80s, all the cylinder studs had been liberally wiped in copper grease. So the heads slip off with little effort. It soon becomes clear that both head-gaskets are knackered, which is the cause of all the coolant issues. But instead of coolant leaking into the cylinder, combustion gases were leaking into the coolant passages under compression. That’s why the system was getting overpressurised and coolant was bubbling past the radiator cap. Weirdly, this is good news as it’s an easy fix, but it doesn’t fully explain the low compression readings. So the next job is to remove a couple of pistons. Cylinders nine and ten had the worst leak-down results, so these pistons are removed first. I’m hugely relieved to discover that the big-end shells show little wear, but the less-good news is that as each piston comes clear of the block, the piston’s top compression ring drops to the floor because they are broken in half. The middle oilscraper rings are very worn, too.

    It’s the same story on ten of the twelve pistons: no wonder the engine breather was puffing so heavily at tickover.
    Again, this is actually good news because we have the answers to all of the engine’s ailments and none of the causes are very serious. It looks as though new piston rings were fitted to the old pistons the last time this engine was rebuilt, but either they weren’t matched exactly or the ring grooves in the pistons have worn. Iain Tyrrell measures the top compression rings at 1.55mm thick while the groove in the pistons is 1.66mm, so each ring has been oscillating up and down at high frequency in the piston and eventually breaking up.

    There are no more surprises inside. A bit of wear in the valve guides needs attention, and all the valves had been fitted with rubber valve-guide seals from a Ford Pinto during the last rebuild. These look as if they have been capturing oil and then leaking it down the guide, making oil consumption worse, rather than better as the previous engine builder must have hoped.

    So I’m finding that, far from being the nightmare it could have been, this whole engine-rebuild process is enthralling. The next job is to extract the cylinder liners from the block and send them off for a slight overbore to 88.5mm (88mm is standard). New forged pistons are on order and the beautiful steel crankshaft, milled from a single billet, will be polished and balanced.

    I’ll report back once the rebuild begins but, for now, I’m just happy that the Espada engine is in such good hands. I look forward to its return, probably even better than it was when new way back in 1970.

    From top A big space where the engine used to be; stripdown begins with removal of front-end drives; coolant loss was down to leaking head gaskets but head castings are fine; top piston rings had broken.
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  • Post is under moderation
    Diving deep / Running Reports

    CAR #1971-Lamborghini-Espada / #1971 / #Lamborghini-Espada / #Lamborghini

    Harry Metcalfe

    It seems 2019 is my year to do engine rebuilds. First it was the Alfa Duetto that needed open-heart surgery just before its trip to this year’s Mille Miglia ; then my boat’s engine blew up (an 800bhp, 14.9-litre MAN twin-turbo V8 – don’t ask about the bill); and this month it’s the turn of my Espada engine to be stripped.

    An engine rebuild has been on the to-do list for the Espada ever since it developed a serious addiction to coolant on last year’s Espada 50th Anniversary Tour, but then the budget I’d set aside got inadvertently spent on a Lancia Fulvia Sport 1600 – easily done, as I’m sure you’ll understand – so I put the rebuild off until more funds became available.
    But as the months ticked by, I became increasingly concerned that the wait might be causing more internal damage to the engine, as I didn’t really know why it was consuming so much coolant in the first place. There was no give-away steaming exhaust, or emulsion inside the filler cap to indicate that oil and water were mixing. I needed to know more, so decided to get the Espada up to Iain Tyrrell’s amazing workshop on the outskirts of Chester, which is where I bought the Espada from originally, back in 2012.

    Once it arrived, Iain turned detective and performed both a compression and leak-down test on each cylinder, plus a pressure test on the coolant system. The good news was that the pressure test showed the coolant wasn’t leaking anywhere it shouldn’t, but both the compression test and the leak-down test (where each cylinder is pressurised via the spark-plug hole) showed several pots were below par and losing pressure under test quite quickly.

    The diagnosis was possible headgasket failure and maybe worn piston rings as well. There was nothing for it but to remove the engine for a full strip to find out. This generation of Lamborghini engine is magnificent to behold, with its quad cam-covers, tubular manifolds, all-alloy construction and delicately finned aluminium sump. It’s also a bitch to extract from the engine bay because a) the front oil pump housing hits the front chassis member, and b) the gearbox needs to stay attached, and that includes the chromed gear-lever that constantly gets fouled on the transmission tunnel. Fortunately, Iain has been doing this for over 35 years and makes it look relatively easy. About three hours later he had the engine out, on the bench and ready to strip. Next month, I’ll let you know what we found.

    From top Harry’s Espada rests up during the 50th Anniversary tour in 2018; at speed, in between top-ups with coolant; engine out for stripdown at Iain Tyrrell’s workshop.
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