The Solid Parts of an Esprit
Discussion
Lotusacbc said:
As we all know by now, the Esprit isnt exactly a bullet proof built car. Not that any car is. So my question to you guys would be what are the solid parts of an Esprit. The parts that just take a lickn' and keep on tickn'!
If any exist LOL
Hi,
The most overbuilt part of an Esprit is it's crankshaft. The 9XX engine was originally slated to be a V8 motor, which is why the cylinder bank is inclined 45°. It is essentially half of a V8. Originally the Esprit was to be a V8! Lotus ran out of development money to produce an alloy V8 casting. At the same time (circa. 1967/8), Jensen-Healey was in the market for an engine for their two-seat roadster. To shore up their finances, Lotus offered the 907 engine to JH. The 907 is really a re-worked, alloy, 4 cyl. Vauxall block w/ Lotus Twin Cam head.
Anyway, the crankshaft was designed for the V8 and consequently was made that big and strong (weighs over 30lbs.!). I have never heard of a crankshaft failure in a 9XX engine.
When I rebuilt my engine two years ago (where does the time go?), I brought the crank to my machinist to have it polished and balanced. On 1st inspection, he remarked "What truck did that come out of??" I explained it was a 2.2L 4 cyl. and he was amazed. Then he showed me a crank from a 2L Honda 4cyl and it looked positively puny next to mine.
So, despite all the foibles and warts in Lotus design and construction, you can sleep nights knowing that the crankshaft, at least, is likely to outlast you! Happy Motoring! ...Jim'85TE
>> Edited by lotusguy on Thursday 20th May 20:16
I've had my Esprit almost 4 months and there's hardly an area I haven't looked at, fiddled with, fixed or drawn a sketch of 
It's typical British cottage-industry. I expected something better, but it's staggering how similar it is to the TVR Wedge in methods of assembly - and the parts used. For example the glovebox lid catch is sold for loft hatches...
The trim panel on the firewall is held in using radiator pipe clips and a length of wooden dowel. There's more timber than an Amazon rainforest hidden away in dark corners.
Some bits are so flimsy it's hard to believe they've lasted 20 years.
And yet.... the chassis is fine. I sandblasted the front suspension components and found solid metal under the muck and surface rust. With a little attention, all the faulty electrics now work. The interior looks its age, but it's all still there and basically sound. The exterior is dull and has more stress cracks than a space shuttle. The car wouldn't start when I bought it, not even a click from the solenoid or fuel pump. Once I'd freed them off and put some petrol in, it started first turn - after standing for two years.
Overall, though, it doesn't conjure up images of Jimmy Bond.
Yet.
It's MOT time on Saturday, and if it passes, the paint will be getting a quick cleanup and then I'll find out whether the Esprit lives up to its reputation. I reckon that the whole will prove to be more solid than the individual parts 
Ian
Edited for the hell of it
>> Edited by wedg1e on Friday 21st May 02:56
It's typical British cottage-industry. I expected something better, but it's staggering how similar it is to the TVR Wedge in methods of assembly - and the parts used. For example the glovebox lid catch is sold for loft hatches...
The trim panel on the firewall is held in using radiator pipe clips and a length of wooden dowel. There's more timber than an Amazon rainforest hidden away in dark corners.
Some bits are so flimsy it's hard to believe they've lasted 20 years.
And yet.... the chassis is fine. I sandblasted the front suspension components and found solid metal under the muck and surface rust. With a little attention, all the faulty electrics now work. The interior looks its age, but it's all still there and basically sound. The exterior is dull and has more stress cracks than a space shuttle. The car wouldn't start when I bought it, not even a click from the solenoid or fuel pump. Once I'd freed them off and put some petrol in, it started first turn - after standing for two years.
Overall, though, it doesn't conjure up images of Jimmy Bond.
Yet.
It's MOT time on Saturday, and if it passes, the paint will be getting a quick cleanup and then I'll find out whether the Esprit lives up to its reputation. I reckon that the whole will prove to be more solid than the individual parts
Ian
Edited for the hell of it
>> Edited by wedg1e on Friday 21st May 02:56
lotusguy said:
Lotusacbc said:
As we all know by now, the Esprit isnt exactly a bullet proof built car. Not that any car is. So my question to you guys would be what are the solid parts of an Esprit. The parts that just take a lickn' and keep on tickn'!
If any exist LOL
Hi,
The most overbuilt part of an Esprit is it's crankshaft. The 9XX engine was originally slated to be a V8 motor, which is why the cylinder bank is inclined 45°. It is essentially half of a V8. Originally the Esprit was to be a V8! Lotus ran out of development money to produce an alloy V8 casting. At the same time (circa. 1967/8), Jensen-Healey was in the market for an engine for their two-seat roadster. To shore up their finances, Lotus offered the 907 engine to JH. The 907 is really a re-worked, alloy, 4 cyl. Vauxall block w/ Lotus Twin Cam head.
Anyway, the crankshaft was designed for the V8 and consequently was made that big and strong (weighs over 30lbs.!). I have never heard of a crankshaft failure in a 9XX engine.
When I rebuilt my engine two years ago (where does the time go?), I brought the crank to my machinist to have it polished and balanced. On 1st inspection, he remarked "What truck did that come out of??" I explained it was a 2.2L 4 cyl. and he was amazed. Then he showed me a crank from a 2L Honda 4cyl and it looked positively puny next to mine.
So, despite all the foibles and warts in Lotus design and construction, you can sleep nights knowing that the crankshaft, at least, is likely to outlast you! Happy Motoring! ...Jim'85TE
>> Edited by lotusguy on Thursday 20th May 20:16
That old chestnut about the block being based on a Vauxhall raises its head again.
Yes, they did use a Vauxhall block to develop the head, and fitted in Bedford vans to do on-the-road development, also the LV220 race car.
BUT, no Vauxhall block ever had a ladder frame main bearing cap assembly, and its distributor and oil pump were in a totally different location.
The Lotus block is a pure Lotus design, the only similarity to the Vauxhall is the bore spacing and being canted to one side.
The earlier twin cam did use a virtually off-the-shelf Ford block, so it is tempting to think something akin to that happened with the 9xx series.
I do agree though that the engine (not just the crank) is one of the strongest parts of the car if properly maintained.
Paul.
PS 1967/8 is a bit early. More like very early seventies.
>> Edited by B16 RFF on Friday 21st May 11:17
A little while ago I was posting questions on which parts of an Esprit were forged or cast. A couple of folks responded that the Esprit had all forged internals but one fellow emailed me off list with different info.
He was an English fellow (engine builder by trade I believe) and had been building Esprit/Lotus motors for years, one of which was in a dragster (Esprit motor). He indicated the pistons were forged but the crank was cast and was a bit they always replaced on the high (over 400hp) applications. He also had some nice info on stroking and overbore for the motor too.
Make what you will about it, he seemed to think the crank good to about 400hp but they could let go around this mark. Just looking at them they seem quite stout to me when I compared them with other cranks, but looks can be deceiving. Just made me a little concerned as I am definitely trying to build the 400hp Esprit motor.
>> Edited by rlearp on Friday 21st May 13:42
He was an English fellow (engine builder by trade I believe) and had been building Esprit/Lotus motors for years, one of which was in a dragster (Esprit motor). He indicated the pistons were forged but the crank was cast and was a bit they always replaced on the high (over 400hp) applications. He also had some nice info on stroking and overbore for the motor too.
Make what you will about it, he seemed to think the crank good to about 400hp but they could let go around this mark. Just looking at them they seem quite stout to me when I compared them with other cranks, but looks can be deceiving. Just made me a little concerned as I am definitely trying to build the 400hp Esprit motor.
>> Edited by rlearp on Friday 21st May 13:42
B16 RFF said:
That old chestnut about the block being based on a Vauxhall raises its head again.
Yes, they did use a Vauxhall block to develop the head, and fitted in Bedford vans to do on-the-road development, also the LV220 race car.
BUT, no Vauxhall block ever had a ladder frame main bearing cap assembly, and its distributor and oil pump were in a totally different location.
The Lotus block is a pure Lotus design, the only similarity to the Vauxhall is the bore spacing and being canted to one side.
The earlier twin cam did use a virtually off-the-shelf Ford block, so it is tempting to think something akin to that happened with the 9xx series.
I do agree though that the engine (not just the crank) is one of the strongest parts of the car if properly maintained.
Paul.
PS 1967/8 is a bit early. More like very early seventies.
>> Edited by B16 RFF on Friday 21st May 11:17
Paul,
You misunderstand. The block is totally a Lotus design and casting (sand casting to be precise), but it was fashioned after the Vauxall block. It is not a whitesheet design, but as I said a reworked vauxall block, not confusing it with the 'Girdle' main bearing panel.
Agreed that the Twin Cam block is sourced from FORD, even stamped as such on the side.
The 9XX engine was in development in '67-'68 and the JH goes back to '70, so allowing for production and assembly of the '70 model year, yes, '67-'68 is about right. Happy Motoring! ...Jim'85TE
rlearp said:
A little while ago I was posting questions on which parts of an Esprit were forged or cast. A couple of folks responded that the Esprit had all forged internals but one fellow emailed me off list with different info.
He was an English fellow (engine builder by trade I believe) and had been building Esprit/Lotus motors for years, one of which was in a dragster (Esprit motor). He indicated the pistons were forged but the crank was cast and was a bit they always replaced on the high (over 400hp) applications. He also had some nice info on stroking and overbore for the motor too.
Make what you will about it, he seemed to think the crank good to about 400hp but they could let go around this mark. Just looking at them they seem quite stout to me when I compared them with other cranks, but looks can be deceiving. Just made me a little concerned as I am definitely trying to build the 400hp Esprit motor.
>> Edited by rlearp on Friday 21st May 13:42
Ron,
Your source is correct, the crank is in fact cast as are the camshafts. The 907/912/910 pistons (prior to the HC engine in '86) were cast as well, a weak spot once the engine was turbocharged. Lotus fixed this with the HC engine changing over to Forged Alloy Pistons and Nikasil lined alloy liners. As far as rating to 400HP, I suspect other internals would fail before that level were reached such as the ConRods (cast) or even the bearing carrier itself. Happy Motoring! ...Jim'85TE
Might be true on the failure, but I hope not!! I'm already at around 322 crank hp (if you use a 13% loss at 285 rear wheel) and of course we should see more. But, I do fear failure of components.
However, I'm not so scared of cast parts (even though my latest 342 Ford is all forged) - I mean the rods are beefy and so is the crank. Bearing surfaces are generous too, so I'm hoping it'll be okay. I've made in excess of 500 rear wheel using 5.0L Ford stock cast cranks (did break one once though) so I hope the Lotus will do well. And if it doesn't, well, we can always rebuild it!! ;-)
However, I'm not so scared of cast parts (even though my latest 342 Ford is all forged) - I mean the rods are beefy and so is the crank. Bearing surfaces are generous too, so I'm hoping it'll be okay. I've made in excess of 500 rear wheel using 5.0L Ford stock cast cranks (did break one once though) so I hope the Lotus will do well. And if it doesn't, well, we can always rebuild it!! ;-)
wedg1e said:Yep, the build quality on these things is shocking.
Some bits are so flimsy it's hard to believe they've lasted 20 years...
Big lumps of fibreglass and plywood loosely held together with self tapping screws....
Every time I do a job, I tend to replace the rusty screws with stainless fasteners.
My car has led a very pampered 24,000 mile life, but most of the bolts had to be cut off when changing the radiator.
Those aluminium "rivnut" inserts that fail to fasten the undertray onto the tub are another crap piece of non-design that needed fettling on my car.
Having examined TVRs, I can confirm that they are just as bad, if not considerably worse than the Lotus.
Can anyone comment on how 1980's Ferraris compare in the quality of the fixtures and fittings?
Pat.
B16 RFF said:
britten_mark said:Bits that are always solid?? Usually every single cheapo nut & bolt, with rust!
That's odd, they were OK when Lotus put the car together. Must be what owners do with the cars.
Paul.
I dont get it :scratcheshead:
Boy you hit the nail on the head with that one! I am continuously replacing all those little bits that seems to be slowly dissolving with stainless product. Especially the belly pan, heat shield washers and the myriad of little phillips head screws that must be drilled out when you go to repair or reseal a panel.
Normally I'd chock it up to a 15 year old car - but this thing only has 30k on it and really has not been around the neighbourhood when the snow is coming down. You wonder how long these fasteners actually spent in the plating basket.
My HUGE plus - the chassis - always sprays off to the beautiful little dull zinc finish when it needs a bath. No wonder they were willing to give 8 years warrranty for corrosion. Nice workmanship and great treatment with the zinc dip.
britten_mark said:Bits that are always solid?? Usually every single cheapo nut & bolt, with rust!
That's odd, they were OK when Lotus put the car together. Must be what owners do with the cars.
Paul.
I dont get it :scratcheshead:
Boy you hit the nail on the head with that one! I am continuously replacing all those little bits that seems to be slowly dissolving with stainless product. Especially the belly pan, heat shield washers and the myriad of little phillips head screws that must be drilled out when you go to repair or reseal a panel.
Normally I'd chock it up to a 15 year old car - but this thing only has 30k on it and really has not been around the neighbourhood when the snow is coming down. You wonder how long these fasteners actually spent in the plating basket.
My HUGE plus - the chassis - always sprays off to the beautiful little dull zinc finish when it needs a bath. No wonder they were willing to give 8 years warrranty for corrosion. Nice workmanship and great treatment with the zinc dip.
Lotusacbc said:
B16 RFF said:
britten_mark said:
Bits that are always solid?? Usually every single cheapo nut & bolt, with rust!
That's odd, they were OK when Lotus put the car together. Must be what owners do with the cars.
Paul.
I dont get it :scratcheshead:
Neglect. More so in the UK with it's salt laden roads in winter.
A rather weak joke I'm afraid.
>> Edited by B16 RFF on Friday 21st May 23:07
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