Suggestions for Budget Project?

Martin_S said:

IOLAIRE said: there are quite a few variants on the theme, so you get different grills but they're all false anyway coz the radiator is in the back beside the engine!. Unless, of course, a front radiator has been installed! No being facetious here - it is quite a popular modification on tuned Imps and since quite a few of the Imps still in existence have been tuned, there's a fair chance you will come across a front radiator. Otherwise, good advice: if the car still uses a rear radiator, remove it to back flush the rad and spray through the gills to clean out leaves and crap at every 6,000 mile service. Also use decent antifreeze at the correct concentration. Radiators, and even cylinder heads, silt up with deposits of oxidised aluminium if you don't. The wate pump is remotely mounted and can easily be wrecked by over-tightening the fan-belt. The cooling system is the Achille's Heel of the Imp and was marginal even when new. You can resolve the shortcomings by fitting a double-cored rear, or decent front, radiator, but you will still need to keep the system well maintained or you will suffer from blown head gaskets and warped heads. As Iolaire says, corrosion is no worse than most Brit classics and a lot better than some, but the earlier cars (pre-Chrysler takeover) allegedly used thicker and better quality steel, so are preferable (and you get free road tax, of course!) I'm a big Imp fan myself - I've owned several - so I know that parts supply of mechanical items is generally very good. Body panel availabilty is not bad. Interior trim is very hard to get hold of, but people don't worry too much about originality with Imps, yet, so you cam make your own door cards and fit seats from an XR2 or similar if all else fails. If you haven't come across it already, check out the Imp Club website (www.theimpclub.co.uk/) : loads of cars for sale (and occasionally given away free, via the 'paper scrapyard' in the ads) and the club is an excellent source of parts and advice.

Hi Martin,
you're spot on with your Imp advice. I didn't want to go the whole hog and baffle the lad on his first car!!
My best Imp started out as a standard Stiletto with twin Strombergs.
You probably know that one of the problems with the Imp is that they tend to be light at the front.
One answer to this was a bag of sand, I'm not joking!!
Problem is it adds unnecessary weight.
But I found that once I started to modify the car by fitting a front rad, and simultaneously lowering and stiffening the suspension it was spot on.
Most Stilettos had a nitrided crank and were very well balanced, so I just fitted a Piper cam and stiffer springs and a pair of 38 DCOEs, (I found that on such a small engine the 38s gave better low down throttle response than the 40s), and that turned it into a little animal that would whizz round to 8000 RPM effortlessly!
I had to sell that because it was one of the few cars that my wife banned the kids from!!
By the way, the best mod for any Imp is an electric water pump, an insant cure to any potential cooling problems and, if I remember correctly, a must if you're going to put the rad up front.
Happy Days!!

Martin_S said:

IOLAIRE said: Hi Martin, you're spot on with your Imp advice. I didn't want to go the whole hog and baffle the lad on his first car!! My best Imp started out as a standard Stiletto with twin Strombergs. You probably know that one of the problems with the Imp is that they tend to be light at the front. One answer to this was a bag of sand, I'm not joking!! Problem is it adds unnecessary weight. But I found that once I started to modify the car by fitting a front rad, and simultaneously lowering and stiffening the suspension it was spot on. Most Stilettos had a nitrided crank and were very well balanced, so I just fitted a Piper cam and stiffer springs and a pair of 38 DCOEs, (I found that on such a small engine the 38s gave better low down throttle response than the 40s), and that turned it into a little animal that would whizz round to 8000 RPM effortlessly! I had to sell that because it was one of the few cars that my wife banned the kids from!! By the way, the best mod for any Imp is an electric water pump, an insant cure to any potential cooling problems and, if I remember correctly, a must if you're going to put the rad up front. Happy Days!! Yep, shortened springs (refered to as 'Monte Carlo Springs' in the Imp community, IIRC) transform the handling with no other mods necessary. You can also get wishbone mounting brackets which give a bit more negative camber at the front for a bit more improvement. The suspension on the 'standard' cars was, in fact, 'jacked up' by the factory when they realised that the headlamps would be too low to meet legislative requirements, so these mods are pretty much returning the car to how it was originally designed to be. Dead easy car to work on and modify in many ways - the engine can be removed without a hoist (I used to unbolt the rear crossmember, then sit behind the car with my legs stretched forwards under the engine - drop the engine onto your legs, then shuffle out backwards!) and there are various cheap mods for more power, disc brake conversions etc. We used to use the engine in racing hydroplanes, in which application we eventually saw over 125bhp at 5-figure RPM's from a 998cc, though not very reliably, and the cost was pretty frightening! We used to use front rads in the cars without an electric water pump, with no real problems, but then the Davies-Craig electric pumps simply weren't available in the 'olden days' (actually, only the late 80's/early 90's!), bu I agree they'd be a big benefit. For non-competition cars where weight was not critical, I tended to just leave the rear rad in as well as a front rad, plumbed in series, which well and truly sorted any overheating tendencies! My favorite Imp was a Stiletto, too - a standard gold one - which I much regret selling. I'd have another today, if I could find a really good one for sensible money, but Stilettos are becoming much sought-after and I'm simply not prepared to spend £4-£5K for an Imp, no matter how nice it is!

In the early days I used to specialise in tuning a lot of the Yankee cars from the American lads at the Polaris base in Dunoon, so I could get my hands on the most exotic stuff imaginable, that's where we got the electric water pumps, they used them on dragsters!
The beauty about an electric pump is it will give you a high volume supply at idle, which is great in really hot weather or slow traffic.
I would just add that if you go down that road you have to uprate the alternator because you also have to fit an electric cooling fan for the rad.
Your remark about the price of an Imp, think about it this way. You will be able to buy a reasonable second hand Fiesta for about the same; it will depreciate at a rapid rate of knots just sitting outside your front door, it will rust away probably quicker than the Imp!, and every second person you see is driving one.
For the same money you have a mint Imp; No contest!
By the way, just as a point of interest, the Imp engine was actually developed by Coventry Climax and was also used in the Lotus Elite, but in original 1.5 litre form. Now THAT was a beast!

Andrew Noakes said:

IOLAIRE said: By the way, just as a point of interest, the Imp engine was actually developed by Coventry Climax The Imp engine wasn't developed by Coventry-Climax, it was designed in-house by Rootes based on the Coventry-Climax unit. It has a different head, different block, different dimensions... IOLAIRE said: ...and was also used in the Lotus Elite, but in original 1.5 litre form. Now THAT was a beast! The original was the FW fire pump engine, which was 1020cc. The Elite was 1216cc.

By God, don't you get some pedantic people on this site!
Andrew, Rootes paid Coventry Climax to manufacture the engine under licence.
Coventry Climax designed, developed and manufactured the original engine, all rootes did was change the design to suit a small vehicle like the Imp.
I know coz I was there!
I humbly apologise for my slip up about the capacity of the engine, but it stems from two sources.
The first is that the Elite did come with a 1.5 Litre engine, but it was the Lotus twin cam, an entirely different unit.
The second is the fact that Rootes rather secretly did build a 1.5 litre version of the engine and fitted it to a standard car which was an animal; and I seem to remember that this engine is in the Imp that's on display in the Glasgow Transport Museum, although I wouldn't swear to it, because it's a great many moons ago.

IOLAIRE said:

By God, don't you get some pedantic people on this site! Andrew, Rootes paid Coventry Climax to manufacture the engine under licence. Coventry Climax designed, developed and manufactured the original engine, all rootes did was change the design to suit a small vehicle like the Imp. I know coz I was there! I humbly apologise for my slip up about the capacity of the engine, but it stems from two sources. The first is that the Elite did come with a 1.5 Litre engine, but it was the Lotus twin cam, an entirely different unit. The second is the fact that Rootes rather secretly did build a 1.5 litre version of the engine and fitted it to a standard car which was an animal; and I seem to remember that this engine is in the Imp that's on display in the Glasgow Transport Museum, although I wouldn't swear to it, because it's a great many moons ago.

I'm not being pedantic, I'm just trying to be accurate - otherwise why write anything at all?

So let's get right, at least, that the production Elite was not a 1.5 anything, it had a Coventry-Climax FWE of 1216cc. And that the Lotus Twin Cam, except for a very few early engines in the first Elans, was always a 1.6, actually 1558cc.

I've read a paper by three Rootes engineers where they describe designing the Imp engine, though I guess they might have conveniently ignored any Coventry Climax involvement. Presumably they were there too, though, so argue with them - not me!

IOLAIRE said:

This is an interesting point about the Ford block and it's capacity.... But I have to be honest and say I don't remember if there was actually any difference in capacity or if it was simply a renaming exercise; you might be able to confirm this from your archives. The first twin cam Elite had to have been the 1500 engine because the cross flow hadn't been developed at that time. This was a seriously rapid little car, but suffered from build quality problems.

This is all getting increasingly off-topic, but, for the record:

The original prototype and very early production Lotus-Ford Twin Cam was 1498cc. Only eleven engines of this capacity were built nad none of them was ever fitted to an Elite. Six were fitted in Lotus 23's and the other 5 were fitted in early Elans. The 'normal' Lotus-Ford Twin Cam came about when Ford agreed to provide 'graded' cylinder blocks to Lotus (ie. blocks specially selected because the casting tolerances were capable of being over-bored), and the capacity changed very early in the engine's production life. The Lotus Twin Cam uses special pistons, anyway, so the capacity was not dictated by Ford pistons.

The production Lotus Twin Cam never used the Crossflow block; in fact the death of the 1500cc pre-crossflow Ford engines precipitated the Twin-Cam's demise. Caterham later used Crossflow blocks to build a few post-production Twin Cam engines for the Seven, but these were 'Bitsa' engines using spare heads and other parts from Lotus to make up individual units, rather than a genuine 'production' motor. It is possible to use Crossflow blocks to build up into Twin Cams to this day - either because the original 1500cc block is beyond economic repair, or to give increased capacity (over 1800cc is possible) - but you need to use a spacer plate between the top of the timing case and the head to make up for the Crossflow block's greater height.

The Twin-Cam Elite was a one-off, developed by a Lotus Formula 1 mechanic by the name of David Lazenby in 1967 (ie. long after the Elite had been superceded by the Elan), using an Elite shell that happened to be kicking about at the factory doing nothing. Colin Chapman, never a man to turn down free publicity, let the press run away with ideas that it might be a prototype for a MK2 Elite 'Twin Cam', but in truth it was nothing more than Lazenby's own pet project for racing. Since it came well in to the Elan's production life, it used a standard 1558cc (nominally 1600cc) Twin Cam, not one of the handful of early 1498cc units. Several Elites have been fitted with 1500cc Climax engines (either the SOHC 1460cc FWB unit or the DOHC 1460cc FPF engine), but again, this was nothing to do with Lotus themselves - always owners either seeking more power or finding a convenient replacement for when the original FWE had destroyed itself.

None of the above has anything to do with Imps, of course!

There is no doubting the Climax ancestry of the Imp engine - visually it looks extremely similar to the FW Series Climax's. AFAIK, its closest Climax 'relatives' were the 1098cc FWA and the 742cc FWC (which was merely a short-stroke version of the FWA, anyway). The Climax design was re-engineered by Rootes for mass production, including repositioning of the distributor and other ancillaries and re-engineering of the block for production by die-casting (very advanced at the time!). You really wouldn't want a road car powered by a thoroughbred Climax engine, anyway - the oil consumption is horrendous and you are lucky to get 20,000 miles between full rebuilds!

Yeah, there will no doubt have been many engines fitted by now - spares for Climax engines are rare and expensive, and as I said, the FWE needs a full rebuild every 20-30K miles. The Lotus-Ford Twincam is as good a choice as any - it at least preserves the Lotus DNA and is still reasonable easy to find and cheap to rebuild (at least in comparison to an FWE!)

There are some very accurate replica Elites running round with Ford CHV's under the bonnet, and I know of at least one original Elite that now sits on a modified Elan chassis with a Datsun automatic transmission -doesn't mean they were anything to do with Lotus, though!

The fact remains that all factory built, production Lotus Elites were fitted with Climax FWE engines.

Presumably in 40 years time, people will be bickering about whether Lotus built supercharged K-series, Honda VTEC or Audi TT engined Elises - such cars already exist, but they sure as hell aren't anything to do with the Factory!