PLus 2 weight, what to do, Introduction.

[Berw]

Hello long post as an introduction, no doubt I?ll be back with other questions.
So 36 years after I sold my Sprint I?ve bought a Plus 2 S130, I've had a few Lotus in between, Including a Europe Twin Cam and a Sunbeam and I currently have a 7 and a Lotus Carlton, I live in Malaysia. The Carlton is the only one in S E Asia and the Plus 2 is one of 2 in Malaysia, I also know there are 3 baby Elans in the country, none of these are on the road. My car is actually registered and taxed for the road, so can be a road car without further problems when I rebuild.
At the moment I've stripped the car completely and the body will be lifted off this weekend. The car has stood for 7 years and needs a complete rebuild, Engine is in good condition and was prepared by Tony Thomson who also supplied uprated half shafts.

So now I have to decide what to do,
I rebuild as a road car, I know what I want to do if I go this route, and will use electronic ignition, electric water pump, Electric Fuel Pump etc, and put in a leather interior. But
2 I'm thinking about a race car to run in Class B of the Asia Classic Car Challenge, I have a car which has won class C a few times, (The black Sylva if you look on the web site) but Class C cars are not eligible for the overall championship win, which I would like to do once.
To build a car for class B, it must be pre ?88 and I am allowed 0.37 Kg per CC of engine, so for a 1558 twin cam I need a weight near 577 Kg, a bit more if I re=bore.
Does anyone know if it is possible to get anywhere near 600Kg for a +2, with a full cage, but no glass, (all poly), no head lights, basic instruments, no dash board, no hand brake, 30 liter fuel tank, etc. I have a carbon fiber race seat spare that is only 5 Kg. and I can easily build single skin bonnet and boot, I would probably change the uprights and go for bigger brakes and wheels.
So to repeat the question what weight is possible for a plus 2, using a road shell as the base? If I can?t get the weight low enough to be competitive I?ll build as a road car.

Thanks

[rgh0]

You can get an Elan down to around 600kg or a bit less if you build it light for racing. A lightweight Plus 2 will be closer to 700 kg with its heavier body I think.

cheers
Rohan

[gus]

If you want a road car build a road car if you want a race car build a race car.

IMHO no, you cannot get a street car with interior windows etc that low. Once you get that low you will not want to drive it on the street, due to lack of window mechanisms, heater interior etc

[Berw]

Sorry if I was vague having never posted here before, without being rude, but really don't care if its a road car or a race car, I have 5 road cars and 3 race cars, with a lotus in both category, if I build a track car it will be a pure race car, so I'm not worried about striping to minimum weight, everything can come out, all I need Is rev, oil and water gauge, don't even need an alternator for 10 laps, but I don't want a race car if I have no chance of getting to near 600kg as the car would not be competitive in class, I have loads of bits for twin cams, and living in Asia I can get things like alloy radiators built to my spec very cheap, as an example I can get things like evo brakes for a few hundred pounds, car doesn't need to be to fia regs so I can change the front windscreen to poly for example. I would put a single skin carbon fibre bonnet and trunk, no bumpers no head lights, just plastic shell h3 lights, so what do you think, can I get close to 600kg?
Of course a race car would be cheap, I could sell bonnet, knock on wheels, uprights etc, in fact I could probably sell the bits for more than the race car would cost to build.

[rgh0]

Extreme light weight Elans are down in the 550kg range I believe. That's with a special "light" drop head shell and alloy 26R components and no glass and trim.

A Plus 2 even with poly instead of Glass, and lightweight bonnet boot and door skins has a roof and longer and wider body and chassis. The Plus 2 also has a lot of double panels in the body and the door sill beams that will add weight (but potentially could be removed in a race car).

Maybe 650kg is possible if you worked on it very hard but I think you would be lucky to get to 600 kg. If your going to rebuild the car either way as a road or race car then take the stripped shell and weigh it and the rolling chassis with engine and drive train and weigh it and see what it comes to then add a little for seats and roll cage and the other bits and pieces and if its near your target then build as a race car if not the finish the build as a road car.

Can you go to a bigger capacity engine? to compensate for the extra weight or do you have to stay with a 1558 cc engine. At .37 kg/cc a 1700 cc twin cam which is easily done on a standard block would be allowed.629kg. Depending on the blocks your allowed capacities of up to 2.1 litres are possible which would give you 777 kg.

An extreme lightweight plus 2 should be great fun and competitive in other respects as its braking and handling is superb and apart from a few other more purpose built "race" cars such as Marcos or Ginettas or Lotus Sevens not many other cars should be able to beat them if the rules are based on weight per cc and you can get to that target.

cheers
Rohan


cheers
Rohan

[Berw]

Thanks Rohan,

Yes I can bore, and strock to get extra capacity, I could change block if it was period, I have a few 1600 cross flow blocks, and various rods, but pistons are a problem, I have a set of twin cam plus +60 pistons in the garage, plus 60 would add around 60cc I would think, (without detailed calculation),
I would take to door bars and everything else out, I agree about the double skin, I was amazed when I stripped the car, at how much there was, but again I could chop that out if I put in a cage.
Do you know where i could get information on blocks, I'm assuming big capacity would use a pinto block, but that would give very high compression ratio without head work.
The thing about the series I'm interested in is that it does not require FIA rules, and there are no noise limits so I don't even need an exhaust, I would probably only use one door the other could be single skin,

The story is that the owner of this car died 8 years ago, his widow eventually wanted to sell, she engaged her brother to sell it, He is into 1950's cars and asked me to look at it, I offred 6000US$ for it, purely because I had an Elan in my youth, a local dealer offered 10K but she accepted my offer as I did not plan to sell on, but I don't actually need it.

I have a big advantage that I can get carbon fiber work done for very little money, my careham has a full carbon body and seat and that was 2250US$, So while a whole body would be expensive bonets etc would be affordable


Thanks for your input and advice.

[rgh0]

You have many options if you want to build a big capacity engine and all the components needed are readily available.

The options basically are

1. The original Ford 1500 block - with a long stroke 77.6mm crank and 83.5mm bore you can achieve around 1700cc or 1760cc if you bore to 85mm which some block may do if you ultrasonically check them and offset bore them. Most blocks will do 83.5mm, maybe 10% will do 85mm

2. The Ford 1600 block from the same period which is around 11mm taller - using slightly different rods and pistons you can achieve the same capacity with same bore and stroke. You can potentially get a longer than 77.6mm stroke crank into a standard block with a little work but I have never tried it. I have heard of people using Datsun L20 cranks at around 84mm stroke. This would give 1840 cc on an 83.5mm bore.

3. Specially cast, iron blocks by QED in the same style as the above Ford 1600 blocks but with siamesed bores so you can go to 90mm I think without the oil gallery cross drilling. Cosworth made a similar block in the period so I guess it should qualify?

4. Specially cast alloy blocks in the same style that were used in period BDA open wheeler race engines that again can be taken to 90mm bore and up to 84 mm stroke for 2.2 litre capacity see. Wilcoxengines.co.uk who is the company specialising in these big capacity engines.
These blocks are designed to be dry sumped and don't have the normal cross drilling between cylinders 2 and 3 so you can get the larger bore to fit.


The pinto blocks were a significantly different design and had larger bore spacing's so a twin cam head does not fit them. If you go for a big capacity engine then you need a head that breaths well to suit. The new SAS heads or the Converted Stromberg heads done by John McCoy are the best way I believe to get a twin-cam head that breaths well with a big capacity engine under it

A big engine block with the right internals and one of the SAS or McCoy heads and the right cams, valves, carbs and exhaust system and you should see well over 200 hp Building one will not be cheap but doing it right should make a lightweight Plus 2 a hard car to beat. Given the range of capacities you can get you should be able to match the weight you achieve for the ,37cc / kg target

cheers
Rohan

[Berw]

Hi,
I know about the Datsun crank, I was going to go that way on my Caterham cheap way to get a steel crank, I have a few crossflow cranks and at least two blocks, need to get the 1558 engine down and look at parts interchangeability..

Don't want to spend huge money, so may be I'll look at the engine I got bored +60 and see what weight I can get down to for 2015 season, then if I need more cc look at spending money on engine for 2016.

I can sell things like the knock on wheels, hubs calipers glass bonnet etc for good money certainy more what I will pay to get replacment parts from Japan, My Sylva runs ford uprights but I know I can fit Evo ones so I should be able to put evo brakes and uprights with 114.5 PCD wheels on for less than I can sell the Lotus Uprights for..
Thanks

[davidj]

Afternoon,

I does seem a shame butchering one of two +2's in Malaysia. However, it is your car!
What Sylva do you own? I am pleased and surprised they have made it out to the far east, although not surprised they are winning races, as they are quite good at that.

I have a Sylva Stylus, which is a bit civilized for Sylva!


David

[Berw]

Yen David I do agree I may build a road car, as I say looking at options. I have a phoenix with my own design IRS, SR20DET Running gear, big turbo evo brakes, ARB, 410bhp, its a monster its on my face book page, its fabulous, its on a one of chassis JP built for me to run A lotus 910turbo but that was unreliable.
Probably I will build the Elan into a road car, my problem is living in Asia I have funny cars I need moral support for the lotus so thanks for your comments.