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View Full Version : Tune a 1.2? Not Worth it, stick a bigger lump in it mate!?



MC
05-02-03, 11:12 AM
How many times have you seen this conversation?

Q. How can I make my 1.2 Merit faster?
A. I wouldn't bother mate, it'll never be fast, stick a bigger lump in it, you're wasting your time really.

Well, I disagree. That statement is not true for a number of reasons.
Firstly you might not truly understand someone's reasoning behind wanting to do this. For some, it might not be about having the fastest car on the road, maybe just making his or her car faster for what it is, or a little faster than his or her friends car. I gained a lot more respect for having a very fast 1.4 than a very fast 1.6. I'd imagine the same could be said if you managed to produce a rapid 1.2. Whatever the reason, the statement was still not strictly true. It is possible to make a 1.2 fast.

I'll give you a little background behind the decision to modify this particular Nova. This is a personal crusade for me. I want to encourage more people with 1.2's to be proud and to actually attempt some real modifying. Anyway in my current situation, I drive a Polo 1.4i, and a Golf V6 4-motion. Unfortunately I spend less time driving the latter, and have become bored to the point of crying with driving the Polo. Having the sort of mind that constantly wants to modify and improve things, I started planning what I could do to the Polo. The only snag with this is that the wife wasn't too keen on her baby becoming a stripped out racer. Charles (a.k.a CP) could see the frustration in my eyes and kindly offered to donate a spare 1.2 Nova to the Mark (a.k.a MC) salvation fund. So here the story begins, and over the months ahead, you should see the transformation of an unmolested baby Nova into a fire breathing track weapon.

To wet your appetite, I'll give you a small taster of my plans. Obviously, regardless of what miracles are performed, there will always be the issue of slightly less torque than one would ideally like, so weight will be more of an issue than ever, and will be kept at an absolute minimum.

In the real world, no amount of horsepower can make up for a lack of handling and braking, so getting these areas spot on in conjunction with the 'Slim Fast plan', should start levelling the playing field.

You must be starting to get the picture now. Ok, one thing that I am not flexible on is changing the capacity of the engine. If I say it will be a 1.2, I'll stick to it, and this does bear some benefits. The 1.2 engine has about the best gas flow of the range (forgetting about valve size for now) and it can rev higher than average due to its short stroke. That's the type of engine I'm gonna aim for, high revving peaky power. Using twin 40's, large valves, a 300 deg cam and a few other goodies, it should have good peak power, but will need to be kept in the torque band. I also have a home built Nitrous kit sitting unused!

So here's the idea, I'm going to build this Nova on a budget, and I'm going to report back to Novaload on a regular basis, hopefully inspiring a few members to take up their spanners and do the same.

MC
05-02-03, 11:42 AM
And now we begin:

26th Jan 2003
The time is about 10:00 and I'm already going at the pretty much standard 1.2 Nova with spanners, sockets, screwdrivers, knives and hammers. It took a while to get CP to realise I was waiting outside for him (bit slow these country folk).

After about six hours of graft I had managed to remove pretty much the entire interior, roof lining, sun-roof, some of the loom, and a few other bits. That is almost 100kg saved, and the bulk of it was insulation, seats and the glass roof. I only managed to cut myself once, and I'm proud to say that there were no tears.

Still to come is window removal, and changing over the tailgate. I'm going to use polycarbonate instead of window glass as the weight difference is immense, and the mk2 tailgate I have has got the smaller roof top spoiler rather than the mk1 rap-around style one. The rear wiper mechanism and wires have also been removed, so there's a bit more weight to be had. I'd guess there is another 30kg or so to be had, and possibly the same to go back in with a bucket seat and some strut braces.


2nd Feb 2003
So, a second day of work, well not quite, spent a while discussing plans, sifting through parts for sale, and drinking coffee. Once in the workshop, I set about removing yet more stuff. I said goodbye to windows, bumpers, lights, winder mechanisms, and many other things.

Whilst I was doing this, CP set to welding the rusty patches at the back. About an hour was spent removing engine parts and the engine itself, leaving a clear bay, and revealing absolutely no rust. The engine bay is sound. This left us debating whether the seem welding was needed. Still not decided.

I also spent some time stripping gear from my old Nova shell that is slowly rotting away in CP's yard. I removed the bumpers and tailgate along with the mk2 grill. I Haven't decided what to do about the front end yet.

I'm starting to get a full image of the car now, and we've pretty much decided the engine, suspension, brakes and chassis spec:

Engine: 1200cc 8v bottom end, with de-seemed and shot peened rods. ARP bolts. 1200cc head, ported, enlarged inlet and exhaust valves and skimmed to raise compression. Piper 300 or 307 deg cam with solid lifters. Irmsher manifold matched with Weber twin 40's. 4 branch comp manifold and system. Rev limiter and shift light set to about 9k rpm.

Transmission: Undecided. Dpends on budget, possibly F10/5 CR or Quaife cluster.

Brakes: Astra 16v conversion with braided hoses, standard rear.

Suspension: Adjustable: Undecided.

Chassis: Strenthened TCA's, rose jointed. Lowered, adjustable tie bar mounts. Rear beam from SR (for ARB) with poly bushes. No front ARB. Selected strengthening with seem and stitch welding. Front and rear strut braces with possible roll cage.

Wheels: Undecided on type, but will be 15" with cut slicks.
Interior: erm' not much, single bucket seat. Home made aluminium gear knob (courtesy of Paynter Motorsport technologies, a.k.a. PMT!)

As I'm not aware of anything being done to a 1200 like this before, I'm not sure of the performance we will achieve, but I'll lay money on it being pretty quick.

Watch this space.

CP
25-11-03, 03:00 PM
UPDATE
25.11.03.

The shell remains stripped.

Progress has however been made on the engine.

The bottom end has recieved a complete race re-build by Velos and is back ready to be built into the car.

Heres the list of work done ( costs are apporox):

1. 4 new piston crowns complete - ?160
2. Full set of ARP big end bolts - ?75
3. Crank polished ( wasnt worn enough to require re-grinding)- ?80
4. Bearings etc - ?55
5. De- seamed and shot peened rods - ?100
6. Various machinings etc - ?275
7. Engineering, assembly and sundries - ?200

In line with our request this engine has had extensive machining to raise the compression ratio which adds a fair bit to the cost.

The head has recieved some benchflow testing ( cheers Cambridge :D ). This revealed an area of improvement that we guessed was possible - please contact Cambridge if you want to know the details - he did the work so its up to him what he tells you.
The 1.2 head has puny valves so new valve seats have been cut in to accept valves roughly the same size as 1.6 ones. The final porting work has not yet been done but there's not a huge amount to do cos the ports are large on the 1.2. The new valves are quite heavy so I am considering re-profiling them at the back to help flow and lose some weight. In any event we will prolly have to add stronger/assistor valve springs.

At the moment a Piper 285 cam is awaiting installation. Its probable that a 300 cam would suit better. However the high revs are expected to cause problems with the hydraulic lifters. It is very likely that solid lifters will be needed. Not too sure what to do with as the engine will need to be an everyday runabout - its a question of judging where to draw the line.