Rolling Road

Setting Up on the Rolling Road (2001)

I had my Capri set up by Peter Baldwin at Wilshers Garage in Wimpole, near Cambridge. Peter took quite some tracking down as he used to be based at Marshall's in Cambridge where he was quite well known for his racing of Minis. So I had to ask around before locating him. In fact rolling roads are not easy to find and they are few and far between (See the technical article on how they work).

I had booked a couple of hours with Peter to set the engine up properly. His garage was about 15 miles away so I set off in plenty of time so as not to stress the engine out.

First thing was to get the car located onto the rollers which were set into the floor of the garage. It was obvious to Peter that the engine was not set up correctly at all but he sympathised with my problem that I could not do much on my own because she just would not tick over.

Peter had a full set of electronic diagnostics which showed the strength and frequency of each spark, and the decay pattern of the condenser. All the initial settings were made using the standard ignition rather than the electronic. He soon discovered that the dwell and timing were out; in the case of the timing it was actually set to 6 degrees AFTER top dead centre! No wonder she drove like a tractor! With the timing set correctly and the dwell set to exactly 50 degrees the car started to tick over a bit better.

The carburettor was adjusted so that the tick-over mixture was a bit richer. The fueling from the carburettor seemed OK during the initial adjustments. Peter experimented with the ported vacuum switch (PVS) to see if it was working OK. It was. Incidentally when I stripped the carburettor I discovered that the PVS valve had been deliberately blocked off by someone, who had inserted a length of metal to block the topmost tube. I removed the blockage during the rebuild and queried it with Peter. It turns out that the PVS was a late in the day modification to improve cold starting. The PVS valve is activated by the temperature of the water in the inlet manifold and during cold start up enriches the fuel by activating the low vacuum enrichment device (LOVE). The device is a bit hit and miss and can cause the carburettor to run permanently rich, especially in high mileage cars. So it is not uncommon to find that the PVS has been blocked off and indeed Dave from the Capri Club advised me that this might be the safest option. However Peter found the device to be working perfectly so we were happy to leave it attached and working as Ford had intended.

On to the actual road tests themselves. This requires running the car up to high speed on the rollers and being that Peter had his head in the bonnet it was up to me to do the driving. I can't tell you how much fun this rolling road business is. As we were inside the exhaust was attached to an extraction system and a great big fan was placed in front of the car. We wore head phones during the testing as it was quite noisy.

Driving a car on rollers is a bit strange. You have to pretend you really are driving along the road (even though the bonnet is up!) So the clutch was depressed, first gear selected and off we went. I increased speed gently up to around 60mph and then into 4th gear. At this point I floored the accelerator and watched the speedo rise and rise until 120mph was reached (note however that my car read 110mph at a true speed of 100mph). Peter was busy waving his hands at me, either asking for more power or to hold off. Meanwhile he made several adjustments to the carburettor to optimise the fueling. After a few runs he announced that the carburettor would not require re-jetting as the fueling was absolutely fine. She was starting to run a bit lean when flat out but this is very common in 'street' cars.

On the note about the speedo Peter explained that by law speedos must read fast and typically Fords have speedos that are 10% fast. This was confirmed by my observations and meant the true top speed of my Capri was actually about 110 - 115mph. The rev counter was found to be much more accurate and the tick over was adjusted to give 750 rpm.

Peter advised me that the car would easily pass its CO emissions test for the MOT (<3.5%) but the hydrocarbons were a bit high (>1200ppm) at tick over. This is typical behaviour of performance cams which make the engine run much more efficiently at higher revs but tend to run a bit rich at tick over speeds. He told me that the MOT tester is required to retest the hydrocarbons at 2000rpm at which point they were dropping off to below 600ppm. So no problems there then.

With the ignition and carburettor set up and tested over the power range, it was time to set up the cam shaft. The only tried and tested way to do this is to make small adjustments on the vernier and retest. So we tried several different settings and it soon became obvious we were getting more power in one direction as opposed to the other. So after a few more attempts we fixed the vernier in place and the result was a staggering 118 bhp at the wheels.

This new power figure was compared with 97.5bhp from my previous rolling road session in 1995 on an unmodified engine. So my budget modifications had given me a 20% increase in available power which is quite noticeable I can tell you.

With the K & N air filter off the car managed another 2bhp. This power drop is much less than what you would get using a traditional air filter. In fact in some cases the presence of the (performance) air filter can even increase power slightly.

After nearly two hours worth of adjusting and testing and almost half a tank of petrol used up (you get only single figure consumption figures testing at high speeds!) it was time to go for a test drive. I remember roaring off down the road yelling like the Dukes of Hazzard. The difference was unbelievable. There was so much more power and she really felt like she wanted to pull harder. No flat spots on the fueling whatsoever. To say I was chuffed is understatement of the year. The only downside is a noticeable increase in exhaust noise but I have to say it has a nice 'sporty' roar and is not too intrusive.

The two hours with Peter cost £85 plus VAT and it is the best money I've spent in ages - great fun.

So the next challenge to overcome was the dreaded MOT. I booked a trip to a local garage where I sat patiently waiting. The verdict? - she failed on three things: misaligned headlight, the obligatory windscreen wiper blades and she failed her emissions test. What? shock horror. This can not be. I mentioned that the car had just been set up on a rolling road and was within the limits. The test had come back 3.8% CO which was a fail and had passed the hydrocarbons. I was not happy at all and to be fair to the garage owner he sympathised with me but 'his hands were tied' He did however suggest that as the engine was so new it might be worth 'going for a spin' to clear her out a bit. He offered to retest it afterwards so of I went up the A1 for a few miles at high speed. On returning to the garage she was retested and this time passed with flying colours (CO was less than 2% and the hydrocarbons were <800ppm). The garage owner said that it is always a good idea to go for a good spin to get the engine fully hot before going for an MOT test. This is very good advice indeed!

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