The Mercedes 190E Cosworth – a definitive modern classic and less common than a BMW E30. This one came in for a couple of jobs. Primarily, checking the cam timing and running it on the rolling road. It is a new engine and the owner wants to make sure everything is spot on before he begins running it in.
With new engines on the rolling road we limit the load and the RPM’s. It’s important to make sure the fuelling is ok with a new build. You don’t want to be running-in with a lean or rich fuel mixture.
Additionally, we took the car for an MOT and did a couple other little jobs. The owner is working toward a 2-week European road trip in May, taking in the Stelvio Pass and the Nurburgring. Can’t think of a better trip to do in a Mercedes 190E Cosworth.
First, we established a baseline. We made sure the fuelling was adequate and did a power run. This data was saved on the computer so we could compare the torque and power curves as we worked through the day. Baseline power peaked at 155.3bhp. Next, we advanced the ignition timing to see how the engine reacted. Power dropped to 151.2bhp so we set the timing back to where it was.
Next, we tried a new inlet manifold and short trumpets on the Weber DCOE carburettor. This time the power jumped up to 160.2bhp. Great result. Torque was down to 141.7lbft so we tried some long trumpets. Power was virtually the same at 160bhp dead but the torque came up to 143.7. Lastly we ran the car on an open exhaust. We adjusted the jetting in the Weber carburettor to compensate and it made the best power of the day at 162.2bhp and 144.7lbft of torque.
A day well spent and a Riley 1.5 rolling road tuned to peak performance.
Grant Williams has been back on the rolling road for a final tune ahead of the 2019 Goodwood Revival. Following a refresh of the 3.4 litre competition engine the car went back on the rollers to setup the triple SU carburettors. Grant will be competing in the St Mary’s Trophy race. He is sharing the drive with sports car racer and BRDC member Ross Hyett.
Development of our 1958 Volvo PV544 for Goodwood has continued following a successful test at Brands Hatch. We spent some significant time on the rolling road and tried out some different things. Ultimately we have gone up on the choke size, changed the emulsion tubes and re-jetted the carburettors and found an incredible 21bhp (flywheel) with an increase in torque across the whole curve. We’ve got some suspension changes to make this week before heading back out on track for our second test.
Jentree Classics brought in this lovely little Lotus Elan Sprint for a rolling road tuning session. Until recently this car had been in the same family since it was new. A beautiful car in a not often seen colour.