The previous articles endeavoured to offer some practical suggestions for Fulvia engine development. They were meant to provoke thought rather than to provide all the answers.
Now I propose to wander into the land of dreams, the place where the lottery win finally came and where the budget is no longer a factor, a place where the ale is real and good and cheap, where there are no speed cameras or traffic wardens, where all Fulvia spares are available off the shelf, where the women – oops! I was getting carried away...
The suggestions I make here will horrify many traditionalists, but I don’t care; these ideas are the results of hundreds of hours of thought and discussions in pubs… They are mostly intended to address some of the limitations I pointed out when I started this series. I hope at least they are interesting.
I would first set out to mount the engine vertically. This is possible, I know because I once “mocked it up” - the bonnet would just shut. I would scrap the original crankcase; it is structurally far too weak and there is a distinct lack of support for that all-important centre main bearing. I would have a new one machined from a block of suitable aluminium alloy such as HE15 or 30. All the main bearings would be fully integrated into the structure; the caps, a precise fit into the crankcase, would be arranged in a one-piece “ladder” and cross-bolted. There would be a dry-sump installation, with two scavenge and two pressure pumps – one of the latter being solely for the centre main and its associated circuits. The piping could be external.
I would probably opt for a different bore and stroke from original; of course this would have to be drawn up, but probably around 85mm x 70mm to give 1589 cc. This would provide an additional 7% of piston area for about the same capacity as an original 1600. I would have the block cast in aluminium with Nikasil coated bores. There would have to be a special crankshaft of course; this would have a 60mm diameter centre main bearing since the original has insufficient area; the crankshaft would be made from EN40B or 40C steel and nitrided to 0.040” (1mm). I would arrange for a ball race on the other side of the timing sprocket to provide proper support for the front of the crankshaft. Pistons would be as light as possible and the rods would be titanium to improve balance by reducing reciprocating weight.
It would be too complex to make a new head, so I would bore out the ports and have aluminium tubes pressed in to seal them. I would move the two LH rear mounting bolts to allow for better port diameter (and probably the two RH front ones). I would consider reducing the included angle between the valves which would be larger, probably 42mm and 38mm; this would mean a great deal of welding and machining and also special rockers – the camshafts would be special anyway. The inlet valves would be of titanium and I would use titanium valve caps. Dual ignition would be nice to have but probably impossible to arrange. The vertical installation of the engine would allow a straight inlet tract to accept the throttle bodies. I would continue with the Lucas injection, but this would be mounted at the rear of the head, driven from the inlet camshaft – the vertical engine installation would allow room for the metering unit to clear the cross member that contains the front spring (which would be composite instead of steel or possibly not there at all!). To provide more room around the engine I would mount the alternator on the back of the gearbox. In fact there would probably be a six-speed dog clutch ‘box with limited slip differential. The vertical engine would allow plenty of room for a proper exhaust manifold which would be developed on the dynamometer together with the fuel injection calibration and ignition curves.
The aim would be around 190 hp at around 7500 rpm with the engine safe to over 8000… These would be very expensive horsepower indeed when one considers that 180hp are relatively easily extracted from the 8-valve Lotus-Ford 1558cc twin cam engine that is older than the Fulvia 1600 in design terms, a fact that almost takes us back to the beginning of this series of articles.
My thinking is that all the modifications listed above could have been done in 1970; I believe though that I would be unable to resist installing digital programmable ignition – the alternatives are simply inferior.
I should add that I have similarly radical ideas for the rest of the car in my dreamland. Would it still be a Fulvia? I don’t really know. In the end, it all depends upon how you define “Fulvia”.
To me it would be.
I hope that you have enjoyed reading this series - I look forward to comments and criticism.
A pair of much-modified Fulvias at a Goodwood track day
Photo: Morgan Jones