Fiat Spider, 8V engine and things
Posted: February 13th, 2009, 4:27 pm
Hi Guy and all in the forum, although difficult to find the time I'm always keen to browse through this forum as I'm an admire of Italian machinery and even more so of the twin cam engine.
I've own my SC2 spider for nearly 15 years now and besides the usual messing around to get more power with cams compression and twin 44's it was about time I took it it to the next level. So a year ago I decided to spend every available lunch hour having another go. This time it was going to be fuel injection. And must reduce the weight. I'm privileged to be working in the motorsport engine industry so i twisted all my suppliers arms to get the max discount and most were very happy to do so.
I've kept an excel file with the weight records and even though the engine is not complete yet 6.1 kilos have gone! Amazing. Most of the weight has come off the right areas like piston / rod assemblies (steel rod/forged piston), replacing heavy steel bracketry and plates with aluminium, and with the abundant use of titanium bolts courtesy of a friend who works for an F1 team and titanium bolts are no longer allowed to be used there. I completely removed the Auxiliary shaft and instead modified the housing to run 2 roller bearings. 1 kilo came off that. The valve spring retainer was re-designed to have a smaller disk shim and without machining the cam carrier used a solid tappet. More weight off the valve gear. For those who own 124 Spiders and the known ground clearance issue on the sump pan. Initially i was going to go wet sump big wing but when a pump assembly became available to me at the right price I decided to go dry sump instead.
I'm nearly there now, but still have to sort out the air box, the alternator, the dry sump tank in the car and the ECU. Can't wait now.
I've own my SC2 spider for nearly 15 years now and besides the usual messing around to get more power with cams compression and twin 44's it was about time I took it it to the next level. So a year ago I decided to spend every available lunch hour having another go. This time it was going to be fuel injection. And must reduce the weight. I'm privileged to be working in the motorsport engine industry so i twisted all my suppliers arms to get the max discount and most were very happy to do so.
I've kept an excel file with the weight records and even though the engine is not complete yet 6.1 kilos have gone! Amazing. Most of the weight has come off the right areas like piston / rod assemblies (steel rod/forged piston), replacing heavy steel bracketry and plates with aluminium, and with the abundant use of titanium bolts courtesy of a friend who works for an F1 team and titanium bolts are no longer allowed to be used there. I completely removed the Auxiliary shaft and instead modified the housing to run 2 roller bearings. 1 kilo came off that. The valve spring retainer was re-designed to have a smaller disk shim and without machining the cam carrier used a solid tappet. More weight off the valve gear. For those who own 124 Spiders and the known ground clearance issue on the sump pan. Initially i was going to go wet sump big wing but when a pump assembly became available to me at the right price I decided to go dry sump instead.
I'm nearly there now, but still have to sort out the air box, the alternator, the dry sump tank in the car and the ECU. Can't wait now.