Advice On Springs And Cams Needed

[finn]

We are currently restoring a S3 Elan for racing in Road Sports.

We have fitted TTR Koni adjustable shocks all round and used uprated springs on the front. It's been suggested that we use original used rear springs on the rear. I have also seen somewhere else that 2 1/4 are recommended! Can anyone suggest what the best set up would be for race and some road use?? Has anyone tried both?

Also we are starting to rebuild the engine and are about to purchase some L2 cams, are these still regarded as the best to use?

The engine has had uprated cams but we are uncertain of what type they are, they have VG5 on the side, does anyone know what that means.

Any comments welcome.

Thanks

[types26/36]

Finn,
There has been posts on L2's before, I have used them with no probs but some people end up with flat spots, use the search and put in "L2 cams" it will bring up the posts.
Brian

[steveww]

Be careful when looking at cams, you have to consider the engine as a whole. How stong is the bottom end on this engine? For long duration like the L2 you need high rpm and for high rpm you need a steel bottom end.

The Lotus twinc does not really need a lot of duration but it does like lift, although there are issues ensuring that high lift cams will fit. There is a lot of potential locked up in the head, a good flow job is worth a lot more than some cams. A good flowing head with 45 carbs can see 150bhp on Sprint/SE cams @ 6500 - 7000 rpm.

[types26/36]

Burtons list the L2 as a "Good fast road cam, similar to a BLL 14" which has a power band of 2000 to 7000 rmp. It does have a 296 degree duration but a good standard T.C can handle that without the need of a steel bottom end.
Brian

[rgh0]

Finn

For springs I would go for around 150 lb/in fronts and around 110 lb/in rear and a bigger front roll bar around 22mm. If your planning to run 5.5 or 6 inch wheels and 175 or 185 tires then smaller rear diameter springs a must. This setup will give excellent track handling and still be usable on the road. You can go to higher spring rate of say 250lb/in fronts and 150 lb.in rears but at these levels its too stiff for road use and is very nervous on the track and a handful in the wet. I have a box full of different springs I have tried over the last 10 years and this is where I have ended up for competition use with a little road use. If the bias was road use with a little competition use I would reduce the fronts to around 120 Lb/in and the rears to around 100 lb/in

The L2 cams are very old technology and were a bad solution even when new. Too much duration and not enough lift. They appear to have been invented as a cheap way to get more power without modifying the valve gear for more lift. The end result is a little more power if you rev it above 6500rpm but a big hole in the torque curve. Its much better to spend some money on a high lift valve setup and porting. Look for cams with .410 plus lift and seat to seat durations less than 300 degrees if you want a good competiton engine.

If you have some unknown cams take them to a cam specialist and have them measured. Cost me about A$40 for a pair of cams I had checked recently.

Rohan

[finn]

Guys,

Thanks for the advice so far.

The comments have made interesting reading.

Finn.