A question of timing..................

[mark030358]

Gents,
Can some one clear up a timing issue for me. On a sprint fitted with Dellortos, the timing figures given in the lotus manual state 5.6 drgs advance at 1000rpm and thereby increasing with engine speed. However, my miles wilkins book states no advance to begin until 2000rpm. Which is correct if either and what should it be at say 1000, 1500, 2000 and 2500 rpm.

many thanks
Mark

[Hamish Coutts]

Mark,

From my workshop manual both are right, I'm afraid.

For a sprint:

Distributor despatch No or 40953 or 41189a
1000 revs - 5.6 deg BTDC
2000 - 16.0
3000 - 17.8
4000 - 19.5
6500 - 24.0 (max advance)

Distributor despatch No 41189 or 41225 when 5deg suction retard capsule fitted:
1000 revs - no advance
1250 - 2.4 deg
1500 - 4.6
1750 - 6.8
2500 - 14 (max advance)

Remember to add the static setting to the above figures. I use 12deg static for my Elan +2 s130 big valve. My engine also uses the latter distributor & Dellortos.

Hope this helps,

Hamish.

[mark030358]

Hamish,
So If I read you right then you set your timing at 1000rpm to 17.6 degs

Cheers
Mark

[Hamish Coutts]

Mark,

With the engine running at 1,000 revs the spark should be firing at 17.6 deg BTDC - for that particular distributor.

On my engine, the spark would occur at 12 deg because it uses the latter type of distributor which has no atvance at 1,000 revs.

Regards,

Hamish.