2 replies to this topic

[Raz]

Can anyone tell me what the standard timing should be for an 1098 engine ....also would it be diferent for the same engine tuned to with a kent 266 cam and a big valve gas flowed head ..alloy inlet and a 1 1/2 carb

Cheers Ray

[dklawson]

I can't comment on the stock timing for any Mini engine. I know there are specs for it but I've never paid much attention to them.

As soon as you start modifying your engine you have to set your timing by trial and error. The common method I use for this is to bring the engine up to 4k RPM and set the advance (at that speed) to about 32 BTDC. After returning the car to idle, you test drive the car and listen for pinging while accelerating under load in high-gear. If you hear pinging you retard the timing in 2 degree steps until the pinging goes away. This gives you the maximum advance your engine can handle for its current state of tune and the fuel you're running. (Incidentally, once you've set the high-speed timing like this your subsequent adjustments to retard the timing can be done at idle speed). Once you've determined the maximum advance your engine can accept, you can record what that value is at idle and set your dynamic timing at that point... rather than setting it at 4k RPM.

[cooper_shaz]

Vacum advance disconnected
1500 rpm,
9 degrees btdc
in standard tune.

changing the cam etc will change the ignition timing,
in real terms a rolling road session will give the best result, and just note down the settings
after the session.