Big cams and standard ecu for ignition. will it work???

[ChaosAD]

Hey, Ive got a bluetop with an MSII aftermarket ecu controlling fuel-only and the standard ecu running spark.

Im giving my engine an overhaul and want to put my big cams in it (240 deg at .050" & 8.8mm lift).

I know their is no way the standard ecu will run these. but what if its only controlling spark? I know it wont give the best power, but this is just till I get the msII doing spark.

if it wont run it could I just dial the cams out a bit for a bit more vacum?

Thanks

[spencer]

mine give a ok basic advance curve with no map just based on rpm but it was far from optimal. I now run a ford edis unit which I got for a real good price from a website in the states havnt tuned the ignition curve yet but soonish

[suberimakuri]

it'll run fine, but you may need to pull some advance out in high rpm, by reducing the base timing.

theory is the cams will be more efficient at higher rpms and thus won't need as much advance.

unfortunately they'll be less efficient down low, and will need/take more advance down low.


damn the MSv3 VR pickups too.

[ChaosAD]

Wiked, had to pull the base timing back when I upped the compression as there was too much advance at lower revs. but top end suffered. this should even it out.

will the map signal be an issue though?

[suberimakuri]

yep, if you're really worried just unplug the map sensor and run diag mode.