strange question, but is the cam timing - the gearing at the back of the 2-4 cam that connects to the dizzy - different between NA and turbo cams? different between 3 plug and 4 plug ecu models???

 

the reason i ask is because i have just done a swap. I used to have a 3 plug turbo engine, and now i have a 4 plug NA engine with the 3 plug turbo and bits on it.

 

obviously the turbo engine requires timing of 20 degrees BTDC with the vacuum line disconnected and the NA engine requires 8 degrees BTDC. if i put the dizzy (3 plug dizzy) in, on 1 cog i cant get any more timing than about 14 degrees BTDC, if i then move the dizzy 1 cog, i cant get any less than about 22 degrees BTDC - basically i cant get in between. i thought maybe the gearing on the cam was different between NA and turbo cams.

 

any thoughts??? obviously i'd prefer to keep the NA cams to get a little more poke...

Are you sure you aren't moving two teeth instead of one? It's really easy to miss a tooth.

 

And if the teeth mesh - then there is the same number of them - ergo it shouldn't matter where the teeth are cut in relation to the cam profile. There are enough teeth that the slot's for the distributor can move fully between the increment's of the gear teeth.

 

GD

i'm sure i'm not moving it by more than 2 teeth - that's what is worrying me.

I had to lengthen the slot in my ea-81t.

the slots on the dizzy so it can turn around further? that's a good idea!

Ended up grinding away a significant part of the stud too,IIRC.