7" rods, 10:1 comp.- what timing numbers/curve???

[trfourtune]

7" rods, 10:1 comp.- what timing numbers/curve???

Hi all,
i am hoping someone can give me advise as to what ignition timing numbers/curve i should have for the following combination:
7" rods with flat top 89mm pistons, 10:1 compression ratio, 290 degree cam, headers 4-2-1,twin dellorto dhla's. redline@ 6200-limiter set @6100-staying below the 3rd harmonic.

i need to buy some springs to fit my lucas lotus excell electronic distributor (no vacuum)
i think it will be something like 12-14 degrees initial with an all in @ 30 degrees. (correct me if this is a bad starting point) I am liooking for when "all in" rpm is and if i should have a 2-step timing ramp and what and when it should look like-rpm vs degrees at all points of interest.
thanks

 

[rlandrum]

Re: 7" rods, 10:1 comp.- what timing numbers/curve???

Actually, it'll probably end up depending on the type of gas you run. You should be fine with 93 octane at 30 degrees, but anything else, and you'll probably want to move it forward a little.

Of course, my experience is limited to chevy engines. Iron headed, 10.56:1, 93 octane, I run 31-33 degrees.

 

[RonMacPherson]

Re: 7" rods, 10:1 comp.- what timing numbers/curve???

Give Jeff at advanceddistributors.com a call. He probably knows more than anyone else. Ideally a dyno test with pyrometers on the plugs will give you what the ideal timing should be....