fe timing help with msd dist

[otto]

hi, i am getting ready to set up my msd dist and i am looking for some help, i am guessing base timing of 10-12 degrees total maybe 35 degrees all in by 28-3000 rpms , my engine is 427 s/o flat tappet cam with a lift of about .560 ,750 holley carb on a dual plane alu. intake with cast iron med rise heads. any help or info would be great
thanks Bob

[concobra]

May I ask some questions?

1. What is your static compression?
2. What is your cams duration at .050" lift for both intake and exhaust.
3. What is your cams LDA?
4. What is you cam installed at?
5. What type of fuel are you running?
6. What is your final gear ratio and tire diameter?
7. Is you intake manifold a dual plane or single?
8. What does you car weigh?
9. Does your MSD distributor have the vacuum advance or is it the mechanical advance only?
10. What type of starter do you have?

thanks
Concobra

[Keithc8]

Depending on the compression of the engine and the fuel you have a FE engine will make max power at 38 to 40 degrees. If the compression is to high for the fuel used you will have detonation problems and pulling some timimg out will help this but also hurt power. This is why it is so important to get the compression right when building the engine for fuel available. The camshaft does come into this as well as it affects the compression as well and cylinder pressure.
But with all of that said I normally see about 14 to 16 initial and 38 total timing. These are areas where an engine dyno or chassi dyno can help you with some of this.
Thanks, Keith

[elmariachi]

As a point of reference, I have a 427 medium riser with a Comp 294 flat tappet, 10:1 compression and it requires 18 degrees initial and 36 total. Anything more in total time and it detonates on our crappy coastal pump gas. Anything less on base timing and it idles like crap and idle temps are up 10-15 degrees. I am running the MSD 8594 distributor with two blue springs and the black bushing.

Base timing of 10-12 seems low.

[wideglidejoe]

almost same as elmariachi.........

428 w/4.25 stroker crank (455 ci) 10.1:1 cr, alum heads, Comp 294 flat tappet hyd, MSD 8594 distr w/black bushing, but I think I have one blue & one silver (?) spring in it now. Currently set at 18 initial & 36 total.

Once this summer heat in Okla breaks, I'm thinking of bumping it to 20 & 38 and see how it does.

Base timing of 6, 8, 10 is from the old reference books back in the 60's. I started at 8-10, it was very sluggish and idle temps were horrible!

Good luck!

[otto]

Thanks for all the replys , i bought the cobra used and the owner was unsure of the engine specs so i did alittle digging and found some info. thanks again Bob

[Barry_R]

We do most of them with the same spring/bushing combination referenced above - black bushing with one light silver and one light blue spring. Usually somewhere right around 18 initial and 36 total - but as Keith noted - the combination will decide what's best.