45 fe distributor curve question

wrench87 · #1 (**permalink**) 02-05-2012, 05:32 AM

i ordered a new steel gear for my msd 8594 distributor so i figured it would be a good time to change the springs and bushing. wha t would be a good starting point for a advance curve 445, cam specs .598-.617 duration at .050 230-238 112 lobe seperation lobe lift .3400-.3510. 108 intake centerline.

patrickt · #2 (**permalink**) 02-05-2012, 07:33 AM

Here's my curve. The light silver and blue combo is tried and true. My all in timing is 35 degrees, so I use the silver bushing and that translates to around 10 at idle. The benefit of that is very easy cranking. Make sure your colored bushing and initial timing add up to what you want, then you can monkey with your springs.

blykins · #3 (**permalink**) 02-05-2012, 07:43 AM

Quote:

Originally Posted by wrench87

i ordered a new steel gear for my msd 8594 distributor so i figured it would be a good time to change the springs and bushing. wha t would be a good starting point for a advance curve 445, cam specs .598-.617 duration at .050 230-238 112 lobe seperation lobe lift .3400-.3510. 108 intake centerline.

My Cobra FE stuff is usually centered around a total mechanical advance timing of 36-38 degrees, all in by about 2800.

patrickt · #4 (**permalink**) 02-05-2012, 08:00 AM

Take my curve above, set your initial at 12, and Brent will be happy.

wrench87 · #5 (**permalink**) 02-05-2012, 11:00 AM

i wasnt sure what fe's liked for total, i know on my 342 34 degrees was the best. how far off idle do you want the advance to start? i guess as long as i stay away fro the 2 light silver springs i will be alright, how much initial can a fe take with out hard starting i have 10.0 compression.

blykins · #6 (**permalink**) 02-05-2012, 11:09 AM

A lot of things affect how much total timing an engine likes....such things as chamber design, compression ratios, etc. On a CHI headed Cleveland, total timing of 28-30 degrees is not unheard of...

You won't really know how much total is perfect for your particular combo without sticking it on a dyno, but if you stick it there, you'll be pretty stinkin close.

I've ran 18-20 degrees initial on some FE's, and it's not a problem if you have the starter to flip her over.

The beauty of the MSD is that you can change the curves pretty quickly. I would look at MSD's charts, aim for around a 2800 "all-in" rpm, then experiment from there. The reason I said that you won't really know what's best for you unless you stick it on a dyno is because a Cobra is so quick anyway that you probably won't be able to tell a 15-20hp bump by the seat of your pants. However, it never hurts to try different things.

wrench87 · #7 (**permalink**) 02-05-2012, 11:17 AM

i have a cvr starter so i think i would be ok, being a street engine sounds like 10-13 initial silver bushing and light blue and light silver springs will be fine?.
now i hope the distributor gear swap goes well.

blykins · #8 (**permalink**) 02-05-2012, 11:19 AM

You'll be fine. I've turned over an 11:1 428 with 20 degrees initial with a CVR starter without any issues at all.

Don't worry so much about the initial, once you get off idle, it doesn't stay on initial for long at all....just aim for the total advance and the correct spring rates.