I am currently putting the finishing touches on my new N.A. 540. I am trying to decide how to set up my ignition timing curve. I have an MSD Pro Billet distributor. See attached link for engine specs and dyno results.

http://www.offshoreonly.com/forums/s...light=540+dyno

When the motor was on the dyno, we used a Magneto set to 34* with no advance. I was thinking about going with setting the base timing to 10* with the silver 25* bushing. With 1 silver and 1 blue spring, the full advance should come in at about 2900 rpm.
What do you guys think?

I'm running locked at 34 degrees. No problems starting or idling.
This was a recommendation from Dean Nickerson and my engine builder.
And yes, I use an MSD distributor.

Vinny,
I am running 10:1 compression and using the flat tappet cam I locked my distributor in at 32*. I never had any issues with starting or knock, that I could hear or see with my knock sensor. It would idle great. If you want to have a curve, I would put as much timing in as possible on initial and very little advance with weak springs, coming in as soon as possible. I dont think you will have any problems running 34* with a quick curve.. Unless your cam specs bump up the compression drastically..
Lets see what everyone else has to say about it..

Dick

Dick and Russ,

I remembered that both of you were running a locked distributor. I am a bit afraid of doing that. I am still using the stock Merc. starter. My concern is being able to spin it over when hot.

Ttt

I hear you Vinny, I am running a 3.5hp starter motor.. well that's what they told me.. LOL

I would make the advance as small as possilbe and then the rest at intial. It will idle a lot better and I dont think you will have any problems with hot start. Of course if you do.. just go to the next smaller bushing.. and readjust. I would think, you would see a problem right away if it were going to suface..

Thats the fun of boating.. wrench till it's right.. right?

Dick

Just got off the dyno last week. By setting my MSD up with the weakest springs so timing comes in asap, exhaust temps were dramatically better. Set at 34 total on 540.

I always run locked as well.

I lock all my motors out.


My new 500efi's with whipples . the computer will do the timming .

Rob

On My small block I made a larger diameter than the black one to limit mechanical advance .I think I ended up with about 14 degrees of mechanical advance.So I set the timing at 18 degrees and end up with 32 total.I have posted a picture of the spacers.I would make you a couple to try if you want.

ROB