Has anybody locked out there timing? If so what are the advanges of doing this and what did you set your timing at.

i locked it out on my na and blown engines, running crane hi 6 ign which takes care of the timing advance. there are several different curves for various applications.

I locked mine out set timing at 34 deg no problems. I did this after Nickerson re-worked my carb it was there recommendation. I have full MSD system which made it easy to lock it out.

My 510 c.i. 645 h.p. N/A Sterlings have the timing locked out @ 34*. No problems with in-gear idle @ 600 rpm.

What are the advantages?

Mostly for better idle with big cams. 20 years ago when cars had distributers, they ran vacuum advance. You would set your timing at about 12 degrees before tdc and during periods of high vacuum,(idling and cruising) the vacuum advance would add another 16 degrees or so. Add to that the mechanical advance and there were periods of time when you would be cruising on the highway at 45 degrees of advance. Locking out the timing is not such a radical idea.

I have never locked out timing due to driveability Marine and auto, even with cams @ 625 lift 112 deg duration and have had excellent results. HOWEVER, I will be running a blower this year and many blower guys run it locked. So, for those who know.... What are the advantages? I believe that running locked at too high an advance creates starting problems as well as detonation down low in the RPM band.... Am I wrong here????

Yes it will start hard. I added MSD start retard boxes and use Tilton style starters. Before that it ate a bunch of starters. If you lock the timing in an engine with a mild cam, you will build a lot of cyl. pressure at lower rpm's. It probably would detonate a lot. Again the only reason I know of to lock the timing is to improve the idle in engines with big cams.

I ran locked on my blower motor and presently running locked on my NA 540.
29-30 degrees Blower.
33-34 degrees NA.
Cam in 540 is 236/240 @ .050
I also use an MSD Digital 6 Plus ignition. It has a start retard feature.
I have experimented with using the start retard and not using it. It does make some difference but actually have disarmed the feature. Motor starts fine without it.

I'm leaning toward the six cylinder Thunderbolt box with a B&M 420 MB, I think it has about 12 deg or so advance. This would let me have initial at approx 19 deg and full advance at 31 or so. Have you guys had any luck with this setup?