Total ignition timing?

[tmdog]

Modified 350 sbc. At what rpm should the total timing be in at on a 18 D. Also what rpm should it begin to rise? I heard it starts at 800r's and have all timing in by 32 to 34k. Does this sound right?

[Pismo]

You want the advance to be zero up to around 1000rpm and start climbing from there so its all in by 3000-3200 rpm tops for maximum cruising efficiency. 35 total is pushing things unless you run premium fuel with not too much compression. 22 to 24 max advance over a 10* base. From OSO.

[MOP]

The post below shows the advance rates for Tbolt's, but the advance rates will apply to most all applications. So far I have stuck with 31 total even though 32 is probably a little better and like "Pismo" said 34 is pushing it. One load of bad gas and it all goes to hell in a hand bag.

Good post worth reading #6 give the advance rates
http://www.donzi.net/forums/showthread.php?t=38371

phil

[MOP]

More!

http://www.donzi.net/forums/showthread.php?t=42654&highlight=Tbolt+ignition

[tmdog]

Have to bake a cake. Be back w/ some important info. Thanks to all that responded. Just what I was looking for. Tkanks, JIm:beer:

[tmdog]

The reasoning behind that question was I was always setting my total timing at 3500 and got poor performance. The timing module is a 22A and according to "Dennis Moore's" book the 22A is suppose to be all in at 3500. Well, the info in that book is a typo and in realty the 22A is all in by 4500 + or - 200 rpm, according to the Merc articule. I have no idea what marine engine the 22A would be installed on. I always suspected the ignition was at fault. First, I burned way too much fuel. Second, I turned a 23 Turbo to 5250+ and tried a 25 Turbo and was lucky to turn 4200 and hit a wall. From 4k to 4.2k was a struggle. Most notable prop shops said I was not in my power band and that was true. Because the engine was running too retarded by about 3-5*. Is the poor performance caused by this module?

[tmdog]

To replace the timing module is costly. Remedy, sprung for a DUI dist. and will have it set up for a total of 32* @3200. The only drawback is the shift interrupter and how to wire that to dist. Any advice on how to hook that up?

[Rootsy]

probably gonna have to spring for an MSD Shift Assist module.. bout 80 or 90 bucks... you should be able to find the wiring diagrams at msdignition.com... or i guess i could break out the tech notes and see if there is a diagram and take a photo of it for ya...

[onesubdrvr]

If you need the MSD Marine Shift Assist module, I have one, brand new, still in package, I bought from jegs for 86.99, I'll sell for 70 plus shipping. I went with a different distributer.


Thanks
Wayne

[tmdog]

I am still working on it, thanks for the offer onesubdrvr. What and how does this module work? Anyone?

[mrfixxall]

I run mine at 36 deg and had no problems. i run it so high because the engine coolent temps are way lower then a car.Whan i dynoed my engine we put 38 deg total in the engine and it didn't ping(said the knock sensor)so i figure 36 would be safe....