A friend of mine recommended that i join this site to find technical help on how to fine tune the super charger set up in my boat. The motor has been in various stages of rebuild(as well as the boat) for the past 3 years and is now running once again. Before I splash this thing in the water and take it out for a run, I want to be be sure I've dialed in the motor as best as I can. So here is the question: how do I set the timing for a roots type super charged GM 350 engine with a Mercruiser Thunderbolt IV(v-6) ignition.

You probably want to run about 30* of total timing. The V6-14 Module will only give about 6-10* of timing on a V8 engine and the module will be at full advance around 2000rpms. Set timing at idle to about 20* initially. Then rev it up to about 2000 rpms and see what the total timing is. It should be between 26* and 30*. Then set it to 30* at full advance when its above 2000rpms. You will need a timing light with a dial indicator or a timing tape on the balancer to do this since the timing marker does not go that high.

If you can find a digital timing light like my matco you can just punch the buttons to whatever advance you want to see & it will show you the timing at zero so you dont have to mess with timing tape plus you can shoot it down a carb
or tbi injection & check out fuel delivery. Its pretty cool to see if you work the advance up & down you can see the fuel spray

bump to top any more opnions on this I think its a 177 supercharger

You what it to run on the rich side

You should run no coolant tsat and an oil tstat that starts to cool at 180f. A/f reading should not exceed around 12:1 at wot.

run good fuel and watch out for detionation.blowen motors dont like low grade fuel and heat.

any more info on initial timing does 20 degrees seem right to everyone. thanks