chuckpp

Just wonder have a 540 ci bb chevy with small blower two carbs just wondering what everyone is running for timing at basic and total or do you just lock it?

tks

MILD THUNDER

iTrader: (3)

I recommend either a daytona sensors, or MSD programmable ignition system. Every engine is different as far as what it may like, or not like for timing. Too much is not good, and too little is not good. Many look at timing as a "power adder" or "power reducer", but that is simply not the way to setup a marine engine, especially a supercharged one. The goal is fire the plug at the right time, for best combustion event. Firing to early even without preigntion, still doesnt always mean the best power. Fire the plug when the piston is still too far down in the bore, creates negative work, or force against the piston trying to come up. Firing to late, simply wastes power, and can make EGT's skyrocket. There are many factors, and this is where dyno tuning is invaluable.

What are the details on the build? Small blower? how small? What heads? What cam? What compression? Intercoolers?

chuckpp

I believe its a 250 series b and m with two 750 carbs Big brodie heads 253 intake 263 ex @50 114 lsp
540 ci BB chevy 8.0 to 1 Yes intercooler

tks

MILD THUNDER

iTrader: (3)

Thats alot of cam for a 540 with a blower. You are probably gonna want lots of advance at idle.

Thats not alot of blower for a 540. What ignition system do you have

Bawana

I totally agree wild Mild Thunder...with that much cam you will need to run some good boost to take advantage of that cam. With that small a blower with the cubic inches you run & with an inner cooler that will lower overall boost, you are not going to get much boost. Sell that blower and get a bigger one ie. 8 or 10-71, you will be way better in the end, with alot less problems.

chuckpp

Msd, how much total timing? Are you talking about 12, basic timing or more.

This thing ran the balls just rebuild it...

Black Baja

iTrader: (2)

Brodix Conventional heads typically like 36,37,38 degrees of timing. 36 is a good starting point.

sutphen 30

get a 4l whipple and turn that puppy up tp 1100hp.then I'd tell you to run 31° of timing.