Offshoreonly.com - how many of you are using locked distributors on your motors ?

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I Run 32 Total,locked Dist,540 Blower Motor,easy Starts,clean Idle,i Do The Same For Mt 572 Motor.

distributor locked is alot more for top end performance not so good for any crusing around, if your boat is heavy in the mid range you can run into detonation problems, all depends an your application/use

I have run locked timing for years. It's best for engines with a lot of cam duration. Most distributers are all in by 3000 rpm anyway and I never cruise below 3000. The extra timing helps your idle but it is hard on starters. I broke a lot of starters before getting MSD Starter Savers.

Quote:

Originally Posted by mike tkach (Post 2976602)

I Run 32 Total,locked Dist,540 Blower Motor,easy Starts,clean Idle,i Do The Same For Mt 572 Motor.

Ditto on the locked @ 32, blown 540's - same setup since 2004, no problem on mine.

After I did take a look at the timing at higher rpms and found out that the timing retards even with a locked out distributor... It retarded maybe 2-3deg from idle to 3500rpm.

I searched on the internet and found this on another forum:

Quote:

FYI for Racers who run MSD ignitions. We run an MSD distributor and an MSD 7 box and have seen it retard up to 6 degrees over 5000 rpm. We tested the distributor on a distributor machine and it confirmed that it was advancing all by itself after 5000 rpm(FYI - our distributor was locked out). Our mechanic said that he had seen this before. We went and bought a brand new dual pick up MSD distributor and tested it on the distributor machine, it lost 5 degrees on one pick up and 4 degrees on the other. We were thinking/hoping that a crank trigger system may stop this but we've been told that isn't necessarily true.

The following are what we've been told on another forum

The term hysteresis is often used to discribe the effect. What this means is the circuit operation in one direction won't be the same going in the oppisite direction. In this case you see a distortion resulting in a curve instead of a linear function with time and rpm.
I have also saw it in simple magneto systems.
The cause is the parts and circuit inability to do the same function in respect to time interval where magnetics and rise time are involved.
Indeed a parts selection and testing can minimize this effect.
There are some engine combinations that can use some retard at high rpm, for various reasons but that gets into advance curve as opposed to the ignition it'self retarding as an unintended action..

Also:

at higher rpms you will see a retard condition even with a crank trigger. some of the newer digital msd boxes have a mag compensation circuit where an adjustment can be made to allow for the retard. it was explained to me that it was an inherent thing with manet triggered devices. the amount of retard is rpm dependant and gets worse the higher the rpm. the 7531 digital 7 box has a automatic mag-comp circuit and cannot be adjusted

yup locked at 34 i run an HEI no box

I run Pertronix that has limiters to stop the weights. Their 12 degree limiters were 15 degree advance so I bent them and now only advance 9 degrees. This is not far from just being locked. Starts fine w/standard marine starter.

Quote:

Originally Posted by Mr Gadgets (Post 2976298)

I ran locked out for years... 32* timing, bigger roller cam. Always worked good. MSD dist. Now I run a crank trigger with a home made box to control the timing..

Great set-up. For those who don't want to make their our timing control box, use this one from MSD. You control start retard, full rpm retard, and your timing curve. What is sweet is the high end retard. Done with modules. Don't have access to your favorite octane fuel, pop in a few degree's of retard and motor home safely. Knock free ride home. :coolcowboy: