BAD-HABIT

Can I use my Merc Dist. with the crane box and how involved is installation. Most Important is how easy would it be for me to switch back in an emergency(on the water) Same with the MSD...I have read posts about splicing in the MSD to the factory distributor but MSD and Teague say no way! It's not possible
Thanks

mcollinstn

Crane Hi6-M works great with stock distributor.
The Crane unit has programmable advance curves that you can select (and one of them is a stock Mercruiser curve).

The factory distributor has no mechanical advance at all (which is a wonderful idea in the corrosive environment it lives in) and all of the advance is done in "the box" electronically.

MSD does not offer a "marine" unit with that capability (they do offer a box that will accept progammable curves but is has not been "marinized" - any of their boxes designed to work with a crank trigger unit will do so).

A MSD unit is usually paired with a trigger mechanism that provides an advance mechanically.

As far as swapping back anf forth between Merc box and Crane, I don't know that I understand why you'd want to do this but, if you keep all of the connectors intact, I guess you could.

BUT
There are some on the board who run "locked" timing. They run 30 degrees locked. In those cases, either box will work fine with the Merc distributor. Either box cann accept the trigger signal from the Tbolt distributor (so it IS possible with MSD, but not advised due to the advance curve issues)

The only way you can run locked timing, though, is if you have enough cam to bleed down cranking compression a bit.

blown1500

mcollinstn,
I con't know how to make the MSD work with the Mercruiser distributor. The trigger signal from the Merc is oposite that of everybody else, so the trigger occurs out of phase with the rotor. If you know how to make it work, please inform

formula31

My vote is for the Crane

Brad Perry

I've been told the same from MSD. Had to buy a new distributor..just to run locked out timing.

blown formula

I don't want to bust any bubbles here BUT: The Jacob's Marine Master ignition system is designed to work with the stock Merc distributor and if a malfunction occurs, the the Merc can be fully reactivated by moving only 2 coil output wires. In addition it is a multi-spark variable duration (on demand) type system & works great. It help clear up my smoky transon (in the past) & added 500 rpm to the top end. No more fouling plugs in long wake zones. Jacobs get's my vote.... and it is a Marine unit!

Brad Perry

No arguments here! The MSD stuff is ancient technology...

blown1500

No the MSD just works different . NHRA,WINSTON CUP and about everyone who is anyone in racing uses the out of date as you say stuff !!!
How many Jacobs units do you see ?? Not many .It may work with merc but thats the only thing it does that MSD won't due better !

Mbam

We have used the MSD box and Merc distrubutor along with the stock Tbolt IV module (with the curve of your choice). The grey Tbolt wire that would normally go to the coil - is hooked to the MSD points trigger lead, (white if my memory is correct) the MSD then sees essentially the same signal it would see if there were points triggering it. If you give me a fax number I will send a diagram.

Brad Perry

Well, I stand corrected! Blown formula, you might as well throw that Jacobs in the trash. Same with the Crane, apparently. Someone might want to call these two companies and let them know that they are wasting their time even competing with MSD, because they are the ONLY thing going for those who know.