Let's talk ignition
 

I'm curious what you're running? Not stock power with stock merc. Who's doing what with ignitions. What problems have you seen? What do you like and dislike?

I've been talking with Joe, MT about some 600hp 502s. We have not yet discussed this so I was curious what the concensus was.

I know that I own 4 Marine MSD boxes that are only good for boat anchors...lol. I had mercv6 module ignition on my 700 hp blower motors and they worked flawlessly. Now I have EFI merc power and I don't worry about it.

If you run MSD always carry a spare box....

If you run twins bring 2 spare boxes...lol

I'm running pertronix flame thrower dui's. Only reason why is because I did exactly what your doing and came to the conclusion KISS. Keep it simple stupid. Lol. Never chasing problems etc, Lots of good ignitions just what I chose. If your a gm guy you've obviously ran HEI at some point. Ever have any problems?
on dyno with all the latest and greatest msd ignition etc there was no difference between the two.

Engines dyno'd were 496's and the other ignitions used were in the dyno room. I would not have bought for testing purposes and turned out I was pleased with what I had purchased.

+1 to GETRDUNN...as you know I'm partial to HEI mod by DUI. Strong, Reliable, Simple...one wire...KISS.

I was told by my engine builder that the stock GM HEI distributor starts to spark scatter above 5000 rpm. He was part of the development team (at McLaren I believe it was) when Mercruiser was developing the 502 Mag.

I went with the MSD 8366 distributor on my build which is a direct replacement for the Computer Controlled GM HEI. The only problem with this distributor is the MSD module is junk. I replaced mine with a genuine GM module and have had no problems since.

I am running the Holley HP system on my boat and when I initially went to start my fresh build I was not getting an RPM signal from the distributor. Without an RPM signal the Holley will not fire the injectors. Swapped out Modules and fired right up.

For what you're building you can certainly stick with the stock Merc ignition. On my 454's I ran last year I used the V6-14 modules. I ran a Crane 741 cam, in what were pretty much stock Merc 420 hp engines. Even with that large of a cam I could idle the boat down to 7-800 rpms and never had any issues with docking. I've now installed engines very similar to what you want to build. 509's that are around 650-675 hp, I'm also running the Crane 741 cam in these engines as well, but here I'm using the Merc V8-HP module. So far I like the V-6 module better as far as idling, however I feel the V8-HP has a better advance curve. I believe the idle issue I'm having with the 509's is related to the carbs, so I'm going to go through them this weekend. In my option either module would serve you well, I've never had an issue with the Thunderbolt system...

I know that Joe really likes the Daytona Sensors set-up. It is a great piece, but not inexpensive, and I doubt you will need the special features it offers for your builds. I looked at them for my engines, and decided to stick with the stock set up.

I have seen merc v6 thunderbolt ignition that looks like it was picked off the bottom of a swamp, rusted to hell and still kept on firing. The MSD boxes that I have are potted and nice and shinny. However, no spark....lol. I can also tell you that the components that are in the MSD distributor just never seem to hold up in the marine environment. Just my 2 cents, KISS method, why introduce another variable that is prone to failure without noticeable gains..

I refuse to run anything MSD(may soon die) as to their crap is just that...last several setups I ran a H/P HEI and have had not spark scatter over 5000 by the way...

It's the stock in cap coil GM HEI's that have issues over 5k. They where designed to be put in motors that where done producing very weak hp at 4k. The aftermarket took care of that quickly. I ran one (aftermarket fortified) to 7k+ for years.

But, as soon as GM introduced the external coil hei (EST) set up that had no weights, I never looked back.

Second this recommendation if you are looking for something GM. The EST distributor is rock solid, has a nice curve (with the marine module), and you can chose what coil you'd like. A bonus is the distributor straight from Delco was used by Merc an others with no mods (spark screens etc are standard), and it is marine approved. I've had zero problems from mine. Cheap, reliable, good spark. I turn mine at 5300 with no problems.

Does anyone have a graph of the advance curve on the HEI EST distributor? I've never had an issue with the Thunderbolt system, but if I do I may look into this. What advantages does this system have over the Thunderbolt IV? I'm guessing easier parts availability, and potentially less wiring.

http://bpi.ebasicpower.com/downloads...structions.pdf

Jeff

Great info guys.

Those look like my factory ignitions. So that's easy enough.

I have used the Delco in quotes below and had 22* all in just before 3000rpm. I always check up to 4000rpm just to make sure.

Note, these modules will usually start advancing before 600-800 rpm, so set total timing and let initial just fall where it is.

Note,some aftermarket part store replacements won't have any advance curves or some crazy thing like 10* or so.

lol. You. :wink:

One thing nobody mentions is rev limiter.

ICU peepin, im guessing based on the cam/build combo we discussed, you will be wanting to turn 5500-5800rpm. A stock merc rev limiter isnt going to let that happen. I certainly would not run witbout a limiter myself.

In saltwater, i would not run anything that uses centrifugal weights and springs for advance. I dont even care for it in freshwater.

As far as daytona being expensive, a msd marine box is 350, a comparable marine coil from them, is over 100 dollars. Thats 450 dollars. You are left with no electronic timing curve, no data logging, no idle stabilization, no ability to choose between preset timing curves, 2d or 3d timing maps, start retard, and some other cool stuff you get for an extra 100 bucks over the msd marine box.

The stock mercury igntiion is good, but doesnt leave alot of room for fone tuning your timing curve, and the rev limiter is an issue .

I just purchased the Daytona kits. I've always have had in gear idle problems on my 588s. I used a stock merc dist and I believe the kits were 500each with the coil. I'll tell ya this, things r unbelievable my boat idles at 700 all day and will still run upper 80s Very user friendly. I've had msd, dui Hardin distributors etc. this is by far the best working kit imo!

Good points on the rev limit also.

I just swapped this week from the IV to the EST. The Thunderbolt IV parts are obsolete and I had an Amplifier go bad....you can take your chances on ebay and thats about it.

The EST is much less wiring and is a simple install. Swapped out and timed in less than an hour. I got mine from Michigan Motorz and the boat is starting better than it ever did with the Thunderbolt.

I really appreciate the simplicity of my DUI ignition, but it is very basic and does use centrifugal weights. I'm mostly in fresh water so it's no big deal but MT's concern is valid. I'm on on the opposite side of opinion and appreciate mechanical gizmos because I have no patience for ghostly electronics.

It still uses a magnetic pickup and electronic module.

Put something electronic in my hands and it's guaranteed to go wrong or malfunction in some way or another. I can walk in a room and set off or activate alarms or walk in any yard and sprinklers turn on.

I have a Delco Voyager distributor from about 1998 from a MEF1 fi setup, it looks to be the same as the EST. If so, what do I need to do to make it work on a carbed application? How do I wire the weatherproof connectors? thanks

Thunderbolt IV doesn't use a rev limiter. I'm going to run an MSD rev limiter on my setup. They only run around $140, and unlike an MSD ignition box, I've never really heard anyone having issues with them.

Ha- guess I need to look at my own notes!

It is the EST. Schweet huh ? No ignition system to buy when swapping to carb.

Keep and connect the two wire harness that goes from coil to distributor.

The other two wire harness that goes to other connector on your coil is the ign + lead and the other is your tach.lead.

The bigger connector with wires that plug into right side of distributor is not needed. If you have an alpha drive , these use a shift interuptor, and can be wired to one of those wires...I'd have to look that up as I forget which one.

That's it . Simple.

I do this all the time ! Way too many notes.

i ran locked timing on supercharged engines tor years,boats&cars.after seeing the benefits of the daytona marine cd1 ignition i sold all my msd boxes&coils and went with the daytona setup.i have not run the boat yet but it will be done soon.i installed the daytona setup on my buddy,s 42 fountain with 1000,s and i am pleased with the results.imo the daytona cd1 is the way to go on a supercharged marine engine.i have a procharged 565 that also has the daytona setup and will be on the dyno thuesday.i am goung to run it with locked timing first them back to back with the daytona with a 3d map.if anyone is interested i will post the results.

Harness to coil that has the red and white wires grouped together:
Red = ignition + power
White = Tach (crimp this to the gey wire coming out of the engine side of engine main harness bullet connector is that tach wire that goes up to the gauge)

If you need to, you can reference page 26 at: http://www.boatfix.com/merc/Techbk/96/96HGD4.PDF

Thanks SB....I wonder how many of that have switched to carb went and bought new ignition! (like I was getting ready to do)

I had performance distributor in Memphis TN build me a dui distributor off my engine and boat specs. Timing curve is perfect and couldn't have been easier to install.

A ton !

As example, I did a efi to carb conversion about 12yrs ago, and when I mentioned this online about the distributor the responses, where, well, amazing. And many had done the full MSD dist, coil, and box kit. That's near $700. Yikes ! And again, that was a long time ago.

When you fire up the engine when done, and set the timing, make sure you get the full advance curve as we outlined earlier. As I noted, and am noting again, some replacement ignition modules don't come with a curve or come with an improper one. You never want to assume things.

this OEM crusader inboard, my 92 454's have these dist's oem and the timing info is right out of the crusader manual

found out automotive EST dist modules do not have a curve in them like the marine ones do, but might be able to run locked

Just got 2 of Daytona kits with the coils, software and usb connection etc. I was hoping it would bolt in right in place of the Crane components. Of course it's all different.

Did u get the boat running ?

I took a few months off from it to deal with some health stuff. Just have to rewire the ignitions to work with the Daytona boxes and fab the coil/ box brackets then they can be put on the dyno for the last time. Went with the QF marine dominators.

I bought the Daytona sensors CD-1 for my junk. While I'm not forced induction, I still think it's a worthwhile ignition for my application. (Going to use the RPM based timing curve as a start)

Here's a coil bracket I fabed up in my garage. It will mount on the back of the starboard cylinder head:
http://i205.photobucket.com/albums/b...psbz9vorbe.jpg
http://i205.photobucket.com/albums/b...ps4b5xwwjg.jpg