BAD-HABIT

Running a late model 358 SBC. Full Roller,600 Edelbrock with Performer manifold,Stock Vortec heads,Stainless Marine Thru-Hull exhaust a and Comp Cams Cam. Cam maxes out at about 5200. Compression is about 9:2-1.......My Stock TBolt IV box is going south. I want a RELIABLE,SIMPLE to install and EASY to find parts for ignition box...The Crane looks nice but I am leary of the installation and wheather I can get the curve I need for my motor. Seems the Crane's curves seem to be more for big blocks. Will they work with my mouse? The D.U.I seems the most basic with the most bang for the buck but I am concerend about quality and Ease of replacement parts. Does it use a special cap/rotor (Marine) or stock GM. The TBolt seems like the safe way to go and slightly cheaper. The Idea that I can keep my old box to at least get me in not to mention that most marinas probally would be familar with them is a plus. I just put a new pickup in my stock Mercuiser distributor along with MSD Blaster2 coil and 8mm wires. The MSD system is not a option.......Any opinions VERY WELCOME.

Bad-Habit

formula31

If you are not having idle or starting problems, stay with the T4.

Sonic30ss

This is a good question, I'm in the same boat (pun intended).
Debating how/if to upgrade ignition on my twin efi Merc racing small blocks. I've been told by Teague that the MSD won't work with my early(87) efi setup. So I'm thinking maybe a good coil and cap/rotor/wires tune up is in order.
My question is does the coil have to be a certain # of ohms on the primary side so it will not burn up the stock Merc ignition box?
Some of the new coils have an arc so good you can almost weld with it, but they have a very low primary resistance.
Sorry no answers only more questions........................
Joe

mcollinstn

I've continued to hear the praises of the Hi6M. It has a BigBlock curve program in it, and I can't understand why it wouldn't work just fine for your mouse.

If not, you can plug it to a laptop and download whatever curve you want (guess you gotta get Crane software to do this though).

What is it about the BB curve that you don't like?

blown1500

I agree with mcollinstn. You might also look at MSD. MSD has a box that you can adjust almost every parameter of the curve without too much trouble. The curve that comes in the Hi6M looks pretty good for a mouse to me, but each application is different and that would be just a starting point.
Sonic30ss, Most ignition boxes like MSD-6's ,etc. go between the coil and the unit that signals the coil and I can nt recall not being able to use one. Get details. I'd like to know why it can't be done or try to help you do it.
The coil must be compatable and there many different ones out there. Consult your ignition manufacturere.

formula31

Im a strong supporter of the Crane Hi-6 and used it on my formula. I didnt use any curve at all and had the dist locked at 36 degrees. The multiple fire feature fires +/-20 degrees of the fixed timing at idle and below 2000 rpms so the first spark was effectively at 16 degrees at idle. Worked fine for me. I needed the Crane so my not stock engines would start and idle. Otherwise, I would still stick with the T4 for less than 5500 rpm.

TomR

I have the DUI set up and it has worked out very well.
Simple two wire hook up, nice clean package, can use stock cap and rotor if you want.
It will really clean up your engine compartment of all that rats nest of wires!!
You can add a plug in rev limiter if desired.
They will set the advance curve based on your setup.

Gary Anderson

I've had both the DUI anf Thunderbolt. DUI is very good and currently running on its 10th year virtually maintenence free. They do have a Marine cap.
I've also had very good luck with T4s. Unless you want to do a lot of tuning to get the last few hp, I would just stick with the T4. Definitely the easiest to find parts for.
Gary

BAD-HABIT

Well If I go with the Tbolt IV which module should I go with? I don't have my spec's with me right now but I think the Vortec motors like 30 degrees total when stock....Not quite sure though.....Any body know for sure....My motor will idle fine with 6-8 degrees initial....Does anyone have a good recomendation where I can purchase the modules besides here local.....

Bad-Habit

azlineman

What do you guys think about the Mallory HY-Fire VI AL or Jacobs ignition in a Thunderbolt IV application as well as Mallory uni-lite and MSD distributors. Thx.