General MSD 44 setup questions

Hi guys.

Still chasing MSD 44 ignition problems, though beginning to think we have a duff points box and coil. A fellow UK racer has kindly agreed to let me borrow his (He is a member of this board, thank you very much if you read this! )

He also mentioned about proper head-grounding for the MSD, and I wanted to ask others how they have their heads grounded on this board, and wonder maybe if the way we ground ours is too weak, or just plain wrong and not sufficient. I will get photos and quick write up of how we ground ours tomorrow.

Other things we are going to check is resistance of the leads (We are using the correct MSD leads set, but no harm in checking)

Their simply isn't anything else that could cause this lack of performance, at the moment it really has us beat and are running out of ideas.

 

Hi Mike;

The plug leads were fresh 12 runs ago (fresh over the winter). I'll make sure to get a new wire set for next year. We have a spare rotor and cap for the mag too so that will be replaced.

From the sounds of it we have the heads properly grounded. We haven't had any sorts of glitches or weird moments when the motor would feel like it's not grounded properly, so maybe we can tick that off as not a problem anymore.

We don't use a crank trigger, though a lot of racers have said it will be worth the investment.

As for what the car is doing, it's not doing anything particularly abnormal which is the frustrating thing; it's just slow at all of the incrementals.

Here is a list of incrementals (First number is supermags, second is pro mag 44):

60ft: 1.02 / 1.06
330ft: 2.85 / 3.07
1/8th ET: 4.39 / 4.54
1/8th ET: 161 / 152
1/4 ET: 6.85 / 7.17
1/4 ET: 199 / 191

As you can see it's consistency slower, yet it pulls the shift light through the top end and revs fine but their is a general lack of performance.

 

Joe

How much advance were you and are you running?

Martyn

 

we had a similar problem a few years ago that i chased for quite a while. i found the problem out to be with the rev limiter on the box. i had a high side rev chip in it that was too close to the shift point. make sure the chip is at least 800 rpms above the limit chip on your limiter. just another thing to look at.

 

A lot of replies. Here we go:

Martyn / Mike: We ran the supermags at 34 degrees and currently run the ProMag at 28.

Darren: We are running a points box without a rev limiter. A lot of people i've talked to have said about the rpm chip in the box being a problem; but ours isn't a box with a rev limiter so we'd have to rule that out too.

 

Have you tried bumpng up the timing a couple degrees? One thing I have noticed with a Promag 44 is that when you have a timing light on it the mark is 2-3 degrees wide. The fact that the car runs ok just a little weak could simply be that it needs a little more timing (or a little less). When I run mine with the crank trigger the timing mark is only one degree wide when I am looking at it but the mag trigger isn't that stable and the mark is considerably wider (more inaccurate). Dave Germain

 

What type of timing light are you using? I have read on here in the past that some lights don't work properly with the MSD mags.

 

Dumb questions;

1. Are we putting enough fuel in it now that you are burning it with good ignition? If in dought tip more in.

2. What are your plug gaps, what are your plugs?

3. Check phasing of cap to rotor

Cheers
P

 

Valvesprings

Double check your valve springs.

A couple years ago I changed blowers.

I checked the valve springs, they were good.
I made 1 run with the old blowers and all performed fine.
I put the new blowers on and it performed ok. I was fat.
I leaned it up and it performed better.
3rd run on new blowers, it sounded fine, ran smooth, no alky out pipes, but didn't run the RPM we thought it should for the setup.
Some of the intake springs were dyeing, that's all it was, but I changed, rebuilt and changed again all the ignition parts before I rechecked the springs.

Double check your springs.