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Jamesbon
10-23-2000, 08:13 AM
When changing over from my existing Teleflex guages to VDO's, I noticed a difference in the symbols marking the leads which protrude through the back of the instruments. Can I verify my following assumption with you? Please confirm or....

Additionally, each guage has it's own independent light bulb with a positive and ground lead, so the following would not apply to instrument back lighting.

"Upside down looking christmas tree" = ground
"plus sign" = obviously is positive power to the instrument
"S" = sender or wire from the sending unit

Spent Saturday making the boss happy (Kelly), then Sunday "went to town" on the GT. Installed the re-built Morse Shifter, new shifting cable, re-built the little Volvo shifter arm thingy on the back of the drive, started it twice in the driveway for two different friends, tore out all wiring under the dash, and started over. I just have three switches left to wire, all guage backlighting, and the tachometer. (hence my question on "symbols." Can't wait to get home today!!

GeneD
10-23-2000, 08:59 AM
You are right on with your assesment of the symbols!
Get it together big man.
I didn't do a thing this weekend.
I relaced my coil with the correct one. $27.50. Found out some interesting things, and let's see if anyone else has any comments on this.
I read that an automotive coil will not work on marine motors BECAUSE:
The input voltage on auto coils is 8 VDC, whereas the input voltage on marine coils is 12 VDC. Using the auto coil on a marine engine will burn it out.
Is this universal, or is it just a Mercruiser thing?
Forrest, any ideas?
After installing the new coil, I didn't notice the snapping noise back by the coil anymore. The RPM at idle went up 150 RPM's. It is not running any smoother, and I still have a lag when I nail the throttle. Not bad, but noticable to me. I wonder if the cam needs to be advanced. Doesn't advancing the cam tend to put out more RPM's in the high range?
I am still running the 10 BDC timing, and that worries me a bit.
So anyway, I spent the rest of the day waxing the Donzi, it's first wax job by the way. Then I went to the Corvette, and washed that. Noticed a bunch of scratches and wierdo stains. So I broke out the 1000 grit and went to town. I tell you what, there is nothing like buffing out a paint job and eying that glossy finish. I really get off on that.
Of course, after I was done buffing, I found out that I was late for Beer-Thirty.
I hate when that happens!

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GeneD
007
Melbourne, Florida

[This message has been edited by GeneD (edited 10-23-2000).]

Jamesbon
10-23-2000, 10:24 AM
I think you're on to something with the 8v and 12 volt coils. My friend converted from points to Mallory LED, then removed the voltage resistor and something fried out shortly there after. Furthermore he had to replace the coil and add a voltage resistor.....I'll add more as I find out.

I still have the voltage resistor in my set-up, but look forward to removing it....

Pat
10-23-2000, 11:14 AM
When I converted my '47 Willys from 6v to 12v. I used a coil with an internal ballast resistor (2nd trip to the store). You can get automotive coils with or without the ballast resistor. If you get one without (1st trip to the store) and do not have an in line ballast resistor, it will get very hot and will not last long.

Pat (CA)

rayjay
10-23-2000, 01:01 PM
GeneD,

I preface this with "usually", advancing a cam moves the power towards the bottom end of the cam's operating range and retarding a cam moves the power to the upper end of the cam's operating range. Retarding the cam closes the valves later, theoretically giving better cylinder filling further up in the rpm range, but may make the engine run as if you decreased the compression. Advancing a cam has the opposite effect, but I add USUALLY to everything.

Before you get into experimenting with this, or thinking that this may be the cure for whatever you feel is wrong, please spec out the position your cam is mounted in. Stock tolerances and production variances and variations can cause 2 - 3 deg differences. And then find out where the cam wants to be installed, i.e. straight up, advances x degrees, or retarded x degrees. You usually can not notice anything less than a 3 -5 deg change under normal running. But for example in drag racing, you may retard a cam to soften the bottom end in order to reduce tire spin and thereby get a better launch. Even though your mph at the end of the 1/4 mile may go down, you may get there sooner (have a better et.) because of the better launch.

There are cam sprockets (or cam gears for those of us with gear drives) that are "adjustable", allowing cam timing to be changed without taking apart the cam an sprocket for an offset key way or to use a different keyway on the sprocket that gives a different timing. Also. always remember to re-set your ignition timing as unless you have a crank triggered ignition, changing where the cam is set will change your ignition timing. rayjay

[This message has been edited by rayjay (edited 10-23-2000).]

Jamesbon
10-23-2000, 01:06 PM
MP,
Not sure what I'm gonna do with them yet. The tach is FUBAR, but everything else works. They're old...probably the originals?? (1971) Which ones are you looking for?

RickR
10-23-2000, 02:13 PM
Gene
I suggest
Taking 007 out running her hard to clean the plugs off
Let her cool down to normal operating temp
Then set the time by ear and see what you come up with.
Rubber gloves help, salt water sure is a good conductor http://www.donzi.net/ubb/eek.gif

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RICKR
mailto:riggerb@aol.comriggerb@aol.com</A>

Forrest
10-23-2000, 03:14 PM
Generally speaking, the ballast resistor drops the voltage across the points to around 8 volts. This is done primarly to extend the life of points. Also, another funtion is so that if the key is left on while the engine not running and the points happen to be closed, there won't be a dead short through the coil coil's primary windings. For years Mercuriser used a "resistor" wire that connects to the coil's "+" terminal in their wiring harness to avoid having a big 'ol ugly failure-prone ballast resistor hanging off the top of the engine. With this resistor wire, they still used a resistor bypass wire from the "I" terminal of the start solenoid to the "+" to provide full battery voltage to the coil while cranking the starter. Some automotive manufactures and possibly some marine engine manufactures used no ballast resistor or in-line resistor wire, but rather the used an ignition coil that had an internal ballast-resistor.

Now having said that, most electronic ignition systems have an operating range of 7.5 to 18 volts. The key thing with any electronic ignition system is to not let the supply voltage get to low. If the voltage drops to low, the spark quits and your engine dies. Furthurmore, even if the ignition switch is left on with engine not running on a (breakerless) electronic ignition system, there is no short circuit to ground. For that reason, the coil should not get hot due to current flow through its primary windings as is the case with closed points on a breaker-points ignition system. This is because the trigger system does not rely on making and breaking a mechanical contact to ground in order to create a change in current which induces a high voltage/low current into the coil's secondary windings.

Good luck!

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Forrest

[This message has been edited by Forrest (edited 10-23-2000).]

Blewbyu
10-23-2000, 10:20 PM
Madpoodle-I have no idea what Hatuey is,but I have a complete set of Teleflex gauges from my '74 X-18.They have black faces with silver (painted)bezel edges,white numerals with blue lines.Includes:Tach,speedo,fuel,oil pressure,water temp and voltmeter.I was about to "86" the whole works.If you want 'em,they be yours fer free if you cover the shipping.E-mail me if you want 'em.I do procrastinate a bit-may take me a bit to get them to the mail/Fedex place-but what th' H?The price is right???? They all work.BR-Jeff

GeneD
10-24-2000, 08:20 AM
Forrest,
I dug everything you said. But unless I missed something, I don't think you addressed the Merc situation adequetly.
I know all about internal and external resisitors for the coils, I've been there, MANY times in the past.
My old Pacemaker had Crusader 350's, with points type ignition, and so does my Trojan (318 Chryslers).
When first starting out with my own 'yacht' as a young man (22), I found out rapidly about the internal vs external. Being a car guy for years, I never would want to go and blow the money for marine parts. So I would go and get the auto equivalent and change parts "often". Finally wised up and now I only buy 'marine only' unless it's an emergency.
It was my inderstanding at the time that the external/internal resistor was to prevent points burn-out. After blowing a few coils, I decided to go with the externals, and rarely had a problem after that.
On marine, I understand the concept of an exposed "ballast resistor" coil in a closed engine compartment. A definite no-no.
The Crusader external resistor was nothing more than a condensor type thingy that connected to the coil terminal. The Prestolite ignition on the Trojan takes a different approach and uses a sealed ballast resistor (that gets very hot) inserted into the hot lead.
My latest coil emergency occurred in August, just prior to my catatrophic motor "breakage". There wasn't a marine joint close by, so I bought an Accel Universal coil. I figured, with the knowledge I gained from the Pacemaker's ignition, that the universal coil would have the internal resistor and I would be fine.
(though it didn't say a thing about internal or external on it)
Well, sure it did work, but only for a short time. This is when I started doing some research into the marine vs auto coils.
Some web site somewhere said to NEVER use an auto coil on a Merc because of the voltage difference. When I read that, the light bulb came on and I immediately envisioned a coil conspiracy in the marine industry. Seeing how the internal resistor coils worked on my Crusaders, and not on the Merc.
See what I mean?
There is no way there is a resistor wire going to my coil on my Merc unless they are using some kind of space age copper. It is a plain old wire, the purple one (2 purples acutally, one from the harness, and one from the computer). So I have to figure that the coil is special in some way, no?
I guess my real question is:
Does Mercury spec a special coil that requires a full 12 VDC coming in to operate the computer controlled ignition?
Sorry to come off being stupid sometimes, I just need the reassurance of the board every once in a while when I'm out of my mind. It helps to have others back up what you are thinking when you are not really sure what the feak is going on.
Know what I mean Vern?

PS: I jsut re-read Forrest's treatise on the coils and realized that I read it too fast. I see where you're going with this now. I'll leave my ramblings up here for future laughs, but riddle me this Batman...is there a voltage drop in MY harness coming from the starter solenoids? I don't think you addressed the Thunderbolt IV ignition.
Inquiring minds need to know!
How about them Jets huh?

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GeneD
007
Melbourne, Florida

[This message has been edited by GeneD (edited 10-24-2000).]