Crane XR700 or XR3000 - MSD

I am about to replace the points with Crane's infra red set up and have been unable to find much of a difference between the two systems, (other than the 3000 not requiring a balast resistor on the coil). The cost difference is small.

I also have a pair of MSD-5 boxes. Does anyone have any experience using a crane system WITH MSD???

I recently failed two smog checks with 2000+ PPM HC, one smog pump feeding two headers and no thermal reactor & new plugs. got 155-165 psi compression and 1-2% leakdown. So, the shop suggested the crane set up. (Personally, having 0 experience troubleshooting Webers, I am concerned about float levels or leaking cold start devices).

I have cruised the archives on crane set ups and carb work and am leaning toward getting the ignition in "better than new" condition before tackling the carb issue. Fortunately, the shop that sold me the car is responsible for getting the smog done, (don't ask me how it can be done with olny one pump, no thermal reactor, evaporative junk, low speed RETARD or cold start fast idle mechanism). I suspect that a pass on the tailpipe emissions will get the "job" done.

BTW data: 77 GTB with 23k miles, 13.5 mpg on the freeway at cruise, very poor low speed performance esp hot, pulls strongly to redling from 2500-3000 rpm. current set up - 140 mains,200 AC, F6 tubes with 60 idles flowmaster exhaust, K&N. and cd player.

any comments or advice welcome.

thanks,
chris

 

Thanks Mike. Will do the float check.

Hey 308GTS what is the cross talk stuff? is it enough of a problem to outweigh the "advertised" upgrade???

Careaper, Maybe cruise the general forum & find a stock is best purist/restorer to cherish, (buy) your old ignition stuff.

Just in case, does anyone have a good source for cap, rotor & good wires (without the hype-$$$$$$$$)?? I've heard about Chrysler truck wires, magnacore ect, ect.

thanks,
chris

 

Yes, this sure does sound like a carb problem, (way rich). One of my reasons for going to the crane is to eliminate the points, (they are an antiquated, high maintenance item).
On my trip to santa barbara, i would very occasionally experience a stacatto, (1-3 or 4 beat) engine miss. It didn't seem to be associated with any specific rpm or throttle opening. The car scoped fine, (they said). it wouldn't come into adjustment, 2000 PPM hc. fouled plugs were replaced, same problem, carb balance was good and the car ran well above 2000 rpm.
On the return trip, mileage was around 13 and during the last 50 miles, i noticed a much greater frequency of the stacatto miss syndrome. No apparent loose wires or connections.

So, before the car rides back to santa barbara on a flat bed to have the smog done, i want to have the ignition squared away before they work on the carbs. (There was some problem with the dealers original smog, so i left the car with him for a day and he couldn't get it done, so he agreed to have the car brought down and back on a flat bed).

I'd like to up grade the car's maintenance items as time progresses. I'm not looking to throw money at the problem, but rather have seen two situations develop so far:
1) When work is started on the car, I frequently find that something else is needed to finish the repair, (like when doing the front a arm bushings, i found a small tear in the lower ball joint boot, so the car had to sit while i ordered the BJ).
2) The "AS LONG AS" syndrome - While doing the a arm bushings, i found that with the a arms and spring/shock out of the way, it looked like the brake lines would be really easy to replace, and the steering rack gairters looked a bit weepy, so while i'm in there why not do them as well - you know the drill - the car sits while more parts are ordered.
SO, i'm learning to do two things, plan for the worst case scenario and look at what else might be more easily done while doing the repair and to have as nearly as poossible, all of the bits and gubins at hand.

So, does anyone know if the crane 700 will work with an msd box?

Is the hypo or improved coil worth doing? (I'm inclined to put two in when the dist is done just because the originals are almost 30 years old). Ditto wires. The extenders were done at 3 months ago.

Some time in the future, i would like to investigate installing a vacuum advance on the dist with the two new crane "points". (The po installed both high speed ppoints in one dist and installed two msd boxes).
This is the first "modern" car i have seen WITHOUT a vac advance.

Spasso - the engine looks outstanding, definitely shows care. Aeroquipping the fuel lines looks like an excellent idea.

With regard to removing all of the evaporative stuff - don't the tanks need to "breathe", that is, take in a bit of air to replace the fuel that is drawn out, so a vacuum isn't created?? Additionally, as the car is driven, or if the car sits in a hot place, doesn't the fuel expand?? It doesn't seem that it would develope enough presure to do damage, but a bit of pressure relief might be good. I had a couple of original evaporative lines puke a bunch of fuel out after a fill up. scared the s**t out of me and i over reacted and removed the stuff. So, i need to address some kind of venting/breathing.

Mired in ignorance,
chris

 

Dave,
This is a lot of surmise about the two systems:
The msd allows a much smaller, (triggering), current to pass through the points, thus reducing the point related wear, but still having stock rubing block wear, which requires checking dwell and adjusting the timing for drift), and, i think, generate a multipul signal of higher, (than stock) voltage to the coil, which then multiplies the voltage into a multipul, BIG sparks/firing event.
I suspect that the crane system not only replaces the points as a triggering device, (without the wear), but also multiplies the primary voltage to the coil, thus yielding a higher final voltage potential at the plug.

Can I use the crane to eliminate rubbing block wear & point erosion AND use the MSD to achieve even higher final potential and multipul spark fireing per cycle??? (I want it all).

I will contact MSD tomorrow with this question.

What can we do to make the 308 as strong and reliable as current technology allows?????

with a fair amount of humility,
chris

 

Dave,

Had a very informative discussion with Frank at Crane's tec line about the ignition system. He made the following points:

1) Two XR3000 systems cannot be used because of "cross talk", this is still a problem because of the interference between units with a "saturation" feature. This is not a problem with the 700 series.

2) He recommended using the optical trigger assembly # 715-0020 as a points replacement only without the black box and the 700-2231 installation kit, which has the shutter and misc parts. This optical points replacement is designed to send a square wave signal to the MSD box directly.

3) The MSD box has a multipul spark per firing stroke as opposed to the standard ONE. additionally, the MSD box has a higher current, (both volts and amps) than the xr700 black box, so this is a more powerfull system combination

4) Most american made replacement coils, of the oil fill type, are not completely filled and so when installed in a horizontal position may experience overheating/burnout. his recommendation for a replacement was the LX91 epoxy coil, (not a stock looking unit) which is not position sensitive and offers higher output.

5) The optical trigger needs 1.5 to 2.0 volts NOT 12volts, so a resistor is required. The instructions which can be downloaded contain echlin and other specific part numbers for this.

With the taylor spiro wires and separators, two coils and the above mentioned triggers and mounting kits we are probably looking at $350 in parts from Summitt. I will post part numbers and prices when i get this sorted out.

regards,
chris