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Flailing about with SUs after a motor swap. I have a few questions.

Yeah, you should be able to get it pretty smooth.

It's an art, not a science. An iterative repetition of cycles, hopefully with less and less change each time. It's just tricky because airflow affects idle mixture, and the two of them affect idle speed, which in turn affects air flow, which affects mixture...

It's been a long while since I had SU's on my PV's motor, I've had the DCOE's for a long time. Which are even more subtle to tune, because you're doing one cylinder at a time, not two (although perhaps a bit clearer in response because the bores are completely isolated - no crossover pipe in the intake).

And everything else has to be in good shape as well:
- ignition set properly
- no spurious low compression issues
- no flat cam lobes
- valves properly set

The last time I had lumpy idle issues and tried to fix them by fiddling with the carbs - it turned out to be a mechanical issue (cracked piston leaking compression on one cylinder). So just quickly check all that other stuff first:
- set valves
- do a compression check
- set timing and look at plugs
 
Adjusting it a flat richer on the rear carburetor did the trick. The mixture seems good looking at the plugs after a drive.

It has a bit of a lope to it. Kind of similar to my 240 when it was running a more aggressive cam. Definitely lumpier than the C cam in the B18.

Overall it is not too bad. I did notice it was idling a bit lower than I initially observed. Around 700 rpm so I raised it to 800 to 850-ish and it seems happy.

No problems with the compression. None of the cylinders stood out from one another. The cam lobes seem fine from looking at the lift at the rockers. The valve clearances are set properly. The plugs now all look like cylinder 1 and 2 from the photos I posted previously. The ignition seems OK but I am not sure how good my original coil is. The points are set properly and it is timed at 10 degrees BTDC. It right now has 87 in it so I haven't played with the base timing.

I am probably just overthinking it.
 
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Seems like it's ready to enjoy. Those original armored ignition coils do develop a weak spark as they get old. Mine was a bit weak on my car. Adding a pertronix helped a bit as that makes for a cleaner spark trigger making the voltage a bit higher so they claim. Plus I never miss points. Begone you contact burning wearing out failure prone witch.
 
Seems like it's ready to enjoy. Those original armored ignition coils do develop a weak spark as they get old. Mine was a bit weak on my car. Adding a pertronix helped a bit as that makes for a cleaner spark trigger making the voltage a bit higher so they claim. Plus I never miss points. Begone you contact burning wearing out failure prone witch.

Right now I think I will be saving up for a 123 distributor and a new coil to go with it. Or a new coil and an electronic hall effect contraption for the distributor currently on it. I was running the cast iron distributor with pertronix installed on the B18 but I found some bad wear in the mechanical advance system.
 
IMO, the best thing you can do for a carbed car is to run a really hot ignition. I know the benefits of an MSD are disputed, but when compared to original points/ballasted coil systems, it's so much better. I am running a pertronix module in a points dizzy, with dual ZS carbs, and an MSD Street Fire ignition box and I get far cleaner/quicker startups even with a 0.045" plug gap. The idle is amazing as well :). It's worth it for the idle and cruise improvements alone, IMO. Top end is irrelevant, because that's just hype they use to sell products.
 
I have an MSD 6A box on my PV's motor. And the wire I have it wired up, at least, it's easy to bypass (just remove the MSD output wires from the coil, take the inputs off the MSD and hook them to the coil, done), so you can easily do back-to-back comparisons. And it makes a noticeable difference. I used to think spark ignition was graded on a pass/fail curve. It either lights off the fuel/air, or it doesn't. And if it does - not much of a difference between 'barely' ignited and 'lightning bolt explosion happened' ignited.

But that's apparently not the case. With the MSD disabled, it's certainly not missing or misfiring, but with it working the engine starts noticeably easier, has noticeably more pep, especially at lower RPM's. Just feels somehow a bit crisper. How and why? Don't know. In addition to creating a much more powerful spark, MSD also produces multiple sparks at lower RPM's (MED = Multiple Spark Discharge) - so perhaps that does something as well. A crackle instead of just one snap?
 
Is there any particular way to check the condition of the coil I have in the car?

I am going to do some reading on the MSD 6A box.

As far as I can tell the MSD box works alongside the existing distributor (points or pertronix) and an aftermarket coil. I could also just go with the 123 system which would get more multiple timing curves to play with. Or just slap a pertronix unit on the distributor, put in a hot coil, and call it a day.
 
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Yeah, it just sits between whatever ignition system you have and the coil. You can run them from a points dist, or any of the aftermarket ignition systems. The wires that went to the coil get hooked to the MSD, and it now runs the coil.

I'm using it with a Crane optical ignition system. And an MSD Blaster coil. Just those two by themselves produce much stronger sparks. the MSD just amplifies it (and multiplies it too, I guess). Probably stronger than it needs to be really. I've burned a hole through the top of the rotor before.

Back when it had the original firewall mounted armored cable coil, you could pull the coil wire and set it 1/8" away from something metal, and crank the motor. And it would make thin, wispy looking blue sparks. Zip, zip, zip. Now it makes big fat nasty looking red sparks. ZZAP, ZZZAP, ZZAP. The sort of thing that make s you think it would *really* hurt if it got you.
 
It's not quite as easy to measure the primary on those coils but if you measure from the ignition switch to the distributor that would give you primary impedance. For the secondary you would measure from the switch to the coil tower. There are probably specs in the green book. You could also get a high voltage probe and measure the secondary voltage if the meter has a fast enough sample rate.
 
The old classic Bosch blue coil works very well. You don't need a ballast resistor for those so it's easier to wire in. There are probably Asian made fakes out there for the Bosch. So beware of that. I think Bosch makes them in Brazil now, possibly Spain, or Mexico.
 
The old classic Bosch blue coil works very well. You don't need a ballast resistor for those so it's easier to wire in. There are probably Asian made fakes out there for the Bosch. So beware of that. I think Bosch makes them in Brazil now, possibly Spain, or Mexico.

That is the one I was looking at.
 
I'd recommend a real Bosch Blue (3 Ohm resistance) from a reliable aircooled shop. I was running one for a few weeks and had no issues, but with the MSD I'd suggest a non-internally resisted coil. I'm using a stock Bosch black coil from a 1990 VW Golf, but I think the stock fuel injected volvo coil would work too. They're wound pretty tightly so put out a hell of a spark :). Something with a 1-1.5 Ohm internal resistance would give you the best bang for the buck.
 
The blue coil is the recommended replacement for the stock coil. The red one is considered a performance coil.
 
The blue coil is the recommended replacement for the stock coil. The red one is considered a performance coil.

I've got a lead on a good condition red coil for a decent price. Would it make sense to just to jump on that and upgrade it while saving up for a 123 or pertronix unit?

I am aware that with some setups I would need a ballast resistor.
 
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Make sure you buy a high quality ballast resistor. Like an OEM one. I ended up using two of the stock 240 ones in series. They are each .9 ohms and you need 1.8 for those coils. So two in series give you that value. At first I tried an Accel one which burned up with all the heat from the current.

When I did this on my 240 turbo I ended up going back to the stock setup. The red coil didn't run as well and then I noticed it leaking. So, that was the end of using the red coil.
 
Make sure you buy a high quality ballast resistor. Like an OEM one. I ended up using two of the stock 240 ones in series. They are each .9 ohms and you need 1.8 for those coils. So two in series give you that value. At first I tried an Accel one which burned up with all the heat from the current.

When I did this on my 240 turbo I ended up going back to the stock setup. The red coil didn't run as well and then I noticed it leaking. So, that was the end of using the red coil.

It would appear that Bosch made 1.8 ohm ballast resistors. Part number 0 227 901 014. From what I've read it is supposed to go with the red coil and were used on Mercedes.
 
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