I just measured resistance on both coils. My meter indicates that both coils are 1.5 ohms on the primary - above .72-.88 spec, but that may be a meter issue. The Diamante coil secondary reads about 500 ohms less resistance than the Montero coil - both well within spec range, but the difference may explain what I sense in better starting and idle quality with the Diamante coil. That would seem to suggest that I should try a little longer dwell time.

I think I'll take my meter to AutoZone and measure the Beck-Arnley and Duralast coils they have in stock and see if the primary resistance is lower than what my coils measure.

Frank

I've never seen one. I looked around and found these while edicatin meself on henrys and counting same:

"pretty good LC meter"

and:

LC using frq shifted oscillator

I might as well been asleep...thought he said "inductive ammeter" on the primary wire. I have no henry-meter, never even heard of one.

One henry of inductance(1H) makes one volt of counter-force(cemf) when current changes at rate of one amp per second.

Inductance can be measured with meter or the AC-Bridge method

Hehe.... I think I'll pay Sears a call on my way back from AutoZone - take the coil in and ask for a demonstration:

LCR Meter

Frank

Only people I could think of having an LC meter wouls mbe a Ham radio operator. The MFJ 259B model might be able to do it. (RF generator, SWR meter, Freq. meter & inductance/reactance all in 1)

It's meant to measure feedline & antenna properties in a standalone situation. Also can be used as a Dip meter.... Found me real quick...LOL

Ed

I was hoping to find an LCR meter at Sears, but they're special order only. I did test both of my coils again and found the reason they measured 1.5 ohms.... there's .7 ohms resistance in the probe wires and connections that the meter only reads intermittently.... so they're both good.

When I increase the dwell allowance to 3.5ms in MS, the ECU will show only 3.1ms on the display. It does allow slightly longer dwell on cranking, but once the engine starts, it goes straight to 3.1 and stays there. There must be a sense circuit in MS that decides when the coil is saturated. It looks like I have some more learnin' to do.

Exhaust - never thought this would be so difficult to get done. Went to the shop on Monday and asked for a 2.5" system. After putting the truck on the rack and taking some measurements, they said they had no muffler that would fit the space. So, an 18" (length) round Dynomax was ordered.... went back this morning to have it installed - after some more fiddling, it was decided that muffler wouldn't fit either. So, an oval shape reversible style Dynomax has now been ordered in hopes it will fit. There's not a lot of room for anything that not's too loud.

Frank

Frank, do you have an avionics tech around the airport? My son says they should have an LCR there, if you still need it. Tell them an Embry-Riddle avionics grad sent you...

Eddy, I don't know any, but I'll snoop around. Thanks!

Frank

I am assumming that you want to increase dwell. So do the math and put a resistor on the brittle wire. You will get less secondary voltage but maybe you can compensate for that...or so they tell me

"The dwell period on an engine with electronic ignition is controlled by the current limiting circuit within the amplifier or Electronic Control Module (ECM). The dwell on a variable dwell or constant energy system will be seen to expand as the engine speed increases, compensating for the shorter time period.

The term æconstant energyÆ refers to the available voltage produced by the coil. This, regardless of engine speed, will remain constant as opposed to contact ignition where an increase in engine speed means the contacts are closed for a shorter time period. The coils saturation time can be seen on Fig 1.4, where the time available to saturate the coil is a constant 3.0 milliseconds regardless of the engine speed. The saturation time is considerably lower than that of a contact system due to the coils supply voltage being approximately double that of a ballasted contact system and the coils primary resistance approximately halved. This will result in a far higher current, saturating the coil with amperage that would not be possible on a contact system."