Bosch PLATINUM+4

The Bosch don't measure up to the Denso or other Toyota OEM plugs.

Not sure I would switch to a full synthetic at 200,000 miles (or kilometers). Try a synthetic blend 10W-30 or 10W-40.

In news: snipped-for-privacy@4ax.com, Huang Chung being of bellicose mind posted:

I tried a set in my ol 1990 Geo Prizm. When new, the firing voltages were in the 7-9kv range. Next time I put the car on a scope, the plugs had 15k miles on them. All firing voltages were 30kv +/- 3kv. That's a lot of change and there was detectable, sporadic misfiring during warm-up.

No fuel mileage increase or any other driving improvement noted from their installation.

Spend your money on platinum tipped conventional sparkers.

As for synthetic oil, again, I ran Mobil1 in the Prizm from 10k miles until I sold it with 285k on the odometer. Oil consumption was a bit better than 3k miles per quart of 10w-30 wt. Engine was clean as a whistle inside (4-5k mile oil change intervals). I'm also running Mobil1 10w-30 in my 2003 Corolla. This car currently has 36k miles on it and uses almost no oil between oil changes (5k mile intervals).

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- Philip @ Maximum Torque RPM

SNIP

When I bought my 93 Camry, used, last year, I flushed the engine and put synthetic oil in the engine at 238,000 kilometers. It runs great. Mileage is irrelevant. Provided the engine is in good condition.

JP

why do the voltages go up? Is that because the wear on the plugs requires the computer to increase the voltage to bridge the (increased) gap?

In news:Ksz_b.124664$ snipped-for-privacy@twister01.bloor.is.net.cable.rogers.com, Lance being of bellicose mind posted:

(Lance)

Firing voltage is STRICLY a function of resistance across the gap. Four things increase required firing voltage:

1) Larger gap 2) Rounded electrodes (more votage required for electrons to push off a rounded surface) 3) Greater air presure within the cylinder. 4) A drier fuel mixture (ie, comparing gasoline to LPG, all else being equal).

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- Philip @ Maximum Torque RPM

the computer must be sending the signal for the higher voltage in your second measurement in order to compensate for the increased resistance (increased gap, rounded electrode etc etc) that is limiting the current.

voltage does not change for this gap unless it is changed at the source. am i correct?

The voltage goes up because of physics. A higher voltage is required for a electrical circuit to bridge across a larger gap. When the primary voltage in a coil "collapses", the energy generated in (transferred to is probably a better term) the secondary windings has to go somewhere. The voltage builds in the secondary winding until the energy can be dissipated. As long as the secondary insulation is in good shape, the voltage builds until it can bridge the spark plug gap. A larger gap requires a higher voltage for the circuit to bridge the gap (all other things being equal). If the gap is too large, the voltage may build to the point that the circuit is completed through some other component (i.e., through the wire insulation, or arcing inside the distributor, or by arcing inside the coil).

References:

Regards,

Ed White

You are not correct. See my other post. The computer does not directly set the secondary voltage. The voltage generated in the secondary is a function of the coil design, the saturation time (how long voltage is applied to the coils primary), the quality of the secondary insulation, the spark plug gap, the shape of the spark plug electrodes, the conditions in the combustion chamber around the spark plug, etc. The computer controls the amount of time the primary side of the coil is charged, and when the circuit on the primary side of the coil is broken, which leads to the collapse of the magnetic field. This generates the high voltage in the secondary side of the coil. How high this voltage goes is controlled by the nature of the secondary circuit, not directly by the computer.

Regards,

Ed White

In news:gPA_b.124836$ snipped-for-privacy@twister01.bloor.is.net.cable.rogers.com, Lance being of bellicose mind posted:

news:Ksz_b.124664$ snipped-for-privacy@twister01.bloor.is.net.cable.rogers.com,

Lance. FORGET THE DAMNED COMPUTER. The only thing the igniter unit can do is minimize the length of time the spark is maintained across the gap. THE DAMNED COMPUTER cannot determine firing voltage.

One more and final time: The four conditions I mentioned previously determine the required firing voltage.

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- Philip @ Maximum Torque RPM

wow phillip, are you one of those who beats their children when they don't understand you?

you seem almost agitated at my curiousity.

Hi Mr. White,

thank you for that very good explanation. i understand completely.

am

the

the

shape

around

side

coil is

the

is

computer.

In news:V7O_b.4124$ snipped-for-privacy@news04.bloor.is.net.cable.rogers.com, Lance being of bellicose mind posted:

news:gPA_b.124836$ snipped-for-privacy@twister01.bloor.is.net.cable.rogers.com,

(Lance)

Think about what you've been told .... instead of asking the same thing twice, expecting to get the answer you can memorize and not think about. I'll hurt ya by making you think. ;^D

--
- Philip @ Maximum Torque RPM

Both Philip and Lance are correct when looking at case from two different points. Anyway, Philip's explanation is found on page 9 of Toyota technical document "Distributor & Distributorless Types"

Simultaneous Ignitions? Secondary coil will spark two spark plugs. Now voltage applied to each spark plug is a function of the factors Philip has mentioned (from electrical engineering point, spark plug will act as discharging capacitor)

Back to electrical engineering: Coil is a transformer which "is an electrical device used to convert AC power at a certain voltage level to AC power at a different voltage, but at the same frequency. The construction of a transformer includes a ferromagnetic core around which multiple coils, or windings, of wire are wrapped. The input line connects to the 'primary' coil, while the output lines connect to 'secondary' coils. The alternating current in the primary coil induces an alternating magnetic flux that 'flows' around the ferromagnetic core, changing direction during each electrical cycle. The alternating flux in the core in turn induces an alternating current in each of the secondary coils. The voltage at each of the secondary coils is directly related to the primary voltage by the turns ratio, or the number of turns in the primary coil divided by the number turns in the secondary coil. For instance, if the primary coil consists of 100 turns and carries 480 volts and a secondary coil consists of 25 turns, the secondary voltage is then:

secondary voltage = (480 volts) * (25/100) = 120 volts.

A transformer may have multiple secondary coils to feed a number of electrical loads; however, power must be conserved, so the sum of the output power must equal the sum of the input power minus losses. Energy losses in transformers are due to a number of factors: these are copper losses in the coils themselves due to material resistance, core losses due to hysteresis (the reluctance of the material's magnetic domains to reverse during each electrical cycle), and eddy currents."

;^) So THAT's how a clock works! Now ... could you tell me what time it is, please? ;^)

--

- Philip @ Maximum Torque RPM

In news:x_T_b.39820$ snipped-for-privacy@bgtnsc04-news.ops.worldnet.att.net, IceMan being of bellicose mind posted:

news:gPA_b.124836$ snipped-for-privacy@twister01.bloor.is.net.cable.rogers.com,

news:Ksz_b.124664$ snipped-for-privacy@twister01.bloor.is.net.cable.rogers.com,

news:wPr_b.6232$ snipped-for-privacy@newsread1.news.pas.earthlink.net...