Reading Spark Plug

General engine tech -- Drag Racing to Circle Track

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MELWAY
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Re: Reading Spark Plug

Post by MELWAY »

Tuner wrote: Sun Oct 28, 2018 7:55 pm Heat range 5 for street and perhaps 6 for the track.

You are using too much manganese additive. Back off about 1/3. How much are you using now, ounces additive per gallon of fuel?

The MMT makes the orange color on the plug and the too-hot plug ceramic fires the metallic to a shiny glaze, same as coloring or glazing pottery, when it goes in the furnace it looks dull and flat and after "firing the glaze" it comes out shiny because the heat melts the metallic and it flows out smooth and shiny.

With MMT it is normal to see a light tan color, but when it starts looking a wet brick orange color it is an indication of too much.

Tuner
What are the negatives of too much octane booster?
Is it safe to run with Nitrous
I’ve been building a 440 sbf with 13.5 comp. we drag race it on pump gas with double dose of octane boost. Engine runs well
Now setting up a 250 hit plate system that will run VP C23 in plate
3370lb Sedan 9.89@136MPH 358chevN/A
Firedome8
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Re: Reading Spark Plug

Post by Firedome8 »

wilson1970 wrote: Mon Oct 29, 2018 5:31 am I had been using 2oz. Per gallon bringing octane to 95 or so. The thing ran just fine after a hard run. One time last week took it for a drive in the AM air was really cool and crisp and
above 5800 it went bump bump like a miss but not a miss it kept pulling. I then shifted and backed out. Lean maybe??
Put an o2 bung in the exhaust and do some pulls on a chassis dyno. Can not hurt and you may find something.
A good test is worth a thousand opinions.
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Re: Reading Spark Plug

Post by Fireonthemountain »

MELWAY wrote: Sun Apr 14, 2019 7:53 pm
Tuner wrote: Sun Oct 28, 2018 7:55 pm Heat range 5 for street and perhaps 6 for the track.

You are using too much manganese additive. Back off about 1/3. How much are you using now, ounces additive per gallon of fuel?

The MMT makes the orange color on the plug and the too-hot plug ceramic fires the metallic to a shiny glaze, same as coloring or glazing pottery, when it goes in the furnace it looks dull and flat and after "firing the glaze" it comes out shiny because the heat melts the metallic and it flows out smooth and shiny.

With MMT it is normal to see a light tan color, but when it starts looking a wet brick orange color it is an indication of too much.

Tuner
What are the negatives of too much octane booster?
Is it safe to run with Nitrous
I’ve been building a 440 sbf with 13.5 comp. we drag race it on pump gas with double dose of octane boost. Engine runs well
Now setting up a 250 hit plate system that will run VP C23 in plate
Slow versus fast. Too slow and the pop is not happening in the right time frame, and too much octane will cause this. Too fast and you get detonation, and less power as it happens too soon. This is all true whether supercharged, or nitrous, or not.

Like time or fuel mixtures octane has to be in the correct window of ranges, to get the best results.
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