[Fast4Eye]

I've been told that I should run a heat range colder than stock to avoid detonation.

I can't figure out the part number for plugs that fit an e6 head that are a step colder. Is it even worth it or just use motorsport plugs? If I should go colder whats a good plug to use?

 

[96pushrod]

Depending on how much boost and the rest of the engine you might want to go 2 steps colder. Definitely at least 1 though

 

[SNK VNM]

Parts Finder

www.autolite.com

5144?

 

[Fast4Eye]

I already know that the platinum and iridium stuff is pretty well a waste of time and to stick to copper.

I'm a little confused what the difference is between the "254x" spark plugs and the "514x" plugs. But I'm seeing that a 5144 or 5143 would be what I'm looking for, thanks guys.

 

[SNK VNM]

Half thread vs full thread.

 

[Fast4Eye]

Half thread vs full thread.

Whats the difference? Lol.

more thread engagement so they don't go to orbit under boost? Or like better grounding?

 

[SNK VNM]

 

[Fast4Eye]

Alright, so the last question. 5144 or 5143. I know that going too cold is bad so should 1 heat range suffice? Like I've mentioned before its an e6 headed 86 block. Stock cam, flat tops etc. With the stock vortech 8 rib pulleys should I only need to drop a single heat range?

 

[SNK VNM]

5144, you could always pull them and check to see if you really needed 5143.

 

[96pushrod]

The reach on a 5144 looks way too long.

 

[Fast4Eye]

The reach on a 5144 looks way too long.

The reach is the exact same, .708. Looks good to me I was gonna order up some.

 

[pkstang]

Autolite 25 Naturally Aspirated

Autolite 24 1 Heat Range Colder

Autolite 23 2 Heat Ranges Colder

you're in canada, so you can't go by what people in florida are running as you want the coldest plug that you can run until it starts to affect your drivability at which point you go up one heat range.

 

[96pushrod]

The reach is the exact same, .708. Looks good to me I was gonna order up some.

I would’ve thought e6 heads used short reach plugs.

 

[Fast4Eye]

Autolite 25 Naturally Aspirated

Autolite 24 1 Heat Range Colder

Autolite 23 2 Heat Ranges Colder

you're in canada, so you can't go by what people in florida are running as you want the coldest plug that you can run until it starts to affect your drivability at which point you go up one heat range.

If you don't mind me asking, what does my location have to do with the plugs? Air quality or density? I just don't understand what the correlation between southern Ontario and Florida is in relation to plug heat ranges.

 

[Fast4Eye]

Before I place this order, should I be getting 1 or 2 steps colder. I'll probably be about 12# of boost since I'm on the stock V3Si pullies and a power bypass kit. Will 2 steps be too cold?

 

[pkstang]

it's a stock cast iron head, so i'm hoping whoever is going to be tuning this thing won't get greedy or dumb. 1 range colder is probably more than enough although best is to read plugs, or not get greedy or dumb.

your season up north is shorter and overall colder, so you will see drivability issues sooner than someone in the hot climate.

Cobourg Climate, Weather By Month, Average Temperature (Canada) - Weather Spark

In Cobourg, the summers are comfortable; the winters are freezing, snowy, and windy; and it is partly cloudy year round. Over the course of the year, the temperature typically varies from 15°F to 74°F and is rarely below -3°F or above 80°F.

weatherspark.com

Tallahassee Climate, Weather By Month, Average Temperature (Florida, United States) - Weather Spark

In Tallahassee, the summers are long, hot, and oppressive; the winters are short and cold; and it is wet and partly cloudy year round. Over the course of the year, the temperature typically varies from 41°F to 91°F and is rarely below 26°F or above 96°F.

weatherspark.com

 

[Fast4Eye]

Makes sense and I'll trust your wisdom lol.

I'll go with some autolite 5144's, and the tuner is very, very reputable closer to Toronto, all the fox guys near me swear by him pretty well.

 

[Ilusivefox]

What is the part number of the existing spark plugs that were in these 86 heads you have or took out? A 5144 doesn't even look close to what should be in there.

 

[Fast4Eye]

What is the part number of the existing spark plugs that were in these 86 heads you have or took out? A 5144 doesn't even look close to what should be in there.

I currently have the 86 specific motorcraft plugs. The autolite equivalent is a 2545 with a half thread. The equivalent in an autolite full thread is a 5145. The last number is the heat range so going down one heat range would make it a 2544 / 5144.

If the car was stock I would just get the motorcraft replacement but I need a slightly colder plug and autolite is pretty good quality by the sounds of it.

All the specs check out like the threads and the reach so I think it should be good, I'm going to get the full thread over the half thread because why not and its easier to find.

 

[Ilusivefox]

You can't put a full thread plug in a cast iron e6 head. Needs to remain a half thread. The piston would hit the spark plug with a full thread plug in there.