351c hotter spark plug p/n's?

6663a · 06-11-2008, 10:31 PM

I was told to get a "hotter" spark plug to help pass emissions. Engine is a '70 351c with a mild cam and 2 barrel heads. I was real close with a Demon 500 cfm 2 bbl and a guy told me to have the timing at 12 degrees and get hotter plugs. I am currently running stock Autolites. What is the next hotter plug part # and/or will using platinums help at all too? Also have pertronix electronic ignition, MSD 6, and TFI coil. I believe the main reason I failed was that my timing was only about 6 degrees.

Thanks, JR

67mustang302 · 06-11-2008, 11:24 PM

Bump the timing. Hotter plugs won't help with emissions unless they're so cold they're fouling. What do they look like? Post pics.

6663a · 06-12-2008, 09:18 AM

The plugs are fairly new and when I pulled one out it was still like new with no fouling. I'll go over the timing again and lower the jets on my 2 bbl.

JR

65Coupester · 06-12-2008, 10:42 AM

With your ignition upgrades you should have the plugs gapped at 40 to 45.

Might throw in a 190* thermostat for the test, but keep the stock heat range plugs.

Was the problem hydrocarbons?

Fordication · 06-12-2008, 03:53 PM

Hold on folks. That car is 40 years old. There are no emission requirements. What state is this?

Fordication · 06-12-2008, 03:55 PM

Here are the requirements for your state. Go back and tell that SOB to give you a sticker or you will report his arse.

Historic and Collector Vehicles
Vehicles 25 years old or older ("historic" vehicles) or collector vehicles that are essentially used only for exhibition or parades are exempt from general inspections. However, a State Inspection Station will need to verify the odometer reading for a $25 fee (this fee goes down to $10 for a renewal).

Derf00 · 06-12-2008, 04:00 PM

Quote:

ORIGINAL: Fordication

Here are the requirements for your state. Go back and tell that SOB to give you a sticker or you will report his arse.

Historic and Collector Vehicles
Vehicles 25 years old or older ("historic" vehicles) or collector vehicles that are essentially used only for exhibition or parades are exempt from general inspections. However, a State Inspection Station will need to verify the odometer reading for a $25 fee (this fee goes down to $10 for a renewal).

Read the OP, the ENGINE is a 1970 not the car. Depending on what year car the engine was installed in, the car is still held to the same emissions requirements or modified onesas the year of the vehicles body/frame/vin, not the engine's.

What model year caris listed for your registration?

If you go hotter plugs you will need to retard your timing to keep from detonating.

6663a · 06-13-2008, 12:29 PM

Quote:

ORIGINAL: 65Coupester

With your ignition upgrades you should have the plugs gapped at 40 to 45.

Might throw in a 190* thermostat for the test, but keep the stock heat range plugs.

Was the problem hydrocarbons?

Yes, it failed hydrocarbons. CO was very low. I am replacing the converter on the vehicle because it's 10 years old and the insides are rattling like rocks in a tumbler. I'm sure that will help me plus the timing adjustment.

JR

6663a · 06-13-2008, 12:35 PM

Quote:

ORIGINAL: Fordication

Hold on folks. That car is 40 years old. There are no emission requirements. What state is this?

Sorry, I neglected to mention the engine is in my 1980 Jeep J-10. So the engine has to pass 1980 emissions standards which it has in the past. Just having a little more difficulty than usual. I'm in the wonderful state of NJ where I can keep bringing it back and it doesn't cost me a dime unlike my neighboring state of Pa.(can you say RIPOFF!!).

BTW....thanks for all the suggestions so far. I'll have another appointment next week so I'll keep you posted what I did and how it turned out.

JR