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Topic Review (Newest First)
12-01-2012 04:16 PM
Richiehd I think that shorty plug is for angle plug heads, with headers.
12-01-2012 08:33 AM
66GMC

The only "shorty" plug for 75-79 Camaro with a 350 that I have been able to find is an Accel #0276S-4 on Summit

I have checked the NGK c/ref chart, and it's not there.
0276 (without the "S") crosses to a UR5 (one heat range colder than UR4)

I've copied the relevant pages and attempted to highlight the info from the NGK catalog. See attachment
11-28-2012 11:00 PM
cdminter59
spark plugs and gap

Jason, call NGK tech line, the phone number is in post #7. Tell them you want the V Power UR4 in a short plug. According to their website a 1971 Chevrolet Camaro uses a UR4 plug. Their short plugs is suppose to be about the same as Accel shorty plugs.
11-26-2012 05:55 AM
JasonL
thanks

Thanks for the replies. So the Autolite 146 looks like its no existant now. So I dont have dome pistons since my cr is only 9:1, this is a street car not a track car. There are autolite 26's in there but there was a big elgin cam in the motor that I took out.

So what is a solid recomendation for a plug for me? Is there a shortie plug that will work to give me more header room? Thanks Jason
11-26-2012 12:00 AM
cdminter59
Spark plugs and gap

No, there are indexing kits you purchase that has different size shims. Here is an article on indexing your spark plugs. http://www.hubgarage.com/mygarage/su...ng/blogs/10030
11-24-2012 10:39 AM
ChevroletSS
Does anyone know what kind of washers to use on spark plugs to h

Does anyone know what kind of washers to use on spark plugs to have the plug slightly favoring the exhaust valve. Can I use regular washers or lock washers???
11-23-2012 12:42 AM
cdminter59
spark plugs and gap

Nothing like making sure of what you have. Didn't take you long at all to figure it out. Like I said just watch the extended tip R45TS if you have dome pistons. If you like Autolite get the Autolite 146. NGK-YR5.
11-22-2012 09:11 AM
JasonL
numbers

ok, my head numbers are as follows
8991492
J143
GM53

so I assume that J143 = Oct 14, 1973 ?????
tapered plug?
11-21-2012 05:11 PM
Richiehd There sure are many different theories here. I was always taught that .035 gap for points ignition and bigger for Electronic. That was one of the advantages of HEI. I have always used a .040-.045 gap when using a HEI ignition, thus more spark, more burn time. Back in the day of smog motors we had gaps of .060 and even .080 with HEI and stock coils capable of 65,000 volts or more. Im just saying....
11-21-2012 03:33 PM
cdminter59
spark plugs and gap

Jason, The easiest way I know is to pull a valve cover to look at the casting # on the head. Also there will be a date casting # starting with a letter, then three numbers. Example: C 15 0= March 15, 1970. The 1970 head uses a gasketed 13/16 spark plug and 1971 head uses a 5/8 tapered plug. The gap should be set at .035 on either spark plug. Once you have the number, check it out on this site http://outintheshop.com/faq/casting/heads.html. to find out what you have.
11-21-2012 09:11 AM
JasonL
plugs

Quote:
Originally Posted by cdminter59 View Post
The 492 heads are the 1970 LT1 heads. You can use AC R45 for street driving. These heads oridinally used AC R44 but they are no longer made. The AC R43 is used for a colder plug when racing. A Champion RJ12YC can be used also. Gap is .035 for these plugs. BTW do not use any AC R45TS plugs if the pistons have domes. The S stands for extended tip and will hit the top of the domed pistons on 11.0+ compression motors.

Thanks for the response. I pulled the plug out and there is a Tapered plug in there and the AC r45 look to be flat plugs. Is there a pic of how to tell the difference of heads? I am not sure what my heads need.
11-21-2012 06:43 AM
Jimbo17
How abokut indexing the spark plugs?

Which way the open end of the gap faces is another interesting subject.

We used to look at the open end of the plug and put a magic marker line on the white part of the plug and then insert different sizes of copper washers under the plugs to get the open end to line up in between the intake value and the exhaust value.

After doing many dyno tests trying different plugs we found that the job of a spark plug was to fire at the correct time very time.

Now how long the spark fires for is a whole different story which leads to a much cleaner burn of the fuel.

Jimbo
11-21-2012 12:32 AM
cdminter59
Quote:
Originally Posted by JasonL View Post
Quick question, Looking for spark plug advise and gap.

Motor: 355, 9:1 cr, 492 heads with 2.02/1.60, performer intake, holley 670, comp cams 268HE cam.

Thanks in advance
The 492 heads are the 1970 LT1 heads. You can use AC R45 for street driving. These heads oridinally used AC R44 but they are no longer made. The AC R43 is used for a colder plug when racing. A Champion RJ12YC can be used also. Gap is .035 for these plugs. BTW do not use any AC R45TS plugs if the pistons have domes. The S stands for extended tip and will hit the top of the domed pistons on 11.0+ compression motors.
11-20-2012 04:39 PM
66GMC What I took away from the rep's advice was that you should close up the gap and go colder than the recommended plug on a "modified" engine.

Modification was described as ANY performance-oriented upgrade ... even a cold-air kit for example.

How much colde heat ranger? How much to shorten the gap?
I'll leave that to the tech guys for their input, but I suppose the real-life answer would lie in proper "reading" of your plugs?
11-20-2012 02:33 PM
ChevroletSS Have to say thats cool. I never knew that spark plugs had heat ranges. Ill have to find out what my truck needs.
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