spark plugs

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RyanUpdike70

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what kind of plugs do u guys run and what heat ranges

440 bored 30 509 cam 10 5 compression m1 intake quickfuels 850 i run autolites but i think it needs something hotter I was looking at autoliites 3934s but not for sure if they will fit my heads
 
Does it use the peanut plug or the standard flat seat plug ?
 
Unless the engine is a radical one, stock plugs and heat range. 1 step colder if the engine is built up well, 2 if it's a little bit obnoxious.
 
Not really knowing your combo or usage... I'll say sure, go for it. I do remember it is a nice build, on the hot side IIRC. But a cooler plug is what you want, not a step up in heat.

My reply was what I do. Why?

1. Champs are cheap.

At a $1.88 here, I can afford to make a mistake, walk back to the store and get more. Try the heat range and run about with them. Gap, re gap, gap again.

2. I have no problem with Champ plugs. While they do not last as long as other plugs, the state of tune is key to there life. They always start up my fresh engines and I have several sets on hand when I start up a new engine.

At track time, I bring along 2 set (16) of plugs. The drive there is dicey on traffic. Ya just never know. Traveling 50 miles to the city (NYC) then 20 miles getting threw the city....then into N.J. for a E-town shake down, well, I have kicked the plugs arse sometimes. New set goes in before the run.

If it was a bad day, new plugs on the way home.

Most people do not realize that the engine will do fine with the OE heat range, reach and style it came with. Going 1 step cooler is about the best you can do for a high performance engine. (Above stock high performance) to a fairly hot street machine

On my iron headed 10-1 360 with the same cam you have, the purple 292, I ran 1 heat range down with nice results. Maybe I missed something with the OE range? IDK.

I hope this helps you out. When the time comes, run it at the track and see what the engine likes best.
 
If your at even a "true" 10.1 i'd run 1 step colder, I do not like Autolites, they tend to glaze under hard excelleration & hard to read, 85 is a stock plug for 8.5.1, too hot for the compression you have, I ran the NGK V-Power 5670-6s in my 9.73 451, -7s on juice, They are very easy to read, If you see any black specks or shinyness on the porcelin there too hot, Thats if the timing & curve is right along with the proper octane, There is also such thing as silent detination, the 1st. to show it is the plugs, I've had the best of luck running the NGKs, Another thing to remember, Back in the day there were 3 champion plugs for the 440, J13YC for the standard 440, J12YC for the HP & J11YC for the 6-pack 440 & there was good gas back then, If it didn't matter the heat range there would be 1 heat range fits all.

Have you calculated the true compression on this 440, unless you milled the heads some & are running a steel shim gasket & pistons are FTs around .017"-.019" below deck your not even at 10.1 with standard 91cc heads, close but definitly not 10.5.1
 
Thanks for the plug tip. I'll have to try them in the spring.
 
thanks for the info i am going to try a set of those if i can find them i search them on advance auto parts wedsite and nothing so i think i will have to buy them at the local speed shop also should i gap at .035
 
RyanUpdike70 said:
thanks for the info i am going to try a set of those if i can find them i search them on advance auto parts wedsite and nothing so i think i will have to buy them at the local speed shop also should i gap at .035
Click to expand...

If your running an MSD or Mallory box, gap them at .040"-.042", Standard mopar ignition .035", Now you can order them from O'Reilly's, they should be able to pull them up on the pooder, or look through the catalog. Don't get confused on there heat range charting, the heat range works backwards then the rest, The larger the #, the colder the plug, so a -5 is hotter then a -6
 
Just want to clarify something about heat range numbers. On American plugs such as Champion as the numbers go up (N12Y N14Y ect) the heat range gets hotter. On other brands such as NGK or Denso as the number gets higher the plug gets colder.
 
I got the plugs and try them i do belive they help it out and they are very easy to read i leaned it out just a little and it seems to run cleaner and not loading up
 
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