Jump to content
Sign in to follow this  
SRT

Understanding

Recommended Posts

Here's a good read from EngineBuilder mag. I sat an read these a few times. It's a great publication!

 

http://www.enginebuildermag.com/Article/87734/understanding_spark_plug_heat_range.aspx

 

"When in doubt, if you're going to miss it, miss it cold" is my advice.

also don't forget some manufacturers have different numbering for hot or colder plugs.NGK's the higher the number the colder the plug and the lower the number the hotter the plug. with A/C delco and auto lite  the lower the number the colder the plug and the higher the number the hotter the plug. ND's are like the NGK numbering with heat ranges.

Share this post


Link to post
Share on other sites

That was very good stuff.  So who all went out to go get new spark plugs? :superblue:  (yeah...I didn't)

 

Just put new plugs in 3 days ago.

Share this post


Link to post
Share on other sites

NGK makes a great plug. I've tried others in other vehicles but $/quality..NGK is very good. I noticed even the ceramic is clocked the same on a set of plugs I bought once. (I was indexing plugs hoping for gains).

 

Used to do that too. I understand the theory and know it is true, but can't say I have ever seen anything that proves results from it. 20 years later though, I still index the plugs on a race car.

  • Like 1

Share this post


Link to post
Share on other sites

NGK makes a great plug. I've tried others in other vehicles but $/quality..NGK is very good. I noticed even the ceramic is clocked the same on a set of plugs I bought once. (I was indexing plugs hoping for gains).

What shoukd they be gapped at? I'm running a 75hit?

Share this post


Link to post
Share on other sites

What shoukd they be gapped at? I'm running a 75hit?

usually you run .032-.035 for F/I applications. I would try going .045 on the gap. that way if it's acting good on it you could bump up the gap to .047.

Share this post


Link to post
Share on other sites

What shoukd they be gapped at? I'm running a 75hit?

I'd at least go down to .040 if I wasn't sure. You won't be losing anything significant. The heat won't come up the strap as much the less gap you have. If you know the combination you can experiment with wider when you know you are "safe".

 

The other factor is DA, actually. That's less cyl pressure right there so you may be ok going with more gap after you feel you are safe to move up in gap. Removing just the upper to reset gap isn't too bad once you've done it a couple of times.

Share this post


Link to post
Share on other sites

Cool so stock gap its not that big of a hit anyway guess ill be fine

That's what they're showing there but get some input from the locals there too. It cannot hurt to ask. Low side of spec maybe .049.

Share this post


Link to post
Share on other sites

usually you run .032-.035 for F/I applications. I would try going .045 on the gap. that way if it's acting good on it you could bump up the gap to .047.

 

 

NO, that is too much gap with a 75 shot. It might be fine, might not, but I would treat it like boost, run a heat range colder plug and gap it down around .035" see how it acts, you can always open the gap, but if you go too wide you could hurt it on the spray.

Share this post


Link to post
Share on other sites

NO, that is too much gap with a 75 shot. I would treat it like boost, run a heat range colder plug and gap it down around .032"

If I was unclear, the whole time I was speaking of a 1 step colder plug regardless of the gap.

 I should have made that clearer, if I didn't.

 

I'd ask those with nitrous experience with these engines on the gap but that article said for that little a shot, though it's more comparatively to a 3.7, that the gaps wouldn't need adjusting down. I think what you are suggesting is the safest route to go when in doubt. Again, the upper isn't too difficult to remove to regap if needed.

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
Sign in to follow this  

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.