Reading plugs. Plug chop

**roadkill636** · 08-02-2017, 06:28 AM

So i installed some new pluggs and drove a few minutes then did a wot chop at around 5500 rpm and here are the plugs. They look too white to me. These are new NGK pluggs and 50/1 synthetic blend oil on a steel bore 2.4 that has been modded. With square ported pistons and 1.52 exhaust and 1" intake spacer and wh20 carbs. Now here is the crazy part. Im running 90 and 92 main jets. What ya think?

**eli** · 08-02-2017, 07:39 AM

wont be able to read surface gap you will need to install gap plug i think b9hs or 8

**FMP** · 08-02-2017, 08:10 AM

why? a few min. and you see the dark pattern forming.

**kozmic27** · 08-02-2017, 01:40 PM

Because you don't have a strap to see the burn line. Both ignition timing and AFR will effect where the burn line ends up. It tells you if the combustion event is pushing on the piston at the right time. Lean AFR burns faster than rich AFR.

**roadkill636** · 08-02-2017, 02:38 PM

Iv never done a plug chop before. So i didnt know how long to run new plugs before doing a chop. Figured the newer the better. Cleaner.

**Steve Pope** · 08-04-2017, 07:49 PM

Read piston for mixture and plug strap for timing. Jay Smith posted a real good description on correct piston crown reading. Do a search.

**roadkill636** · 08-06-2017, 05:20 PM

I have a set of B9HS plugs comming for another chop test. How long should i run it the chop it?..

Also just from these surface plugs can anything at all be read? Can i go ahaead and install the next size smaller jets?

**roadkill636** · 08-14-2017, 11:00 PM

Got the set of b9hs in it today. Heres what they look like with a 4000-4500 rpm chop..
What ya think?

**rude tim** · 08-17-2017, 01:10 AM

Put a couple of hours on those plugs just cruising a round so you get a little color on them before you do the plug chop.

**W2F a V-King** · 08-17-2017, 05:23 AM

Originally Posted by roadkill636

I have a set of B9HS plugs comming for another chop test. How long should i run it the chop it?..

Also just from these surface plugs can anything at all be read? Can i go ahaead and install the next size smaller jets?

I wouldn't go smaller...those look lean to me.

Steve Pope's post in #6 is what would be helpful ....

**XstreamVking** · 08-17-2017, 05:45 AM

If it's not eating fuel like you own a gas station, it's gonna be lean. Only motor I ever cooked a piston on, just before it went, I was saying how good it was on fuel consumption. And like popey sez, look at the piston tops......

**roadkill636** · 08-17-2017, 07:04 AM

This thing is eatting fuel... i can go thru 25 gallons just after work running arround for a few hours

**Chaz** · 08-17-2017, 07:07 AM

In a perfect world you would put in a new set of plugs , start it up in gear run it wide open for 10- 15 seconds put it in neutral and click it off put the plugs in a rack and look at them with a magnifying light .
The dark ring around the porcelain at the base is the fuel ring . The color at the top is impurities like oil or the additives in the fuel .
The center electrode is the timing mark .
The ground strap show's the overall condition of the combustion cycle .

The long version of the above is here :

http://www.strappe.com/plugs.html

**FMP** · 08-17-2017, 09:28 AM

Originally Posted by kozmic27

Because you don't have a strap to see the burn line. Both ignition timing and AFR will effect where the burn line ends up. It tells you if the combustion event is pushing on the piston at the right time. Lean AFR burns faster than rich AFR.

You index the plug prior? A few hrs on surface gap and you'll see the burn pattern. Also determined by loop charge pattern which changes slightly with rpm?
I'd like to see those plugs after a few more hrs.

**W2F a V-King** · 08-17-2017, 04:08 PM

Originally Posted by FMP

You index the plug prior? A few hrs on surface gap and you'll see the burn pattern. Also determined by loop charge pattern which changes slightly with rpm?
I'd like to see those plugs after a few more hrs.

Wouldn't that be an average of all run time?