Which spark plugs should I use?

[lovemysan2]

I've got 9.5 to 1 pistons and the head was resurfaced when I rebuilt. What spark plugs should I run with this combonation. Right now I have $1.49 denso stock replacement. I took a look at a couple of them the other day and they had amber colored spots on the insulators. SHould I be running colder plugs? Or hotter?

this is for my 96 ka24e pickup

[deviousKA]

well i use just standard densos in my high compression ka24e, and they are burning correctly. ngk makes good plugs as well. What is your timing set at? are you running good fuel, with no detonation? Colder plugs is what you would naturally want to run with higher compression, if they are needed. Check some of the nice pictures places have up on plugs, and compare with yours, that should give you a basic idea. I think many chilton/haynes manuals have pictures of different plug situations.

btw. my e is around 10.7:1 cr.

[lovemysan2]

Well I was informed by the parts people that the denso's are actually a little colder plug than there NGK counterparts. I closely listen for spark knock and don't hear any. My timing is set at 10 BTC, stock. It has to be changed with the nissan consult. You can't change it on a 96. I run premium fuel.

[TrunkMonkey]

excuse my ignorance, but what's stock timing and stock compression for the truck ka24e?

-demetrius

[deviousKA]

Stock timing on the ka24e trucks is 10dbtc. Compression i believe stayed the same throughout the years of the later ka24e's, 8.6:1.

Interesting enough, some of the really late ka24es had some major changes. Trucks from 94 on used sidefeed injectors, and both large and small port heads were used. I have never personally seen or compared the port differences myself though.

You cant adjust your timing with distributor movement? This seems odd, but i take your word for it. Shoot a pic of your distributor if you could, im interested. The timing is set by nissan tech electronically?

[lovemysan2]

The distributer rest at the full advance stop. I have an FSM. It can be difficult to read I'm going to study it real close one more time but I just don't see a way around the nissan consult. You can check the timing just not change it. You can loosen the distributer and move it around it doesn't change anything. There is a chance that I can change the timing by adjusting the cam position sensor but its buried inside the distributer.

Begining in early 96 I believe they started using the big port head. But I've met many who said the older ones were quicker.

Devious have you ever tried running wal-mart gas. There premium always gives my truck the hives. I put 8 gallons and have not been able to run the truck hard since without getting some spark knock.

[deviousKA]

do you mean that the distributor is turned fully clockwise? Can you move it in the retard direction? I havent had the chance to work on many 96-97 trucks, but that seems odd that moving it does not change the timing. Can you retard it? Maybe you are maxed out on your adjustment and need to move your oil pump a tooth. But like i said, not sure, the 96+ maybe need that consult unit. To me this just seems like an odd thing for nissan to do.

I have heard basically the same thing about the big vs. small port ka24e head. Thanks for that added info on the year.

i use only conoco gas mostly, 92 octane. I am using that now with 10.7:1 and 18btc. I have heard from my friends that walmart gas is crappy

[lovemysan2]

Okay I went and studied the FSM again. It appears that the consult is only used to oversee the process. The timing is adjusted by unplugging the thottle position sensor and then adjusting the camshaft position sensor. I'll prolly try this tommorrow.

What should I set my timing at. if stock is 10 deegrees before top dead center. And I have occassional preignition should I further advance it like yours.

What are the pros and cons of running 18 btc? Help me understand this.