Spark plug and timing questions '90 454 Mag
 

I just pulled the plugs from the odd number bank of my engine. All 4 of them came out with oil on the threads. Could someone tell me what that means?
I bought a new set of plugs for it. I was told by a friend to get Champion RV15YC6 plugs. Here are the specs.

hell

• Thread Size: 14mm
• Seat Type: Tapered
• Resistor Type: SAC9
• Reach: 11.6mm (.460")
• Hex Size: 5/8" (16mm)
• Terminal Type: Solid
• Gap: .059" (1.5mm)

Center Electrode

• Material: Nickel
• Type: Standard
• Size: 2.5mm
• Projection: Extended Projection

My engine is completely stock. I want to make the most of it for the season.
I was also thinking that I would turn the timing up to 10 or 11 degrees

I am open to all input on here as I learn
Thanks

kdshouston,

Was there traces of oil on the tip as well or just the threads? As far as timing is concerned, BBC engines respond well to increased timing as you start to upgrade components from stock, however, if you were looking for getting the most out of it for the season, I would leave the timing as is, enjoy the lower gas prices, and hit the water. Turning the timing up may alter the need for higher octane fuel etc. both from filling up at the dock and on the trailer for not much of a trade off if the upgraded components aren’t there yet. Just my thoughts, but if you wanted to mess with some timing to see, fill it up with some 93, bump it up to 10* and see if she reacts any differently. It can always be dropped back down to stock 8* on the water if needed.

Your motor came out originally with Champion RV8C or AC Delco MR43T
Later plugs were changed to Champion RV15YC4 or AC Delco MR43T or NGK RB6FS

In short using what you have is within spec

i use NGK UR5 a much higher quality plug

OP - absolutely, positively do notvrun gaps that large. Murder on your coil, module, cap, rotor, and wires.

.035”-.040” is all that’s needed.

You can take that to the bank. :)

I wouldn't run Champion spark plugs in a lawn mower.

Padraig

UR5 are cooler and equivalent to an AC 41 heat range. AC R43TS is best of both worlds

NGK heat range 5 lines up with Delco’s heat range 43 quite well, with experience too.

The UR5 is a V power NGK . I use the V powers type plugs on many engines.

That said MR43T’s or CR43TS (extended tip) are my go to for non vortec stock small and big block Chevy’s. Gapped at .035”.
M= marine. Extended tip not available
C = commercial. Extended tip (S) available

Isn’t MR43 more resistant to rust/corrosion? Different material or coating or something?

Yes, and easier to read for tuning vs black color of the regular R43T’s and TS’s. But , if you don’t tune this way and change your plugs every 2 -3 yrs, which is good idea ,than not a big deal. Unless maybe ocean going biats but I know nothing about those.