What spark plugs do you recommend for my 1970 LS-5? After I lost the timing chain gear last summer, the engine and heads were rebuilt to 9.0 CR using flat top pistons. Otherwise, the engine is stock. Points, condenser, wires are stock GM/AC Delco as it came from the factory. (Wires are braided R TV 7mm wires). The plugs I was running were AC R44T.
I think I have a problem with the valve seals because I still go through about a quart of oil every 500 or 600 miles. Smoke comes out the exhaust when accelerating and blue smoke after idling at a stop followed by accelerating. I also have some stumbling at low rpm. I feel that the bigger problem of oil loss is feeding and leading to the stumbling problem by oiling and gunking up the spark plugs. But for now, I need some plugs to keep me going till I can resolve my other (bigger) problem- high oil consumption.
Like I mensioned above, I was running AC R44T plugs, I just put in a fresh set of Champion 25 (RV17YC) and the stumbling is gone. I bagged and labelled each plug as it came out. All but one was gunky looking with oily looking black agglomerated carbon buildup. The worse plug was number 8 cylinder which had a bridged gap. The best looking one actually looked normal for a used plug and was the only normal looking one and that was on the other side of the car at cylinder number 7. So based on that plug, I think the heat range of the AC R44T was good.
All recommendations are appreciated.
Tony
I think I have a problem with the valve seals because I still go through about a quart of oil every 500 or 600 miles. Smoke comes out the exhaust when accelerating and blue smoke after idling at a stop followed by accelerating. I also have some stumbling at low rpm. I feel that the bigger problem of oil loss is feeding and leading to the stumbling problem by oiling and gunking up the spark plugs. But for now, I need some plugs to keep me going till I can resolve my other (bigger) problem- high oil consumption.
Like I mensioned above, I was running AC R44T plugs, I just put in a fresh set of Champion 25 (RV17YC) and the stumbling is gone. I bagged and labelled each plug as it came out. All but one was gunky looking with oily looking black agglomerated carbon buildup. The worse plug was number 8 cylinder which had a bridged gap. The best looking one actually looked normal for a used plug and was the only normal looking one and that was on the other side of the car at cylinder number 7. So based on that plug, I think the heat range of the AC R44T was good.
All recommendations are appreciated.
Tony
Comment