i dunno, my 72 &75 L6 165hp mercruiser states right on the engine, use premium leaded fuel. also the 75 has a sticker that's almost gone right by the filler cap that says the same thing......unlessI don't know of any (non race) motor that would require a lead additive
cashtim, we need to know what year and engine ya got if ya want to know if it was designed for leaded fuel or not.......I would just not use the additive and do a valve job at a later date if/when the valve seats wear out.
i dunno, my 72 &75 L6 165hp mercruiser states right on the engine, use premium leaded fuel. also the 75 has a sticker that's almost gone right by the filler cap that says the same thing......unless
cashtim, we need to know what year and engine ya got if ya want to know if it was designed for leaded fuel or not.......
yep, i do add lead additive. worthwhile or not. i dunno. but i have a stock engine and fig. if the mfg. wanted lead, and i have the option of additive. why not.....other than it may be a waste of $'s
i think ya may have miss read......nowhere did it say use premium unleaded?
for my 72 L6. mercuiser service manual #1, tune up specs, fuel required. "93 Research Octane Minimum - Do NOT USE Lead-Free or No-Lead Fuels"use premium leaded fuel.
that may all be true. but were talkin boats, not cars..........I understand, and I'm aware of what you're saying, but By 1971 all vehicles were made to run on unleaded 87 octane. That's when all the motors began to take a large compression drop, and were reconfigured to milder cams, by 1975 every car had a catalytic converter on it, for unleaded fuel only. This created a big drop in performance for quite a few yrs. Back around this time, Oldsmobile designed their engines with an exhaust valve rotator, to help prevent any issues with unleaded fuel, and the other car companies changed the metal compound in their exhaust valves to work better, & last longer, with unleaded fuel.
yep, thats the real question for sure. of corse, one question always brings up another. so how many hours would be enough hours to warrent the use of lead? i'm just gonna keep usein the additive. at least i can feel like i've tried to do the best for my engine that i can.....when it's time for a valve job i'll cure it with hard seats at that point.....Now the question is, do you put enough hours on your motor to hurt the exhaust valves and seats without lead or it's substitute.
point taken........However, adding a lead additive is probably not as effective as one thinks and will not break the bank by using it, is a waste of money. Run it until the engine needs a valve job (if ever). If and when that time comes, install hardened valve seats and you will likely be dead before the engine dies.