Guest JAMIE T Posted June 24, 2001 Share Posted June 24, 2001 I am just getting used to my new car I don't know if I should add lead additive to the gas or not. Jamie Deathstar Quote Link to comment Share on other sites More sharing options...
DavyZ Posted June 24, 2001 Share Posted June 24, 2001 Hrm, the car was originally built to run on leaded gas, but if the head was ever redone, they probably installed hardened valve seats. The leaded gas provided lubrication for the valve against the seat (this is too my knowledge, correct me someone if I'm wrong) and would eventually wear down overtime if only unleaded gas was used. If you are going to keep the car as is, it's cheap insurance; but, I'm inclined to let the car run with unleaded and take my chances. If I guess wrong, I'd rebuild the head correctly. Heck, I'd just pull the 6 banger and drop in a V8! David Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted June 24, 2001 Share Posted June 24, 2001 Yeah it was added to keep from pounding the valve seats to death (buffering the seat with the lead as the fuel mixture passed over them), later versions must have gone to hardened seats when they used Cats and unleaded. Being as it probably has a number of miles on it anyway, and you'll either rebuild it or drop another engine in, I would'nt bother with the lead additives, its just expensive and you'll still end up doing the top end anyway. IMHO. Regards, Lone Quote Link to comment Share on other sites More sharing options...
Guest JAMIE T Posted June 24, 2001 Share Posted June 24, 2001 Thanks David, I do plan on swapping in a V8(remember that Northstar ) But I need to drive the car as is for a while. Its nice having a fun car that runs good. You are correct about lead as a lubricant. I have had Drag cars that would only run on 115 octane race gas. When I was working on Corvettes, I worked on a '68 427 car. The guy was complaining that it would'nt run good, even if he ran 93 octane(yuppies ) I told him to get some Cam 2 race gas for it, as it was built during a time when 100 octane leaded gas was at every pump. He couldn't beleive the differance it made!!!, oh yeah, thank you too Lone, you posted while I was posting;d Jamie Deathstar [ June 23, 2001: Message edited by: JAMIE T ] Quote Link to comment Share on other sites More sharing options...
Drax240z Posted June 24, 2001 Share Posted June 24, 2001 I am not 100% sure, but I think that all the Nissan L series engines had hardened seats from the factory. (Yeah the valve seats too! ) Quote Link to comment Share on other sites More sharing options...
jimzdat Posted June 24, 2001 Share Posted June 24, 2001 I think you just might be right Drax-I took my E31 in a few years ago to have 280Z valves put in it, and they said that the head already had hardened seats in it, and they were just able to cut them oversize for the new valves-ran that head until I took apart my car with never a single problem. (And that was with a .460" lift cam in it to boot) Quote Link to comment Share on other sites More sharing options...
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