I was wondering if anybody has had experience with unleaded on the stock seats.Please respond good or bad.I dont know of a machine shop around here that can do the hardened seats on a flathead.I would like to know mileages driven with stock seats and unleaded. Thanks

 

Although it's not a flathead I started running my '58 F-100 (223 6 cyl) on Amoco Premium in the early 70's. It's been about 35 years since its last tank of lead and I have no idea how many miles. Before I restored it, I used the truck to tow other cars around and hauled many yards of top soil, stone and fill. I even used it as the shop road service truck for a while. The engine has been worked pretty hard but it still hasn't been apart and I'm not aware of any ill effects caused by unleaded.

Lou

 

usually, the hardened seats are required more by the hot, high-performance engines... unless you run at speed (over 65MPH) for long periods of time, you shouldn't notice any probs for about 40-50K miles, according to my sources.

ymmv

 

When I first found this site about 4 months ago, I read throught the whole Y-block forum and this was discussed there in two or three different threads over 4 or 5 years. Anyway, the condensed concensus is that there are no problems with unleaded fuel and stock valve seats. The caveat being that the engine will not be used at high rpms for racing or stressed over extended periods.

Daily driving with moderate loads every once in a while created no problems above and beyond normal wear-n-tear.

 

I think I read somewhere the flatties came with hardened valve seats. Anyway, I have run regular gas in my flat six for eight years without a problem and I don't baby it.

 

Can't say about the 6's, but yes, all 8BA/8RT's came with hardened seats, except I believe '51's, when they tried a valve rotating spring assembly. They went back to hardened seats after that.

 

You can always put some lead additive in. I use it in mine. Once every few tanks.

 

Every test I've seen of these shows no significant benefit. They aren't "real" tetraethyl lead, which is extremely toxic. Most are just upper cylinder lubricants.

Lead was actually bad for valve seats, except for a minor benefit under very heavily loaded conditions. It was bad for everything except octane ratings. Spark plugs, rings, oil were all negatively affected.

 

I have read several studies by Gasoline Companies that show no adverse effects from using unleaded gas in old engines originally requireing leaded. I have 2 such vehicles and use unleaded in both.
fking1

 

Me, too. Ditto, all of the above, I totally agree!! I had my engine rebuilt in 1979. for a while I tried to put the lead additive in maybe a year or 2, when I thought of it, etc. After discussing this on this site years ago (back when it was an email listing) I stopped worrying about it and have seen no ill effects. So, 28 years since the rebuild and no problems!