Been thinking. My 1965 Volvo 122S was run on leaded fuel for years, then unleaded fuel up to the present. I remember back when lead was being taken out of fuel there was concern about damaged valve seats resulting. Over the years it seems that the lead residue affords protection to the old seat. What if a FP, MMO, or Techron is run in these older engines. Will they clean away the protective lead cushion on the valve seat?
Unleaded fuel and valve seats
- Thread starter Cornbread
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there hasnt been any leaded fuel sold in MA in about 15 yrs. I imagine the same in GA. I doubt there are any lead deposits remaining in that old B20.
I'm not familiar enough with Volvo's that old, but if it has an aluminum head it must have hardened steel valve seats. Hardened steel valve seats don't need lead.
If your Volvo has a cast iron cylinder head, then over time the exhaust valves will erode their seats in the head, causing the valves to burn. When this would happen is different for each manufacturer, as it depends on the metallic composition of your cylinder head. However, it doesn't happen right away. For instance, I know that on old big-block Chryslers, it usually takes 60K-100K miles of running on unleaded gas for the exhaust valves to start to go bad.
If they do go bad, have a valve job done, and have the machinist press in hardened seats.
Again. as was said above, if your volvo has aluminum cylinder heads, then all this is moot-since aluminum heads have hardened seats in the first place-
Fitz
If they do go bad, have a valve job done, and have the machinist press in hardened seats.
Again. as was said above, if your volvo has aluminum cylinder heads, then all this is moot-since aluminum heads have hardened seats in the first place-
Fitz
Yes I do add at each fillup, but this car sits at my Mom's and I drive my mazda for my daily driver, so it doen't get driven as often as it used to. It has turned the odometer over once since I've owned it so I'm guessing it has 117k on it.
I think the rate is 1oz/10gal for lead substitute, so it wasn't too costly, but premium gasoline sure is.
I think the rate is 1oz/10gal for lead substitute, so it wasn't too costly, but premium gasoline sure is.
Good old iron blocks in those volvo's are bulletproof. I have a 1968 122s (my first car) and my Mom has a 1971 P1800E (fuel injected B20). I've always added a lead substitute to the gas (usually CD2 instead-o-lead) and ran the highest octane to help with pinging. The lead substitute must be good b/c it says "For off-road use only".
Y`all have convinced me. Not driving it much right now, but would like to eventually use it as an alternate daily driver. Don`t know if previous owner ever used a lead substitute, but I guess better late than never. Wonder what the "substitute" is? Certainly not lead?!
Cornbread: Go to www.batterystuff.com and get
yourself some Real Tetra Ethyl Lead. Yes they
sell it and it is the real thing and gives you
mixing instructions for octane requirements and
they will ship it to you.
yourself some Real Tetra Ethyl Lead. Yes they
sell it and it is the real thing and gives you
mixing instructions for octane requirements and
they will ship it to you.
I have five vintage Chevrolets...three of them are older 6 cylinders.Have had no valve seat problems and have driven them on many high speed trips over the last 30 years.It was common to grind valves on those cars at 30,000 miles when they were new.The lead deposits would form on the valves and valve seats causing to not seal fully and the valves to burn.Removing the lead was the best thing that ever happened.
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