Need opinions and facts.

Had a Mechanic tell me his son insists on using 96 Octane Lead Replacement Fuel, which is available in Australia.

I know Unleaded Fuel has been available (only) for maybe 10 or 20 years in North America.

As you know, I drive a 1981 244DL with B21A, Zenith-Stromberg Carb, and BW55 Auto Trans. My Owner's Manual does not mention any requirement for "Leaded Petrol" (Gasoline). It only specifies minimum Octane.

We know Tetraethyl Lead was used to effectively increase Octane and provide Valve Seat Lubrication. We all know about the effects of ghetto children eating Lead Paint Chips and inhaling Leaded Petrol Fumes belched from Momma's Welfare provided Cadillac . . . when she was between US Postal Service and Government jobs.

But, let's keep this focussed on what, if any, effect the use of Unleaded Premium has on Volvo B21 Engine Valve Seat Recession.

Does anyone really know what time it is? Does anyone really care? Does anyone really know the truth, whether the 1977 to 1987 Volvo Valve Seats, Valves, Stems, and Guides, from the Factory are hardened, sufficiently to tolerate Unleaded Fuel, without additive Upper Cylinder Lubricant, and not suffer from abnormal Valve Seat Recession?

Seems there is no concen real agreement on the internet? I saw the B20 Engine, stuff, but he abused his engine (racing). I am talking a different engine and everyday family car, city driving, some highway, some up steep hills.

Thanks.

From the UK Volvo Owners Club web site, by courtesy of Volvo Car UK:
http://www.volvoclub.org.uk/unleaded.htm

Erling.
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My 240 Page

I also live in Australia and have a 1980 245 2SL with a B21A engine and an M46 gearbox. I use Premium Unleaded (RON 98) in mine, and I have noticed quite a sizeable increase in performance over the standard Leaded Petrol (Now known as Lead Replacement Petrol; LRP). I was told that if the head is aluminium, then it is quite alright to use Unleaded petrol, although Premium Unleaded is meant to be kinder to the engine then just standard Unleaded.

Canada has had unleaded fuel since 1986. The generally accepted fact is that aluminum heads with hard steel inserts do not experience valve seat recession. Only cast iron heads with intergral seats which are not locally induction hardened have recession, and then only under certain operating conditions of very high constant load or high RPM. Pleasure boats and hard working trucks are about the only applications that have a problem. I have rebuilt lots of B21 and B23 heads, mostly because of blown head gaskets or excessive guide wear. I have never seen recession on any of them. Some B20's have recession, and some don't, probably because of the engine seeing lots of high RPM service. I rebuilt a B20E head two weeks ago that had recessed exhaust valve seats, but that was the result of a customer that drove across North America with a non-working overdrive, averaging 4000-4500 RPM all the way. The valves were fine - I re-used them, but the seats were down over .080 inch.
I would not worry about recession on the OHC engines at all.