Peter Gennuso

Is there anyway to visually tell the difference between a 71 and 72
detuned engine. I recently bought this car thinking it had the 240 hp
engine but when I went to get a new air cleaner, the 71 cleaner was too
big (thats what the autozone computer called for). the air cleaner for
72 fit. which engine do I have? thanks for any help.

C. E. White

"Peter Gennuso" <petergen@webtv.net> wrote in message
news:17531-4327B615-158@storefull-3335.bay.webtv.net...
> Is there anyway to visually tell the difference between a 71 and 72
> detuned engine. I recently bought this car thinking it had the 240 hp
> engine but when I went to get a new air cleaner, the 71 cleaner was too
> big (thats what the autozone computer called for). the air cleaner for
> 72 fit. which engine do I have? thanks for any help.

I thought the biggest difference between a '71 and '72 351W was how they
rated the engines - gross HP in '72, Net HP in 72. Otherwise I don't think
the actual power output was much diffrent.

Ed

Peter Gennuso

thanks ed, the autozone man tried to explain that to me. it says on the
air cleaner "regular gas" but wasnt regular gas a higher octane back
then? my son thinks I should use midgrade at least.

lugnut

On Thu, 15 Sep 2005 00:54:45 -0400, petergen@webtv.net
(Peter Gennuso) wrote:

>thanks ed, the autozone man tried to explain that to me. it says on the
>air cleaner "regular gas" but wasnt regular gas a higher octane back
>then? my son thinks I should use midgrade at least.


No. The octane ratings for all grades was the same then and
now. They changed the display on the pumps by using the
average of the research and motor octane ratings. If it was
a regular fuel engine before, it is still a regular fuel
engine. If the engine has collected a bit too much carbon
over the years, it may be experiencing what is commonly
called octane creep such that it will need a step higher
octane gasoline to prevent detonation or "ping". That said,
a little "ping" is not bad for an engine as it can help
reduce the rate of carbon buildup. A slight "ping" of short
duration is also one indicator that the engine is near
optimized for best performance and fuel economy.

Lugnut