Bob and Dick are absolutely correct. In all the heads we process, valve
recesson is minimal. This is true of TR3, Spitfire, MGB, TR6, etc. The
peopel that sell the "unleaded conversions" are making money for a
non-needed service. If you have a later car - say mid-70's Brit car,
they wre already set-up for low lead. Everyone in the industry knew it
was coming soon. I have an original TR3 that has never been changed
over, and we do this for a living. Ted
Robert M. Lang wrote:
>On Tue, 24 Jun 2003, steve bridge wrote:
>
>
>
>> In my TR6 motor, I use Aviation fuel from the local depot. They have a
>>pump around back, I think it is at $2.20 per gallon. Expensive, but if you
>>only put 3-6 thousand miles on your car per year, the actual difference in
>>the dollar amount spent is insignificant. I had seats and bronze guides
>>installed so I can run fuel as dry as Av gas with no fear.
>> The bonus is Av gas has no sulphur to rot your babbits!
>>Steve
>>
>>
>
>Please note that running a street car with av gas is a violation of
>federal law (for a number of reasons, including road taxes and EPA
>guidelines). This assumes that you are a US citizen though. If you live
>elsewhere - check with your local laws.
>
>Please also note that running 110 octance (r+m/2) is completely
>un-neccesary unless you get to insane compression ratios (more than 10.5:1
>in an iron engine) and/or serious ignition advance (like in the 30 degree
>range total).
>
>The fact is - using your 2-3k mile per year logic, that the payback for
>using av gas is _never_. If you run 2-3k miles per year, you'll get 20-30
>years of driving on your TR6 before you'll have to think about doing ANY
>valve work, even if you run it on (legal) pump gas. Think about it.
>
>Now for my opinion. If you put in bronze guides and you don't have a race
>motor, well let's say that you probably could have got more value if you
>spent the money elsewhere.
>
>Sorry to be a crumudgeon, but this is a hot-button topic for me.
>
>I'll make the statement (again) for posterity: A TR6 engine running mild
>compression increases or stock compression will run a long, long time on
>the stock valve seats and guides. If you pull the motor for a rebuild,
>don't waste your money on new seats and guides _unless you have measurable
>valve-seat recession_. Only then do you need to consider installing new
>seats.
>
>regards,
>rml
>
>p.s. and now for some levity - there's an av-gas dispenser near me. The
>local import/tuners come down and buy the fuel ($5/gal!) to "make thier
>cars run better". Surprise, surprise - a few weeks later, they come back
>FURIOUS because thier cars won't run anymore. Gee - the cat converter is
>bad, the O2 sensor is dead... I wonder how that could be?
>
>:-)
>------------------------------------------------------------------------------
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>Consultant MIT unix-vms-help |
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>
>
>
--
Ted Schumacher
tedtsimx@bright.net
http://www.tsimportedautomotive.com
108 S. Jefferson St.
Pandora, Ohio, USA 45877
Fax: 419.384.3272 (24 Hrs.)
Phone: 800.543.6648 (US & Canada)
Tech/ Gen. Information/ Worldwide: 419.384.3022
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