If you would like to read a real explanation of this (pretty technical) in
addition to hearing lots of opinions, try the website
http://www.faqs.org/faqs/autos/gasoline-faq/part4/preamble.html
page 4 specifically addresses valve recession in older engines. Unfortunately,
the
author does not give analyses of specific product results.
Dr G W Owen wrote:
> Now the European Gov has seen the light and decided to poison us all with
> Benzine instead of lead, in the UK we no longer have a sourse of Leaded
> Petrol.
>
> Whilst Lead Replacement petrol will (probably) cope with the stresses of
> ordinary motoring in the UK, does anyone out there have any experience of
> "hard motoring" using unleaded on engines designed for lead. By hard
> motoring I mean racing/fast road cruising at engine speeds of 4500rpm
> plus.
>
> The questions that I (and many others) would like answers to include
> 1. Which adddatives are people using abroad.
> 2. At what doesage rates
> 3. Does anyone have any experience of teh Redline addative?
>
> If you have any input and would like to send replies to me, I will collate
> them and reply to the list
>
> thanks
>
> Geraint Owen
>
> Dr Geraint Owen
> Department of Mechanical Engineering
> University of Bath
> Bath
> BA2 7AY
>
> tel 01225 826826 x4033
> fax 01225 826928
> email ensgwo@bath.ac.uk
>
> On Tue, 9 Nov 1999, JOHN HARDEN wrote:
>
> > Brian is correct. We have the same problem with Dunlops on heavier cars. You
> > must drift the car thru the corners if you want to keep the buildup off the
> > tires. regards, John
> >
> >
> >
> > ----- Original Message -----
> > From: Brian Evans <brian@uunet.ca>
> > To: <Gregory_Schulz@mil-elect-tool.com>; <vintage-race@autox.team.net>
> > Sent: Tuesday, November 09, 1999 1:33 PM
> > Subject: Re: Hoosier characteristics (bias)
> >
> >
> > > This may or may not be what you want to hear, but...you're probably not
> > > driving fast enough! Racing tires do tend to pick up rubber, but if you
> > > get to where you're cornering consistently with a reasonable slip angle on
> > > the tire, the build up won't build up, so to speak. The tires will start
> > > to show an even graining across the tread instead. The rears are probably
> > > better than the fronts now because you're spinning the inside rear coming
> > > out of corners.
> > >
> > > Another indication is that you've got 7 events on them and still have
> > > "healthy" tread. Many guys will be buying new tires before 7 events have
> > > gone by! So next year, you have a new goal - wear out your tires! Even a
> > > lower powered Spridget can still have quite respectable cornering speeds -
> > > just don't use the brake as much ;)
> > >
> > > Cheers, Brian
> > >
> > >
> > > At 01:42 PM 11/09/1999 -0500, Gregory_Schulz@mil-elect-tool.com wrote:
> > >
> > >
> > >
> > > >Well, the bugeye is just about ready for winter storage. My first year of
> > > >vintage racing with VSCDA up here in the Midwest was better than
> > expected: 7
> > > >events with no "dnf's" and only one "dns". I wasn't very fast running a
> > > >modestly
> > > >prepped 948, and I kept an open 4.22 rear in the car at every track. But
> > > >we got
> > > >what there was out of the car by season's end, had a blast living out a
> > > >childhood dream, met alot of good folks, and that adds up to a successful
> > > >season
> > > >for me.
> > > >
> > > >But, there's always something a (new) guy just doesn't get.
> > > >
> > > >I ran Hoosier A70-13 Street TD bias tires this year. I was pleased with
> > their
> > > >general on-track performance, but it was the condition of the tires after
> > the
> > > >race sessions that distressed me the most. It never failed that by the
> > time I
> > > >got back to the paddock I had a terrible build-up of rubber on the tread
> > > >surface. At Road America, where there are 3 brutally long straights,
> > vibration
> > > >was a definite problem. Even at shorter tracks with modest straights,
> > similar
> > > >unwelcomed vibration was a problem due to this build-up. It seemed that I
> > > >could
> > > >scuff most of it off the rears during a session, but the fronts never
> > really
> > > >cleaned up very well. In-between sessions a knife worked well for the
> > bigger
> > > >chunks, but that persistent layering...
> > > >
> > > >I looked at them last weekend as I carried them down to the basement:
> > complete
> > > >rings of this stuff go around the entire circumference of the tires in
> > erratic
> > > >thicknesses from 1/16 to over 1/8". I thought to myself 'these suckers
> > aren't
> > > >even round anymore'. They were brand new this spring and have healthy
> > tread. I
> > > >can't imagine anything I could do to them would be worthwhile. Do I need
> > to
> > > >rotate front to rear/rear to front between sessions next year (since the
> > rears
> > > >do clean-up a bit)?
> > > >Any thoughts from experienced Hoosier users?
> > > >
> > > >Thanks,
> > > >Greg
> > > >'58 A-H Bugeye #517
> > > >Cedarburg, WI
> > > >
> > >
> > > Brian Evans
> > > Director, Global Sales
> > > UUNET, An MCI WorldCom Company
> > >
> >
> >
--
uncle jack
TR4 - 10 mpg
TR6 - 30 mpg
(diligently engineering my way to the back of the pack)
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