Dam typos..That should have been ..."NOT chosen for its looks or
sidewall appearance" Please pardon my tipying! 8-)
Rich
> ----------
> From: Richard Atherton (Entex)
> Reply To: Richard Atherton (Entex)
> Sent: Monday, September 15, 1997 2:57 AM
> To: alpines(at)autox.team.net; 'GDWF22A(at)prodigy.com'
> Subject: RE: Reply to Steve, Rich and Jarrid
>
> The tire presure I chose was chosen for its looks or sidewall
> appearance. It was however chosen for it's stability and handling on
> a
> curvey down hill road near by. When I buoght the tires they were at
> 28
> lbs front and rear. It handled better than it did with the previous
> bias ply tires, but they still squeeled and rolled way to much in
> medium
> to hard cornering (2 X Posted speed limit through turn). It had
> exsesive roll and had a great deal of under steer. I played with
> presures until I found what gave me the correct handling for a car
> with
> the Alpines weight distribution which as I remember was 51/49. At the
> presures I mentioned, it gave me very predicatable steering with the
> bias easily controlable by throtle position. Drifting through a turn
> was a choice and was fun instead of being scary. I haven't had a car
> since that I could balance as well.
> It wasn't the presure that made these tires bad in the wet.
> They wre AWFUL in the wet regardless of presure. That's why they
> changed the design a couple of years later. Back then the two
> performance tires were the BFG Radial T/A's and the Goodyear GT
> Radials
> with the Kevlar belts. Things have changed just a bit since then
>
> Rich
>
>
> > ----------
> > From: GDWF22A(at)prodigy.com[SMTP:GDWF22A(at)prodigy.com]
> > Reply To: GDWF22A(at)prodigy.com
> > Sent: Wednesday, September 10, 1997 5:00 PM
> > To: alpines(at)autox.team.net
> > Subject: Reply to Steve, Rich and Jarrid
> >
> > Steve; the Alpine does have a nice X member frame as well as rails
> > forward
> > of the firewall to which the cross member is bolted.
> > Jacking points were mentioned to you a day ago and this is all
> > correct.
> > Also, you can floor jack this car and also position support stands
> > under
> > any portion of the lower cross member, lower A frames, side frame
> > members ,
> > rear axle housing and rear springs themselves. This car is light
> and
> > those
> > various places can handle the weight without deforming or bending.
> > Avoid jacking under the thin wall portion of the rocker panels or
> > other
> > actual body sheet metal.
> > I see NO reason not to trust four properly placed stands or
> supports.
> > use of drive-on ramps is OK and certainly are solid but they
> encroach
> > too
> > much around the front car area and hamper certain work areas.
> > ------------------
> > Rich; you mentioned using BR60x13 tires with 42 and 45 psi front
> and
> > 40
> > psi rear. No wonder you slide around a lot !
> > These are radial tires and as we know, they look somewhat bulged or
> > underinflated when set at recommended psi.
> > The idea of the radial (which makes it so much better than a bias
> ply
> > tire)
> > is that when a radial is inflated PROPERLY, it will not lift it's
> > trear off
> > the ground in a hard corner and will instead just keep it's tread
> hard
> > on
> > the ground and allow the side wall to flex over to one side.
> > A bias ply tire in a hard corner, keeps its sidewall rather straight
> > but
> > lifts the tread off the road.
> > To get a better handle on this, stand up with your shoes a few
> inches
> > apart
> > and just lean your body to one side. The shoes remain flat on the
> > floor but
> > if you had ridgid ankles, you would have tipped up or lifted up the
> > outside
> > edge of your shoes, like tilting a statue off it's base.
> > Now....when you air up a radial way too high, you make it act like a
> > bias
> > ply tire. It cannot flex and keep it's "footprint" on the ground
> > properly.
> > Also, whenusing too much air, the front-rear length of foot print is
> > shortened a lot . The result of all this is as you alreadu found !
> No
> > grip
> > and lots of skidding.
> > By law, tires are marked on the side with their MAXIMUM load
> carrying
> > capacity when aired up to a certain MAXIMUM pressure. This marking
> is
> > misunderstood by far too many people in the tire and garage
> business.
> > The marking represents a max pressure you "could" use if you had to
> > carry a
> > max weight on that tire.
> > A typical text may read: " Max allowable weight 1020 lbs (at) 35 psi
> > inflation". This sidewall pressure marking is NOT the pressure
> you
> > would
> > normally inflate the tire to for road use!!!
> > By law, cars sold here after approx 1972 (?) must display a sticker
> > telling
> > the tire pressures (cold temps.) for normal driving and normal
> loads.
> > If
> > the mfr. wants some increase in pressure for heavy loads or high
> speed
> > driving, this must also be on the sticker !
> > Your BR60x13 certainly won't have normal footprint size nor flexible
> > side
> > wall action at the pressures you have used.
> > I am rusty on this subject but will guess you need around 24 psi
> front
> > and
> > 22 psi rear (cold setting) to obtain proper "radial tire grip".
> > Perhaps
> > some reader with current data or tire industry technical book can
> > reply
> > here and supply the actual correct data if I am off a bit.
> > Also be aware....different brand tires as well as different
> > construction
> > variations makes for different psi requirements (2 ply, vs. 4 ply ,
> > steel
> > vs nylon or rayon cord belts etc. etc.).
> > ----------------------
> > Jarrid; your interesting comments re. lifters require me to offer
> the
> > following comments .
> > When you state that regrinding the lifter base to obtain the
> "concave"
> > affect, this is not correct. Due to being positoned off-center from
> > the
> > cam lobe, the lifter is expected to be rotated by the cam lobe. This
> > results in the lifter receiving equal wear all around it's base but
> > also
> > gives the lifter a "concave" wear pattern which we would NOT want to
> > intentionally put back onto the lifter.
> > The cam lobe is ground dead flat (not rounded in any way) and we
> need
> > a
> > dead flat lifter to carry the extreme pressures present all the way
> > across
> > the cam lobe evenly. After long use, the lifter and lobe will of
> > course
> > have worn into a slightly curved shape but they MUST start out flat
> > when
> > new .
> > I found it also interesting that you "never saw Alpine lifters
> without
> > pits". Well of course we all have seen pits but I would say that
> most
> > lifters I have seen were without pits and could be refaced and made
> > serviceable again. Hmmm...wonder where all the badly pitted Alpine
> > lifters
> > have gone to?
> > Now for the last point you raised (and it is one I failed to comment
> > upon).
> > This matter of the internal cup shape base in the lifter and the
> > bottom of
> > the push rod which rides in it.
> > The radius machined on the push rod bottom is NOT designed to match
> > the cup
> > radius in the lifter. This intentional difference is done to create
> an
> > "interference angle" which in turn gives "line contact" between the
> > parts.
> > In my opinion, the burr or ridge you may have seen in a few cases on
> > the
> > push rod is of no importance and does not result in any change in
> > valve gap
> > after the engine has miles on it.
> > Due to where this exists it would not be seen by the eye but by the
> > use of
> > some machinists "blueing" called Prussian Blue paste, we can apply
> the
> > blue
> > to degreased parts, assemble them and note the area of contact.
> > When I have been concerned over a slight little ridge worn on the
> rod
> > base
> > I did check out a few rods by this method and found the ridge was
> not
> > making contact at all and that only a nice polished spherical ball
> > area on
> > the push rod base was in contact with the lifter . Result... no
> wear
> > expected nor found later and no early readjustment of valve gap
> > required.
> >
> > Re. the cost of case hardening lifter base if major regrind was done
> > and
> > too much metal had to be removed....The lifter is cast iron, not
> steel
> > and
> > all that needs to be done is to buy some gunsmiths hardening powder
> > and the
> > one I use is called Casinet from Brownells catalog.
> > The lifter base is simply heated to a red glow with a torch and the
> > powder
> > applied . It provides a high carbon case hardening of unknown depth
> > but
> > then we don't need more than a few thou. So I feel this is so cheap
> > that
> > anyone could afford a couple bucks for the powder and this makes
> > rehardening lifter bases not as costly, as you suggested.
> > Dick T.
> >
> > As we both know....there can be exceptions to just about everything
> > which
> > we write about or try to share with others. There is rarely a clear
> > black/white condition. Our various opinions are the results of our
> > own
> > experiences, tests, investigations, and mistakes. Readers don't
> have
> > to
> > accept anything we say but are at least benefited by having seen the
> > comments and they in turn are then alerted to conditions they may
> not
> > have
> > even considered. They can then check out their own cars to see if
> what
> > they
> > have read here applies to their own situation.
> >
>
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