A dyno is a great place to decide what your timing should be. It's
unusual for an engine to need much more than 30 degrees, but i suppose
some do. I don't know that much about car engines, but with bikes it's a
function of the kind of squish band, compression, and cooling. Years ago I
did a lot of testing with a single cylinder motorcycle engine on a dyno,
varying compression ratio with "infinite" cooling. The most advance we
ever reached that actually increased power was 33 degrees.
-----Original Message-----
From: Tom Strange
To: Charly Mitchel; Chuck Arnold; 6pack digest; FOT
Sent: 4/29/2003 8:03 AM
Subject: Re: Report on mods and performance
Charly,
Absolutely right... on almost any engine you start running the risk of
burning the pistons & lots of other bad things at about 33 to 34 degrees
before tdc. If you can run the engine up to 2000 or 2500 (all your
advance
should be in by then) and have it hold steady at 32, you are probably at
about optimum.
At 32 you should be safe, I wouldnt worry about backing it off to any
less
than that....
just my humble opinion ......
Tom
----- Original Message -----
From: "Charly Mitchel" <charly@mitchelplumbing.com>
To: "Chuck Arnold" <chuck.arnold@oracle.com>; "6pack digest"
<6pack-digest@autox.team.net>; "FOT" <fot@autox.team.net>
Sent: Monday, April 28, 2003 11:04 PM
Subject: Re: Report on mods and performance
> I'm trying to figure out where to set the timing on my TR6. My engine
is
> set up similarly, it has a stage 2 head also done by Performance, D9
cam
set
> precisely with vernier gear, triple Webers, long center branch header,
> engine has been balanced, pistons (.020" over) matched for height and
block
> decked .018", rods lightened, flywheel lightened, I also modified the
thrust
> washers so as to have four instead of two. I'm using stock valve
train
> except for the solid spacers between rockers. It has a Lucas Sport
coil
and
> racing wires, I built a distributor that has a 13 degree mechanical
advance
> and use a Pertronix ignitor with out a vacuum advance.
> My question is where should I be with the timing at an idle? or even
static
> if easier? If it's easier to set the timing at speed I could do that
also.
> Everything I read says I should be around 32 degrees total advance at
the
> flywheel. This would be 13 distributor degrees X 2 plus 6 degrees.
Does
> this sound right?
> Chuck, who did your Dyno work, are the local? Thanks for any input.
> Charly
>
>
>
>
> ----- Original Message -----
> From: "Chuck Arnold" <chuck.arnold@oracle.com>
> To: "6pack digest" <6pack-digest@autox.team.net>; "FOT"
<fot@autox.team.net>
> Sent: Thursday, April 24, 2003 6:17 PM
> Subject: Report on mods and performance
>
>
> > I have a TR6 that I did a lot of work to this year. I got it to the
> > dyno last week and dialed in these maximum results [though I think
there
> > is definitely more there though more tweaking with the Weber jets].
> >
> > Maximum HP at the wheels: 158 at 5500 and over 150 from 3000-6000
RPM]
> > Torque 170 at 4800 [pretty peaky, but over 150 from 3000-6500]
> >
> > My modifications include:
> > Head ported and valves radiused, milled to 3.30 [12:1 or so]
> > [PErformance Automotive, Tacoma WA]
> > Heavy duty springs
> > Tubular push rods
> > 1.55:1 roller rockers [the above all from TSI]
> > Triple Weber Carbs and Cannon Manifold from British Parts NW [ended
up
> > with 140 mains, 60 idle jets]
> > K&N air filters
> > Electromotive HMX crank fired electronic ignition [no more dizzy,
and
> > knob tunable advance at 1000, 3000 and 8000 rpm [can roll off or
retard
> > linearly from 3000-8000, but doing so with initial set at 16
degrees,
> > 3000 at 32 degrees and 4 degrees of rolloff lowered HP to 148, so
set
> > 8000 at 0 change from 3000 -- am using 101 Octane racing fuel].
> > Jet Coated 6:1 header
> > 2.5" single exhaust to a Flowmaster 50 series exhaust and Monza
> > Resonator [Summit] and local muffler shop
> > Oil Cooler
> > Balanced engine
> > .03 over pistons
> > ARP head, rod and crank bolts
> > Flywheel lightened to 22 lbs [wish I'd seen this month's Grassroots
> > Motorsports first and read Vizzard's article on weight -- 12 lbs
> > flywheel and smaller diameter clutch = same as 320 lbs weight off
the
> > car]
> > Electric Fan
> > Mallory fuel pump [and battery in the trunk]
> > Oil Cooler
> > Tilton .75 dual master cylinders [with necessary balance bar welded
to
> > the brake pedal] -- think these are too large as pedal pressure is
high
> > Herman Van Den Akker Toyota 5 speed with annular throwout bearing
> > Goodparts 300Z viscous limited slip kit [locally sourced 4.08:1
diff]
> > --gearing change made for 112 mph at 6500 on the dyno so will need
that
> > 5th gear at Pacific Raceways
> >
> > I use 16x7 Panasports with 205x50 Kuhmo Eksta V700's. Have tube
shocks
> > in rear, a rear anti-roll bar and stiffer front anti-roll. Stiffest
> > front shocks I could buy and fairly stiff rear springs, Adjustable
SPAX
> > up front, KYB's in the rear. Nylatron bushings. Toyota 4 Pot
brakes to
> > vented rotors and Carbotech Panther Plus pads in front [bought the
Kit
> > on EBAy from the Canadian], 7/8" rear brake cylinders to Carbotech
> > Kealated pads in the rear with Nissan 280Z aluminum finned drums. I
> > have lowered the spring perch in front about a quarter of an inch.
> > Frame is about 2.5" off ground in front.
> >
> > I have aluminum front hubs on order.
> > Am investigating going to Nissan stub axles in the rear [anyone have
any
> > TR experience with this -- how to fasten the bearing carrier to the
> > trailing arm is the issue.
> >
> > First time on a track last weekend was good and bad. Good because
the
> > car ran really well [and sounds awesome], bad because my shifter
decided
> > to depart from the housing leaving me only 3rd gear during my second
> > session. Have new parts to fix the problem -- thank you Edward Hamer
for
> > the spring retainer and Herman for the non obtanium shifter cap.
> >
> > Car is very neutral, though I am pretty good at going too fast in
some
> > turns, and quite bad at catching it, so I did manage one spin [at
least
> > I now can catch those in time to keep from killing]. Hard to tell
how
> > much faster it and I am. Know my times at Pacific last year were
about
> > 2 minutes flat. Am going there next weekend, so we will see what we
can
> > do not [presuming I learn to keep it on the road at 5b -- spun twice
> > there last year].
> >
> > Hope to get enough lap times/driving experience/training this year
to
> > build a legal, competitive 6 for SOVERN vintage racing next year.
[by
> > by tranny, diff and HMX], hello A type overdrive, electronic
distributor
> > and Salisbury 4:11 expensive rear end, and of course the 16" rims
[will
> > keep them all in this car and build another I think]
> >
> > Chuck
> >
> > [demime 0.99d.1 removed an attachment of type text/x-vcard which had
a
> name of chuck.arnold.vcf]
>
> [demime 0.99d.1 removed an attachment of type image/jpeg which had a
name
of apr18#03.jpg]
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