Larry and Sandi Miller wrote:
>
> Hey Hans, you stole MY Haynes.
>
> Larry
Larry, It's not yours, it's MINE!
You should see my Bently manual, I think it needs an oil change!
> -----Original Message-----
> From: Hans Huber <hans@desmodromic.com>
> To: spridgets@Autox.Team.Net <spridgets@Autox.Team.Net>
> Date: 29 July, 1998 10:46 AM
> Subject: Re: Timing the '72
>
> >
> >Chuck,
> >
> >Advancing past a certain point won't actually do any good.
> >That point is called MBT (Mean Best Torque (unless my
> >notoriously porous brain dropped something)), and anything
> >beyond that will just increase your problems (as Jeff Z said)..
> >
> >Having said that, the '72 is a hard puppy to get to ping,
> >since they lowered the compression to 8.0:0 (for the US)
> >for emissions-related reasons (meaning I really don't know).
> >My guess is that they wanted to increase the advance for
> >more complete combustion..
> >
> >My technique is to leave the vacuum advance connected,
> >and advance the timing until it sounds like too much (starts
> >to stumble a little), the back it off a bit past the
> >ideal (fastest smooth idle) point, then a touch more for
> >safety. and listen carefully for knocking. This is a crude
> >and indefensible method of setting the timing, but it's
> >always worked for me (with apologies to H.S. Thompson, and
> >real mechanics, and my mother (sorry, mom)).
> >
> >Looking at my trusty (and usually trustworthy) Haynes manual,
> >I see that they indeed made the advance curve steeper for
> >the emission control models (although I think there's a
> >misprint here, as 2 advance levels (19 and 23 degrees) are
> >labeled "2,300 to 2,500 rpm".
> >
> >In any case, it's difficult to figure out what they're saying
> >here, but it looks to me like it wants more than 10 degrees
> >at idle. Big news, that. Looks to me like it might want
> >as much as 26 degrees at idle, depending on what the hell
> >that "19' at 2,300 to 2,500" line is supposed to be. You
> >might try timing it statically, and see how much (centrifugal)
> >advance you're actually getting at idle. The centrifugal
> >advance comes in at 500 RPM on emissions distributors.
> >
> >I'd never heard of a timing light with an advance dial, as
> >Jeff Z. just described. Woo hoo! Gotta get me one of those!
> >
> >As Jeff said, the best way to set the timing (from a
> >performance standpoint) is to set the correct total (full
> >advance) timing, and Jeff's light sounds like the easiest way
> >to do that (you can also guess and/or mark off the total advance
> >on the timing cover, but that's a crude hack (cough)).
> >However you do it, you should rev up the engine after
> >setting the timing, and see that the timing mark moves to
> >somewhere in the vicinity ofthe total advance figure
> >
> >It looks to me like your engine ('72 emissions) wants
> >37 degrees total advance (7' static + 30' advance at ?? RPM)
> >
> >Enough nattering on. Good luck with it.
> >
> >-Hans "advanced *way* beyond MBT" Huber
> >
> >P.S. Does anybody have a newer revision of the Haynes
> >manual that has the correct info on centrifugal advance
> >for emissions dizzys? My Haynes is old enough to be missing
> >the title page (and at least pages 111-116), and is nicely
> >rebound with black duct tape, so I don't even know when it
> >was printed.
> >
> >On Wed, 29 Jul 1998 08:24:19 EDT Chuck Ciaffone wrote:
> >> It happens every time I tune my '72. I set the timing,
> >> using a timing lite, to about 10 degrees advance with
> >> the vacuum advance disconnected and plugged. It runs OK.
> >> Then I start turning the dizzy for more advance, and it
> >> runs better. SoI would guess that I probably run normally
> >> with about 15 or so degrees of advance, AND it still
> >> never seems to ping. Can/should I just keep advancing
> >> the timing till it pings? What's probably going
> >> on here?
> >>
> >> chuck
> >> --
> >> =====================================================
> >>
> >> chuck ciaffone chuckc@ibm.net
> >
> >
> >
--
Frank Clarici Toms River, NJ
Too many LBCs
3 Sprites, an Austin A40, and an Austin Mini all on the road.
1 Jaguar XJ6 family car, 1 Racer Midget project , & 2 Parts Spridgets
Check out my home page at http://www.exit109.com/~spritenut
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