At 01:33 AM 10/19/97 -0400, Les Myer wrote:
>>Clip........Anyhoo, the 1500 makes the 1275 a total road rocket in
>>comparison. In an attempt to make the 1500 more responsive, last week I
>>removed the air pump belt and reset the timing from 2ATDC to 12 BTDC. This
>did >not make any difference to the acceleration. What's puzzling is that
>the >sluggard has an approx 20% increase in engine displacement over Binky.
>The mpg >is also abysmal - 20 compared to about 28 for Binky. The plugs
>seem to look
>>OK - no carbon at all. The drive seems a little more smoother than Binky
>>but that is a combination of many things, I suppose. I'm wondering if I'm
>>missing anything. Of course, Binky has twin SU's and Doe-Doe has a single
>>Z-S - is that the problem?
>>
>>Regards, Adrian
>
>Hi Adrian,
>
>I'm no expert on 1500s,
<SNIP>
>I imagine the 1500 would respond dramatically to the right combination of
>modifications that deal with all of these areas, but someone else will have
>to tell you what they should be. The 1275 happend to be before the advent
>of most of the emissions controls. I'm just trying to help explain your
>observations.
>
>Good luck
>
>Les Myer
Hokay, I'm no expert on the 1500 either, but here's what's been done on
mine over the past 3 years, and the results:
Original Carb Cleaned & Overhauled
Smog Pump Gone (courtesy of PO)
Could get out of it's own way, but not much more, 20 MPG.
Crane Allison ignition (due to death of Lucas OPUS unit)
Lucas Sport Coil (due to death of original coil)
Timing set to 10BTDC
Barely Freeway driveable, 24-25 MPG Highway
Replaced deceased Catalytic Converter <<<IMPORTANT>>>
Checked Valve Clearances
Adjusted Carb to lean out mixture (was WAY rich)
Ignition timing to 12BDC
Respectable acceleration, 27-28MPG Highway
Replaced cracked exhaust manifold with PaceSetter header (less $$$ than stock)
Replaced rest of exhaust system with free-flow system (less $$$ than stock)
Adjusted carb slightly to deal with reduced exhaust restriction
Reset Timing to 14BTDC
NOW we're talking, 29-30MPG Highway, 25-27MPG City. Gotta start watching
out for State Troopers & the like.
The biggest single improvement was to check the catalytic converter. The
matrix inside had crumbled into a mass in the bottom of the case. The
exhaust back pressure mush have been enormous. After I fixed that, it went
from having to have it really rich just to keep running, to needing to be
leaned out about a full turn. Come to think of it, really rich input into
the catcon is probably what made the mainfold crack (excessive heat).
Anyway, hope that helps.
Chris Kotting
ckotting@iwaynet,net
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