Engine mod...challenge???

mrvette

Phantom of the Opera
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Mar 24, 2008
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It is not that I remember this little happening very often, but that Jay Leno 1 liter engine post reminded me of something that happened some years ago to my TPI on the '72 350 engine vette......

Another story and posts about it, but I had a bad cam that gave an idle rough as a cob for a LONG time, the engine vibration was so bad it would cause wiring harness fatigue....nuff said.....

Well so it seems one of the wires that broke was the +12 feed wire for the injectors on the driver/left side, but comic is, the engine would run rough as a cob at idle, and be struggling, but at speed it seemed more or less ok,

NOW it makes me wonder, in that I had made up a harness variation to change up the injector batches, as we know, it's left bank all at once, and then right bank all at once....Well, the old Bendix system on mid 70's Sevilles had it 4 corners, and 4 middles.....in other words...1-8-2-7 at once, then 4-6-5-7 at once......engine ran the same far as I could tell....

SO, the obvious implied question, what if I killed say one bank, and drove the car, I would be using 1/2 the gas at cruise....but the question is....since compression is still working on the dead cylinders, obviously there is a loss in there, but I dunno how much....second off, just what would be the best arrangement for cutting fuel to 4 of the cylinders, talking about stresses on the crankshaft.....bottom end, doubtful the valves would give a shit one way or another....

Another thought, what about some reversion allowing just a slight amount of gas into the 'dead' cylinders, would that cause such a lean burn that it would do damage??? or set off the knock sensor??

what arrangement would you guys try it on???

4 corners, 4 middle, one side?? which side?? and why??

:amazed: another concept, to alternate sides back and forth via electronic piggyback on to the computer, controlling only the 12 volt injector feed to the banks, and alternating back and forth between banks....so each one is cut 50% of the cycles.....

:skeptic:
 
That system in the Seville was a POS- even in it's day. The fix was to clip the wire to the trans that told the system it was in 4th gear.

It's all about engine balance. Drop a cylinder or 2 and they have to be covered up by the cylinders that are still working or it'll shake. That will be the way to figure it out. Wire up a cutoff switch bank to drop a cylinder- pick your speed, drop a cylinder, then another and then another. Find the sweet spots. The trick will be to setup a TPS so if you add ANY throttle, everything comes back.
 
That system in the Seville was a POS- even in it's day. The fix was to clip the wire to the trans that told the system it was in 4th gear.

It's all about engine balance. Drop a cylinder or 2 and they have to be covered up by the cylinders that are still working or it'll shake. That will be the way to figure it out. Wire up a cutoff switch bank to drop a cylinder- pick your speed, drop a cylinder, then another and then another. Find the sweet spots. The trick will be to setup a TPS so if you add ANY throttle, everything comes back.

You mean 3rd gear, I not aware they had any OD trans from '76-79? when they made these systems, the one I had on my Pontiac, you seen the induction I still have, NO?? anyway, I got the entire system off a '79 Sedan Deville 425 engine, played with the water temp sender to lie about water temps a bit, so computer ran just a tad richer.....car picked up about 4 mpg for the effort, and starting/running was ever so much better.....1000 cfm t-body up top, talk about instant torque....550 ft lbs not to be denied....

:bounce::rofl:
 
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