New product from Doug Pelmear's HP2g

[ecomodded]

It reminds me of the 81 Cadillac with the 8 , 6 & 4 cylinder mode.
It was called a 8-6-4 engine, a de-tuned big block.
The variable displacement was done by electronic solenoids on the valves along with different fuel mapping when in 6cyl or 4cyl mode.
This guys fuel cut off idea seems very simple yet i am betting it will be very expensive.
I Think a similar effect could be had for $10 by wiring in a kill switch to 1, 2 or 4 of your fuel injectors.

[t vago]

Originally Posted by Frank Lee

Repeat after me: Pumping losses. Pumping losses. Pumping losses.

I doubt if it makes a difference if you sequence amongst cylinders or go whole hog.

To expand upon Frank Lee's explanation as to why this won't work for a gasoline engine:

We can all agree that shutting off half of the cylinders in a gasoline engine will make the remaining cylinders work harder. This will cause the throttle valve to open so that the remaining cylinders can get more air. I've included two diagrams below, of an idealized throttled gasoline engine. One is with true valve-based cylinder deactivation, and the other is by simply cutting off the fuel injector to achieve cylinder deactivation.



For a true cylinder deactivation system, the valves are deactivated, and nothing is pumped through a cylinder. This makes the p-v diagram of the engines look like the above. Half of the cylinders are actually pumping, while the other half are simply compressing and expanding the captive air mass within the cylinder. The net result is that engine vacuum is decreased, causing the engine to work less in drawing a vacuum. This results in fuel savings.



Now, for schemes which only shut off the fuel injector, the deactivated cylinders are still pumping air through them. This will cause vacuum to rise between that of an engine with true cylinder deactivation, and that of a normal working engine. It'd have to, because the deactivated cylinders are still contributing to vacuum formation.

Now, since the deactivated cylinders are still doing work, that work has to be taken away from the generated power that the firing pistons are producing. The firing cylinders are effectively making twice the amount of effort they'd normally have to make to draw the vacuum. Worse yet, the combined effort for each firing cylinders is going to be more than for the normal engine that doesn't have any deactivated cylinders!

No, simply shutting off fuel injectors will not save gas. It'd have exactly the opposite effect.

[Chipster22a]

No, I'm not involved in the company other than as a taxpayer.

I live nearby in the same county that loaned him the $50,000.

I am skeptical and interested the discussion.

[nimblemotors]

I think it was Ford that determined if they shut off a cylinder injector every other firing, the engine could continue to run without radiator water to limp home. So it might have some effect by allowing a grill block and reducing the heat losses in the engine.

Originally Posted by drmiller100

diesels are different then gas engines in how they manage air. by definition, a diesel has "unlimited" air already. if you want less power, put a little less fuel to the combustion. By defintion, the engine is ALREADY loaded with most efficient air.

I still think this idea has merit on a gasoline engine. Do a misfire by skipping gasoline on one rotation.

In order to maintain same power, you would have to have MORE air, so you would open the throttle more.

Hence, less pumping losses.

This is basically pulse and glide thousands of time per minute.

[mechman600]

There are a few OEM 6-cyl diesels that run the engine on half the cylinders at idle to facilitate quicker warmup. They switch between the front three and the rear three cylinders every few seconds. Older Cummins ISBs and Detroit 60-series are examples.

DOD gasoline engines must disable the valvetrain when "misfiring" to maintain an exhaust composition of a stoichiometric air/fuel ratio or the extra air pumping through renders the cat and O2 sensor useless. That's what I would be worried about if attempting to concoct some sort of pikey DOD system.

[Chipster22a]

A bit of an update for those intersted in the HP2g saga. Local newspapers reported last week that Henry County is filing a lawsuit to recoup the $50,000 loan given to Mr. Pelmear. None of it has been repaid so far although it was due in 2011.

[Frank Lee]

Bwahahaha, Henry County now owns that valuable patent!

[Frank Lee]

Originally Posted by nimblemotors

I think it was Ford that determined if they shut off a cylinder injector every other firing, the engine could continue to run without radiator water to limp home.

FWIW the first I heard of it was on the Cadillac Northstar.

[pgfpro]

What ever happen to our friend Doug? Is he in jail or living the rich life?

[oil pan 4]

Hopefully in a wheel chair eating baby food caused by owing the wrong people money.