Living Throttleless

[Frank Lee]

Nope, sorry, this is a whole "different" combustion process; the Honda isn't.

[theunchosen]

as Frank said... this is nothing like I-VTEC. OEM across the board on gassers still have several hundred pounds of pumping losses per stroke. Diesels don't... no throttle plate, no valve restrictions no pumping losses... sort of. Just gotta push the burnt fuel out of the cylidner and suck it back in.

I-Vtec is still going to have that.. whether the losses are generated at the plate or at the valve makes no difference.

As to the OP.

Not happening. Its possible to make the engine run lean. It is not very... convenient. Power would flood in as the revs increase combustion events would start to go off early or with heavy det.... engine goes toast... back down the resistance.. AFR steady state would be around 20:1. Which returns some pretty decent fuel savings...

Savings are devoured when the engine gets ahead of you every time you have to find the sweet spot with that specific road condition, wind speed, relative traffic.... at that specific moment.

Project at hand is a J32a2 in a custom chassis out of CF/FG twin turbo charged, with J35A4 crank, massive ram air intakes, massive ram air vents to cool the pre-coolers, massive radiators to cool the engine... and everything else is lifted from an Accord 97 and made to fit. not too terribly concerned about FE since the CL gets 30+ and this weighs about half as much and is more aero friendly....

[Christ]

Aw... I was hoping to see this one come through...

[theunchosen]

It may still happen.

It's just going to require some custom head fabrication to allow for SFI, in-cylinder cooling, and greater cylinder intake and exhaust capacities.

That may happen anyway on the MK II prototype, because its going to need it for higher compression, higher boost pressure, and marginally larger displacement.

I may try it on the MK I. May.... Its going to have an underbody radiator and coolant well for 3-4 gallons of coolant and surface area of at least 10 square feet as well as two large oil wells and oil coolers for about 10 quarts. It's also going to have water injection to cool the boost using one 330cc/min per fuel rail, so amping up the amount of fluid to cool the engine will be easy.

So I may restart the frankenstein project... but I may not. the J32-35A2 will be substantially more expensive than any of the parts in my D15Y. beefed up pistons and rods for one are more expensive and way more valves is another issue. so I may do it. But I don't really need to... my estimated range so far is 1K miles with a 30 gallon tank....

[dwtaylorpdx]

Originally Posted by Frank Lee

Incidentally, years ago I read about BMW's experiments with no conventional throttle. They manipulated the intake valves to provide the throttling.

The new 3 series does exactly this, it does have an Emergency throttle plate that slams to stop runaway if needed.

I also wondered if gasoline was the only option?

I've run engines on Kerosene, Methanol, Nitro-Methanol.

Klotz makes a nitro propane additive that mixes with either gas or methanol.
Methanol drops you valve temps by 20+% Nitro takes it even farther.

I would think any alcohol would be better than gos for lean burn.
Also add a little lubrication and run hyper cold spark plugs, ALA Rotary engines.

Dave

[theunchosen]

Alot of cars come OEM with variable valve timing these days. I actually don't think any of the MCs don't manufacture at least one VVT car(actually its the intelligent VVT(I-VTEC)).

My concern is not producing an engine that can run lean on any ole fuel. If that were the objective.... I would just go buy a diesel engine. My objective was develop an engine that could run straight gasoline and commonly available components at lean burn ratios to achieve greater FE. Also I have no concern for the ecological influences of the engine, only the economical ones. Those other fuels would be much more expensive to run than Iso-oct and water. Namely because water is pretty much free... and gas is cheap.

The concern at the time of its birth was to develop it in an inexpensive way(the system itself, not the very costly research and debugging phase). New fuel systems require new ECU mapping. What i proposed only required i lie to the ECU about some numbers.

[dwtaylorpdx]

I was thinking E-85, relatively available. But I get your goal state, I use the same logic for lots of other stuff. Nothing like being able to walk in to a grocery store and buy what you need...

In the late 60's Buick was playing with lean burn, they had a fancy ignition and carb to try and control detonation.

The Klotz or Motul additives are not badly priced especially if you purchase them in the bulk sizes. Mix alcohol 50/50 in the water tank it will reduce the needed volume of water..

Just thinking its a cool idea, if you can slay the detonation dragon...

Dave

[Shawn D.]

Originally Posted by dwtaylorpdx

The new 3 series does exactly this, it does have an Emergency throttle plate that slams to stop runaway if needed.

I also wondered if gasoline was the only option?

Yes, BMWs with Valvetronic are gasoline-only. The throttle plate is not there to prevent runaway (the ECU would shut off fuel instead), but for emission functions & vacuum during warm-up and for limp-home control if Valvetronic has a failure.

[theunchosen]

I thought about the topic a little more. After I have replaced my daily driver with a reliable build I will pull the D15Y hook it up to massive radiator fins along its body and run a lean bench test. On a stable non-moving platform i could limit variables and changes. Also I could much more carefully measure fuel consumption(on a mass balance) while the engine runs or for quickie tests just add a very small exact amount of fuel and time how long the engine is able to run.

I changed my mind because my D has very little life left in it(50-60K)... and the J block should have at least half its life time left(100K miles) if not much more.

[usergone]

Why not go low-tech, instead of keeping the ECU?

I had the idea of a "throttleless carburetor." It is just a throttle body with 2 jets. The jets meter their fuel by means of a tapered needle that pushes in to slow (or stop) flow, and pulls out to increase flow.

One needle has the gasoline, so whenever you push on the "go pedal" (sorry, I guess that in this application it really would be the "gas pedal") the gas needle opens. The other needle is water. It would be somewhat inversely proportional to the gas needle, so if the gas needle was almost closed (idle) the water would be injecting a good amount. If the gas needle was open (IE, flooring the pedal) the water would be injecting very little.

The water and gas would both have to be pressurized, so that you don't care about the Bernoulli effect sucking the fuel (and water) out, like a normal carburetor.