Cylinder deactivation discussion

[Peter7307]

Honda's new (to the Australian market at least) Accord Euro V6 3.5 litre also has cylinder de activation.

The normal six cylinder runs on six , four or three cylinders depending on the load required.

Honda are very quiet about the actual amount saved.

Pete.

[diesel_john]

my project is on hold until the head has new valve seats and guides.

[diesel_john]

Ended up buying a new head, from TOP LINE the reman. cores are drying up for the VW diesels. If you got a worn out VW diesel that's a good core, the engine is worth $250. 5 speed manuals worth $'s too.
Now back to cylinder decomissioning project.
I think i'll go even fire and not worry about the balance.
Fuel flow will be easier to verify, because i'll measure the fuel from the two unused cylinders and return it to the tank. This will be exactly the same as the amount of fuel that i am using.

[diesel_john]

1/ Checking the new head over, i found that the intake valves will miss the cam with the buckets out but the exhaust will not. I can over come this by putting in a couple old exhaust valves and grind off the valve tips enough to clear the cam.

2/ Also the timing belt would be seeing unusually spaced pulses with the buckets out scenario. it would be very jerky.

Will the uneven loading cause a belt failure?

[diesel_john]

Frank, i'm trying to think of a an belt driven OHC 2cyl. My 2 cyl. are all gear driven ,push rod. I just noticed turning this cam with 4 valves decommissioned that there is a real unevenness in the torque required, so i thought i'd pose the question. i will cut the bottom half off old rods and clamp them solid to the crank if they will clear the crankcase.

[elhigh]

Originally Posted by Frank Lee

^YES and no!

It has been done before. I've seen where some college kids back in the day pulled 2 cyls. out of a VW Bug and coaxed 58 mpg out of it, IIRC.

I think I read the same article.

As I remember it, those kids 1) installed the engine and tranny in a lighter chassis - a Fiat if I remember rightly and 2) they did more than just pull the conrods and whatnot - they converted the engine to a two-cylinder. They cut down the block and everything.

It looked really weird. You'd think that if they had wanted a two-cyl aircooled engine, they'd just use a Citroen 2CV mill. That's ready to go, proven tech. And French tinkerers have been sticking the 2CV engine into ultralight chassis for a long time, for either speed or super economy.

[elhigh]

Originally Posted by RH77

Does anyone remember the "Push-Pull" Chevy Citation X11 with 2 engines: front and rear ('85 I think)?

RH77

Never saw that. I did see a magazine crank out a Honda Civic with dual engines. Then they decided that wasn't enough go, so they did it again, but with Accord engines. Crazy. Can you say Polar Moment of Inertia? I knew that you could.

Mosler - the guy that makes the Consulier - made a Caddy with two engines, and some guy did a Hyundai Tiburon (!?) with two, for Sport Compact Car magazine. He won the burnout contest by a wide, wide margin: rear engine in reverse, front engine in forward, and pirouette slowly across the tarmac in a cloud of tire smoke. Made for weird video too.

[speedemon247]

I have a question! If I were to modify the ECU of a LS-3 corvette which uses cylinder deactivation to make the deactivation process manual and automatic what constrains should I put in ?

[diesel_john]

Welcome, speedemon247, great project. being able to lock it in 4 cyl mode of course. when in cruise control being able to adjust the delta about the speed setpoint. so it could go over setpoint down hills and lag under setpoint going up hills. being able to adjust to leaner burn than is normal, while watching the instant MPG. limiting the acceleration with the cruise buttons to avoid a downshift. being able to force the torque converter to lockup before the engine is warm, if an automatic.

[nemesis]

I wouldn't waist my time on this, there are easier/more efficient mods.