Elio Engine Valvetrain

[powerup]

Guys, thanks for the welcome. To add a bit more to the valvetrain discussion, I have it on good authority that VVT is not completely out of the picture. It will be employed if required once by the testing is completed and the engine does not meet targets. VVT systems are expensive and technology that will not make as much of a difference on this motor as it is already designed and maximized for mileage. If you look at the current design you can see there is space around the cam drive to add a cam phaser as well as cast features on the head to be machined for the placement of control solenoid.

 

[goofyone]

Guys, thanks for the welcome. To add a bit more to the valvetrain discussion, I have it on good authority that VVT is not completely out of the picture. It will be employed if required once by the testing is completed and the engine does not meet targets. VVT systems are expensive and technology that will not make as much of a difference on this motor as it is already designed and maximized for mileage. If you look at the current design you can see there is space around the cam drive to add a cam phaser as well as cast features on the head to be machined for the placement of control solenoid.

Thank you for the great info and feel free to share anything else you can as we would love to know more about this engine.

I know one big question many of us have is will this be an interference engine? I know with the timing chain this should not be much of an issue however it would be nice to know.

 

[Snick]

Not if they are built right and maintained properly, I had an 1984 BMW 325e with 532k that ran like a top until some lady wasn't paying attention, ran a stop sign, and T-boned me.

It was broad daylight and she tried to tell the officer that she didn't see me. He immediately asked if she was color blind? LOL

My car was as pictured below. A color BMW refers to as "Hennarot". It's like a cross between the color of a stop sign and a road cone.

Interesting color and an interesting color name, too. Henna is of course brick red. Rot is German for red. The color looks like a balance of pure Rot and brick red.

 

[Snick]

Welcome powerup and great first post!

I can verify that powerup is correct about the variable lift system.

Also I can confirm that variable valve timing is not currently planned for this engine.

I had to go back and re-read the Tech Talks a few days ago and discovered that Elio Motors has actually all along stated that this engine would feature variable valve lift and not variable valve timing. In the very first Tech Talk IAV/Elio states that this engine will use 'two-step variable lift technology' and in Tech Talk v24 EM confirms that VVT will not be used in this engine. This information is further corroborated by the IAV/Elio demo engine spec sheet stating that 'switchable tappets' will be used as switchable tappets are specifically used to change lift. Switchable tappets are commonly used as one component of a VVT package however there is nothing to say they can not be used on their own. You can also see the arrangement of the intake cam lobes in the Elio engine animation video.

Tech Talk V1: http://us6.campaign-archive2.com/?u=24b371802c83d81776b06aa68&id=545e7f615f
Tech Talk V24: http://us6.campaign-archive1.com/?u=24b371802c83d81776b06aa68&id=4801365dc7

Interesting! VVL seems like a cheaper way to accomplish psuedo-Atkinson cycle. Less pumping losses at part loads. but going to have to have a really accurate and fast acting MAF sensor. If MAF sensor fails, fuel economy is going to plummet. I guess that makes it easy to diagnose.

 

[skygazer6033]

Powerup's statement makes a lot of sense. I too have spotted features on the head that seem to have no reason to be there. It possibly could be IAV is keeping VVT as their "ace up their sleeve" to be pulled out if the engine fails meet efficiency parameters. By having these "fantom" features already in place the implementation of VVT would be a "bolt on" rather than a complete redesign of the head. Of course this assumes control wiring is in place and the ECU can be set to control it. (Speculating again I know)

 

[Joshua Caldwell]

The Elio will be using a dual lift or shifting hydraulic bucket on the intake. This allows for high and low lift based on engine RPM and load demands. There are three lobes per intake. Effectively the same system as Porsche uses as it's Variocam Plus System. As pointed out earlier in this post the bucket tappets are hydraulic. The integral cam cover with integral cam bores, would require a lot of tooling to allow the use of a shim style mechanical adjustment.
View attachment 2219

To clear up any doubt, the cams run in the parent aluminum of the camcover and cylinder head. This is a proven method in engine design for 35 plus years. It does require tighter design and manufacturing tolerances with today's lower viscosity oils.

Welcome

 

[Edward43]

Thats true. I bought one of them used world famous GM diesel powered Olds Delta 88's. It ran, smoked, rattled, blew head gaskets, leaked oil, but got me where i needed to go.
Gotta do what you gotta do until you get to the point you can do what you want to do.

I had one of those Delta's as well, buuuut, we were invisible to GM. I was still riding high on the memory of that '57 Chevy. Found it hard to believe they would not stand behind a newly recertified vehicle. I shoulda known, they started slipping in '58 and on. It is easy to produce a car if you ask the customer what they really want instead of telling them.. Things. They are a changing.

 

[wizard of ahs]

Great info....AND....

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To The ​

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[goldwing06]

will be interesting to see what the maintenance schedule is such as oil changes, valve adjustments, transmission servicing. Hopefully not too bad because some of the folks at pep boys aren't the best of mechanics and they will be practicing on the real deal.

just looking at the animation of the engine again, and noticed that the valve train appears to be flat tappets instead of roller tappets. most engines today are going to roller tappets to get better gas mileage because of reduced friction. even an engine of this small of displacement would benifit from roller tappets. wonder if the final ideration of the design will have it?

 

[goofyone]

just looking at the animation of the engine again, and noticed that the valve train appears to be flat tappets instead of roller tappets. most engines today are going to roller tappets to get better gas mileage because of reduced friction. even an engine of this small of displacement would benifit from roller tappets. wonder if the final ideration of the design will have it?

My guess is that this is just an area where they have decided that cost wins. We just have to keep reminding ourselves that Elio Motors is not trying to build the most fuel efficient vehicle possible but strike a balance between maximizing fuel efficiency and minimizing cost.

I foresee plenty of performance mods on these engines in the future as I am sure people will rebuild them with a lot of nice upgrades for more power.