Elio Engine Valvetrain

[skygazer6033]

I do a lot of research on technical aspects of the iav engine. I have read that the valve clearance is adjusted by the use of classed shims. This is a common practice on high performance motorcycles. However the innovative iav cylinder head utilizes a cam cover with integral cam bearings. This design would not allow access to check valve clearances or replace shims to make adjustments. As soon as the cover is removed for access the valve springs will kick the cam up and make it impossible to check the clearance. Iav seemed to be really proud of their design in that it cuts down on the number of individual parts allows use of a smaller oil pump etc. It is my contention that if your going to cut corners the head and valve train is not the place to do it (nor is the crankcase and bottom end for that matter).

 

[tim]

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.

 

[outsydthebox]

I do a lot of research on technical aspects of the iav engine. I have read that the valve clearance is adjusted by the use of classed shims. This is a common practice on high performance motorcycles. However the innovative iav cylinder head utilizes a cam cover with integral cam bearings. This design would not allow access to check valve clearances or replace shims to make adjustments. As soon as the cover is removed for access the valve springs will kick the cam up and make it impossible to check the clearance. Iav seemed to be really proud of their design in that it cuts down on the number of individual parts allows use of a smaller oil pump etc. It is my contention that if your going to cut corners the head and valve train is not the place to do it (nor is the crankcase and bottom end for that matter).

I agree with what you are saying. Because (from the pics) the cam cover is also the upper cam bearings. Small access doors, or large "pipe plugs" could be added to the cover for checking valve lash.
All I want to say is, I trust EM to Work this issue out before it reaches production. I am confident that they are aware of the costs involved if warranty service or regular maintenance, becomes "labor intensive" ($$).

 

[skygazer6033]

Never trust the engineers. Sometimes they will overlook the most obvious things. Years ago I had a Pontiac TransAm. On a hot Atlanta Georgia evening on the way to a cocktail party I discovered the air conditioning and the power windows were powered by the same fuse which of course blew leaving my wife and I with no a/c and usable to open the windows. I you see something that isn't right point it out. BTW where in E. Tn. Are you? I was born in Crossville.

 

[zelio]

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.

Current information provided by EM says oil changes are supposed to be every 3000 miles. :-) Z

 

[Ty]

I do a lot of research on technical aspects of the iav engine. I have read that the valve clearance is adjusted by the use of classed shims. This is a common practice on high performance motorcycles. However the innovative iav cylinder head utilizes a cam cover with integral cam bearings. This design would not allow access to check valve clearances or replace shims to make adjustments. As soon as the cover is removed for access the valve springs will kick the cam up and make it impossible to check the clearance. Iav seemed to be really proud of their design in that it cuts down on the number of individual parts allows use of a smaller oil pump etc. It is my contention that if your going to cut corners the head and valve train is not the place to do it (nor is the crankcase and bottom end for that matter).

I was wondering that very thing. Is it possible they'll use some kind of hydraulic lifter which effectively makes the valves self-adjusting? I haven't had a vehicle that required valve adjustment since my 1980 Mazda and I didn't think anyone still did that. (I know they do on motorcycles but am not sure why)

 

[goofyone]

I do a lot of research on technical aspects of the iav engine. I have read that the valve clearance is adjusted by the use of classed shims. This is a common practice on high performance motorcycles. However the innovative iav cylinder head utilizes a cam cover with integral cam bearings. This design would not allow access to check valve clearances or replace shims to make adjustments. As soon as the cover is removed for access the valve springs will kick the cam up and make it impossible to check the clearance. Iav seemed to be really proud of their design in that it cuts down on the number of individual parts allows use of a smaller oil pump etc. It is my contention that if your going to cut corners the head and valve train is not the place to do it (nor is the crankcase and bottom end for that matter).

I am just wondering where did you read about the classed valve shims?

I have read a lot of speculation however have not yet read any detailed information from IAV or EM on the actual valvetrain components and how they are installed other than the inclusion of simple simple two step variable valve timing which my guess will be accomplished by advancing the timing. They have published this video which does show bucket tappets but not whether they are hydraulic or not or any other solutions which IAV may have included in the design.

 

[Dustoff]

Elio Motors Tech Talk V24 - The Elio Engine - Your Questions Answered
Discussion in 'In The News' started by protias, Jul 9, 2014.

A self-adjusting hydraulic valve lifter for an overhead cam engine wherein this pressure fed hydraulic valve lifter is interposed directly between a valve and cam, the lifter including an upright, cup-shaped plunger engaging on the valve stem and being reciprocally received in a larger, inverted, cup-shaped follower which engages the cam and which is slidably guided in a fixed bore surrounding the valve stem, a pressure chamber being formed between an end of the plunger and the follower, with a helical compression spring positioned therein to normally bias the plunger and follower against the valve stem and the cam, respectively, and a fluid supply passage is provided to supply fluid under pressure to the pressure chamber, the fluid supply passage including a V-shaped groove with an O-ring seated therein to serve as a one-way check valve controlling the flow of fluid to the pressure chamber.
Looking at the cutaway of the valve train you can clearly see the oil groove in the hydraulic camshaft follower.

 

[Dustoff]

I do a lot of research on technical aspects of the iav engine. I have read that the valve clearance is adjusted by the use of classed shims. This is a common practice on high performance motorcycles. However the innovative iav cylinder head utilizes a cam cover with integral cam bearings. This design would not allow access to check valve clearances or replace shims to make adjustments. As soon as the cover is removed for access the valve springs will kick the cam up and make it impossible to check the clearance. Iav seemed to be really proud of their design in that it cuts down on the number of individual parts allows use of a smaller oil pump etc. It is my contention that if your going to cut corners the head and valve train is not the place to do it (nor is the crankcase and bottom end for that matter).

Just how did you get access to IAV and their development of this engine?o_O

 

[Kuda]

Snipped: They have published this video which does show bucket tappets but not whether they are hydraulic or not or any other solutions which IAV may have included in the design.

Interesting concerns. Having worked on quite a few sports car motors
over the years, I get wanting the hands on aspect, but things have come
a long way & I don't miss setting points, etc. Do like driving the twisty
roads though................any way this ain't IAV's 1st Rodeo................

https://www.eliomotors.com/iav/