How's my valvetrain geometry look? Options

[Cevan]

I'm attempting this for the first time. I'm using 1.7 rockers that have been decked .060 and 911 swivel adjusters. The cam I'm using has an advertised lift of .465 for both intake and exhaust.

On the intake side, my lift was .482 with the geometry at its best, but still not straight. It seemed I needed to back the adjuster out even farther. I had the adjuster about 3 turns in from when the threads started disappearing.

So I used .030 washers under each pad to see what shimming the rocker assembly up would do (this is only to see how shims will effect things). At about 3 turns in (as above) on the intake, I got a net lift of .482, within the 5% limit per Jake's valvetrain geometry article.










So I go over to the exhaust side. Again, I need to keep backing the adjust out to get the geometry looking correct. At 3 turns in, my net lift is .453.




Both the intake (.482) and exhaust (.453) net lift are within 5% of the advertised lift. Is this much of a difference going to be a problem? The motor is a 2056.

[ChrisFoley]

Are those pictures at full lift?
The adjuster should be in line with the valve at half-lift.

[Cevan]

The pictures are all at half of net lift.

[VaccaRabite]

At 1/2 lift, the look good, like they are in 1 plane with each other.

Zach

[Dr Evil]

I cant believe Zach didnt mention, you are going to need to grind down and re-slot the the adjusters lest they impact your valve cover over and over again (IMG:style_emoticons/default/wink.gif) Looks good otherwise.

[Cevan]

I was going to check the adjuster to valve cover clearance with clay. I assume I'll need to take about .030 off. Will I have an issue with the difference in intake and exhaust lift?

[VaccaRabite]

You should not, so long as you are within the 5% tolerance... We had to grind down all of mine a little and re-slot them.

Zach

[type11969]

I cant believe Zach didnt mention, you are going to need to grind down and re-slot the the adjusters lest they impact your valve cover over and over again (IMG:style_emoticons/default/wink.gif) Looks good otherwise.

Checking this is a good idea but I have two engines running 1.7L rockers with 911 adjusters and have no valve cover interference issues. Just saying you don't need to pull out the grinder yet.

-Chris

[Cevan]

I cant believe Zach didnt mention, you are going to need to grind down and re-slot the the adjusters lest they impact your valve cover over and over again (IMG:style_emoticons/default/wink.gif) Looks good otherwise.

Checking this is a good idea but I have two engines running 1.7L rockers with 911 adjusters and have no valve cover interference issues. Just saying you don't need to pull out the grinder yet.

-Chris

I think because I'm using a shim uder the rocker pads, everything will sit a little higher.

[type11969]

Ahh, missed that

[VaccaRabite]

I had to space mine out a little to get them right. W/O the spacers, I could not get the geo right.

I ended up using my calipers to find 4 washers exactly the same thickness AND the thickness I needed to get things to work. Once spaced, the geo pretty much fell right into place. I think we ended up grinding off a little more then the thickness of the washers off the top of each adjuster and then just recutting the slot. on mine they JUST barely kissed the inside of the rocker cover when the engine was cold, but you could hear them start to "tack tack tack tack" against the rocker cover as it heated up.

Zach

[Cevan]

I ordered a spacer kit from Aircooled.net, which has 3 different thickness shims. Right now I'm just using .030 washers to see if that would work.

In the meantime, I've got to remove some material from the other 3 aluminum rockershaft spacers to get the right gap (.003-.005 I believe). Always something to do. These are definately not slap together engines.

[Cevan]

With the .030 rocker pad spacers in place, I used some clay on the back side of the rocker cover. With the valves closed, I have at least .100 between the top of the adjusters and the cover. I think this will be enough.

[Als914]

With the .030 rocker pad spacers in place, I used some clay on the back side of the rocker cover. With the valves closed, I have at least .100 between the top of the adjusters and the cover. I think this will be enough.

Are you using stock valve covers. I am in the process of setting up my VT geometry but I have the polished aluminum covers. I have had these on the heads for years so I can't remember which one or the other has a taller internal stance?

[Cevan]

With the .030 rocker pad spacers in place, I used some clay on the back side of the rocker cover. With the valves closed, I have at least .100 between the top of the adjusters and the cover. I think this will be enough.

Are you using stock valve covers. I am in the process of setting up my VT geometry but I have the polished aluminum covers. I have had these on the heads for years so I can't remember which one or the other has a taller internal stance?

I'm using the stock covers. I haven't heard any good things about the aftermarket covers that are bolted on.

[Als914]

With the .030 rocker pad spacers in place, I used some clay on the back side of the rocker cover. With the valves closed, I have at least .100 between the top of the adjusters and the cover. I think this will be enough.

Are you using stock valve covers. I am in the process of setting up my VT geometry but I have the polished aluminum covers. I have had these on the heads for years so I can't remember which one or the other has a taller internal stance?

I'm using the stock covers. I haven't heard any good things about the aftermarket covers that are bolted on.

I have had them on my daily driver for over 200K miles (I am the original owner) with no issues. My question wasn't what your preference is, I was hoping to find if there is a difference in internal hight from the gasket seat, one to the other.

[r_towle]

Chris,

It looks wicked pissa.

[Cevan]

With the .030 rocker pad spacers in place, I used some clay on the back side of the rocker cover. With the valves closed, I have at least .100 between the top of the adjusters and the cover. I think this will be enough.

Are you using stock valve covers. I am in the process of setting up my VT geometry but I have the polished aluminum covers. I have had these on the heads for years so I can't remember which one or the other has a taller internal stance?

I'm using the stock covers. I haven't heard any good things about the aftermarket covers that are bolted on.

I have had them on my daily driver for over 200K miles (I am the original owner) with no issues. My question wasn't what your preference is, I was hoping to find if there is a difference in internal hight from the gasket seat, one to the other.

No problem. I only have experience (limited at that) with the OEM covers.

[Dave_Darling]

The stock covers curve inward at the top and bottom. The aftermarket ones are just about square, so they have more room at the top and bottom.

And I'm quite surprised that you're getting the bolt-on ones to fit and seal up! Good job, hopefully you'll write up a thread on how you did it.

--DD

[watsonrx13]

I'm attempting this for the first time. I'm using 1.7 rockers that have been decked .060 and 911 swivel adjusters. The cam I'm using has an advertised lift of .465 for both intake and exhaust.

On the intake side, my lift was .482 with the geometry at its best, but still not straight. It seemed I needed to back the adjuster out even farther. I had the adjuster about 3 turns in from when the threads started disappearing.

So I used .030 washers under each pad to see what shimming the rocker assembly up would do (this is only to see how shims will effect things). At about 3 turns in (as above) on the intake, I got a net lift of .482, within the 5% limit per Jake's valvetrain geometry article.

So I go over to the exhaust side. Again, I need to keep backing the adjust out to get the geometry looking correct. At 3 turns in, my net lift is .453.

Both the intake (.482) and exhaust (.453) net lift are within 5% of the advertised lift. Is this much of a difference going to be a problem? The motor is a 2056.

Chris nice job. I'm curious what your final push rod length was for intake and exhaust. Also, can you describe and/or photo how you mounted the dial indicator?

-- Rob