Just got this solid roller motor and I guess I oughta check the lash. What is everyone's technique or is there just one way? Also, is there any "signs" that an adjustment is needed?

 

Dave,

Just like on any solid:

Bump it around, when the exhaust just opens lash the intake,

when the intake just closes do the lash on the exhaust.

See ya' out there,
Dave

 

Thanks Dave..so if I am watching say the intake rocker start to compress to open the valve, I can assume that the exhaust is closed and can be adjusted at that point (and visa versa)? When they get out of adjustment, does the lash typically increase causing clattering or tighten causing poor performance. I have yet to adjust mine since I got it back but it seems to be running well. Hate giving myself more work

 

There's an overlap period while the exhaust and intake are both open some. Lash the intake when the exhaust starts to open. Lash the exhaust when the intake is closing.

Lash changing can be a sign of bad things to come. If the lash tightens up it's a sign of that valve stretching or tuliping. If it loosens up it could be stud flex if you've got studs, or a sign that there's wear going on. Also lash will increase if you set the lash cold and then check hot later on.

Personally, I use a go / no-go way of setting lash. If I'm setting lash at .016, I'll have a .016" feeler guage and a .015". When I can force the .016" in but the .015" won't go, I've got the lash right. This also makes it easier to judge if your lash is changing

 

I used to adjust half of them on #1 TDC , then the other half on #6 TDC. I've got the info on which is which laying around somewhere if you want to do it that way

 

He might be reffering to a a .017 instead of a .015, but anyway lash gets looser. allen locking nuts and stud girdles can reduce the frequency of needed adjustment. You generally hear increased noise as a sign of needing readjustment. quite often it might only be a couple that need adjusting.

The Crane Cams web site has a good adjustment proceedure so I'm not going to type it all out.

I use T-handle allens and angle feeler gauges it makes the job go faster.

 

Valve Lash Adjustment

Every cam company is different so you need to know if they want you to set the lash when the engine is either hot or cold. You should find this and the setting values on your cam card.

You need three tools: a wrench, an Allen wrench, and feeler gauges.

1. If you need to adjust while the engine is hot (at operating temperature) remove the valve covers and pick the cylinder you are going to adjust first.

2. Hand-turn the engine in its normal direction of rotation while watching the exhaust valve on that particular cylinder. When the exhaust valve begins to open, stop and adjust that cylinder’s intake valve. (Why, because when the exhaust is just beginning to open, the intake lifter will be on the base circle of the lobe, so the intake is the one we can now adjust.)

3. Using your feeler gauge, set to the correct valve lash, and place it between the tip of the valve stem and the rocker arm. Adjust until you arrive at the proper setting and lock the adjuster in place. Hold the wrench steady and tighten the center with the Allen wrench to lock it.

4. After the intake valve has been adjusted, continue to rotate the engine, watching that same intake valve. The intake valve will go to full lift and then begin to close. When the intake is almost closed, stop and adjust the exhaust valve on that particular cylinder. (Again, when we see the intake valve almost closed, we are sure that the exhaust lifter is on the base circle of the lobe.) Use the feeler gauge and follow the procedure described before in step 3.

5. Both valves on this cylinder are now adjusted, so move to your next cylinder and follow the same procedure again.


With an iron block and aluminum heads, subtract .004” and this should be the setting when cold as compared to when set hot. In other words, if you set the lash at .020 when the engine is hot, then you should read about .016 when the engine is cold.

 

Thanks guys. I love this forum. Wish me luck

 

Another thing you can do is set the valves hot, let them cool and see what the lash is cold. Then you can use the cold setting which is easier on hands, etc.

 

I have found that hot/cold lash varies by 2 to 4 thousanths.
I set the cold lash 2 thousands tight.

 

Wow that's exactly what I do Travis, .016" exaust, .014" intake

 

Hey Wayne, just got back from the track. Look for an Air-Gap post tomorrow sometime. The track prep was AWEFUL tonight, will be running the slicks with the bracket cars tomorrow so we'll see....