Tappet Screen

[1955fle]

Is anyone not running a tappet screen? Is there a big problem waiting to happen by not running one? What do you think?

[NightShift]

Is anyone not running a tappet screen? Is there a big problem waiting to happen by not running one? What do you think?

Dear 1955fle,
If you are running hydraulic lifters then you really aught to have one.

R'spectfully,

[PanPal]

You can also run the later style screen with a spring.

[SFMike]

Pretty basic trouble prevention item to me.

[hjans]

What's the problem to use a screen for you ??
I cannot imagine one NOT to use it.
I agree : pretty basic trouble prevention .

[1955fle]

I don't have a problem running a screen. I opened the tappet screen cap for the first time since I purchased the bike 12 years ago and there does not seem to be a screen in there. I had the motor rebuilt when I first purchased the bike. The rebuild was done by a very reportable shop that has been working on these for years and still does. All I have found in the cavity so far is a 2" long stretched out spring and not much else. I need to do some further investigation to see what is actually there. It may be the later style, but not sure yet. I hope to get to it in the next couple of days and see what is up. I will report my findings.

If it is the later style is there any value to go back to the original style?

-Carl

[fourthgear]

Even if you are not running hyd. lifters , the oil that goes through that screen gos up to the rockers .

I think the screen slides inside the spring . The spring forces a flange on the bottom of the screen against a seal , to seal against the bottom of the tappet screen hole .

The other type is like a cartidge with a check valve . Look at your manual ,to show the early one . Others here will give more info ,I'm sure .

[NightShift]

Dear Carl,
The only advantage that I can think of for the earlier capsule with a ball and spring in it was that it kept the heads from bleeding down for a minute. And like I said earlier it its all for the hydraulics benefits.

But catching any flying chunks is good,

[Dave_R]

Hi Carl,

Nightshift has it correct.

The earlier pans (52-62) that used to have the hydraulic units needed the check ball and spring to keep the oil inside the pushrod tubes. The intent was to ensure that the hydraulics had oil for the initial startup, and kept them from bleeding down after shut-down. But, as you may know, keeping oil inside a pushrod tube that doesn't seal real good causes a big oily mess, and it did not work very well anyways.

The big thing years ago was to get rid of the hydraulics and go solid, and remove the check ball and spring to allow the oil return to flow freely through. So, I'm not suprised that a good engine builder probably removed them, as that was the thing to do.

In 63, it looks as if the assembly changed to just a screen and spring, without the check ball.

You might be able to fit the newer assembly (screen only), but I personally have not tried it. I currently run with the screen/check ball assembly removed and solid lifters, with no screen to keep any restriction out of the oil return.

But, it can be a way to catch any debris. This post now has me thinking........

[panz4ever]

My 65 pan was built without that assembly. Keep my oil changes at 2500 miles with 60wt. So far so good since I bought her in 1970. But if ya have the spot I say use it.