Topic: Tick tick...

[whwright]

Hello again.  You may recall that a month or so ago I put a new camshaft in my '78 Trans Am.  It's an L78 Pontiac 400, but now it has milled 6X-8 heads, an "RV" cam, and new lifters.  Other than that it's an original 150k mile engine.

After all the work, it fired right up, broke right in, and ran great.  I drove it around for a couple days before putting a cover on it and moving on to my son's '69 Firebird project.  I didn't start it for about a month.

When I started it the other day, it went "tick tick" pretty loud.  Two ticks, then the sound went away.  It fired up pretty good for having sat for a month.  The "tick tick" bothered me, but I hoped it was just because I let it sit so long.

The next day, it did exactly the same thing.  Two ticks.  The third day, two ticks again.  It sounded exactly the same each time.  If I turn the engine off and immediately restart it, it doesn't tick.  But if I let it sit for an hour or so, exactly two ticks every time.

I suspect (and hope) it's a mis-adjusted lifter.  I used chevy rocker arm nuts to adjust the rockers, so I probably didn't get one just right.  Would I have turned too far, or not far enough?  Or am I paying the price for buying cheap lifters, and one is leaking down?

Lemme know what you think.

Wayne.

[Tin Indians Rule]

If the valve was too tight and you were bottoming out the pushrod in the lifter the sound would not go away once the lifter pumped up with oil. So, it doesn't sound like a tight valve. I've always adjusted the valves again on a fresh cam and lifters after a 100 or so miles at various speeds to seat everything and get a good wear pattern on the lifters, valve stems and rockers. Did you initially set the valves close and then fine tune with the engine running or did you set them with a feeler gauge at install? I'd suspect that you have a loose valve or weak lifter. More likely a loose valve.  I'd type a great way to check your valve lash but I always refer to this article for heads that have been milled and using locknuts.  Here ya go...Use this link and you can't go wrong


http://www.boyleworks.com/ta400/psp/rockers.html

[whwright]

Well... actually... that's the EXACT page I printed and used as a go-by in the garage.

I guess I'll have to pull the valve covers and check the rockers.  The driver's side is easy enough.  The passenger side is another story.

Thanks for the input!

Wayne.

[Eagle 1]

I hope your right about it needing adjusting again, but I am not so optimistic.  Anytime I had a lifter tapping, it either had a small piece of trash in it, or the lifter itself was defective.  What brand of lifters did you use this last go around?  I have always had good luck with comp lifters, even though they are a little more expensive.

[whwright]

The lifters came with the camshaft I bought on eBay.  If I remember correctly, the box said "Clevite" on it.

I suspect they are the cheap import lifters that Hot Rod warned us about.