Engine noise - New head - help

#1

I just installed a new head and have excessive clacking noise; it sounds like it’s coming from the top of the engine. The valves are adjusted and I’ve checked them hot & cold multiple times.
The sound is linked to RPM. the noise is not present initially when the engine is started and idling. after about 10 seconds, the noise starts, increases frequency with RPM, and remains present back at idle. The behavior is same hot or cold. The frequency of the clacking is about 1/6 the of RPM, so when idling at 900 RPM, the clacks occur about 140 times per minute.

Here is an amr audio file of the sound. I can play this file with QuickTime. [attachment]Voice 003.amr[/attachment]

If not valve adjustment, what can this be? Rod knock? ???
(FYI, the leak down test is ‘Low’ for all six cylinders)

All suggestions welcome and appreciated.

#2

Robert probably has the best perspective on this, but it seems possible that the valves are hitting the pistons.

Perhaps head was milled too much or gasket not thick enough.

#3

Did you install the oil bar when the head was installed? Chuck

#4

Jon, email the file to me and I’ll put it on an ftp site.

When we talked on the phone yesterday I thought that leakdown was “in the green” but not that high?

A good leak down test is actually kinda tricky. If all cylinders are showing roughly the same #'s, compression might actually be ok.

#5

The oil bar was on the head. (I probably put it there a few months ago.)

The leak down readings were all in the 15% to 25% range.
The head is a reman unit form Cylinder Heads International. This is it’s first install since I received it from CHI about 2 years ago.

#6

Audio file at

ftp://filesharing.brasselerusa.com/E30/

#7

New information (Ranger suggested this yesterday.)
The new head was installed without the front alignment pin (near cyl #1). That little SOB stayed with the old head and did not alert me about its migration. So, I placed the new head with only the rear alignment pin (actually a sleeve that fits in a coolant port)

could there be just enough mis-alignment of head vs. block to create a little contact and this noise? Ranger said he’s seen this issue.

I may try to raise the head, insert guide pin and reinstall later today.
Thanks again for the input.

#8

A missing alignment dowel will almost always result in pistons kissing the head. Pull head head off and install the missing dowel.