99-00 Head/Valve Noise Concern
 

I've logged almost 200 miles on the new engine setup now without any problems, however, there's a ticking in the head that sounds loud to me, maybe I'm being overly sensitive to it since it's all brand new, but I haven't heard another 99-00 head tick like this that I can remember. It reminds me of the ticking that would occur right after I started my car when it had the '95 head with HLAs, except this won't go away, and during engine braking, it's louder.

The head is stock except for Supertech valves, new viton valve seals, and some light porting around the valves, deshrouding, and blending that was done by the machine shop. The valve lash was clearanced using the values found in this thread: https://www.miataturbo.net/forum/t31128/ . The oil pressure overall is good and I just went from some cheap 10w40 oil that I ran for about 130 miles to a 15w50 oil that the machine shop recommended and provided, and this was the second oil change, the first oil change occurred after 20 initial miles.

I can't really think of any other details that would help right now. I have uploaded a couple of short video clips of it to YouTube, but that site killed the sound quality, but you can still hear it if you listen closely enough. I'd appreciate any input or insight.

well other than the fact that forged internals equal a louder motor, i cant hear anything different than what other built motors ive heard sound like. The first vid though does sound a little concerning though.

The only forged parts are the rods, the pistons are tri-coated OEMs. This noise is coming from the head and the video was shot after 45 minutes of driving, so everything was nice and warm.

oohhh then yeah something doesnt sound right at all.

My 99 rebuilt head has tapping too. The guy who rebuilt it said that the valve lashes may need to be reset after the engine is ran. How the he'll do I/we do that?

http://img27.picoodle.com/img/img27/...3m_c012f60.gif

http://img30.picoodle.com/img/img30/...4m_f359a9b.gif

http://img29.picoodle.com/img/img29/...5m_5563a8a.gif

Im guessing the 99 head doesnt use hydraulic lash adjusters?

I never heard of requiring adjustment on a newly built head, maybe on an old head due to changes in the metal from age. I spoke to my mechanic a while back about engine building and he told me stuff like knowing how much clearance to leave for things like heat expansion and stuff. I think your builder may have messed up and doesnt want to fess up to it.

Nope. They switched to a shim-over-bucket design for the NB. Same concept as most modern sportbikes.

Thanks for those pages Joe!
What Artie's builder told him seems to be the case regarding solid lifters. Now that I've checked into this issue in a few places, it seems a lot of people have been told the same thing.
Can I hurt anything by driving on it while it's in this condition until I can get the time to check it out?

So that means that the clearances have to be perfect, compensating for everything that will occur in the next 100 miles. Heat cycle, stretch, initial break in.

How do the cars not require adjustment after 100 miles when they leave the factory?

The video sounds like an exhaust leak at the manifold flange too. Did you put a stick/pvc pipe to the head and make sure it's coming from under the cam cover. If not, might check all your flange bolts first.

I'm willing to bet you're valve clearance is too loose.
Let it cool overnight, and follow the procedure on the first page that Joe posted.
The first time I did a valve clearance adjustment on my old integra I set them ~.002 too loose and they made a hell of a racket.

That's a good question.

I haven't done the stick/pipe test, but there's no indication of a leak in person and all the manifold/turbo bolts were retightened after one of the first test drives. Of course, with the exhaust being in it's current state (no mufflers, just dp, cat, and enthuza midpipe), it might have caused a problem. It's one one hangar and I used a universal hangar to help support it until Jason (Enthuza) gets a chance to help me fix the clearance issues I was having. I'll recheck the bolts to make sure.

That's what I'm going to try for sure. I need to go pick up a feeler gauge, someone walked out of my garage with mine and never brought it back.

Here's the results of the measurements I took, all in inches. The feeler gauge I borrowed did not have the mm increments listed unfortunately:

http://img2.pict.com/b7/61/3a/993be9...clearances.jpg

Next question, where do you find replacement shims? And how do I know which ones I need? I know I need a thicker shim on all of them to close the clearances up, does it require knowing what shim is in there now? I was also thinking that I could take the 0.012 and 0.013 measured shims and swap them over to the exhaust side since that would be proper clearances.

I have done the same adjustment on my -99 some time ago. It is not a big deal. You must first measure the gaps (done that!) and then measure the shims now in place. Then you can calculate what shim you need to get the right gap. Mazda has a standard 1 page chart over what sizes of shims are available. Error on a short gap / large shim if you have to. Moving shims around is perfectly fine, they are the same on intake and exhaust.

The size of the shims are typically written on the bottom side, but on some the text can be worn away. I borrowed a “mm-screw” (or whatever it is called in English) from work to check the thickness of them. If you are careful, the shims can be lifted out with a magnet without removing the cams, just by loosening the cam holders. You are going to want to make a seriouse XL-sheet, notes and stuff to keep track of what old shim should move from where to where and what new shim be placed there instead and so on.

Thats what I was going to say something about an exhaust leak also. But it looks like he might have found the problem.

Oh yeah, double checked the exhaust. Still nice and snug from the second round of tightening. Noise is definitely in the head.

I've got the same problem, noise it coming from the back of the head for me. Not sure which side, intake or exhaust. I'll just end up replacing all my shims and hopefully that will fix it.

My head was reassembled 8k mi ago and has 44k mi on it with 2k boosted miles on it.

Not so sure this is a good idea. If you err with a large gap/small shim you are risking increased noise + reduced valve lift = reduced power. Not great, but whatever. However, if you err on the short gap/large shim side you are risking the possibility of the valve not fully seating = burnt valves = rebuild head. Much worse.

Shims are available from the dealer, usually for about $10/ea. Randy Stocker used to have a pretty comprehensive list of shims & part numbers on his solomiata site. Sadly it's now gone and anyways Mazda, for whatever reason, has discontinued many shims. Therefore you probably won't find the shims needed to get your setup dead-on.

Post up the sizes you need & I may be willing to trade.