New Z1 short block very noisy HELP!

[magnoman]

Hey Guys,
I am new to this site but have been on 300zx.com for many years and have owned two Z's 92 NA and 92 TT.

I decided to do a build this summer on the TT . Purchased a Stage 2 short block from Z1 with 675 turbo kit among other things.. spent more than $8k on the this motor build and it's been the biggest nightmare of my life!.

Had a issue with the first Z1 block. There so called high end machine shop they use forgot to pull the oil galley plugs when the hot tanked the block and I found oil soaked metal filings in the block when I took out the oil galley plugs to attach the turbo oil lines! Thank god I did not fire the motor up !
Had to pallet and ship the block back after I had the entire motor together! countless hour of labor.
waited a almost a week and half turn around time because they siad they did not have one on the self to send me.
received the block back went to install the clutch pilot bearing and come to find they send me a AT block and it had the AT Trans adaptor in the back of the crank. They sold me a AT block had to cut out the adaptor to install the pilot bearing.
Finaly got the motor back in and running since August and know have a noise coming from the bottom end of the motor that sounds like marbles rattling around! I got under the motor with a hose to my ear and running , it's coming from the back of motor back side of oil pan? sounds like a blender..
Does not seem to be there when cold. I know forged pistons will rattle a bit when cold not it..
I am so fed up the entire thing feel like burning this car!

p.s I am a experienced certified class A mechanic having worked for Ford for years.. and have been building motors since I was 16 and know 50..
This noise is baffling me ???

If it does come down to another block issue Z1 is going to be held responsible for all ....

[marty1mc]

Sorry man, that sucks. I remember reading about this on 3ZC. I can't come up with anything that would rattle in the bottom end. Have you thought of getting your oil analyzed? That may give you a hint if you have a major problem.

Is it possible you used a needle bearing for the pilot bearing and that is making noise? I have heard a few that have had issue with those. Just a thought...

[magnoman]

Thanks for the responce.. I did use a Needle pilot bearing but its a knocking sound motor sounds like a light diesel motor?
I have made short video clip and sent it to Z1, Greg Dupree at SZ and Rich at RDZ. Z1 has not responded at all. Greg has been a lot of help and very knowledgeable..
this is what he says.

Nothing in the clutch/flywheel area can make that sound.

It is a engine speed sound and the knock is a direction change sound or clearance issue. Could even be a exhaust leak.
Again from the clip it sounds like cam speed.....It is possible it is in the lower end rotating assembly , but hard to tell from your clip.

The clutch/flywheel/pilot bearing/ stuff is just rotating in a circle and can not knock.

An on/off the throttle will offer a more distinction in the type of sound through a clip.
In person it would be easy for me to know the sound. The clip at only Idle is really hard to tell.