hi.
my car started making this knocking sound around 3.000+ rpm after few hard pulls, hitting a rev limiter nearly each gear
around 3000k miles on built 2.0 buttom end, hks 272 cams, 6262, pumpgas.
oil used valvoline race 20-50 for a break in, then switched to mobil one 10-30 synthetic oil.

any input is appreciated.

 

What's your rev limiter?
Also, that mobil 10-30... I though people were advised not to use it because of it's low viscosity IIRC.
It does sound bad though, hows your oil level?

 

i think it's set at 8000 RPM. oil level is fine. drained oil, nothing suspicious , checked cylinder compression all show 150 even idk. guess it's time to pull the oil pan

 

Time to drain and inspec the filter for metal flakes. Sorry man.

 

And next time please use oil with a higher zinc content in it Brad Penn 20w-50, Valvoline VR1 20w-50, something like that

 

yea prolly has to do with oil i used.

 

Time for a rebuild and high compression.

 

Should you run that on stock block, non-built?

 

PS... who built your motor OP?

 

by me just had some local machine shop here in Austin Hone/balance/Polish/assemble my short block. pulling the oil pan will see what i can find. at this pont, im pretty sure my oil choice and driving ruined this motor

 

it made almost 500 whp and 400 trq on 23-25 psi on pump gas

 

You don't have to but it's a safety factor issue. FP will not warranty your turbo (if you have one from them) if you use oil with low zinc content. This is how a huge impact oil choice can have on the durability and reliability of parts that require lubrication. In other words, use a heavier weight oil (20w50) with higher zinc for your own benefit.

 

This one works fine too... for me anyways.
http://www.walmart.com/ip/Mobil-1-Hi...l-5qt/17034353

 

I just figured 20w50 on a stock built motor is really heavy for stock clearances. Heard that oil is like honey

 

No, a stock block has tighter tolerences and should run 10-30, and adding a higher zinc oil will help. ZROD 10-30 is a great choice for stock blocks.
20-50 is recommended for build motors with more tolerence.