help: Engine Question
 

hey yall. im new here... well for posting at least, been reading alotta the great posts and theres just tons of information on this site. ive tried searching for info on this but so far have come up empty.

i have a 89 s5 n/a and with magnaflwo exhaust, 2mm streetport and when i rev the ngine up to about 6 -6.5 rpm it sounds great but after i go any higher than that the engine itself starts to make alotta noise not sure how to describe the noise. at theat point the engine sounds louder than the exhaust. and im just wondering if this is normal or if there is some sort of problem here. it also vibrates a bit not extreme vibrating but there is a noticealbe difference once i get into the rpm range of over 6500. oly thing that comes to my mind is maybe if the rotors are somehow unbalanced or soemthing along those lines. other than that the car runs really awesome. so if u guys have any info that would be greatly appreciated

You need to find out who built the motor, and ask them about it.

It sounds like something is out of balance. Maybe mis-matched counterweights?

It could be you tach is reading low & you're actually hitting the rev limiter.

the engine was rebuild by mazda rotorysports

not to sure about that tac thing cause i can still rev it up more but i havent really becasue im not sure if this will dammage the engine it also sems to do it worse if i pull in hte cluth while im driving instead of just siting somehwere in neutral. could just be me though....also something i just thought of (might not have anything to od with this) my 56h and 6th ports are siezed also

soo not sure but could that have something to do with it there closed all the time.... those will be takin care of on monday