ahhh!

[chad021]

so lately now when i really pin the throttle in every gear except first in high rpm i get the sound of metal tap? not the normal cam noise but a distinct noise at certain rpm's. could this be a "ping" from runnin regular gas? or could it be slop in the valves?

 

[deadaim]

What comp. piston do you have?

 

[ratchracing]

If your running a high-comp piston (like a 10.25:1 Wiseco) then regular octane gasoline will pre-detonate making a "ping" sound in the engine. Try draining the regular fuel from your tank and carb and fill up with something in the 91-93 octane range. Try this and see if it solves your problem.

BTW: I'm running a Wiseco 10.25:1 piston and run 91 octane fuel with no detonation issues.

 

[chad021]

its a 10.25:1 pioton and its only seems to make noise at 3/4 throttle on up, sounds like a rattle until it warms up and than the sound seems to go away, just checked valve clearance and there in spec now.

 

[ratchracing]

Another thing to check when your getting unusual top end noise is to check that you have good oil pressure to the top end my losening the check screw on the right side of the head. Oil should squirt out pretty hard, if it just trickles it can be an oil pressure problem. Just a thought.

 

[chad021]

thanks but i'm finding out that i'm going to have to rip her down again any way, top end didnt seal right and im actually getting wisps off smoke coming from the top gasket, she is gettin good oil pressure tho