Engine knock

[xsteamer]

I recently changed the exhaust manifold to a header and also installed crane electronic ignition. Everything is fine except at high revs in second and third gear there is a knocking resembling the sound of a nail gun that is used to remove paint off metal. I thought it may be timing (ping) so I retarded timing which reduced it slightly. But a friend of mine who is more knowledgeable than than I advanced the timing to where he thought the car ran and idled better. Anyhow I still have knocking. Anybody?

 

[aeronca65t]

It is likely to be a timing problem. This can cause very serious damage.
First, be sure that your new exhaust is not banging against the frame.
If it's not, check to be sure that your timing is set at factory specs using a timing light. Do not adjust the timing "by ear" to create a smooth idle. If the car will not idle properly wth the correct ignition timing, something else is wrong (and it could be as simple and cheap as readjusting the idle speed screw).
Proper idle timing on most cars is rarely more than 10 degrees advanced, but a car can be made to idle smoothly with as much as 25 degrees of timing advance. During acceleration, the normal advance system could bring this up beyond 50 degrees, resulting in pinging and/or detonation (which is similar to hitting your pistons with a sledge hammer!).

 

[spit_head]

I would suspect the header. Especially if it is a pacesetter brand.
Good Luck!! /ubbthreads/images/graemlins/hammer.gif

 

[Super 7]

Its probably not opportunity, it only knocks once.

 

[John Loftus]

[ QUOTE ]
Its probably not opportunity, it only knocks once.

[/ QUOTE ]

funny .. how about an engine knock knock joke to go along with it:

engine knock knock
who's there?
retard
retard who?
retard my timing please!

o.k. I'll go crawl back under my rock ...

 

[Kim de B]

Ouch, that was a very painful joke ...