Ticking noise

[even_u]

Have got this really loud ticking noise, prob from the valve train?
Starts 5 minutes after engine startup - no noise when engine is cold. 
'68/440/727, manifold-not headers. Running 95-98 unleaded with no additives.

Thoughts?

[Hemidog]

Could be an exhaust leak between header/manifold and cylinder heads.

[ChargerST]

When talking about 95 unleaded he means 91 unleaded. Octane ratings in Europe are different from the US.

[Belgium R/T -68]

A lifter giving up?

Per

[even_u]

Could be an exhaust leak between header/manifold and cylinder heads.

But wouldnt a leak cause ticking from the start - even when engine is cold?

[doctor4766]

The manifold may not be true and could be warping more as the engine heats up.
May need to check it with a straight edge and have it machined if found to not be dead flat.

[bobs66440]

I agree. I would check for exhaust leak first. If that isn't it, I would invest in a mechanic's stethescope to try to isolate where the noise is coming from. I have also used a long screwdriver up to my ear but a stethescope is better.

Worse case scenario, it could be a lifter, wrist pin or piston slap. With a stethescope you should be able to determine if it's coming from the top or bottom of the engine. You could try checking for a loose rocker arm and re-adjusting the valves.

You can also check for a piston/wrist pin issue by pulling the plug wires one at a time while it's running If the noise goes away or gets quieter with one particular wire, then you've isolated the cylinder (though this method could could get dangerous trying to dodge the high voltage and the burns to your hands...especially with a big block).  Just make sure it's safe to do with your ignition system...I've heard that it can damage some ignition systems, though I don't know if it's true...

[Hemidog]

Check the easiest thing first, before tearing into the engine.

Lykke til!

[even_u]

I'll try to figure out where specifically the noise comes from
Thanks

[green69rt]

Just the result of my limited experience.  "Ticking" is almost always an exhaust leak, header to head flange (tighten the bolts and see if it helps or changes), header to exhaust pipe (ditto), cracked head (weld up or replace.)  Sometimes a lifter going bad sounds more like a rattle than a tick and should start the minute you start the engine.  My bet is on a cracked exhaust manifold.

[even_u]

Exhaust leak detected between manifold and flange (good call everyone - thanks). Dunno if its a crack or just bad sealing yet, but the manifold is 40 years old so might as well replace it with new headers.

Recommended place to get new ones?
What about this place? Pricy?
http://downloads.classicindustries.com/Catalogs/mopar/mopar_sec_l.pdf
What brand and coating?
Anything I should check or measure before ordering?

[Hemidog]

Do a search for header threads on this site, there are plenty of opinions, but most seem to agree that TTI makes the best ones (I've got them, and they fit great!). They are a bit pricey, but I definitely thought they were worth it, it's a pain to "modify" headers that don't fit.
I see Hedman Hedders in that catalog, and I've heard some stories of poor fitment and clearance issues.
If you're replacing manifold with headers, then you need new pipes underneath, or modify the ones you have. Maybe it's a good opportunity to replace the whole system? 

[bobs66440]

Glad it was simple! 

[even_u]

I'll get the car up in the air this weekend and check the connection points of the exhaust system. Gonna shoot some pics for you experts to look at.

Except from the manifoil - the pipes/mufflers are all fairly new - so I'm not sure I'll replace the lot.

[Hemidog]

Allright.
Where in Norway are you located?

[even_u]

I'm down south in Kristiansand.
Gonna se if I can team up with Suntech, (I know where he lives - and from what I hear he's highly skilled )

[Hemidog]

I know Rolf, he's just pretending