Valve colors ,340 with Trickflow heads .your thoughts , thanks

[Tim Lynch]

 

[Xcudame]

Tim, how many miles? How is the car run (i.e. street, racing, combo)? What spark plug are you running ( heat range is more important than the brand. What ignition (and coil)?

Exhaust valves look good. the one intake is a little black and there carbon build up in the combustion chambers that suggest maybe not all the fuel is being burnt well. You only provide two cylinders. What do the other six look like?

 

[Tim Lynch]

Ac plugs ,one step colder than recommended with Trick flow heads .street strip , about 1000 miles on plugs .Pertronix distributor and matched coil .Car runs great for a low compression motor ,12.90 qtr .FI tech six pac setup 13-1 AF ratio ,I can text you some more photos if that helps .The discoloration wipes off fairly easily so I am thinking it’s the 92 octane fuel .The plugs look good, thanks Tim

 

[Steve340]

Can you post pics of the plugs.
Why did you use the colder plug than recommended?

 

[Chryco Psycho]

Plugs look dark , overall sightly rich , l , how much vacuum at idle in gear if Auto ?

 

[Steve340]

Also there seems to be evidence of a fair bit of electrolysis or corrosion in the cooling system.
Not enough grounds can do that and it can mess with the fuel injection.
These days when fitting aluminium heads I fit ground cables to the body on both heads.

 

[Tim Lynch]

vacuum on that engine was 15 ,AFR is set at 13 to 1 .I have since pulled the 8.5 pistons and upgraded to 10.25 and a 4.18” stroke crankshaft and a bigger cam .The discoloration on the valves just wipes off I am thinking it’s the fuel .

 

[Xcudame]

Besides running a ground strap to each head (great idea - the factory had the battery ground going to the driver's head/intake and a strap going from the rear passenger head to the firewall), I'd run a zinc metal bar inside the top radiator tank. It will greatly help will any electrolysis problems.