imariver

I told the guy, that did the dyno test, that I wanted it tuned for street and freeway cruising only, but he was more of a numbers guy . . . .trying to ring as much power as he could out of this engine. He also told me that I had, (more than likely) a burnt valve "Somewhere on the right bank"

5-7-6-8 exhaust valves are whitish, 1-3-2-4 exhaust valves are blackish. The tops of ALL the pistons are blackish / dark gray, with no deposits. Two compression tests reveal that the # 8 cylinder is a little lower than the rest, 150 versus about 170 for all the rest.
Right now I'm waiting for a leak down tester, so I can determine if there are any leaks anywhere.

The Holley is 100% factory right out of the box, nothing has been messed with other than the idle jets. However . . . . I did talk to a tech guy at Holley, just yesterday and he told me that all holleys are calibrated at sea level and at 70 degrees F
At 2100 feet altitude, he said that I definitely need to go to smaller main jets and "Don't change the power valve"
LOL . . . . Lots of fun on these warm rainy days, (see you next Wednesday)

682XLR8

Hey Steve...strange how this is showing up on half the motor (front to back), interested to know what's causing this

Dynra Rockets

Never bolt on a carb strait from the box and just run it. It will not be tuned to what the car wants. That is a recipe for a bad experience.

Buy the $15 bolt in O2 sensor bung from FiTech and install an O2 gauge. While there are old school methods to tune such as reading plugs, and jetting for best vacuum, etc - IMO, its all a ballpark guess unless you use a O2 gauge. (ie, when I tuned for best vacuum I was waaay rich)

Holley assumes you are not bolting on to a stock engine and you have made some performance improvements such as a cam and headers, as well as they are tuned a 70 degrees at sea level. That means it will run rich for most people.

My 4165 came with a 62 primary jet, an 83 secondary jet, 25 primary squirter, a 37 secondary squirter, and a 6.5 power valve. When I bolted it on the engine ran fine overall but was very rich at idle, very rich at cruise, lean at WOT and there was a slight hesitation at transition from primary to secondary.

After some quality time with an O2 sensor I changed to an 8.5 power valve, 59 primary jet, 89 secondary jet, and a 40 secondary squirter. Also adjusted the idle circuit screws and now all is great with the world.

Friends don't let friends bolt on a Holley with tuning out of the box.

TCracingCA

I have been an air cooled guy while always having V-8s and deposits in the gas burning off can give you white valves in an air cooled engine!

But generally you could have a coolant leak, but it would have to be a common source or problem! I personally think that your white valve cylinders are healthier than the others or running more proper! If it isn't a Head Gasket thing, then head has combustion chamber cracks in the white ones or guides in the darker ones are going!