plug coloring

[cowboy4]

Got a good one here.
Last trip out the beast ate a pump impellar. No biggie 10 min later the spare is on.
I go to wakeboard and it seems kind of weak. Well decide it's to rough to wb so we sac it out for surfing. Then the dang thing won't even get out of it's own way. We go to the beach and finish off the beer(well all but me gotta love work after the lake). I then go to leave, it starts first time yet won't go over 25 and took forever to plane out.
I pulled the plugs and the front 4 look perfect, yet the back four look black.
My buddy thinks my valves are out of adjustment but I think it's odd that it's all 4 of the back cylinders? I know I need to work on the valves adjustment but I think I may have to do it in water as out of water I can't hear the motor over the exhaust.

[rickr]

How hot did she get before you shut her down?

Hyd lifters on a BBC do not have to be adjusted unless the seats or the cam has failed.

Is your oil pressure good?

Stock dual plane intake? Did overheating your engine loosen some crud in the secondaries on the Holley causing your engine to flood?

If problem persists I would change plugs and do a compression check.

[cowboy4]

The motor is new this year. I thought I had everything adjusted but I could very well not gotten it adjusted right from install.
The motor got to maybe 180. The carb is brand new so know it's not that.
I am gonna change the plugs and do a compression check after work.

[rickr]

What year is the engine? Gen V and Mark VI BBCs have non adjustable valve train.

We have had BIG problems with cam break in on High Performance, flat tappet BBCs. Supposedly no Zinc in the modern formula oils????? Last flat tappet 454 I built had 2 cam failures during break in and the 3rd was getting ready to fail after 200 hrs :(
I am using hyd roller now, see avatar ;)

[87SunSportMikeyD]

Hey if you just ate an impellor the little pieces are probably clogging a line somewhere.

[wotan2525]

What year is the engine? Gen V and Mark VI BBCs have non adjustable valve train.

We have had BIG problems with cam break in on High Performance, flat tappet BBCs. Supposedly no Zinc in the modern formula oils????? Last flat tappet 454 I built had 2 cam failures during break in and the 3rd was getting ready to fail after 200 hrs :(
I am using hyd roller now, see avatar ;)

I wiped my cam after 50 hours -- rebuilt it and blamed it on a rogue oil starvation issue.... but who knows. In hindsight, I should have used roller lifters.

[cowboy4]

I have a piece of mesh covering the inlet to my water neck. Only had to dig pieces of rubber out of the waterneck once to learn that one.
Just did a compression check and all came out 150psi within a psi or two of each other.
Got to dark and started storming so didn't get the new plugs in it.

[agetech]

Sounds like carb problems if the plugs are black. Is fuel leaking into the engine through the carb? Were the plugs wet? (with fuel) If the compression is good the cam timing and cam are good to go. How hot did engine get? How long? Not that familiar with 454 but did anything melt on top of the engine like a vacuum hose?
I started using Rotella truck oil in my engine after I put in my Comp cam. It still contains sulpher.

[cowboy4]

But why would the front 4 cylinders burn clean and perfect and the back 4 get black?????
It got warmer then it usually runs so I hammered it and used the scooper to shove water in it to get it to the beach that was only a hundred yards or so away. The motor was not cool but I still could lean up against the exhuast manifold and hoses while working on it.

[agetech]

I got my engine so hot one time I could hear it sizzling, found my oil cooler plugged with river debris. It didn't do any damage. Doesn't sound like yours got anywhere near that hot.

One side of the carb that feeds the back cylinders may be leaking fuel. But I don't know if the intake runners are seperated on the chevy, or if the carb feeds all the cylinders from a common plenum chamber. Need a picture of the top of the manifold without the carb. Or maybe someone here knows.

[cowboy4]

It's a edelbrock dual plane intake, if that were the case half of the cylinders would be fouled yet it would be every other cylinder.
I will hopefully get don e looking at houses early enough to get the new plugs in and test it out of water for a bit.