Fouling #2 on BBC
 

I put this post out when I had the engine on the stand. 454 Mag. Was having a problem with #2 fouling after about 2 hours of run time. I checked everthing... piston rings, cracked piston, bad intake seal, bad valve (got valve job), head gasket.... thought I had it when I found a small crack in the intake runner going toward the lifter galley. Nope. All back together and running great except I need to keep cleaning this plug or it starts fouling/missing.

Any more ideas?

BT :cool:

no body seems to use them anymore, vaccum gage will tell you a lot and it is quick and easy .:cool:

Thanks Florida... they used to call me "vacuum man" because I could figure damn near anything out with a vacuum gauge. Musta been having a brain fart on that. Thanks for the reminder!

Any other input?

BT :cool:

hi BT,
did you check the ignition system too? cap and wires. is it definitely oil fouling the plug.

Are you sure it isn't the carb. bleeding down and fouling the plug out???

I had one a while ago that did the same thing, #2 running rich/cold. I tried different carb, intake, head, never did find the problem. But, and everyone can laugh now, I stuck a splitfire in it and a hot coil and never touched it again. As far as I know, that engine is still running.

No Excaleagle... I don't know that it is oil. When I had the motor apart though there was oil in the exhaust manifold. Really thought I fixed that.

Gearhead... I rebuild the carb since and still have the problem. Before my last outing last weekend I moved the plug and wire to number four and fours to number 2. That should define if it could be ingintion related.

Formula... I actually thought about changing the plug because it is only fouling on 1/2 of the plug tip... why do you think that worked for you?

Thanks,

BT :cool:

It didnt really fix anything and it still showed colder tha the others but it never fouled or misfired again so I ddint mess with it anymore. Engine made good power. I tried a smaller jet in that corner but then #4 got too lean so I left it the way it was. An engine guy tried to convince me it was because the #2 cylinder runs cooler (water flow or something) than the rest but Im not sure about that theory.

Thanks formula31... I'm gonna go there and the vacuum readings.

BT :cool:

BT, my thinking was; i know you said you had the heads done, but if you didn't have the cast guides changed to bronze inserts, it is possible to have a hairline crack in the valve guide where it meets the head.
if in the end you don't find the problem, a plug extender although not a cure may work to keep it from fouling as fast.
Fran