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

Just a thought, I don't know if we are talking about a QJ or not but if we are did you j.b. weld the base? The small ports that are lead sealed they are prone to leak gas into intake.
Good luck:)

I agree with Formula 31 that if you can't jet the carb to fix the problem, there is only one other part of the equation and that is the plug. Step that plug up one or two hotter heat ranges. People act like that is against the rules to run a different plug in one cylinder. Really a motor should be tuned cylinder to cylinder if we had the diagnostic equipment to do so, most of us don't, but that would be ideal. I guarantee Pro Stock or other forms of racing do this because they have unlimited resources and data. There are no perfect castings and a lot of this could be in poor transition from carb to intake to head air flow or turbulence. A buddy had this same problem with a Dart intake, that had been worked and flowed, put an untouched intake on the motor and it cured it. He used a one step hotter plug in #2 for a year, but it would always foul at the wrong time, just when someone was wanting to play.

Good stuff guys... if I had to guess, I would say this problem is being caused by my crappy aluminum rectangle port intake. These are quite a specimen in poor workmanship - casting wise. I really should buy some good performance oval port intakes... I've heard oval ports work well combined with performance rectangle port heads on boats due to mixture velocity and the torque characteristics.

Excaleagle... I have aluminum eldebrock hp heads with bronze guides. I believe them to be ok. What is a plug extender? Never heard of that. I run A/C R43XLS plugs now.

Blueman.... just rebuilt the stock QJs, but didn't pay any attention to the area you discussed. Can you expound on that any further? I'd be happy to go back in if I had a clear understanding of what I was going to look for and do with the JB.

Jspeeddemon... is going up a heat range in plug simply getting a higher number plug... In my case it would be a R44XLS. I agree with your setting up each cylinder independently idea.

Thanks fellas... keep the ideas coming. The wife and I are hoping to partake in a couple poker runs in the next month or so and would like not to have this problem lurking.

BT :cool:

BT
blueman, yourself, and jsspeedemon are going about it the right way with good ideas.
the plug extender looks like the bottom of a spark plug except it has a round hole in the bottom. you screw your plug into it and it into your head. it shrouds the electrode of the plug so it can't foul. they work very well. they are available in any automotive parts store "help" section. they are more of a last resort though.
good luck,
Fran

I'm gonna get the plug extender too if I can find them. Thanks Excal... were you on the C&D last weekend? I saw the boat I thought might be your "little" one.

BT :cool:

yep BT,
i was in the canal with the little one. i out ran the coast guard too. they called the marine police to cut me off while i was still in the river. i didn't know they were behind me with the lights on. oops:D may be they need a faster boat. good thing i knew the guy in charge on patrol. then my bravo broke in the delaware mouth of the canal. it started making a whining noise while running. i don't know what it is yet . it was hard coming out of gear. when i got it home and started it up, drive down and centered, it was making a grinding noise. :mad: i only have about five hours on that drive too. guess the guy that was with me isn't buying the boat now. any ideas? i would like to have it fixed to join in on the poker runs too. you guys with the newer boats will have to take it easy on the guys driving the old ones.
Xcal

blue thunder
When you take the base off the body of the Qj in the center of the front plates. It would be where the needles set above when the body is attached to the base. You will not miss it when you take it apart. It looks like two frog eyes on the inside of the carb. it looks like a hole in the bottom of the base and that is why it has to be sealed on the inside. They are bad to leak fuel into the intakes. Sorry I can not put it better

Hope this helps :)

Thanks Blueman, I think I know what you are talking about.

BT :cool:

Major bummer excaleagle. You where in the black boat with eclipse on the side? I saw that boat just as I was getting on plane going towards the chesepeake right after schaefers.

Sounds like time for a tech post on that drive. Obvious questions are///how did the lube look... how much metal on drain plug etc..

BT :cool:

Bt,
i was in the red 25ft. donzi. there is a picture in the classifieds on this board. i will do a post if after i look at the obvious stuff, still can't figure it out . probably not to hard to find where the noise was because it was making a lot:rolleyes:

Ecaleagle.. did Mr Policeman write you a nice citation? That would be insult to injury with the drive problem. No, I didn't see the Donzi, but I'll remember it next time... nice boat. I like the classics too. Keep in touch,

BT :cool:

BT- generally speaking increasing the number of the plugs is hotter heat range, and it is that way for a AC plug. Also the extended tip which you are using is better for staying clean. I ran R45XLS plugs in a 11:1 454 with no problem with detonation, and I would try a 46XLS in your motor. I feel real strongly that you have a fuel distribution problem between the intake and the head down to the valve.

Yeh JSpeed.. I'm betting on intake problem. I got the 44xls and 45xls to try. Will start with the 44 and if still rich go to the 45s. Hope I don't need to go all the way to 46, but will if necessary. If I can make a go of it through the summer, I'm going to pull both motors over the winter and make them right. If not, I'll need to buy two new intakes, install now and hope that fixes the problem. What do you all think of using oval port intakes on rectangle port heads? I hear this is great on boats because it give good runner mix velocity at the relatively low rpms a boat sees and boosts torque. I have Hi pro alum heads now.

BT :cool: