Holley Carb Woes - DCDoug Pay Attention (Long Post)

[dcdoug]

Originally Posted by elmariachi

Just to be sure, I tore this 3255-1 LeMans that I have been struggling with apart yesterday and checked every single orifice: Nothing extraordinary. However, I have noticed something peculiar though from running this carb.....several of my spark plugs are showing a single, focused dark spot about the size of a pencil eraser on the side of the insulator near the tip. Imagine spotting it with a Sharpie right below where the isolator touches the electrode tip. All the plug reading charts I can find call this "splash deposits" related to a gunked up carb or fuel additives. I am running Redline lead substitute but haven't seen this in 3500 miles with the Mighty Demon. Anyone seen something like this?

Why are you running lead substitute? Don't you have hardened valve seats?

[elmariachi]

Originally Posted by dcdoug

Why are you running lead substitute? Don't you have hardened valve seats?

Nope. Go here and start with post #20. My builder overwhelmingly concurred.

[Rick Parker]

Are you running the addative in the same concentration?

[elmariachi]

Originally Posted by Rick Parker

Are you running the addative in the same concentration?

Running it per the bottle's recommendation. maybe a little heavy. Redline says its not being caused by their product. NGK says its a cold spot on the plug caused by being near the intake.

[Excaliber]

Pat, what kind of lining is inside the metal wrapped tubing on your fuel system? I would think it would be rubber as well?

Perhaps the ultimate solution is to use fuel injection hose, expensive stuff, but I would think that would eliminate any possibility of hose break down from alcohol? Not that I'm worried about that myself, I've got rubber fuel lines, been running alchy mix gas for years, never had a problem to date...

[patrickt]

Originally Posted by Excaliber

Pat, what kind of lining is inside the metal wrapped tubing on your fuel system? I would think it would be rubber as well?

It's that Russell/Edelbrock crap. I don't like the Red/Blue on it anyway, so that's a good excuse to just change it all out anyway.

[RodKnock]

Originally Posted by patrickt

It's that Russell/Edelbrock crap. I don't like the Red/Blue on it anyway, so that's a good excuse to just change it all out anyway.

Agree 100%.

[Excaliber]

Non hardened valve seats with unleaded gas is for the most part is over hyped, in my opinion. The potential for trouble is in extended miles at highway speed, over heating the seats in due time.

Other than that, I wouldn't worry about it, unless your planning a 500 mile trip in one shot at speed.

[elmariachi]

Originally Posted by Excaliber

Other than that, I wouldn't worry about it

Of all the crap that worries me, that ain't on the list.

[dcdoug]

Originally Posted by elmariachi

Of all the crap that worries me, that ain't on the list.

You gave me something new to worry about (only a little, but still). When I spoke with my builder, I confirmed that it wasn't a problem to run 93 octane unleaded. I assumed that also meant that he put in hardened seats, but I don't remember actually confirming that specifically. I too had NOS MR heads that had never even had valves in them. Now I wonder whether he just shared the opinion of Ernie that concern about unleaded gas on unhardened seats is overrated or whether I have hardened seats.

This may be a dumb rookie question (feel free to give me some sh!t, but I'm still learning), but is there any way to tell without pulling a head? Can I tell from the valves that I have?

EDIT: Oh, the most important part, my builder passed away in January, so I can't call him.

[CobraEd]

get a borascope and put it in the spark plug hole.


.

[patrickt]

Originally Posted by CobraEd

get a borascope and put it in the spark plug hole.

Hmmm, I didn't realize ElM. and DCDoug were that close....

[elmariachi]

Originally Posted by dcdoug

I too had NOS MR heads that had never even had valves in them. Now I wonder whether he just shared the opinion of Ernie that concern about unleaded gas on unhardened seats is overrated or whether I have hardened seats.

There are varying opinions on this, sorta like Republican vs Democrat. For every person who says you are screwed there is another that says "No worries." Try a borescope and if that doesn't solve your burning desire and you can't sleep, use an additive. But in all honesty I am doing it not as a preventative but as a little insurance. When I finally move up to Blue Thunder or KC heads, if my valve seats are damaged, then I'll have seats installed before I sell the heads. And if the heads are toast (highly unlikely) then I'll add that to the list of sh!t I wasted during my Cobra learning experience. Go ahead with that Holley 3255 and your mind will be off of valve seats in no time. I promise.

[Excaliber]

I'm not sure what you would see or be looking for if you did use bora, or pull the heads for that matter. Gonna be hard to tell...

...not to worry, no problem.

[patrickt]

Now that I think about it I should probably pull those little Moraine filters out of the inlets and see if there are little black chunks of rubber in them.

[dcdoug]

Let us know what you find.

[LuvDaBlues]

If I can toss another tid bit of info, if you run a racing fuel, VP or Sunoco, in some cases the dye from the fuel turns into molasses and really goops up the same passages and ports.

The temp and humidity have been pretty high here in Dallas, and I tossed a plastic bag over the carb overnight to keep crap out while running the valves. The fuel evaporated, but the dye stayed behind. The engine ran very sluggish and wouldn't idle. Pulled the carb and spayed and squirted every opening. Blew dry and voilà, ran great.

[Excaliber]

I was professionally wrenching when this change to unleaded and valve seats were a BIG issue. Everyone was panic striken, the sky was falling, were all doomed. Turns out the only folks I ever heard about that had trouble were "traveling salesmen" type. Folks putting a LOT of HARD miles on the engine. Running it long enough that way will eventually damage the valve seat. The face of the valve and the seat tend to weld themselves together. But that takes some pretty extreme heat, temperature AND a lean air/fuel ratio to happen. The way 99% of us drive our Cobras? AND we tend toward the rich rather than the lean side of air/fuel. Aint gonna happen, no way your going to have trouble with the valves/seats.

[Bill Bess]

Put on the biggest fuel filter, one with a cartridge that you can inspect when your change it out. Blow out the carb with air....if no results, take it apart and go through it. Holleys are fun..they are good for about two years of service without some kind of problem.
I'm amazed, going on three years now..still workin fine.
Bill

[tmareina]

I've got 2 Holly 4224's (660's) on mine and have had no problems in over 9,000 miles...haven't even had to adjust them. Maybe I've been lucky...thanks for the info...I'll keep it in the back of my head incase I encounter a problem later.

Tom