Spark plugs differ by bank?

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JAV
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Spark plugs differ by bank?

Post by JAV »

I ran a compression check to today on my engine as it's been dormant for about 3 years. Upon pulling all the plugs, I noticed something odd. All the plugs were the same type but for some reason, the plugs on cylinders 1-6 had 2 washers - what looks like a lower copper washer and then a normal crush washer as shown in this pic.

Image



Now the part that has me confused. All the plugs on cylinders 7-12 had 2 crush washers BUT, the lower crush washer had been cut. All the plugs on that side were cut this way and it looks like the cut was deliberate and consistent. Here's a pic -sorry it's fuzzy.

Image


Anyone have any ideas why this might have been done?
John Viveiros
1964 250 GTL
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tyang
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Post by tyang »

Hi John,

Have you measured the thickness of the washers? If they're different in thickness, perhaps someone was trying to index the electrodes in the combustion chamber.

Just a guess.

Tom
'63 330 America #5053
Rudy van Daalen Wetters
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Post by Rudy van Daalen Wetters »

Wrong plug is the reason. BP6ES should not be used. The reason the second washer is on is to give clearance for the projected tip which
typically fouls the inner head at the base and closes the electrodes. Result is no spark.

Someone was monkeying around to make the BP6ES plugs work.

Use B6ES and you should be fine.

Rudy van Daalen Wetters
1963 GTE s/n 4001
1966 330 GT s/n 8705
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tyang
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Post by tyang »

I don't get why people do this. How much trouble is it to find the right plugs to avoid the plug hitting the piston? John, I would proceed carefully. This could point to other things being "monkeyed around." with.

Tom
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JAV
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Post by JAV »

Thanks Rudy- that makes sense . I didn't cathc that and I'll change them.

Tom- yes, proceeding with caution. Good day today- no evidence of hydrolock and liveable compression across the board.
John Viveiros
1964 250 GTL
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tyang
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Post by tyang »

Hi John,

I've got my fingers crossed.

Tom
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Michael Bayer
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Post by Michael Bayer »

To which I add, if the car has sat dormant for three years it will likey take some miles for the rings to free up and the compression numbers to settle in. M
Michael J. Bayer
330GT s/n 9727
365GTC4 s/n 14943
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Post by whturner »

Rudy van Daalen Wetters wrote:Wrong plug is the reason. BP6ES should not be used. The reason the second washer is on is to give clearance for the projected tip which
typically fouls the inner head at the base and closes the electrodes. Result is no spark.

Someone was monkeying around to make the BP6ES plugs work.

Use B6ES and you should be fine.

Rudy van Daalen Wetters
1963 GTE s/n 4001
1966 330 GT s/n 8705
Hi Rudy:

Why do some cars have a problem with the extended tip, but most (I think from looking at the various posts) do not? I believe the extended tip plug is currently recommended by NGK - did they change the plug a bit perhaps?

Cheers
Warren
330 GT Series II sn 10069
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Post by Rudy van Daalen Wetters »

Hi Warren,

When I first bought my GTE it was running on 11 cylinders. All 12
plugs had the extended tip. The clearences were so very close, but
it worked ok on 11 plugs but not number 12. By design, the head was
not machined to really accomodate the extended tip plugs.

I like to follow the manufacturer's recommendations. Like most
manufacturers, NGK may make certain recommmendations but
not be aware of the whole story. As owners, we need to use
professional skepticism when it comes to what vendors say is
correct or even incorrect.

Rudy van Daalen Wetters
1963 GTE s/n 4001
1966 330 GT s/n 8705
whturner
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Post by whturner »

Hi Rudy:

Strikes me as peculiar, that Ferrari precision would let 1 cyclinder/piston be that different from the other 11. And I wonder if a 330 with different dimensions would have the same potential for interference that the 250 would.

Just a puzzle.

Cheers
Warren
330 GT Series II sn 10069
John Vardanian
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Post by John Vardanian »

Hi John,

Are all 12 plugs the same model number? Could it be that one of the heads is a replacement?

john
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JAV
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Post by JAV »

John Vardanian,

I suppose one head could be a replacement but I tend to doubt it since the old owner was pretty adamant that the engine had never been apart and has under 30K miles original. I had the oil pan off this weekend and inspected the crank, rods and lower sleeves pretty well. Nothing looked amiss. The lower sleeves still showed some good cross hatch and the color of all components was very consistent. It didn't look like any parts were mismatched or newer. I suppose anythings possible though.

Yes, all the plugs were the same exact part number... it's just the washer arrangement that was different.

The other thing that has me a little confused is my valve covers. I've seen 3 different versions with the most common being fully wrinkle black. I'm told this is the only "correct" finish. Yet mine have the "FERRARI" script painted silver (not polished or sanded through the black). I've also seen some valve covers with both the script and lines silver. I suppose someone could have painted my script right on the engine but find that a little odd given that the engine has never supposedly been apart. The spark plug washers also me wonder but other than those 2 anomolies, eveything else appears original and not monkeyed with.
John Viveiros
1964 250 GTL
Rudy van Daalen Wetters
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Post by Rudy van Daalen Wetters »

Hi Warren,

I believe "Ferrari precision" is a relative term. Depending on the casting molds for the heads, state of tooling, and day of the week, anything is
possible. The original design did not allow for the extended tip plugs.
No two cars are exactly the same. Perhaps in some cases you can get away with it. I can show you on my car that it won't work on the number 12 cylinder. One of the popular reference books on the V-12's also
discourages the use of the extended tip plugs due to clearance issues.

Rudy van Daalen Wetters
1963 GTE s/n 4001
1966 330 GT s/n 8705
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tyang
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Post by tyang »

The other thing that has me a little confused is my valve covers. I've seen 3 different versions with the most common being fully wrinkle black. I'm told this is the only "correct" finish. Yet mine have the "FERRARI" script painted silver (not polished or sanded through the black). I've also seen some valve covers with both the script and lines silver. I suppose someone could have painted my script right on the engine but find that a little odd given that the engine has never supposedly been apart. The spark plug washers also me wonder but other than those 2 anomolies, eveything else appears original and not monkeyed with.
Hi John,

Painted black wrinkle. Nothing else. I've seen a lot of Ferraris with the contrasting color, or bare aluminum treatment. Kind of like gilding the lily. The same guys tend to put SF fender shields on their cars in case you didn't know it was a Ferrari.

Tom
'63 330 America #5053
Rudy van Daalen Wetters
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Post by Rudy van Daalen Wetters »

Yes, and those same guys also wear gold chains meant to hang chandeliers.

We will be seeing some prime examples in Monterey.

Rudy van Daalen Wetters
1963 GTE s/n 4001
1966 330 GT s/n 8705
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