Bosch spark plug failures

[audifreakjim]

From Andy's 20vt coupe this weekend.. I have heard Bosch plugs suck, but this is insane. I feel bad for his turbine, I hope it's not too beat up

.

[Mcstiff]

[EDIGREG]

wtf? Something weird going on there... ya they are known to fail, one plug failing happens, but all 5?

more detailed photos of the electrodes?

FWIW I have never seen FR5DTC fail, only F5DPOR

[SEStone]

That sucks. A similar type of failure wrecked the engine on Keith Anderson's white UrQ racecar last Summer. We finally got it running right after three events of trying, and after about 6 laps it dropped a cylinder. The electrode bounced around the cylinder, wrecking the piston and valve and damaging the head.

[loxxrider]

That's why it's only ngk for me.

[audifreakjim]

That's why it's only ngk for me.

No kidding. I tossed my spare set into his car and he was of and running.

[ringbearer]

Sucks, I lost an electrode with the same plugs in my dads S6, didn't help anything downstream...

[All_Euro]

Wow - I've been running this plug for almost two years... no issues but good to know about this!

[audifreakjim]

I looked at his tune, while it may have a bit more timing than I run, it certainly wasn't lean and I could not hear any knock. This was at the track, so while these may get by for onramp blasts, I would not trust them under heavy load.

[Audilard]

That's why it's only ngk for me.

No kidding. I tossed my spare set into his car and he was of and running.

Which NGK is recommended?

[quattro87]

It's hard to tell from the pictures, but it looks like they are melted rather than broken to me. Getting hot enough to melt doesn't sound like a fault of the plug. Hank and I have been running Bosch tri-tip plugs in our 20vt cars for awhile now and other than fouling under high boost haven't had any come apart failures. Do you have better pictures Jim? Did Andy's engine sustain known damage?

[Audilard]

It's hard to tell from the pictures, but it looks like they are melted rather than broken to me. Getting hot enough to melt doesn't sound like a fault of the plug. Hank and I have been running Bosch tri-tip plugs in our 20vt cars for awhile now and other than fouling under high boost haven't had any come apart failures. Do you have better pictures Jim? Did Andy's engine sustain known damage?

I run those tri-tip plugs too and I pretty sure mine failed. Cracked the porcelain and melted the plug. I think this may have been an isolated event though.

[audifreakjim]

That's just damage from detonation on your plug Darin.

So this all started as a miss under boost. First thing we did was inspect the plugs, They were all on one piece at this point. We narrowed it down to cyl 4, I handed him a new plug wire and plug, said swap these out and I am going out for another session. Go back and miss was still there, but I didn't know he didn't actually swap the plugs.

This is when I thought it was a coil, Nate actually sent a few down with a truck they had headed our way if we needed them! We ruled out a coil by swapping in from my car and at this point I was back to the plugs. Pulled it again and the ground strap was gone.

Replaced with my ngk and he half of Sunday before the rest failed.

Not sure how I could take a better pic, the ground staps just fell off. It's like the metal fatigued and fractured. No melting. They are just garbage in my opinion.

Ngk bkr7e. Brett says he runs one stage cooler bkr8e, but it think I fouled those when I tried.

I think the oem style Bosch plugs are fine, it's the generic plugs that suck.

Ngk plugs are cheap, they have relatively good life span, and don't fail like this. Plus you can gap them.

[All_Euro]

Handy heat range chart...

[20VAvant]

Anyone have the NGK part number for the 3B 20VT?

I'm pretty sure I have the second set of Bosch plugs in @~180K....

[highlander69]

Never really seen any bosch wire failures on my end, however I will never run bosch platinum
plugs in any car that I own.

Cheers,

Craig

[loxxrider]

Anyone have the NGK part number for the 3B 20VT?

I'm pretty sure I have the second set of Bosch plugs in @~180K....

I was also going to Suggest det on darins plug.

The NGK bkr7e is what you want. I believe the part number is 4644, correct me if I'm wrong.

[amd is the best]

BKR7E is an NGK 4644 which is a 7 heat range. Plug I run in my car on pump fuel.

NGK 4554 is the Racing 8 heat range plug too if you want colder. Plug I run with E85.

[20VAvant]

BKR7E is an NGK 4644 which is a 7 heat range. Plug I run in my car on pump fuel.

NGK 4554 is the Racing 8 heat range plug too if you want colder. Plug I run with E85.

Good info. Would you be able to share gapping information as well?

[amd is the best]

I run .024 usually without an issue.

[FRP]

Hi guys, Jeff @ FRP here, IMO the majority of this plug damage is strictly tune related. Too much timing and or too lean, or both, as related to the fuel being used at the time of the damage.

I run the Bosch triple electrode copper core plugs in the Bonneville engine and they come out looking like new with just a nice chocolate tan patina on the insulator tip.

[Hank]

A little late myself, but did you see the rest of the motor Jim? The headgasket was pushed out on the fire ring... Andy's motor detonated, period. I agree with what Jeff said.

Hank

[audifreakjim]

No, I didn't. Glad to hear you got a look at it.

[Audilard]

I'm still running the Bosch triple electrode copper plugs on my E85 470whp engine. I'm curious, what's the typical life span in an high output engine for plugs?

[SEStone]

I'm still running the Bosch triple electrode copper plugs on my E85 470whp engine. I'm curious, what's the typical life span in an high output engine for plugs?

I typically got 7-10k miles out of a set of those. Running NGK coppers now. Had to regap them after two tanks of gas, PITA. I'm down to a .028" gap, which is kinda on the small side of things IMO.