School me on spark plugs.

[16GoManGoHC2]

So after evaluating the data, the knock is not coming from the cylinders. On first drive it was smooth. Still going to replace the knock sensors but I’m glad plugs are done.

View attachment 53896

Stock healthy Hellcat cold compression is around 210 PSI, did you have the butterfly TB valve blocked wide open? My opinion from these numbers if TB was open is you may have cylinder sealing issues. Only way to know for sure is do a leak down test if it’s still apart, it’s the only way to know for sure what if anything is going on.
Plug removal, inspection, Leak Down test, bore scope, plugs back, ready to start up about 6 hours start to finish, that’s including pulling the cooling lines off the blower to get them out of the way as mine are insulated and fat and no getting by them. That’s doing each cylinder 2-3 times following the firing order round and round about 8 complete engine revolutions going the same direction always, don’t reverse direction if you go past TDC as you could loose ring seal in the piston grooves and get false low results. I just did this this past Saturday on mine, 3% leak down all cylinders, that’s with .026” ring gaps. Here is what plugs look like after 3000 miles on corn, F gasoline!!

 

[coolblue]

Stock healthy Hellcat cold compression is around 210 PSI, did you have the butterfly TB valve blocked wide open? My opinion from these numbers if TB was open is you may have cylinder sealing issues. Only way to know for sure is do a leak down test if it’s still apart, it’s the only way to know for sure what if anything is going on.
Plug removal, inspection, Leak Down test, bore scope, plugs back, ready to start up about 6 hours start to finish, that’s including pulling the cooling lines off the blower to get them out of the way as mine are insulated and fat and no getting by them. That’s doing each cylinder 2-3 times following the firing order round and round about 8 complete engine revolutions going the same direction always, don’t reverse direction if you go past TDC as you could loose ring seal in the piston grooves and get false low results. I just did this this past Saturday on mine, 3% leak down all cylinders, that’s with .026” ring gaps. Here is what plugs look like after 3000 miles on corn, F gasoline!!
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210PSI! . I'm surprised. That's gotta be with the VVT being full advanced. With a a static 9.5:1 in the old days you'd get 160/165.

 

[BULL]

Stock healthy Hellcat cold compression is around 210 PSI, did you have the butterfly TB valve blocked wide open? My opinion from these numbers if TB was open is you may have cylinder sealing issues. Only way to know for sure is do a leak down test if it’s still apart, it’s the only way to know for sure what if anything is going on.
Plug removal, inspection, Leak Down test, bore scope, plugs back, ready to start up about 6 hours start to finish, that’s including pulling the cooling lines off the blower to get them out of the way as mine are insulated and fat and no getting by them. That’s doing each cylinder 2-3 times following the firing order round and round about 8 complete engine revolutions going the same direction always, don’t reverse direction if you go past TDC as you could loose ring seal in the piston grooves and get false low results. I just did this this past Saturday on mine, 3% leak down all cylinders, that’s with .026” ring gaps. Here is what plugs look like after 3000 miles on corn, F gasoline!!
View attachment 53982 View attachment 53983 View attachment 53984 View attachment 53985 View attachment 53986 View attachment 53987 View attachment 53988

Those plugs are amazingly clean.

With that said, I do see a pattern amongst the different plugs, slight as it might be. Makes me wonder what's causing that...?

 

[16GoManGoHC2]

I am using that post on the “other” forums lol. So far Ive found that the previous owner was a jackass. Ran boostane…

View attachment 53774

Ugggg What I experienced with extended use of a MMT based octane booster is the exhaust valves looked 10 times worse then the plugs did, and these plugs look pretty bad as far as MMT fouling goes. The Tulips in exhaust get totally packed with that rusty looking stuff upping the compression ratio which increases the chances of detonation, ie knock. Run some E85 clean it up? Yea right, nothing cuts it short of abrasive removal. Your compression test results may be on the low side because you may have excessive leakage past the exhaust valve seat. That MMT builds up in the seat area and kills the seal, I’ve been there, only valve lapping with a Diamond compound restores the seal. Again, a leak down test will tell you if this is where your leaking at or not.

 

[16GoManGoHC2]

Those plugs are amazingly clean.

With that said, I do see a pattern amongst the different plugs, slight as it might be. Makes me wonder what's causing that...?

Break In, these plugs are the original start up plugs so they saw varying degree of blow by until rings sealed up. Plus their first 1000 miles of life was on gasoline so some show signs yet of its staining. The shading difference also comes from where the ground strap is verses the intake charge flow. Even though they are all indexed toward center cylinder and the intake valve some aren’t exactly facing the intake valve so they have some shading differences from that effect.

 

[Magnified]

First 16 plug mill for me was 2001 S500. Comparatively easy swap out (no supercharger or other components in the way). But still got old.

Like the use of the blocks, unlike those guys who just throw them in a tupperware bowl. lol

 

[Mean Cat]

I wonder if unbolting the motor mounts & jacking up motor some would help when do the plugs ?

Has anyone tried that ?

 

[16GoManGoHC2]

I wonder if unbolting the motor mounts & jacking up motor some would help when do the plugs ?

Has anyone tried that ?

Its really not that bad, drivers side a piece of cake, passenger side is a bit of a bitch but really with the right tools not that bad. You ever see the picture I posted maybe 2 years ago on the ratchets, extensions, and sockets that make it not that bad? Part I hate the most is the damn electrical connectors but a cotter pin removal tool makes them a snap too.

 

[Magnified]

lol, listen to what we're saying here. "unbolt the motor and jack it up to change the plugs" What the F is the world coming to.

 

[Xylander]

lol, listen to what we're saying here. "unbolt the motor and jack it up to change the plugs" What the F is the world coming to.

Hell, try changing the plugs on an older early-mid 90s American V8 cars where you had to remove the AC compressor, alternator, and then still remove the trans and driveshaft, then drop the engine at the rear to get at the rear plugs. At least ours CAN be done in state without the need for all that nonsense.

 

[Mean Cat]

lol, listen to what we're saying here. "unbolt the motor and jack it up to change the plugs" What the F is the world coming to.

Well sometimes you gotta do what you gotta do, just a thought.

And you know what this world is coming to, shit !

 

[Mean Cat]

Hell, try changing the plugs on an older early-mid 90s American V8 cars where you had to remove the AC compressor, alternator, and then still remove the trans and driveshaft, then drop the engine at the rear to get at the rear plugs. At least ours CAN be done in state without the need for all that nonsense.

Yeah, there are several cars in the past that the fender wells had to come out & jack up or lower the engine to get to plugs, so it's not something new.

 

[Hickster]

3 words/// Mag knee toe. Time for shine.

 

[Magnified]

Hell, try changing the plugs on an older early-mid 90s American V8 cars where you had to remove the AC compressor, alternator, and then still remove the trans and driveshaft, then drop the engine at the rear to get at the rear plugs. At least ours CAN be done in state without the need for all that nonsense.

Man I must have missed that shit. What kind of car was that?

 

[Magnified]

Yeah, there are several cars in the past that the fender wells had to come out & jack up or lower the engine to get to plugs, so it's not something new.

I was not blessed with possession of one of these gems. Give me the 1966 Mustang 289. I can get in the engine bay with the motor and knock that out, and that was a tight fit at that time! In the 1973 Ford LTD with a police interceptor in it you could play basketball in the bay while doing the job.

 

[Hickster]

And or MG GT Spider Monkey with electric fuel pump. Speaking of crap. Or Tennessee carp. Crap eater also.

 

[BULL]

Its really not that bad, drivers side a piece of cake, passenger side is a bit of a bitch but really with the right tools not that bad. You ever see the picture I posted maybe 2 years ago on the ratchets, extensions, and sockets that make it not that bad? Part I hate the most is the damn electrical connectors but a cotter pin removal tool makes them a snap too.

Based on most members here, it sounds like you should do up a dedicated thread showing your tooling setup.

@fumanchu182 about lost his temper more than once doing it.

 

[moparjim]

I was not blessed with possession of one of these gems. Give me the 1966 Mustang 289. I can get in the engine bay with the motor and knock that out, and that was a tight fit at that time! In the 1973 Ford LTD with a police interceptor in it you could play basketball in the bay while doing the job.

If I remember correctly if you go up a couple of years and swap that 289 for a 390 or 428 in the Mustang. Shock towers are pretty close. I think it can be done without doing it but easier if you raise the motor. Not a big deal back then. 2 bolts and no miles of wire tied tightly in the way. LOL

 

[coolblue]

Those plugs are amazingly clean.

With that said, I do see a pattern amongst the different plugs, slight as it might be. Makes me wonder what's causing that...?

Agree about the plugs but I'm still skeptical about longer term wear on the E85 motors. They look pretty on tear down but they're almost too clean. It looks like a wash down to me. If that's what the plugs (and exhaust) look like, the cylinder walls have to be squeaky clean also. The squirters are oiling the walls but the E85 is washing them clean on every stroke. Plus if it contaminates the oil its also got to effect oil lubricity. And it's pouring into the motor with 35/40% more volume. I'd like to see the results from the lab analysis after Mike and Jay send theirs out. I want to do another tune on my car for E85 but that's one of the biggest reasons stopping me (and oh yea, the money. Lol).

 

[16GoManGoHC2]

Agree about the plugs but I'm still skeptical about longer term wear on the E85 motors. They look pretty on tear down but they're almost too clean. It looks like a wash down to me. If that's what the plugs (and exhaust) look like, the cylinder walls have to be squeaky clean also. The squirters are oiling the walls but the E85 is washing them clean on every stroke. Plus if it contaminates the oil its also got to effect oil lubricity. And it's pouring into the motor with 35/40% more volume. I'd like to see the results from the lab analysis after Mike and Jay send theirs out. I want to do another tune on my car for E85 but that's one of the biggest reasons stopping me (and oh yea, the money. Lol).

I just mailed an oil sample to Blackstone yesterday to see just that, what’s in the oil. I change oil frequently, that oil had 800 miles on it, and use the best oil within price reasoning at frequency I change it, that was Amsoil 5W50 Signature Syhthetic, 70% more anti wear agents then most oils. If the tune is right wash down won’t be that bad. Another reason for using gapped rings verses gapless rings, the vacuum created during the intake stroke leaking through that gap pulls oil up in between the first and second ring to help keep oil on the top ring. Also the plateau cylinder hone spec
had a deep Rvk value Spec’d in it for a reason, deep valleys in the cylinder wall to hold oil for ethanol use. It was all part of the build plan .