I now have 1200 miles on the car since the motor was rebuilt and decided to pull the plugs just out of curiousity. Guess what I discovered. RUST on the plugs. All six of them. Same amount and all plugs looked identical. I should have taken a picture but didn't.

Obviously water is getting into the cylinders. Where and how I don't know, but I guess we are bound to find out.

I chose to run distilled water in my cooling system vice 50/50 coolant since I live in southern Texas.

The car does not overheat and I have not noticed any water in my oil or oil in my water at all.

Heads are not tightened down enough? Water in the gas?

Any thoughts on this is appreciated!

 

What kind of plugs, for the record?

 

Have you driven in the rain much? Could your Injen CAI be ingesting water???

On a side note, it gets really hot where I live too. It's been known to reach 110, but 100+ degree summers are typical. I use coolant all year because using plain water makes me nervous. Our cooling systems contain various metals and coolant has anti-corrosive additives. Heat also speeds up the rate of corrosion. If using plain water you should be using additives to help fight corrosion. To me it's just easier to use coolant and maintain the recommended 50/50.

Just some thoughts....

 

pics please....

 

Actually I am running it as a short ram setup now so I doubt that I am getting much water into it at all. However anything is possible, but I have not driven in much rain, if any at all since the build.


I was using distilled water for 30,000 miles before the build and everything looked fine. The water that we drained when we pulled the motor was crystal clear and there were no signs of corrosion throughout the cooling system.

NGK platinum in stock heat range.


I will take some tonight for ya.

 

now are you sure it was rust, i had a nice pink/orange corrosion on all my plugs when i took them out. i was running nitrous on them....

 

Yeah, it was rust. There is no pink to it. It's just a nice brown rust.

There has been no nitrous use on this motor yet. These plugs were brand new 1200 miles ago when I started the motor for the first time after the build.

 

A little off topic: Have you dynoed your car since the build?

 

Are you sure its rust? Could it be carbon deposits? How rich are you running?

 

Could it be accelerated Galvanic Corrosion due to the heat & pressure? You have a lot of Disimilar metals in there that might not react well together under the heat and pressure (Think Dust/Shavings Bonding and breaking down). A few deposits of Galvanic Rust could be forming.

 

Intresting theory....

 

Is the rust on the inside of the plug (electrode) or the outside threading? If its the inside then you have a problem. If its the outside its normal in damp and wet climates.

 

I am not absolutely positive, but very very confident that it is rust. I will be taking pictures tonight when I get home from work and posting them here.


It is definitely on the inside covering the electrode along with the ground strap and inner threads.

 

One thing that I should mention is that the car is definitley not producing the power that it should be. It pulls less than it did prior to the build.

The differences between pre build and built were the addtion of:

11.0 to 1 pistons
Eagle rods
JWT cams
JWT spings
Supertech valves (1 mm oversized)
Ferrea valve guides
Solid motor mounts
Updated VTC cam gears

I understand that the motor still needs to be tuned, but it is no stronger than a z with a couple of bolt ons. In addition, a good friend of mine has the same cams and there is a noticeable transition over 4000 RPMS in his Z where the power really comes on. Mine exhibits none of this. just pretty much the same throughout the powerband.

I blamed most of the lack of power on it's untuned state, but with the discovery of the rusted plugs, I now suspect there is a lot more to this.

 

do you have anything to monitor your AF ratios. any kind of computer to change anything. i wish i had that stuff done to mine, i would MAKE it faster... hehehe

 

probably not rust. rust requires several things, and the combustion conditions inside the cylinder is not one of them. if you run enough water in there to rust, how is it running? besides, the electrodes are not ferrous and they won't rust.

 

Please Post Pictures.

 

I wouldn't think that using 100% distilled water is the best idea, especially in Texas where the temperature goes 90,50,80,30 all the time. Is there any specific reason you run water with no coolant mixture?

Also, who built your motor and what engine management are you running?

-Acree

 

How are those pics coming along.

 

Hey guys. I really apreciate all the suggestions that you are throwing out there!

Here are the pics. From left to right they are in cylinder number order. Cylinder 1 on left and cylinder 6 on right.

Besides the obvious discoloration, the only other thing I noticed was oil on the cylinder 1 plug.

I did a compression check while changing the plugs out and all cylinders were pretty much the same with the exception of cylinder 5.

Compression:
#1 - 210
#2 - 190
#3 - 192
#4 - 212
#5 - 183
#6 - 211

The motor had cooled down just a little prior to beginning the check. I only did it to check to see if anything was severly out of whack, so I wasn't concerned with trying to get a super accurate warm reading. My understanding is that warmer would have been higher.

I replaced these plugs with the new ones and the car is much smoother now and has much better throttle response.