I was going to post on this also, but Pop beat me to it. I used Ti valves, intake and exhaust in the below pictured car. At the cost of those valves 25 years ago, I damn sure would not want to pay for a set of pistons. Not many people would.

 

In Racing they like to use Inconel for the exhaust valves. Better than Ti i think...??

 

I'll claim been out of it too long. Never even heard of it. But you can bet your bippy that if it was available and better I would have had it.

 

I hope I never have to start one of these threads.

 

the new accert cat engine has steel pistons

 

It's not fun at all.

 

The threads following it, posting up your progress, well they ARE fun!

 

Hmm... Now...a completely honest question - Do you think this would have happened to a non-tuned engine with no HP- increasing modifications? Any ideas of the cause? Possibly just a faulty casting? Sorry to hear about this, but cant believe the engine still ran half way decent. thats damn tough!

 

The motor ran, and I could not tell a power difference but this also happened gradually, which could have made the power loss happen much slower than I could feel. Maybe the butt dyno needs a calibration. It didn't just start one day and make the noise, just sounded like it was a ticking time bomb right to pop. My initial plans were to run until it blew, but the thoughts of a rod sticking outside the block were scary(very scary lol). Honestly I have no clue what caused the failure. I am almost certain if this motor was bone stock, this would not have happened so soon, but the failure would have happened. At least that's my thoughts. Right now I am thinking about heat mixed with timing. My truck always made that noise, some of you know what I am talking about(think fuel 7). On the higher settings, that sound like its falling apart noise. From TS, to another tuner, to DP, its made the noise, the noise got much better(as in not nearly as loud) when DP redid the tuning but it was still there.

What I am thinking as of right now, that the pistons got hot at the top so many times, it went through a lot of heat cycles that weakened right were the skirts are(crown is hot, skirts are not as hot). Then since when the truck is tuned, the timing is increased, thus causing more pressure on the piston. This over and over again kept weakening and weakening the piston then it decided it had enough and decided to just give. That's my best explanation right now. The casting failure is also in for a suspect, but for right now, I am going with heat cycles causing the failure. I guess that's what happens when you buy a vehicle with 4 previous owners. FWIW all the pistons are cracked, none of them look serious, as if causing a failure itself, but are still cracked.

Sorry I kinda made that come out wrong, what I meant was 12 oclock when looking at the top of the piston, Since the engine is on a stand with the motor leaned so that side was straight up, I took the picture from the one side which made it come out the other way. Basically it is directly across from where you chopped it.

I am hoping I am the luckiest person alive, but until the other head is off, Ill just keep praying. Ill know for sure by Sunday(ill probably get home tomorrow and just start pulling the other side apart lol). If I end up with no more damage then a few bad pistons, at this point, my plans are to punch it out, do a rebuild on the motor, couple hipo parts that need to be installed with machining and since I will need machining either way best to do it now. Then Mahles that are coated to help prevent this again. I can't see any other broken pistons, just two, but until I have everything apart, I wont know the damage. I can't believe the chamber, it looks perfect, can see the cross hatches perfect. Thats my plan for now anyways, things can change faster than anything.

Kinda on a time line crunch since winter is approaching. Driving my car in the winter around here is not going to be ideal and I really do not want to, but If I have to Ill have to. Like Jeremy said these posts are not fun, the next part is fun, but makes my wallet a lot lighter than it already is.

Now, here is something I can't understand. Even though I see the failure, I can't see what the noise was. Those pieces appear(as of right now) to have fallen right off, went into the pan. A lot of you know what the noise was(almost like a valve train noise/dead miss sound), but I can't understand, someone who understands please explain it to me, what was causing that noise. Just piston slap like pop was saying? I'm still confused, the rod is on my bench, and the connecting pin is still in the piston along with both compression rings and oil ring. The other piston I can see appears to have the same failure, so I am assuming as of right now its the same. Any ideas?

 

I have to agree with Payson. That is where I thought your crack was though now I see a smaller one where you describe. I say that piston had two cracks.

 

Tear it down completely before you try and answer that question.

 

Me to, fortunately the only wrench that has touched my truck was for filter changes and a few mods.

 

Other head is off, still see no damage to the cylinder wall. I would like to say I will have some nice pictures tomorrow, but tomorrow I have a very busy schedule, and there would be no way for me to work on it. Sunday I should have some nice progress.

I am going to post some pictures of the rod bearings also, seems to look awkward to me on the #7hole, odd wear patterns. Looks like I might have dodged a bullet, but I am still pissed about the whole thing.

Lesson learned: This will be the last time I buy a 4 previous owner truck as a DD. This truck was abused before I got it, and I got the end results. I will also being researching much more before I buy anything over the price of $100. Glad I learned this lesson before I bought my car, since that purchase was thought out very well before I did anything. Do I regret my decisions, nope, learned a valuable lesson first hand, the best way.

 

FYI

You can find a rebuild kit that has Mahles, and everything you need to put it back together. Shop around.

 

Ford ho 302s have forged and all of the Yale and Hyster fork trucks come with forged. Also new Zo6 vets with titaium rods. They are alot of forged pistons used i wander why the 7.3 dont .