Another one bites the dust - a few questions

[mackdog2008]

Realistically the car usually will see half an hour driving at a time, I blew it up because I abused it at the track after a 3 hour drive through traffic. Since my pistons cracked on the ring lands and not on the top I'm assuming the heat expanded the rings. I'm not sure forged pistons would do any better, or do less damage to the cylinder walls. I'm going to run a little looser of a ring gap this time, theoretically a free solution. If I were racing the car I would consider it, but I don't even street race. I'll do an occasional pull and burnout, but I don't hit track speeds on the street or drive it anywhere near as hard as I would at the track. On paper I'm looking at $400 to get my car back up and running, I honestly can't justify spending 5x as much to possibly just break something else. It's kind of a crapshoot to me no matter how much you spend, so I just try to keep things cheap.. I've been driving my 04 mountaineer with chunks missing from the piston for almost a year now and if it blows up it blows up. I avoided pulling the engine when I put it back together and got a lot of use out of it. No I didn't fix it the right way, but it was cheap and I was driving it a lot sooner than I would have been had I pulled the motor and replaced the piston. Different strokes I guess

Wow!

 

[twistedneck]

I probably missed this above, but did you run E85? the pistons are nice and clean!

 

[downwardspiral]

I probably missed this above, but did you run E85? the pistons are nice and clean!

Nope, just premium pump gas. My tune was a bit rich in decel and light load, so that may have something to do with it.. I was surprised too though.
Didn't post this yet, the chunk stayed it place just right and didn't screw anything up. I didn't realize it was removable until the next day when it was laying on the bench and the chunk was pushed out. I measured my bores and they seem fine, I won the engine blowing lottery. I just started ordering parts. I screwed my balancer up so I need a new one. Total cost will be $500-600 including every torque to yield bolt, head gaskets, coolant oil etc. I just cant find cam cap bolts at the moment. There is a very slim chance it maybe will be running next weekend.

 

[downwardspiral]

Just for fun here's the breakdown of the cost, could be missing something but that's basically it.

I messed up my balancer pulling it off, and fried my battery fuse. I'm waiting to drive the car and update my sct to see if I need to pay for a clutch reflash, I'm also doing a new clutch and 3.31 gears which I've had sitting around and isn't included for obvious reasons.

 

[gimmie11s]

Hmmm. I might spring for boss rods and Pistons while you're in it.

You'd still be under a grand total ... Or close

 

[downwardspiral]

Hmmm. I might spring for boss rods and Pistons while you're in it.

You'd still be under a grand total ... Or close

I can't seem to find it anywhere.. I already ordered everything in green, the damage is done IMO

 

[gimmie11s]

Tasca has them

Piston is cr3z-6108b...$72 ea
Rod is cr3z-6200b...$23 ea

 

[downwardspiral]

Tasca has them

Piston is cr3z-6108b...$72 ea
Rod is cr3z-6200b...$23 ea

next time lol

 

[hand-filer]

Not a drop in procedure due to the Boss pistons and rods being heavier than the coyote parts. You need to rebalance the crank or use the Boss crank.

Hmmm. I might spring for boss rods and Pistons while you're in it.

You'd still be under a grand total ... Or close

 

[gimmie11s]

Nonsense. Have them all balanced to each other and install.

Do you tear down the motor and re balance the crank when you install a new clutch or converter?

The crank is individually balanced.

 

[TurboX2]

The bobweight difference for Boss vs Coyote looks like 64 grams, so 32 grams per rod/piston combo, that would be a ton to remove to make them equal....

OP, where are the crank bearings in your list? If you had detonation they are likely beat up and should be looked at / replaced also...

 

[downwardspiral]

The bobweight difference for Boss vs Coyote looks like 64 grams, so 32 grams per rod/piston combo, that would be a ton to remove to make them equal....

OP, where are the crank bearings in your list? If you had detonation they are likely beat up and should be looked at / replaced also...

I don't want to buy the gorillian main bolts. The rod bearings weren't too bad, I couldn't see the mains being much worse.

Edit: you're killing me dude, now it's bothering me. I guess ill bite the bullet and replace them too. If they are perfectly fine expect a picture of my balls in your pm folder lol

 

[jlm961]

I don't want to buy the gorillian main bolts. The rod bearings weren't too bad, I couldn't see the mains being much worse.

Edit: you're killing me dude, now it's bothering me. I guess ill bite the bullet and replace them too. If they are perfectly fine expect a picture of my balls in your pm folder lol

Damn. That's just wrong. But funny as hell. Sig line material right there.

 

[downwardspiral]

Day 10345, still waiting parts. I've decided I want nothing to do with main bearings. If my oil pressure is low I'll pull the engine again and replace them, I need to build an AR in the meantime. TurboX2 is safe on the dick pic front

 

[gimmie11s]

meh... if rods were fine there is little chance the mains are any worse. Did you measure crank endplay by chance?

 

[DrTriton]

Your ring lands are cracked and your cats are melted because your tune is messed up. Better get that fixed before you make any WOT pulls.

I dont generally see worn out main bearings on the 5.0L unless a lot of crap went through the engine, but I would at least pull a cap and take a look at one to be sure.

 

[jlm961]

If the cats are trashed it might be cheaper to bolt in a set of cat delete mids if you're not worried about passing smog.

 

[TurboX2]

If they are perfectly fine expect a picture of my balls in your pm folder lol

On second thought I agree 1742% with gimme11s....the mains are fine....nothing to see there, move along now...

 

[downwardspiral]

meh... if rods were fine there is little chance the mains are any worse. Did you measure crank endplay by chance?

I was going to put an indicator on it but there is 0 movement. Trust me I'm an engineer....:banana:

If the cats are trashed it might be cheaper to bolt in a set of cat delete mids if you're not worried about passing smog.

I picked up a set of "50 STATE EMISSIONS LEGAL CATS" for a good price. I didn't pass the first time with the cats anyway, I have a "STREET AND EMISSIONS LEGAL TUNE" I can use.

On second thought I agree 1742% with gimme11s....the mains are fine....nothing to see there, move along now...

If you change your mind LMK. I'm a people person, a real giver..

Today I de-glazed the cylinders, went pretty light until I saw a nice cross hatch pattern. I weighed the pistons on my gram resolution scale and luckily the new ones could be matched to the 3 bad ones within 2 grams (2/3 within 1), 4g was the cushion factor my local engine shop told me. I started gapping the rings but apparently ordered 1 set (for 1 piston). The top ring is gapped .020-.024 and the bottom .024-.030. The rule of thumb from what I gather is .0055/inch of cylinder bore(I am supercharged, NA is .0045). 3.63"x.0055=.0198 top ring, then add .004 for the middle ring. Don't touch the oiling ring (squiggly bottom ring). My logic in the loose ring gap is that my pistons cracked because of the expansion of the rings from heat (I've repeated this a million times in this thread, sorry but I'm trying to be concise). The 3 pistons that cracked I'm going to gap closer to .024 just to see what happens. I will order the other 7 rings tomorrow and hopefully finish the assembly this weekend. I did also buy an AR15 and a $500 boat (with trailer, doesn't quite run yet) so I have a bunch of fun shit to do to keep me occupied.

 

[jlm961]

I would think that the looser ring gaps will help some...as long as you're not detonating. Just curious...what grit hone did you use? Let us know how it goes. BTW cool toys.