What went wrong? Help Needed.

[DeNoZZo]

UPDATE**
6-25-10
I had dropped my block and crank off at my machinist a few days ago for inspection. He is saying that my crankshaft mains checked out ok, but the rod journals will need to be ground. He says my bores measure 3.349 which is .003 over factory standard. He said the line bore checked out ok so nothing will need to be done there. He offered me a fully balanced rotating assembly for 1600 with arais forged pistons, eagle forged crank, eagle 4340 H-beam rod, with clevite bearings and piston rings. What do you guys suggest doing? I believe the wise thing to do would be to bore it over. What are the best pistons to go with for the lowest budget in that case? What combination of bottom end parts would you guys suggest? This will be primarily a daily driver, and mild track car. Might do some auto x, but mostly 1/4 mile.

Thanks
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First of all... Read this thread
http://www.dsmtuners.com/forums/hangout/359779-wow-all-i-can-say.html

It will fill you in on the background of the situation.


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On to the now.
I finally got a chance to tear into the motor to try and see what exactly went wrong.
The first thing I noticed after pulling the head of is that the pistons were really covered in a crusty flaky ash

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After pulling out the pistons/rods I noticed the rod that had the spun bearing was very very stiff and didn't want to move at all. Then I looked at the cylinder wall.

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In the picture you'll noticed the discoloration where something was happening that wasn't supposed to. I can't feel the colored area with my nail so it's nothing a good hone won't take care of I think. The other cylinders have similar marks in the same areas but it's not near as colored. Just barely.

As for the main bearings everything was perfect. Nothing abnormal or out of place there.

So what do you guys recon the damage is? What went wrong based on the whole story???

 

[95blackGsTurbo]

Your quick link doesn't work. I would suggest just adding this to the old thread.

 

[DeNoZZo]

Your quick link doesn't work. I would suggest just adding this to the old thread.

Fixed

 

[JacksonAuto]

What did the rebuild entail? The cross hatch left by the hone looks suspect. Did you use a ball hone or was it done by a machine shop? What were your bearing clearances? What was the piston-to-wall clearance? What methods did you use to measure everything?

 

[DeNoZZo]

What did the rebuild entail? The cross hatch left by the hone looks suspect. Did you use a ball hone or was it done by a machine shop? What were your bearing clearances? What was the piston-to-wall clearance? What methods did you use to measure everything?

I had the following work done by my local machine shop
Head- Valve stem seals, cleaned, decked, valvetrain checked, valve grind.
Block-Decked, cleaned, crack checked, cylinders honed.
Pistons/rods- cleaned, checked=ok
crank- arp main bolts installed and align honed by machine shop, crank polished.

I don't remember the bearing clearanes exactly but I do remember they were within spec (plastigauged). I never checked the p2w clearance. I figured it would be ok since I only had a hone and was using stock pistons with new oem pre-gapped rings.

 

[steve]

stock pistons with new oem pre-gapped rings.

I didn't know there was such a thing as pre-gapped rings OEM or aftermarket.

 

[DeNoZZo]

I didn't know there was such a thing as pre-gapped rings OEM or aftermarket.

Yep, the oem ones are pre-gapped.

 

[subie22]

Something isn't right with your piston to wall clearances. It only had 800 miles on it. Shouldn't of looked like that. I'm no expert. But is it possible for the piston to wall clearances was to tight and gave the crank bearings extra stress to ware away that bearing like that . That rod bearing was really really thin. But if he did a stock rebuild with just a hone it still shouldn't of did that since a hone is basically roughing up the cylinder walls to seal the rings. Like I said I'm no expert. Just makes sense.

 

[JacksonAuto]

There seems to be several things going on here that I think contributed to the failure. Engines all tell a story if they're taken apart by someone who has a real keen eye and knows what to look for. All we've got are a couple pics but some things do stand out to me-

First, the wear in the cylinder looks like you didn't have enough PTW clearance. Did you measure the bores for wear before you had it honed? Looks like that one is out of round which created a tight spot. If you look at the first photo, pay attention to the area just to the left of the obvious wear. There is a spot that looks smooth. This would be a low spot in the cylinder where the hone didn't even make contact with the cylinder. I'm willing to bet that the rings never sealed in this engine. That's why the tops of the pistons look like crap.

Second, did the shop plate hone the block in an actual power honing machine or did they use a ball hone in a drill? The cross hatch pattern does not look right. Without the correct finish and cross hatch the piston rings can't seat or operate properly. Piston rings don't just go straight up and down when an engine is running. They actually spin as they travel up and down the bore. It is the cross hatch that causes them to spin. With the wrong cross hatch angle they wont spin which means they will not seat.

I don't remember the bearing clearanes exactly but I do remember they were within spec (plastigauged). I never checked the p2w clearance. I figured it would be ok since I only had a hone and was using stock pistons with new oem pre-gapped rings.

Two things here. First, if you use plastigauge, that tells you that the clearance in the exact spot where you placed it was within spec. It will not tell you if the housing bore is out of round. This is a likely scenario as I see you installed ARP rod bolts without sizing the rods. The second thing is that you can never assume just because parts are new that they are good. I've seen plenty of times where brand new parts had a problem and if we had not checked everything thouroughly we'd have had a failure.

 

[DeNoZZo]

There seems to be several things going on here that I think contributed to the failure. Engines all tell a story if they're taken apart by someone who has a real keen eye and knows what to look for. All we've got are a couple pics but some things do stand out to me-

First, the wear in the cylinder looks like you didn't have enough PTW clearance. Did you measure the bores for wear before you had it honed? Looks like that one is out of round which created a tight spot. If you look at the first photo, pay attention to the area just to the left of the obvious wear. There is a spot that looks smooth. This would be a low spot in the cylinder where the hone didn't even make contact with the cylinder. I'm willing to bet that the rings never sealed in this engine. That's why the tops of the pistons look like crap.

Second, did the shop plate hone the block in an actual power honing machine or did they use a ball hone in a drill? The cross hatch pattern does not look right. Without the correct finish and cross hatch the piston rings can't seat or operate properly. Piston rings don't just go straight up and down when an engine is running. They actually spin as they travel up and down the bore. It is the cross hatch that causes them to spin. With the wrong cross hatch angle they wont spin which means they will not seat.



Two things here. First, if you use plastigauge, that tells you that the clearance in the exact spot where you placed it was within spec. It will not tell you if the housing bore is out of round. This is a likely scenario as I see you installed ARP rod bolts without sizing the rods. The second thing is that you can never assume just because parts are new that they are good. I've seen plenty of times where brand new parts had a problem and if we had not checked everything thouroughly we'd have had a failure.

First of all I want to say thank you for helping me figure this out.

I had the machine shop check the size of the bores and everything was ok last year
Here is a few pics from after I got the motor back from the machine shop (LAST YEAR)

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The rings had to have sealed. I never did a compression test, but there was no blow by and it had 18psi of vacuum at idle. Theres no way it would have ran as good as it did with no vacuum. Something I should mention however is that when we did the initial startup, I forgot to put one of the vacuum hoses on the back of the intake manifold. And I was trying to keep it running with it like that for a while until I found out. I'm guessing this caused it to run pig rich for a while. Don't know if that would contribute to all that ash?

It was to my knowledge that you have a certain window to break in the rings before the hone wears off. For the break in I did multiple pulls at wot in 3rd gear taking it higher each time and letting it engine brake all the way back down. I did lots of engine braking in my daily driving too.

I didn't install arp's in the rod, I used new stock bolts however. This is one of the things I personally think is what caused this. I simply tapped the old bolts out with a hammer and tapped the new ones in. Just used my hand to hold it, so I didn't think it would affect the big end. Maybe the tapping knocked it out of round? Either way I think you are supposed to have them honed any time you replace the rod bolts. Which I didn't do. The only problem with this is, why did it last 800 miles? I would think if that was the problem that it would have spun much sooner.

 

[pj91gsx]

I didn't install arp's in the rod, I used new stock bolts however. This is one of the things I personally think is what caused this. I simply tapped the old bolts out with a hammer and tapped the new ones in. Just used my hand to hold it, so I didn't think it would affect the big end. Maybe the tapping knocked it out of round? Either way I think you are supposed to have them honed any time you replace the rod bolts. Which I didn't do. The only problem with this is, why did it last 800 miles? I would think if that was the problem that it would have spun much sooner.

bingo when removing the rod bolts and putting new ones in, all of the rods must be resized. my mechine shop did the process for 30 dollars. its suprising the rods didnt lock up on to the crank when you torqued them. Your cylinder walls show rich condition, maybe a 255 in you tank over powering you fpr.

To add a good hone and perfect spec motor holds the hone very well in our iron blocks. My brothers gsx with many boost leaks still had a perfect hone after 180k miles, i was amazed!

PS dont feel bad, it happens you didnt know. you can get the rods resized if they are still good if you need some let me know. Me and a friend bent like 3 sets of valves and forgot a balance shaft bearing to block off and so we had to rebuild his motor like 3 times. However i was lucky i rebuilt 2 motors prior to that and didnt have any problems beside one blowing the HG because i didnt know about torquing in to out.

 

[BLINKY619]

mine had a good cross hatch hone at 107,XXX ive see motors with barely 80,XXX miles and the crosshatch was barely visible...!!!

 

[DeNoZZo]

bingo when removing the rod bolts and putting new ones in, all of the rods must be resized. my mechine shop did the process for 30 dollars. its suprising the rods didnt lock up on to the crank when you torqued them. Your cylinder walls show rich condition, maybe a 255 in you tank over powering you fpr.

I have the stock fuel pump rewired. I did have a couple boost leaks while it was running. No gaping holes in the intake tract, but a few small leaks. Maybe that was making it run rich.

It makes sense that not honing the big end of the rod is what caused this. But why did it last 800 miles. To my understanding, something like this would have happened before 200 miles if that?

 

[pj91gsx]

I have the stock fuel pump rewired. I did have a couple boost leaks while it was running. No gaping holes in the intake tract, but a few small leaks. Maybe that was making it run rich.

It makes sense that not honing the big end of the rod is what caused this. But why did it last 800 miles. To my understanding, something like this would have happened before 200 miles if that?

I think the out of round may have cause your washed cylinders, because in the pic, it looks like its just one side of the walls that was wearing out. When they resize the rods they shave the surface of the cap with sand paper then they resize them. Its not easy to kill a motor always, especially since it was all like brand new and in spec besides the alignment of the caps.

 

[DeNoZZo]

I think the out of round may have cause your washed cylinders, because in the pic, it looks like its just one side of the walls that was wearing out. When they resize the rods they shave the surface of the cap with sand paper then they resize them. Its not easy to kill a motor always, especially since it was all like brand new and in spec besides the alignment of the caps.

I think the wear marks on the cylinder walls are from the piston not wanting to spin at the wrist pin. I said in the first post that when I pulled the piston/rod out that it was very very stiff. I'm guessing parts of the bearing went up through the rod and got jammed up in the wrist pin.

 

[BLINKY619]

I think the wear marks on the cylinder walls are from the piston not wanting to spin at the wrist pin. I said in the first post that when I pulled the piston/rod out that it was very very stiff. I'm guessing parts of the bearing went up through the rod and got jammed up in the wrist pin.

yes im pretty sure thats what went wrong

 

[pj91gsx]

I think the wear marks on the cylinder walls are from the piston not wanting to spin at the wrist pin. I said in the first post that when I pulled the piston/rod out that it was very very stiff. I'm guessing parts of the bearing went up through the rod and got jammed up in the wrist pin.

that is a good observation i just pulled a motor apart that spun all 4 rod bearings i think the reason was because the wrist pins locked up or something idk.

 

[Aproductions]

yeah the pistons flakes are from oil.

 

[DeNoZZo]

yeah the pistons flakes are from oil.

From oil or from it running rich?

If it's from oil, what are some ways I would be burning it?

 

[pj91gsx]

yeah the pistons flakes are from oil.

pistons or piston rings done flake.

 

[Aproductions]

yeah I know, sometimes things when said sound different then when someone reads it.....oil getting past the rings will cook on the pistons and it will make them look flaky.....I'm in the middle of my build and mine were the same, I just used a wire brush and some cleaner.

yeah the pistons flakes are from oil.

I meant the pistons flakes are from the oil getting past the rings and cooking on there.

From oil or from it running rich?

If it's from oil, what are some ways I would be burning it?

from the rings not seating properly, wrong size, etc.

 

[donniekak]

How long was it until you put some high boost/load on the engine. It may have lasted that long, because you didn't stress anything until then.

 

[DeNoZZo]

How long was it until you put some high boost/load on the engine. It may have lasted that long, because you didn't stress anything until then.

No I was doing wot pulls within the first 100 miles. And I did a few hard launches before 500 miles even. Everything held up fine. When I changed the oil at 500 miles it looked perfect. No metal flakes or anything then.

yeah I know, sometimes things when said sound different then when someone reads it.....oil getting past the rings will cook on the pistons and it will make them look flaky.....I'm in the middle of my build and mine were the same, I just used a wire brush and some cleaner.



I meant the pistons flakes are from the oil getting past the rings and cooking on there.







from the rings not seating properly, wrong size, etc.

I don't think it was burning oil... Exhaust didn't smell or look like it at the time.

 

[JacksonAuto]

There are too many things going on here to pinpoint exactly what caused the failure. It was poorly machined, assembled and broken in.

The rings had to have sealed. I never did a compression test, but there was no blow by and it had 18psi of vacuum at idle. Theres no way it would have ran as good as it did with no vacuum. Something I should mention however is that when we did the initial startup, I forgot to put one of the vacuum hoses on the back of the intake manifold. And I was trying to keep it running with it like that for a while until I found out. I'm guessing this caused it to run pig rich for a while. Don't know if that would contribute to all that ash?

This is not a fair or accurate assumption. The rings most certainly were not sealed and there was blowby. Compression and leakdown test or not, I can see that there was oil in the chambers and I can also see evidence on the cylinder walls. The rings never had a chance and washed out as a result of your vacuum leak. Running pig rich during break in is certain death for a new set of rings. Also, the amount of vacuum is not a good indicator of ring seal. Are you measuring vacuum in PSI or in/Hg? I ask because 18 psi sounds like an awful lot. That comes out to 36+ in/Hg.

 

[JacksonAuto]

Do you have pictures of the chambers and spark plugs?