What went wrong? Help Needed.

[steve]

Shouldn't the crosshatching be predominantly at 30* or 45* angle to the bore not parallel to the deck like they look like in his pictures?

Something more like:

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You said the rod was very stiff. Are you talking about it moving at the piston pin?

 

[DeNoZZo]

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



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.

My mistake it was 18 in/hg.

Shouldn't the crosshatching be predominantly at 30* or 45* angle to the bore not parallel to the deck like they look like in his pictures?

Something more like:

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You said the rod was very stiff. Are you talking about it moving at the piston pin?

Yes it was nearly seized up right at the wrist pin.

I will upload pics soon to show the crosshatch better.

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[steve]

Who put the pistons on the rods?

 

[DeNoZZo]

Who put the pistons on the rods?

I don't think they were ever taken off. This is what my recipe from the machine shop says
-check large end of rod=ok
-clean pistons and check size

 

[AlaskanDsm]

I don't really see any cross-hatching on those cylinder walls. Also, I blew my first rebuild after 1,000 miles. This was becasue during the build, somehow the crank bearings got swapped. the bearing that had the oil feed groove went into the caps and the bearing that goes into the caps went into the black. Short story... oil never fed the crank or rods well.

Anyways, I babied my second engine for 1000 miles before I went WOT at all. Now my car is running strong at 12K. I would suggest taking this stuff back to the machine shop and really giving them the what for on not appropriately going through your stuff properly!

 

[pj91gsx]

I don't really see any cross-hatching on those cylinder walls. Also, I blew my first rebuild after 1,000 miles. This was becasue during the build, somehow the crank bearings got swapped. the bearing that had the oil feed groove went into the caps and the bearing that goes into the caps went into the black. Short story... oil never fed the crank or rods well.

Anyways, I babied my second engine for 1000 miles before I went WOT at all. Now my car is running strong at 12K. I would suggest taking this stuff back to the machine shop and really giving them the what for on not appropriately going through your stuff properly!

my friend did the same thing to my brothers motor. it had a forged bottom end too. sad to see it had spun a rod bearing. i had since replaced the rod, salaged the pistons and rods and started over with another block.

 

[AlaskanDsm]

my friend did the same thing to my brothers motor. it had a forged bottom end too. sad to see it had spun a rod bearing. i had since replaced the rod, salaged the pistons and rods and started over with another block.

Thats what I ended up doing for my second rebuild. I needed a new crank and rod. Piston was ok but when they rehoned the one cylinder it was a hair larger so I just did a compression test and while the 3 other cylinders were 170-180, that one is 160.

 

[DeNoZZo]

I was looking at the main bearings and noticed on the block side of the number 4 main bearing that there was an oil hole that lead to metal. All of my main bearings have 2 oil holes on the block side, so it's not an issue of getting the bearings mixed up I don't think. But is this supposed to be that way?

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[AlaskanDsm]

Good question, I don't remember if I had one that wasn't that way or not. But its a good thing that you have those ones in the block haha. I had those in the caps the first time. No idea how it happened as my dad has had lots of experiece with rebuilding engines. I guess some things get away from us all.

At this point, I would try to identify if the issue was from you or the machine shop or both and then identify what you can bring back to the machine shop to have redone at no charge or whatever fits the issue. Of course it was user error, I guess it's just time to move on and rebuild bigger, badder, and FASTER!!

 

[DeNoZZo]

Good question, I don't remember if I had one that wasn't that way or not. But its a good thing that you have those ones in the block haha. I had those in the caps the first time. No idea how it happened as my dad has had lots of experiece with rebuilding engines. I guess some things get away from us all.

At this point, I would try to identify if the issue was from you or the machine shop or both and then identify what you can bring back to the machine shop to have redone at no charge or whatever fits the issue. Of course it was user error, I guess it's just time to move on and rebuild bigger, badder, and FASTER!!

Yes I want to get to the bottom of this and figure out what caused failure and how to not have it happen again. Then I can make a plan on what to use and how to go about when rebuilding it this time around.

 

[xlMcMlx DsM]

The cross-hatch on the cylinders does not look correct at all. Should be about 60* from each other. Also assuming the cylinder bores are ok is not a habit anyone should get into. I know older V8 iron blocks barely would warp and cylinder bores rarely would be out of round, but the amount of people who buy a DSM and piss pound it are astronomical, and this would cause the bores to become egg shaped due to the movement of the rod perpendicular to the crankshaft.

 

[steve]

Do you have pictures of the rods and bearings?

 

[JacksonAuto]

Shouldn't the crosshatching be predominantly at 30* or 45* angle to the bore not parallel to the deck like they look like in his pictures?

Yes. The exact angle will vary between engine builders and ring manufacturers but in the OP's photos the cross hatch angle is definitely insufficient. Rings don't travel straight up and down in the bores. They are designed to spin. The cross hatch is what imparts this spinning action. Incorrect cross hatch angle means the rings didn't spin and would never perform properly.

 

[DeNoZZo]

Yes. The exact angle will vary between engine builders and ring manufacturers but in the OP's photos the cross hatch angle is definitely insufficient. Rings don't travel straight up and down in the bores. They are designed to spin. The cross hatch is what imparts this spinning action. Incorrect cross hatch angle means the rings didn't spin and would never perform properly.

So would you say then that the cross hatch angle not being steep enough is what caused the tops of the pistons to become ashy, and the rings to never really seal properly?

I'm still trying to pinpoint what caused bearing failure

 

[JacksonAuto]

Yes I want to get to the bottom of this and figure out what caused failure and how to not have it happen again.

-Poorly honed block- Looks like your "machine shop" used a ball hone on a drill instead of plate honing it.
-Failure to check PTW clearance
-Failure to accurately measure clearances
-Failure to check piston ring end gaps
-Failure to resize the rods after installing new bearings
-Vacuum leak during break in
-Rings never seated
-Blow by
-Rich condition during break in
-Oil in the chambers plus wacky AFR points to detonation and/or preignition which led to the bearing failure
- Metal contamination

 

[JacksonAuto]

So would you say then that the cross hatch angle not being steep enough is what caused the tops of the pistons to become ashy, and the rings to never really seal properly?

I'm still trying to pinpoint what caused bearing failure

The angle did not allow the rings to spin in the bores. THis didn't let them seat. This caused blowby. Oil causes detonation which likely led to your bearing failure. Not to mention the big end being distorted.

When you assembled the motor, what kind of lube did you use on the bearings? What about the cylinder walls and piston skirts?

I'm off to the shop now, I'll reply when I get back tonight.

 

[DeNoZZo]

The angle did not allow the rings to spin in the bores. THis didn't let them seat. This caused blowby. Oil causes detonation which likely led to your bearing failure. Not to mention the big end being distorted.

When you assembled the motor, what kind of lube did you use on the bearings? What about the cylinder walls and piston skirts?

I'm off to the shop now, I'll reply when I get back tonight.

I used permetex ultra slick on everything that rotates, and put a ton of oil down the cylinder walls before I assembled.

 

[pj91gsx]

Do you have pictures of the rods and bearings?

I agree with steve where are the pics of the rod bearings. Saying that you pressed on the rod bolts yourself, good point steve! Also, i wouldnt have know to have the rods resized, i didnt know how to put the rod bolts out with the tools i had so i decided to take them to a machine shop and they resized them after the rod bolt install. I didnt have to ask them, they did it because they knew the alignment gets thrown off when changing out the bolts.

 

[DeNoZZo]

Do you have pictures of the rods and bearings?

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[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

 

[pj91gsx]

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that rod needs to be resized.

 

[DeNoZZo]

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that rod needs to be resized.

Obviously ....

What rod/piston combo do you guys suggest? I found out today that I am going to need to have it bored .020 over, So I won't be able to use my 2g piston 1g rod combo that I had initially planned.

 

[SleepingTsi94]

I hope you didn't take this back to dewar again? I have heard around about other peoples failures with him

 

[DeNoZZo]

I hope you didn't take this back to dewar again? I have heard around about other peoples failures with him

Nope.... Took it to a guy in grundy center. Hopefully it works out better this time.