[deathbunny]

Why would a rebuilt engine using better parts be less reliable than buying a used stock engine?

[flinchy]

Originally Posted by stratos_335

I measured all the cylinder bores. At the middle of the cylinder, all bores were 84.00 mm. At the bottom all cylinders were 84.01 mm dia. At the top of the cylinder, all were 84.02 except of one cyl which was 84.03 mm dia.

Hell, all cylinders were expanded and had an oval or egg shape at the top. This is an open deck engine. All cylinder walls are so thin and the sleeves inside them are much thiner.

what were the dimensions of the egg shape? widest+narrowest?

Originally Posted by deathbunny

Why would a rebuilt engine using better parts be less reliable than buying a used stock engine?

it wouldn't be

[LoneRanger24]

http://youtu.be/HRC8wrl7vdM.

[chiefsotos]

Originally Posted by stratos_335

Hell, all cylinders were expanded and had an oval or egg shape at the top. This is an open deck engine. All cylinder walls are so thin and the sleeves inside them are much thiner.

The expansion is very common to open deck aluminium engine's block. Thats why people who want to increase the boost the put steell sleeves in the block.

[kalamokid]

is the n54 and open or closed deck?

[135Pats]

Originally Posted by kalamokid

is the n54 and open or closed deck?

Open deck. It’s the only real weakness on an otherwise robust motor. A fully closed deck is without question better equipped to handle lots of boost. With all that said, I don’t think OP’s motor blew due to how much boost he was pushing, there are numerous folks here who run a good deal more without any issues. We’ll see once/if it’s torn down or a proper analysis is done.

[stratos_335]

Originally Posted by deathbunny

Why would a rebuilt engine using better parts be less reliable than buying a used stock engine?

There is a trick: upgraded forged pistons like CP and forged rods like Arrow will handle more boost safely. Machining my sleeves to 84.5 mm to put new pistons will make the sleeves very thin and the engine will not be reliable. If there is any coating on the sleeves, it will disappear after machining and honing.



@flinchy: the bottoms of the cylinders were measured 84.01 mm, the middle 84.00 and the top of them 84.02 and one cylinder 84.03. The stock is 84.00 for all the length of the cylinder.

[kalamokid]

Originally Posted by 135Pats

Open deck. It’s the only real weakness on an otherwise robust motor. A fully closed deck is without question better equipped to handle lots of boost. With all that said, I don’t think OP’s motor blew due to how much boost he was pushing, there are numerous folks here who run a good deal more without any issues. We’ll see once/if it’s torn down or a proper analysis is done.

Thanks. Funny because I thought us N54s were closed deck

[buster84]

Originally Posted by stratos_335

There is a trick: upgraded forged pistons like CP and forged rods like Arrow will handle more boost safely. Machining my sleeves to 84.5 mm to put new pistons will make the sleeves very thin and the engine will not be reliable. If there is any coating on the sleeves, it will disappear after machining and honing.



@flinchy: the bottoms of the cylinders were measured 84.01 mm, the middle 84.00 and the top of them 84.02 and one cylinder 84.03. The stock is 84.00 for all the length of the cylinder.

This might be a good thread for reference to your car since you also tore your engine down. Btw, what year if your car?

http://www.e90post.com/forums/showthread.php?t=464348

[stratos_335]

Thanks, I am already aware of this thread but there is no input after the rebuild is done.

My car is 06-2009 built with 60.000 km, 37500 miles

[buster84]

Originally Posted by stratos_335

Thanks, I am already aware of this thread but there is no input after the rebuild is done.

My car is 06-2009 built with 60.000 km, 37500 miles

Dam only 37,500 miles. Did you try making it stock and taking it in under warranty?

Oh, i was just pointing that thread out as a reference to the damage he had to his engine. I didn't read it, so i didnt realize it wasn't updated.

[stratos_335]

I could try this but it would be a waste of money and time.

BMW warranty is applicable for the first 2 years and after that it expires. My car is 4+ years old so I wouldn't have a chance with BMW dealers and repair shops

[flinchy]

Originally Posted by stratos_335

There is a trick: upgraded forged pistons like CP and forged rods like Arrow will handle more boost safely. Machining my sleeves to 84.5 mm to put new pistons will make the sleeves very thin and the engine will not be reliable. If there is any coating on the sleeves, it will disappear after machining and honing.



@flinchy: the bottoms of the cylinders were measured 84.01 mm, the middle 84.00 and the top of them 84.02 and one cylinder 84.03. The stock is 84.00 for all the length of the cylinder.

so the entire width (around) was 84.03?

taper is completely normal, that doesn't sound egg shaped?


at least the sleeves aren't thin compared to many OTHER open deck blocks lol

and you should be able to get .25mm oversized pistons for an 84.25mm oversize lol

and get some mini block guard things installed 'just in case'

[BMWM.D.]

Originally Posted by boom

If the injector stopped flowing, there wouldn't be fuel in the cylinder. No fuel = no combustion = no detonation.

Normally, I'd agree with that. With meth injection, it would probably just go very lean on that cylinder. It's the reason I don't have fuel cut-off set to active in the rev limiter tables on my Corvette.

[GeorgiaTech335coupe]

Look, our pistons are twins. This was in cylinder 6 for me.

[GeorgiaTech335coupe]

Cylinder 1 wasn't a happy camper either.

[GeorgiaTech335coupe]

Originally Posted by enrita

Thats what happens when u run aggressive with meth. Its always either cyl 2 or 5. Injector is NOT the issue.

Mine was in 6. And a little bit in 1.

[GeorgiaTech335coupe]

Look at all that Aluminum fused onto the rod.

[stashtrey]

These threads scare the sh*t out of me.

[GeorgiaTech335coupe]

My car did not throw any codes before this happened. And only had misfire codes after it happened.
When it happened, car went into limp and acted like it had a misfire where the car is putting.

[GeorgiaTech335coupe]

Stratos, I think you are doing the right thing by buying a used engine. Save yourself the headache. My car has been down for just about 8 months now. And it is still going to be another month at least before we fire it up. Building the engine in this car is not fun, mostly because only a few have done it. It is also VERY EXPENSIVE. Much more expensive than you would think.

[GeorgiaTech335coupe]

Luckily, my block was fine. The sleeve was not damaged and only had some fused aluminum on it. That was taken off when the bored it out for the oversized pistons.