Flashbacks and Block Holes...

[caballo]

Some of you may know that I recently sent a rod through the block of my 00GT w/minimal mods right around 93k miles...

Long story short : rod through the driver's side of the block haulin' ass up an on ramp after "retarding" timing via DSP....

Flashback: About a month ago I decided I was going to start doing some real mods since I got a tuner. But first I wanted to make sure I was running with decent equipment:

Flashback within a flashback a little over a year ago the mustang through a sparkplug on a road trip and I bought all new COP's and plugs and injectors and a fuel pump and it ran fine (after it temporarily developed a knock at the Ford dealership)... when I got it home and replaced all that stuff....

Anyway I did a compression test and all the cylinders were @ 155psi with no apparent leak down.... except cylinder #8. it was at 90psi. hmmm...

I also noticed a slight miss at low load conditions around 1500-1800rpms. All COP's checked out fine and all injectors seemed fine and all plugs seemed fine....

BlockHole:

right above the oilpan mating surface near the rear of the driverside (below Cyl#3) where I had the head helicoiled earlier this year with no problems up to this point (since).

Well when I pulled the oilpan off after taking the engine out I find it was the rod from cylinder #8 that decided it had had enough of the dark and was shedding light on everyone else...

Question is w/93K+ miles doe this sound like it was just a natural progression since last year or could it have been the tune?

 

[the98stang]

Some of you may know that I recently sent a rod through the block of my 00GT w/minimal mods right around 93k miles...

Long story short : rod through the driver's side of the block haulin' ass up an on ramp after "retarding" timing via DSP....

Flashback: About a month ago I decided I was going to start doing some real mods since I got a tuner. But first I wanted to make sure I was running with decent equipment:

Flashback within a flashback a little over a year ago the mustang through a sparkplug on a road trip and I bought all new COP's and plugs and injectors and a fuel pump and it ran fine (after it temporarily developed a knock at the Ford dealership)... when I got it home and replaced all that stuff....

Anyway I did a compression test and all the cylinders were @ 155psi with no apparent leak down.... except cylinder #8. it was at 90psi. hmmm...

I also noticed a slight miss at low load conditions around 1500-1800rpms. All COP's checked out fine and all injectors seemed fine and all plugs seemed fine....

BlockHole:

right above the oilpan mating surface near the rear of the driverside (below Cyl#3) where I had the head helicoiled earlier this year with no problems up to this point (since).

Well when I pulled the oilpan off after taking the engine out I find it was the rod from cylinder #8 that decided it had had enough of the dark and was shedding light on everyone else...

Question is w/93K+ miles doe this sound like it was just a natural progression since last year or could it have been the tune?

Well SOMETHING caused cylinder 8 to have low compression, but many things could have caused it. Retarding the timing would not cause any major engine damage, but advancing it too much could cause detonation, which is not good at all. How many people have owned the car, and what kind of people were they? If some 16 year old kid with a lead foot owned it, that could have contributed. There are endless factors. Nonetheless, you need a new shortblock or rebuild. I would get a VT engine

 

[LaserRed01GT]

You say...

right above the oilpan mating surface near the rear of the driverside (below Cyl#3) where I had the head helicoiled earlier this year with no problems up to this point (since).

The passenger side is cylinders 1-4, the driver's side is 5-8. Do you mean you had the spark plug threads in the head heli coiled? I'm not sure how that is anywhere near the oil pan or mating flange, but if I understand you correctly, you are saying that the cylinder that show low compression was not the same cylinder that kicked the rod....correct?

Whether or not the cylinder with low compression had any thing to do with the cylinder that kicked the rod may or may not be easy to figure out?

What did the rod bearings look like on the cylinder that kicked the rod?
What did the plugs read on both cylinders?
Was there any evidence of prior damage to a ring land or the piston on the cyilder that kicked the rod?
Any piston to head or valve contact?
What did the wrist pin look like?
What did the rod look like?

To have a really good chance at getting an answer, you would be better off in my opinion to have someone actually look at the parts in person....preferable a reputable motor builder.

 

[Rickey_Bobby]

wow, 90 and 155psi....
I thought I had compression problems...

 

[caballo]

You say...

The passenger side is cylinders 1-4, the driver's side is 5-8. Do you mean you had the spark plug threads in the head heli coiled? I'm not sure how that is anywhere near the oil pan or mating flange, but if I understand you correctly, you are saying that the cylinder that show low compression was not the same cylinder that kicked the rod....correct?

Whether or not the cylinder with low compression had any thing to do with the cylinder that kicked the rod may or may not be easy to figure out?

What did the rod bearings look like on the cylinder that kicked the rod?
What did the plugs read on both cylinders?
Was there any evidence of prior damage to a ring land or the piston on the cyilder that kicked the rod?
Any piston to head or valve contact?
What did the wrist pin look like?
What did the rod look like?

To have a really good chance at getting an answer, you would be better off in my opinion to have someone actually look at the parts in person....preferable a reputable motor builder.

You put 2 and 2 together and somehow made 5...

I had the sparkplug hole on cylinder 3 helicoiled in late feb of this year. Rod 8 ventilated my block underneath cylinder 3 at the level that is right above the oilpan mating surface...

as for the rest of what you posted I have yet to finish the teardown... be patient...

 

[caballo]

Well SOMETHING caused cylinder 8 to have low compression, but many things could have caused it. Retarding the timing would not cause any major engine damage, but advancing it too much could cause detonation, which is not good at all. How many people have owned the car, and what kind of people were they? If some 16 year old kid with a lead foot owned it, that could have contributed. There are endless factors. Nonetheless, you need a new shortblock or rebuild. I would get a VT engine

VT is tops on the list...

 

[LaserRed01GT]

You put 2 and 2 together and somehow made 5...

I had the sparkplug hole on cylinder 3 helicoiled in late feb of this year. Rod 8 ventilated my block underneath cylinder 3 at the level that is right above the oilpan mating surface...

as for the rest of what you posted I have yet to finish the teardown... be patient...

I was just trying to clear up your confusing post. You said and I quote"

Anyway I did a compression test and all the cylinders were @ 155psi with no apparent leak down

A leakdown test will show the percentage of leakdown, a compression test does not show leakdown. The 155 is not bad, but obviously the 90 on the suspect cylinder was not too good.

BlockHole:
right above the oilpan mating surface near the rear of the driverside (below Cyl#3) where I had the head helicoiled

You imply that the block hole created by the rod is near where you had the head heli coiled. You are also implying that cylinder #3 is one the drivers side. #3 is the 3rd cylinder to the back on the passenger side.

View attachment 415943

It sounds as if you may be a little new to these motors, and that is OK. It sounds as if you are genuinely seeking help and wanting to learn, that is why I was just trying to clear up your misleading info so that everyone here could properly help you and give you some sound advice.

Now, it is not uncommon for a rod from one side of the block to exit another side of the block. Once those parts start to come apart they can go anywhere.

It is unlikely that retarding your ignition timing a little would have caused terminal damage like this. How much did you retard it?

So, now after looking at the cylinder arrangement picture above, which cylinders were the ones in question?

 

[caballo]

so I got it reversed...driver's vs passenger side... chalk it up to dyslexia... but now you know... #4 cylinder aerated the block underneath the #7 cylinder (that has the helicoiled sparkplug above it in the head) just above the oilpan mating surface of the block...

... anyway... still tearing it down...