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Old 03-04-2007   #1 (permalink)
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Default 2001 Cobra - Unexpected Engine Rebuild

Hey there people who will understand my situation,

I use these forums all the time to keep up to date with what is happening in the Mustang world and to glean knowledge from some of the tech posts.

I just thought that I would post my story about my Cobra - since that is about all I can do at this point because the car has no engine in it.

I bought the car in November of last year and knew that it was in need of some work but since it had a vortech s/c, suspension and exhaust upgrades and the price was right - I thought I would dive in and buy it. (I have always felt an empty place in my driving enthusiast heart since my 1988 Cobra was totaled by an soccer mom in a minivan 6 months after I bought it many years ago)

Never really got to enjoy the 01 Cobra because I knew that I needed to do some work on it. I had no idea. I thought that the oil in the intake what started to show up was from a fauly s/c impeller seal. So I sent the unit to Vortech and - despite some negative things I have heard, recieved great service on the minor rebuild. (Even though they charge you you first born child for some seals and bearings) I was happy when I finally recieved it back and put in in and then I was even more sad when I realized that it was not the problem in the first place. Knowing now that I had spent the money and "fixed" the s/c but knowing that I had a big problem. (The funny thing was Vortech said that the problem was a warranty issue and they would have paid for it if I was the original owner and had the receipt) Besides the oil leaking issue the s/c was working fine - or so I thought.

I had plans of rebuilding the engine in the future which is why I bought it in the first place - I just didn't want it to be so soon. After, searching and struggling with inferior shops and unbeliveably inept dealer mechanics, I found a great shop who was willing to work with me on the rebuild.

The day finally came when we pulled the engine and after only 4 hours (which kinda blew my mind) had the engine out and totally apart - this is what we found: (see below)


3 pistons with holes! What a mess. This was not all together unexpected given the nature of the weak components in the 01 short block when a power adder is used. So here I sit waiting for parts to arrive and sharing my story with others who may be able to relate on some level. Since I know nobody around where I live, save my mechanic, who can sympathize. While it is exciting, it costs $$$ and so I sit - typing.

Estimated time of completion is the end of April - just in time for summer! Since the engine is out anyway - a few more goodies are being thrown in.

Hooker Long tubes
Eagle competition stroker rotating assembly
JE Pistons
B&M Ripper Shifter
New Tuning module
And of course a new dyno tune.

Added to the excisting Vortech SQ-2 (newly rebuilt) and the Eibach suspension I have high hopes for my pony.

So there it is - I never post, and when I do I write a novella! Just needed to get that down. We'll see what happens in a month or so.

Cheers and light'em up for me - until I can once again do the same.
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Old 03-04-2007   #2 (permalink)
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Wow, someone didn't take care of that motor after the blower was installed. Looks like some devere detonation took it's toll on that piston. Make sure you get forged pistons in that thing so you can really crank up the boost. Also might want to get dished pistons to drop the compression on it. Good luck with your build up, I hope it turns out exactly the way you want it.
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Old 03-04-2007   #3 (permalink)
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Yeah, that piston looks really beat up. Good luck with the build, I probably won't be too far behind, just need to get a DD first.
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Old 03-04-2007   #4 (permalink)
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A trully heartbraking story, a tearjerker for any mustang enthusiast, feels similar to when old yeller got shot; at least with a happy ending! hope my pistons never look like that when it's time for a rebuild!
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Old 03-04-2007   #5 (permalink)
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wow, good luck with the rebuild, only can make it go faster so!
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Old 03-04-2007   #6 (permalink)
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Quote:
Originally Posted by BlueStreak03 View Post
Wow, someone didn't take care of that motor after the blower was installed. Looks like some devere detonation took it's toll on that piston. Make sure you get forged pistons in that thing so you can really crank up the boost. Also might want to get dished pistons to drop the compression on it. Good luck with your build up, I hope it turns out exactly the way you want it.
He has a 4V. Flattops are his best choice.
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Old 03-04-2007   #7 (permalink)
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atleast u got a snake.
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Old 03-05-2007   #8 (permalink)
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If the pistons have holes in them, they don't generate any compression anymore right? Doesn't the onboard computer detect something wrong then, and throws on the 'Service Engine Soon' light? (just wondering).

All in all, I feel sorry for the engine. Seeing that abuse, just cause someone was willing to spend some money on an upgrade, but not the amount that was needed to do it right...
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Old 03-05-2007   #9 (permalink)
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The ECU can't detect compression directly. It does seem like a problem that severe should have triggered a 'check engine light' though.
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Old 03-06-2007   #10 (permalink)
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Originally Posted by markwondi View Post
He has a 4V. Flattops are his best choice.
Not really. In order to apply more boost I would rather lower the compression a bit and get some 8cc dished pistons (which I have) Also the stroker reduces the overal compression ratio too.
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Old 03-06-2007   #11 (permalink)
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Quote:
Originally Posted by Neko- View Post
If the pistons have holes in them, they don't generate any compression anymore right? Doesn't the onboard computer detect something wrong then, and throws on the 'Service Engine Soon' light? (just wondering).

All in all, I feel sorry for the engine. Seeing that abuse, just cause someone was willing to spend some money on an upgrade, but not the amount that was needed to do it right...
I was surprised that I was not throwing any codes either. I don't know if the Vortech Tune widens the range of what is considered to be worthy of "checking engine" but if anything is it would be loss of compression.
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Old 03-06-2007   #12 (permalink)
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I've had it a long time back on a Sierra... Two of the four cilinders lost compression. I was kinda wondering if the ECU would actually pick that up or not. Seems it doesn't
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Old 03-06-2007   #13 (permalink)
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Quote:
Originally Posted by Slypstream View Post
Not really. In order to apply more boost I would rather lower the compression a bit and get some 8cc dished pistons (which I have) Also the stroker reduces the overal compression ratio too.
Mod motors repond better to high compression on boost engines. 4V's specifically lose so much low end torque with blowers, and reducing compression will make off boost power seem like a dog. Flattops are only a couple tenths higher compression than stock (stock is 2.8cc). Most will suggest flattops, as reducing compression really is a waste in power.
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Old 03-06-2007   #14 (permalink)
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It is true that the 4v suffer from the lower end torque, but as a FI engine - I will be driving it more at the higher range much of the time. I can gain "seat of the pants torque" by different gearing and rather add a safe guard to the engine by slightly lowering compression. In this case the stroker bumps up the 281 to 302cc anyway so with the lowered compression and forged internals boost at the upper end will be less of a menace (bear in mind I have already had 3 melted pistons in my cobra - I do not want anymore)

Everything is a compromise - I am choosing a little less compression.

Thoughts?
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Old 03-06-2007   #15 (permalink)
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Quote:
Originally Posted by Slypstream View Post
Not really. In order to apply more boost I would rather lower the compression a bit and get some 8cc dished pistons (which I have) Also the stroker reduces the overal compression ratio too.
So how much boost are you planning on running?
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