Want to boost engine power
03-12-2008, 08:28 AM
#41
In that case I apoligize and retract my statement, towards you, I'm just a little heated about this thread and every thread that has to do with engine performance out of these Jeep's.
I have no problem with it in the trail's, I knew going in I wasn't purchasing this for on road performance.
I have no problem with it in the trail's, I knew going in I wasn't purchasing this for on road performance.
03-12-2008, 08:28 AM
#42
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I'm sorry, but if you think that the 3.8 can withstand a 100 horse power gain, you're mistaken and here's why. The weakest link in this engine is the cylinder head/block configuration and head bolt type.
Smack a blower on it and cylinder pressure increases dramatically. The head bolts are called "torque to yield" bolts. Simply stated, they stretch to achieve their final torque value. They are torqued with a torque wrench in steps and then the final step is to turn the bolts down an "additional" amount (measured only in degrees of a turn) to the final value to stretch the bolt.
Once the bolt is stretched, it is now useless for anything other than holding the head on. Once it is removed, it becomes trash can fodder. That's right. Torque to yield head bolts can only be used once. Go buy a head set from Mopar. They come with head bolts.
Where am I going with all this? Simple. The bolts are already stretched to their max simply holding on those aluminum heads. With a blower bolted on top, now we have the missing factor to further cause the already weak head bolts to be compromised. The extra cylinder pressure WILL sooner or later cause the heads to lift, strecthing the bolts beyond their designed capacity, and pass that compromise on to the head gaskets.
It's not a "maybe". It WILL happen. It's just a question of time, especially with the iron block/aluminum head combination. We already have two completely different materials expanding and contracting at different rates (with a gasket in between) to begin with.
Now we have added a blower (and probably all the other goodies that go with it) and are taxing an already weak area even further. Get the Jeep in a bind, tow too much, or simply keep your foot on the loud pedal too long, and that's all it will take. It may a take little while, but sooner or later, it'll happen. Just like using moderate and large amounts of nitrous, an engine has to be built and designed using the power adder in mind. You don't just strap it on and go. You have to upgrade the entire package, or you're asking for trouble.
This is why I keep preaching nitrous. Nitrous in small amounst (like a 50 HP shot) is less likely to cause engine damage. It is not activated all the time. There is no extra fuel injected at such low HP levels. Is there still a risk? Of course.
The engines have the risk in stock form, because of the conditions described above. That's reason enough for me to leave mine alone.
On a side note: To the person who said something about people not knowing what they're talking about before they post, I'll put my creditentials and experience up against anyones here anytime. I've been doing this far too long (over 30 years) to have some snot nosed daddy bought me a Jeep little punk tell me I don't know anything. You can go run that shot off on somebody else.
Smack a blower on it and cylinder pressure increases dramatically. The head bolts are called "torque to yield" bolts. Simply stated, they stretch to achieve their final torque value. They are torqued with a torque wrench in steps and then the final step is to turn the bolts down an "additional" amount (measured only in degrees of a turn) to the final value to stretch the bolt.
Once the bolt is stretched, it is now useless for anything other than holding the head on. Once it is removed, it becomes trash can fodder. That's right. Torque to yield head bolts can only be used once. Go buy a head set from Mopar. They come with head bolts.
Where am I going with all this? Simple. The bolts are already stretched to their max simply holding on those aluminum heads. With a blower bolted on top, now we have the missing factor to further cause the already weak head bolts to be compromised. The extra cylinder pressure WILL sooner or later cause the heads to lift, strecthing the bolts beyond their designed capacity, and pass that compromise on to the head gaskets.
It's not a "maybe". It WILL happen. It's just a question of time, especially with the iron block/aluminum head combination. We already have two completely different materials expanding and contracting at different rates (with a gasket in between) to begin with.
Now we have added a blower (and probably all the other goodies that go with it) and are taxing an already weak area even further. Get the Jeep in a bind, tow too much, or simply keep your foot on the loud pedal too long, and that's all it will take. It may a take little while, but sooner or later, it'll happen. Just like using moderate and large amounts of nitrous, an engine has to be built and designed using the power adder in mind. You don't just strap it on and go. You have to upgrade the entire package, or you're asking for trouble.
This is why I keep preaching nitrous. Nitrous in small amounst (like a 50 HP shot) is less likely to cause engine damage. It is not activated all the time. There is no extra fuel injected at such low HP levels. Is there still a risk? Of course.
The engines have the risk in stock form, because of the conditions described above. That's reason enough for me to leave mine alone.
On a side note: To the person who said something about people not knowing what they're talking about before they post, I'll put my creditentials and experience up against anyones here anytime. I've been doing this far too long (over 30 years) to have some snot nosed daddy bought me a Jeep little punk tell me I don't know anything. You can go run that shot off on somebody else.
EDIT: every engine performance thread ends with a " get a hemi or supercharger" and its starting to piss me off cause i know there are other options. Every time i even mention nitrous or a cam or anything out of the ordinary, the newbs freat out and wont shut up about it. So, i apologize to those who know their shit and can be of helpful information.
Last edited by The Diesel; 03-12-2008 at 08:31 AM.
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03-12-2008, 10:34 AM
#46
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TeraFlex had a JK with a Supercharger on it. Lasted 13,000 miles till a salesman took it up a steep long hill and didn't notice the engine pinging and motor went BOOM!
03-12-2008, 10:51 AM
#47
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funny to hear all these opinions
I added a stage 2 from Jet, airaid cold air box, gibson cat back exhaust and the only thing I noticed was a bunch of noise. I wouldn't even mind the noise if the motor had some balls in the trade off but it's still a dog. I only wish I didn't toss all the original parts or I would put it all back to stock and just accept it for what it is.......a JEEP!
Buy a Vette if you want performance
Jeeps are for wheelin
I added a stage 2 from Jet, airaid cold air box, gibson cat back exhaust and the only thing I noticed was a bunch of noise. I wouldn't even mind the noise if the motor had some balls in the trade off but it's still a dog. I only wish I didn't toss all the original parts or I would put it all back to stock and just accept it for what it is.......a JEEP!
Buy a Vette if you want performance
Jeeps are for wheelin
KSK
03-12-2008, 11:06 AM
#48
03-12-2008, 11:07 AM
#49
03-12-2008, 11:26 AM
#50
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