cobra engine education

Pedrothecobra

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hello,

this is going to be a 2 part question so bare with me im still trying to educate myself.... a little background, i picked up a 96 cobra a few months back. been working out all the bugs mechanically and electrically. now it looks like i have the car running as good as its going to get but its consuming oil. (im trying some backyard fixes but preparing for the inevitable)

im probably going to end up pulling the motor and opening it up, ive been shopping around and since rebuilding a motor is somewhat new to me ( im pretty mechanically inclined) im looking at a forged internals kit from MMR. the kit includes pistions, rods and rings. obviously this is all depending how the cylinders look and measure once i do pull this motor. im sure there has to be some people in here with experience in doing what im about to do. my question is should i go with a different dome piston? the basic kit im looking at comes with -18cc which will put the compression at 8.5to 1. anyone with experience buying/installing one of MMRs kits? i am eventually planning on going with a forced setup just not sure of the route yet. this kit says its good up to 950HP, now im not looking to get too crazy but we all know how this story goes. im trying to build on a budget per say. not sure what that is yet lol. id like to hit around 600hp but i may be way off the mark with that wish idk (trying to get educated)


my next question is what is the difference in the 96-98 4.6 4v motors compared to 99-04 ? id like to pick something up to throw in my car while im building the motor. ive seen some reasonably priced complete motors. i have a stock 5 speed in the car. will the newer motors bolt right up?
 

cobrajeff96

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You'll have to get the motor thoroughly checked (line bore, decked, etc.) and this more than likely can only be done by a local machine shop. Usually backyard projects wind up failing when it comes to rebuilding a motor, especially one that's intended for boosted performance. My advice would be to get some price estimates from the pros, it's what they do all day everyday.

If it winds up being too far outside the budget, consider a Coyote swap. I've seen people getting the hardware required for as little as $5k and this would include motor and ECU solution. There's many ways to do this, but taking on the raw labor of it is risky for any mod motor.

There's no a whole lot different from the two versions of the SN95 4v motors, it's mostly in the heads & induction systems. So...minor changes overall. It's known that the 96-98 Cobra has the potential to flow the most air out of all of them but it's usually not beneficial unless you're rocking a pretty extreme boosted application.
 

07GtS197

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You don’t even necessarily have to buy a whole rotating assembly. Your crank is forged and will hold a lot of power. You could find some used terminator or boss/15-17 gt rods and good aftermarket forged pistons. Have a shop assemble and balance it, clean the block, have the heads looked over or upgraded or supply your own heads and you’ll be in it for less than if you would have bought a long block or had a shop supply everything.
 

Makoto

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A few things.

1. people who build these engines are few and far between. fewer still are really good at it.
2. i got my pistons from https://www.modmaxracing.com/, they were really awesome, helpful, and it was very reasonably priced
3. you get what you pay for. this isn't an LS motor so it'll cost more and some things are really annoying.
4. the best thing mmr has is the head cooling kit. there are 2 kinds, get the one that goes on the back of the motor if you're doing it with the engine out. I made the mistake of ordering both.
5. 99-04 engines will physically bolt right up but lots of things like fuel systems, ecu's, and stuff like that are going to hang you up. I had to use a way overbuilt fuel system for my mach 1 intake to work with my return style setup.
 

badass98svt

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Pedro, where are you from? Finding a builder for these is definitely not very difficult. It's just a modern(ish) engine. Not much different from all the other Overhead came engines.
 
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Pedrothecobra

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Pedro, where are you from? Finding a builder for these is definitely not very difficult. It's just a modern(ish) engine. Not much different from all the other Overhead came engines.
in im south jersey about 10 mins from philly
 
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Pedrothecobra

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A few things.

1. people who build these engines are few and far between. fewer still are really good at it.
2. i got my pistons from https://www.modmaxracing.com/, they were really awesome, helpful, and it was very reasonably priced
3. you get what you pay for. this isn't an LS motor so it'll cost more and some things are really annoying.
4. the best thing mmr has is the head cooling kit. there are 2 kinds, get the one that goes on the back of the motor if you're doing it with the engine out. I made the mistake of ordering both.
5. 99-04 engines will physically bolt right up but lots of things like fuel systems, ecu's, and stuff like that are going to hang you up. I had to use a way overbuilt fuel system for my mach 1 intake to work with my return style setup.
yea i just started exploring doing the motor. i honestly dont know if this is the car i want to build. i really wanted a white cobra, i just couldnt pass up the deal i got on this one. if i can do the motor for about 2500 all in. (minus a blower) ill do it. its just the unknowns of what the cylinders and rod bearing/crank journals look like once i get into it. and the heads while i have it apart should get some attention
 

RAU03MACH

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hello,

this is going to be a 2 part question so bare with me im still trying to educate myself.... a little background, i picked up a 96 cobra a few months back. been working out all the bugs mechanically and electrically. now it looks like i have the car running as good as its going to get but its consuming oil. (im trying some backyard fixes but preparing for the inevitable)

im probably going to end up pulling the motor and opening it up, ive been shopping around and since rebuilding a motor is somewhat new to me ( im pretty mechanically inclined) im looking at a forged internals kit from MMR. the kit includes pistions, rods and rings. obviously this is all depending how the cylinders look and measure once i do pull this motor. im sure there has to be some people in here with experience in doing what im about to do. my question is should i go with a different dome piston? the basic kit im looking at comes with -18cc which will put the compression at 8.5to 1. anyone with experience buying/installing one of MMRs kits? i am eventually planning on going with a forced setup just not sure of the route yet. this kit says its good up to 950HP, now im not looking to get too crazy but we all know how this story goes. im trying to build on a budget per say. not sure what that is yet lol. id like to hit around 600hp but i may be way off the mark with that wish idk (trying to get educated)


my next question is what is the difference in the 96-98 4.6 4v motors compared to 99-04 ? id like to pick something up to throw in my car while im building the motor. ive seen some reasonably priced complete motors. i have a stock 5 speed in the car. will the newer motors bolt right up?
Also take a look at modmax 4.6 5.4 rotating assembly kits
I ended up getting a package deal from them
For my cobra
 
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Pedrothecobra

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this webbing? kinda hard to see this is the only pic i have from a while back when i first got the car
 

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RAU03MACH

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Is that block aluminum
And also look on the sides there will be a stamping with
FE xxxxx-xxx what ever number it is
Look it up on Google
 
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Pedrothecobra

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Is that block aluminum
And also look on the sides there will be a stamping with
FE xxxxx-xxx what ever number it is
Look it up on Google
pretty sure it is. ill double check when i get home later and check the numbers
 

lwarrior1016

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Building these engines is definitely not difficult and can absolutely be done at home. Attention to detail is what makes the engine live.
 
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Pedrothecobra

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Building these engines is definitely not difficult and can absolutely be done at home. Attention to detail is what makes the engine live.
so i reached out to local shop i used for heads on my boat. hes tellin me i should go .20 over to ensure a true cylinder. i obviously havent opened this motor up yet to see what it looks like inside. is it common for these cylinders to need machining? or is it just a case by case basis? i feel pretty confident i can handle this job. i just really dont want to get into punching it out for obvious costs reasons
 

RAU03MACH

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I'll only punch it out more if needed
I try my hardest to keep it standered if possible
Only so I can rebuild it later on down the line
Prolong
 

lwarrior1016

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so i reached out to local shop i used for heads on my boat. hes tellin me i should go .20 over to ensure a true cylinder. i obviously havent opened this motor up yet to see what it looks like inside. is it common for these cylinders to need machining? or is it just a case by case basis? i feel pretty confident i can handle this job. i just really dont want to get into punching it out for obvious costs reasons
It’s definitely case by case and you want to get by with removing the LEAST amount of material possible. It would need torn down and measured before making a definitive statement like that.
 

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