500 Horses!!!!

I would find some used 03 04 cobra rods, pistons, and stock crank and block. I wouldn't buy a short block. too much money.

500 hp and cheap don't go together

If you want to run 500+ horses safely, it is best to do it right and spend the money on quality parts the first time. Have you ever had a 400 wheel horse stang before? That can be achieved safely without breaking the bank too much.

500 hp? Is this a number you just picked out of the air? Do you even understand what 500whp means? You sound like a noob with a big number. Tell us what you know to deserve that sort of number...

JymboSlice said:

500 hp and cheap don't go together

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+1

To answer the OP's question it really depends on what you are able to do labor wise. Do you know how to swap the internals and do all that work yourself? And if you get a short block are you able to do the swap yourself?

If the answer is no to the above two than it doesn't really matter either way. You pay more up front for the shortblock (depends on how many options you add on also) and save a little on labor, or you pay less up front for forged internals but you spend more on labor later..... both ways are expensive.

If you are able to do some of the work yourself than the price is really dependant on what you are able to do- the forged internals (rods, pistons) would be cheaper if you are able to do the work yourself. But the short block could save time and would be easier to swap out.

Also: What are your current set of mods? What kind of FI or nitrous system to you plan to run?

I blew the original motor after about 15K running with the blower. See my Sig., I got a still in the crate Cobra Shortblock, And all OEM Cobra internals. In other words, everthing that should be Forged is Forged. With the 417rwhp I have figures out to be 490hp at the motor. ( 490 X .85 = 416.5. ) I took the standard 15% parasitic loss number. It ran me about 7K, some of you may think that is high, but there was a lot of labor involved, not to mention re-installing the SuperCharger. And I didn't mind paying so much, I had just retired and pulled 10K from my 401k. *****, after 25 rears on the job, the 10K didn't even make a dent into my 401k. It was like found money. Get a used Cobra Shortblock (good luck!) and forged rotating assembly, you shouldn't bust anything with this. I know longer fear breaking anything, and I too will be shooting for 500rwhp. You, and me, will be close to 600hp at the motor. Now that's a nice number.

If you're competent you can take the stock engine out and remove the rods and pistons. Measure the bores. If they're in decent shape, give them a hone to break the glaze, clean it up. Measure the rod journals (don't remove the crank.) If they're all good you can get the good parts:

• a set of Manley forged pistons (e.g. SHM DIF3.552 standard bore size) for $649
• rings (e.g. SHM 7032-STD) $149
• rods - Manley H-beam rods (e.g. SHM 14042SHM-8) for $599
• rod bearings (e.g. SHM 8-1985A STD)

and slap your shortblock together. The cast crankshaft will be fine for 500HP as long as you keep the RPM sane and the forged reciprocating parts will be easily up to the task. An added benefit of using the OE crank is not having to worry about the flywheel since Cobra cranks had 8-bolt flanges.

This type of DIY solution is going to be cheaper than sourcing a used Terminator SB or buying a pre-built SB. But it also assumes (a) that you're competent and have the tools to build an engine and (b) that your existing engine doesn't require any machine work. Of course if you've got lots of miles, a ridge a the top of the bores, taper or out of round cylinders or journals etc then you're in for a lot more expense and time.

Once you've got a decent forged SB top it off with a set of good PI heads with stock or Stg 1 cams and a blower at 14-psi. Of course a blower is big-$$$ no matter how you swing it. And make sure you invest in the fuel system and air metering (MAF) too. This means a Cobra pump setup in the tank (at the very least), 60-lb injectors (42 might work) and a Lightning MAF plus a PCM tune to tie it all together.

500HP is non-trivial. You'll want to think about the clutch and trans at that sort of power if you have traction. What wheels and tires do you have? If you race at all you'll probably want to think about upgrading from the OE 28-spline axles out back and invest in a driveshaft loop. The rear suspension will need help getting that sort of power to the ground and SFCs can help stiffen the chassis. What are your plans for the brakes? It's one thing to be able to get to 100MPH in 10 seconds but you have to stop the thing too...

There's no "cheap" 500HP. It's not just about the rods and pistons. There's a bunch of other stuff necessary to make it all work.

The one thing I've heard over and over when engines bust at 500rwhp is the connecting rods go south.
The advice on a Cobra bottom end sounds like the way to go.

2002GtRed said:

im running about 350 horses with no supercharger but i want to reach 500 thats my goal i know its not going to be cheap but i want to know the cheapest way possible.If get a block from 03-04 cobra would be cheaper then getting all the forged internals. As far as the labor goes my dads a mechanic and we can do that our selfs

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What are your current mods that have you at 350 hp? Going back through your other threads it looks like you only have stock gt and it is nowhere near that 350 number, probably take 100 off of that and its close. These other guys have more info on how to reach your goal but it is going to include forced induction unless you want the on/off of nitrous. It would take some serious work to get 500 NA hp out of a 4.6 imo.

Before asking questions, do some research. Im not trying to be a dick, but there seems to be one of you guys asking "what do I need to make x amount of power" every other week. You have obviously never owned a 400-500rwhp vehicle, or you would not be asking these questions. So you need to be realistic about your goals and make sure you can handle the power.

Here's a general rule of thumb to live by:

Fast
Reliable
Cheap

Pick 2 of the above.

Stumbaugh said:

Before asking questions, do some research. Im not trying to be a dick, but there seems to be one of you guys asking "what do I need to make x amount of power" every other week. You have obviously never owned a 400-500rwhp vehicle, or you would not be asking these questions. So you need to be realistic about your goals and make sure you can handle the power.

Here's a general rule of thumb to live by:

Fast
Reliable
Cheap

Pick 2 of the above.

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AMEN

Classic noob post!!