Lightning motor into my 99 GT

[LaserRed01GT]

I am planning on going with a viper t56.
As for my mustang and its power output, I am aware that other have died at lower power levels, I also know a guy that tossed a rod on a stock 99 cobra. Did your guy that killed his motor at 12 psi have a good tune? intercooler? supporting fuel system? there are so many factors that dictate weather or not you will succeed, one of which is just plain luck. And I run 10psi with a LARGE compressor (t-70) if I were to run 10 psi on say a vortech v-2, I would be getting about 75% the VOLUME of air at the same psi. PSI does not = power. Air volume does. And a large turbo affords me a little mor leway than said vortech.

As for the 5.4, I will be purchasing the block and building it myself. Obviously, I will mic the cylinders and check all specs BEFORE building it. That falls into the "common sense" that I was talking about earlier. I never said I was going to buy a bunch of parts, take them out of the box, and bolt them together with a pack of natty light and a pair of pliers.
If the block needs to be machined, it will go to NAPA and I will drop $150. Either way, I will still be well under the $4800 VT shortblock.

Bill, Do you happen to know the gear ratios for the viper t56?
I looked online and got several conflicting results. Don't know which one is right.
Again, Thanks for all the input everyone.

I wish you all the luck having the courage to prep and assemble your own shortblock, but I can't even begin to tell you how many threads I've read and people I have met in person that attemted this and later end up posting that they have sketchy oil pressure, idle problems, and the worse...a blown motor.

When you say you are going to "mic" the cylinder bores, that tells me right away that you should really consider letting a professional tackle your project. You do not "mic" cylinder bores (unless you were building a motor in the 50's), you use a dial bore gauge graduated at .0001" minimum. That's why there is NOTHING common sense about prepping and assembling a shortblock.

Like I said, a cylinder bore must have a certain amount and type of cross hatch and valley depth to work with the specific ring type you will be using and to properly retain oil. However, it must also provide a relatively flat surface area to allow proper ring seat and to properly support the outer ring surface. I spoke earlier of a roughness average (Ra) and if you will using the commonly used moly faced rings, you will need a 16 to 25 Ra. I promise you the bores are not within that Ra spec right now. Also since most honing machines out there now use diamond abrasives, you must also follow up the hone with a fianal plateau finish using at least a nylon bristle type plateau honing tool.

Once again good luck, I hope it all works out.

BTW the Viper T56 has the following gear ratios:

1 - 2.66:1
2 - 1.78:1
3 - 1.3:1
4 - 1:1
5 - .74:1
6 - .5:1

 

[Rickey_Bobby]

Rickey Bobby,

you might want to check this thread over at mustnagboards.com:

http://www.mustangboards.com/modular-4-6l-tech/9452-anyone-intrested-5-4l.html

about 50 pages of discussion on putting 5.4 SOHCs in Mustangs...

for me, I'm looking for an appx 275/300 hp "daily driver" engine and the huge torque numbers from a 5.4 sounds like a good choice for me

Thanks man. I'll keep this post updated with further developments.

LaserRed01GT: When you say you are going to "mic" the cylinder bores, that tells me right away that you should really consider letting a professional tackle your project. You do not "mic" cylinder bores (unless you were building a motor in the 50's), you use a dial bore gauge graduated at .0001" minimum. That's why there is NOTHING common sense about prepping and assembling a shortblock.

Please excuse my terminology, But I do poses the correct measuring tools. And no, I do not have my own bore/hone machines. NAPA does. I still feel you are putting engine building on a pedestal far beyond where it should be. Making it seem as if only a robot off of startrek could do it. Back in the 30's when people were making rat rods and sling shot style drag cars, they did their work with far less than even I use. Just as my great Grandfather did, look him up. Jules Goux. I respect your opinion, and note your concerns. And will gladly face the music if an "I told you so" is in order.
I just want to show that with a little applied effort and creative thinking, these cars wont be such a bank breaker to make fast.

Much thanks for the gear ratios! Are they the same between the cobra and viper?
-Steve

 

[LaserRed01GT]

Thanks man. I'll keep this post updated with further developments.

LaserRed01GT: When you say you are going to "mic" the cylinder bores, that tells me right away that you should really consider letting a professional tackle your project. You do not "mic" cylinder bores (unless you were building a motor in the 50's), you use a dial bore gauge graduated at .0001" minimum. That's why there is NOTHING common sense about prepping and assembling a shortblock.

Please excuse my terminology, But I do poses the correct measuring tools. And no, I do not have my own bore/hone machines. NAPA does. I still feel you are putting engine building on a pedestal far beyond where it should be. Making it seem as if only a robot off of startrek could do it. Back in the 30's when people were making rat rods and sling shot style drag cars, they did their work with far less than even I use. Just as my great Grandfather did, look him up. Jules Goux. I respect your opinion, and note your concerns. And will gladly face the music if an "I told you so" is in order.
I just want to show that with a little applied effort and creative thinking, these cars wont be such a bank breaker to make fast.

Much thanks for the gear ratios! Are they the same between the cobra and viper?
-Steve

I have had a long standing relationship with NAPA and they are great people, but their abilities to prep and assemble a shortblock assembly are very limited. If you end up taking the block somewhere, I really would encourage you to let a shop that has experience with these modular motors to perform the work. You don't need a Star Trek android to perform the work, but you do need an experienced builder that is intimately familiar with those motors.

Those gear ratios are unique to the Dodge version of the T56. The Cobra had a different 5th and 6th ratio........79:1 and .63:1 respectively. The Viper's T56 was given taller 5th and 6th ratios to take advantage of the Viper's super flat torque curve.

 

[billfisher]

you need to mic the barrel of the spiston for that bore and inside mic the bore. the piston manufacturer has a spec which is different for ever piston . it depends on the silicon content and expansion.

get it right!!!! remember piston velocities. a 275 to 300 rwhp 5.4 is plenty stout at the line. you need to set the car up for hard leaves. it just won't mph. you will put 3-4 cars on another car even with much more HP. you have to get it off the line because they will be catching you in a hurry.

 

[billfisher]

the guy that blew that motor has everything you can imagine. and the money to do it again. he was testing the limits. and found them

 

[Rickey_Bobby]

you need to mic the barrel of the spiston for that bore and inside mic the bore. the piston manufacturer has a spec which is different for ever piston . it depends on the silicon content and expansion.

get it right!!!! remember piston velocities. a 275 to 300 rwhp 5.4 is plenty stout at the line. you need to set the car up for hard leaves. it just won't mph. you will put 3-4 cars on another car even with much more HP. you have to get it off the line because they will be catching you in a hurry.

Well, I have a nice driveshaft already, got a 31 spline rear end w/ the torsen T2 diff waiting to go in. And I drive around on 315 bfg DR's, and have a custom rear suspension that I made. I will have to see how that holds up... If it works as I plan I will post up the how to on it as it was fairly simple and so far works wonders out at sebring, havn't been the the strip yet.
I'm also hoping that the taller gearing in the Viper T56 will help me put down all the torque I will be making as I am keeping my T-70 on this new motor. I do not plan on revving over 6,000rpm with the fully forged/balanced bottom end.

Comparing the flow characteristics of a stock 5.4 at 80% VE and the compressor map of the T-70, I should be seeing full boost of 15 psi @2,990RPM +/- 100rpm. Here is the compressor map of the T-70 with a plot point at which the following conditions are being met on this 5.4L engine:

Engine parameters:
330CI displacement

Environmental parameters
Air inlet temp: 75*F
Ambiant air temp: 75*F
Altitude: 25 feet
Pressure: 14.68psi
Results: Inlet air density: 0.04341 lb/cubic foot

Turbo characteristics
Efficiency: 75%
Manifold boost pressure (w/ 0.5psi pressure drop in intercooler): 15psi
Results:
Turbo temp gain: 183*F
Turbo outlet air temp: 224*F

Intercooler characteristics
Efficiency: 75%
Pressure drop: 0.5psi
Results:
Intercooler temp drop: 165*F
Intercooler air outlet temp: 111*F

Engine variables:
RPM: 6000
VE: 85%
A/F ratio: 12:1
Specific Fuel Consumption: 0.55 lb/HP/hr
Results:
Pressure ratio: 2.06
Air flow: 919CFM
Fuel flow: 5.69lb/min
Engine Horse Power: 691
Engine Torque: 614
Optimum injector size: 850cc/min

Compressor map:
Red dot indicates point at which the above variables intersect the compressor map.

PHEW!
After all that I'm still looking for any reccomendations for a good turbo cam for a 5.4L...
The comp cams supercharger cams really suck for spinning a turbo, I had to go back to stock. Looking for something that will make power from 2K-6K.

Thanks

 

[billfisher]

johnny lightning know everything about 5.4 2v blowing

 

[Rickey_Bobby]

johnny lightning know everything about 5.4 2v blowing

Not really... But I do happen to know a lot about flow dynamics

so...
Cams anyone?

 

[san~man]

He wasn't talking about you, he was talking about Johnny Lightning, the Lightning motor specialist.