billfisher has talked me into a 4v swap...

[Back2Mustangs]

I want to get as much N/A horsepower as possible. I'm hearing numbers of 500HP achievable, and if it can be done, I want it. So now I'm starting from scratch as I know virtually nothing about the 32-vavle motors. If its not too much trouble, I'd like to list what I've been kicking around in the way of parts and get some feedback on what I'm missing so that I can get a more complete picture of how much work this is going to take.

First of all, the car has a new complete driveline, suspension and fuel system prepared for anything I want to throw at it. I was planing on a full 2-valve motor swap, but now I need to figure out how much more is involved with changing over to the 4-valve motor. I'll likely convert to tubular k-member while the motor is out of the car to offset the added weight of the 4-valve heads. I want to start with a MarkVIII teksid block for even more weight-savings and to handle boost if I decide so....even been thinking about manual steering & brakes to dump the hydra-boost weight, but thats another topic for another thread.

Ok, so I can get a complete MarkVIII motor which should take care of the block, head castings, timing cover and misc nuts/bolts/brackets. Below is a list of everything that I know I will be purchasing:

-Steel Cobra Crank
-Pistons(11cc/15cc/17cc?? Assuming N/A - no boost at this point)
-Rods
-Cams
-New valve-train will be installed at time of head-porting
-New harmonic balancer
-Electric waterpump
-New plug wires(GT coils the same as Cobra??)
-Intake
-Throttle Body
-LT Headers

Now for the Q & A to help me figure out what(on the GT)is reusable/compatible/interchangeable:

1) Do I have to have a Cobra Computer or can I make the GT computer do what I need?
2) What Cobra-specific wiring harnesses, fuel parts or AC components or accessory brackets will I need(anything reusable from the GT?)
3) What sensors and emissions parts can I swap over from the GT motor?
4) GT and Cobra use the same size/calibrated MAF??

I've read over and over about how easy the 4-valve motor swap is, but any tips, tricks and "been there done that-don'ts" would be a huge help before I start this project. I'll begin this venture after September and I project the car will be completed, tuned and on the road by March. Sounds like a while, but its really just around the corner, and I want the motor in the car, and tuned in one week, tops.

 

[Disturbed One]

I've done a lot of research on it myself and some of it depends on what year your current car is. Is it a 96-98, or a 99+. Since your asking about plug wires I'm guessing your car is a 96-98. You should be able to reuse the coil packs and wires, just might have to mount them somewhere else. They are capable of handling the power. There's a couple sensors I think they were you'll have to splice in and extend some wire but not as much as a 99+

You can use your stock GT computer to run the car so nothing else is messed up, you just need to make sure when you get it tuned you tell them you have a 4v running off a 2v computer.

 

[CanadaStang]

When doing engine swaps like that, it always make things much easier and cheaper if you can find a complete engine from a doner car so your not having to run around and find or fabricate parts every step of the way.

 

[XtorT'r]

I think the Forum CobrapoweredGT has info there. Some of those guys in there will franken hack wire harnesses for the swaps.

 

[Torinalth]

wasnt that site brought down?

 

[squares98]

Ported FR500 4v setups>*. Save for it, if you are serious.

 

[billfisher]

first, i advise plenty of planning to be sure you get what you want.

in my opinion....

if you are going 4.6, it's easier to get hi po parts, and they fit. 5.4 is very custom.

if you have a 96-98 initial tuning is easier. i advise using your maf/injectors to get it sorted out then use the better parts. get it running, then go for it.

build the basic motor and you can add the intake/ exhaust/cams/springs later, if you have to. if you can afford it all at once then that settles that.

don't fall for useless short runner intakes that give up torque for a few hp at shift point.

1) Do I have to have a Cobra Computer or can I make the GT computer do what I need?
2) What Cobra-specific wiring harnesses, fuel parts or AC components or accessory brackets will I need(anything reusable from the GT?)
3) What sensors and emissions parts can I swap over from the GT motor?
4) GT and Cobra use the same size/calibrated MAF??

1. your computer will work initially, it needs a custom tune when finished. your harness will work also. use your maf,injectors,iac,tps,cam position sensor, etc. use everything off of your motor you can. it makes everything easier, and assure firing at first crank.


if you can get the cobra harness, get it. it's a lot of wiring, and there are issues occasionally when that is done. use your pcm.

everything bolts to the block on MODS, no brackets. the brackets for coil packs/oil reservoire may need to be made.

the mark viii intake is really bad. it will work until you can get better. the mark viii heads are the least desirable 4v heads for 4.6. the ports are huge. they still make killer hp. you will exceed 2v easily.

if you want to make serious power using the mark viii components, get forged rods/pistons/crank. turning it 8000+ needs real stuff.

you won't be able to use fr500 intake with the mark viii heads. i'm using them , but i'm making an intake for myself.

maf is the same size, but the mark uses 24lb injectors. you need bigger for serious power, but 24 is a minimum. that requires pcm calibration. use the 19lb from the GT and take it to get it flashed for 24lb. an adjustable regulator will let you use the 24 lb without flashing the pcm... temporarily. global fuel kinda is half assing it.

i'm doing that until cams then i can finally get a custom SCT tune.

 

[billfisher]

btw get a canton oil pan and or windage tray.

the tray is worth up to 30 fwhp by itself. and at 8000 rpm much more.

 

[Back2Mustangs]

wow...

The car this motor is going into is a 96 GT

Money is not a restricting factor in this project. I'm 26, unmarried, no kids and my girlfriend is as into this project as I am so there's plenty of $$ for whatever I need. I want to get the best parts for the most power and I like to do everything at once, and only once(if permissible). I want to make the installation as easy as possible. I'm having a local shop balance and build the bottom end and mount the heads...everything else I'll do myself until it comes to tuning. So it sounds like I need to go ahead and pick up that Cobra harness.

To confirm:

I just need to get the teksid block & forget about the rest. I should have specified earlier that the internals will be blower friendly as far as strength so the bottom end will be safe for any NA application.

Now I'm learning that there are different kinds of 4-valve heads... How are FR500 heads better than saaaaay Patriot Performance P&P 4v heads? Is there a large difference between FR500 and P&P Cobra heads? What about 03/04 Cobra heads?

FR500 intake is best for 4-valves? Does it need any further porting/polishing? Any other compatible/better intakes?

Why the Canton Pan? Is the stock pan no good for the windage tray?

What size injectors will I need for optimum fuel delivery? You say 24lbs minimum...how much fuel am I going to be pouring into this thing?
Will I need better fuel rails than stock Cobra(assuming different than GT)?
Will the 03/04 Cobra fuel pump be able to keep up?

The things you say about the tuning make me worry for the poor person I find willing to meet the challenge. I mean I just want to put everything together and trailer it to be tuned. I don't know about all of this getting it started with stock/lesser parts, and then replacing those parts to get a little closer to the final tune, and so on.

As far as the headers go, that is deffinitely somthing I want to only do once with Long Tubes.

And I gather most of the sensors are the same between Cobra and GT?

And now Cams...I've read that FR500 camsar "mild?"...What aftermarket/custom-grind cams will blow my socks off?(remember staying NA for now)

I should probably be asking some of these questions over in the 4-valve/Cobra forums, too huh?

 

[Jackie Chan]

skip all of the headaches. build a forged shortblock 2v or 4v and throw some boost at it.

 

[billfisher]

if you can purchase 03-04 or fr500 heads/cams and an fr-500 intake you are there. the mark viii is a teksid block. get it. forgings and the afformentioned heads/cams/intake and 400 rw is there for you. the fr500 intake is the best available.


the order for heads from worst to best

1. 93-98 cobra/mark viii
2. 99-01 cobra
3. navi --- different head altogether larger
4. 03-04 make sure they are later 03-04 heads as the early overheat.
5. 00 cobra 'r'
6. gr 500
7. GT

the fr500 is killer for 4.6-5.0l and the intake is a dream.


if you can get those parts, you don't need stupid boost. but if you do add boost you need lower compression pistons. so decide first. 5.0l cammers go for 15 large. you can build the equivalent for less.

 

[billfisher]

the fr-500 is a better building block and they usually don't have an exhaust to water overheating issue like 99-04 heads. a ported 99+ 4v outflows fr-500 stock, but not by too much. port fr-500 outflow most all. but really 330cfm is enough in ported form eh? they all flow near that much ported.

1.75 inch longtubes or even better edelbrock stepper headers. but 1.75 will work.

30+ lb injectors is mandatory for 400+hp

at 500 fwhp 30 pound injectors are 99.7 percent duty.

the fr 500 makes 450+hp with those 'mild' cams. it doesn't take big cams like 2v or even 3v. the heads flow enough for smaller cams. comp cams sells wild cams. i'm going to use their wildest 4v cam, but that's because i use 5.4 litres. you'll notice .475 lift is all it takes for max HP with 4v. more later

 

[billfisher]

those guys in the 4v forum are the real experts. i am researching my self, and i'm going in a similar direction as you.

 

[Back2Mustangs]

Thank you billfisher

Thanks billfisher. I hate when people act like lazy leaches and try get everyone to do all of their reserach for them. I kinda feel like I've done that here, but you have answered all of my questions thoroughly. You've brought me up to speed and I really appreciate you sharing the information that you have worked to gather for yourself. I'll start dropping some questions in the other 4-valve forums as I move forward with this build.

Now I need to start shopping! When I first decided to keep this project and swap the motor, I thought, "I'll just be practical...330 HP is fine for this car." But the more I sit and think about how unsatisfying that little number is the more I think, "32 valves and a twin screw..." Of course the 'budget' I had projected for the swap is out the window now, but to me its all about whether or not I'll be happy when its finished....and that's worth any amount of money

 

[Torinalth]

you might want to do a little research on the KB site.. if you are going to blow the car with a twin screw, i suggest you go ahead and stay 2v.... go either turbo or stay NA for the 4v. i really dont know how the centri blowers work on 2v vs 4v, but the 2v KB cars are almost dead even with the lead going to the 2v at times.

just some food for thoughht.

Torinalth

 

[Back2Mustangs]

Hmmm

Yes I noticed a while back that the Non-PI 2v heads even responded better to the KB1.7... Its funny stuff, trying to figure out the right combo. I think once I complete the 4v build I'm going to be content with it NA. Especially since I want to move on to other cars I'm adding to the garage.

 

[Dan_Soprano]

you might want to do a little research on the KB site.. if you are going to blow the car with a twin screw, i suggest you go ahead and stay 2v.... go either turbo or stay NA for the 4v. i really dont know how the centri blowers work on 2v vs 4v, but the 2v KB cars are almost dead even with the lead going to the 2v at times.

just some food for thoughht.

Torinalth

why do you say stay 2v if going with the screw? Not to sound like a higher then mighty prick, but there are ALOT more screwed 4v's making TONS more power then screwed 2v's.....Tim's projects @ MPH being the exceptions.

 

[billfisher]

a totally smooth streetable daily driver 10 second screwed 4v is in my car club. he is also a convertable. you never know it until he screws you. comparing 1.7l kb's in 2v and 4v is kinda stacking the deck. the 1.7l is already small for big hp and the 4v needs 2l. i haven't seen very many 1500hp 2v's out there. it's just me maybe.

i'm not knocking 2v. i like 2v. but this discussion is 4v and not saving a few bucks to throw away 200+hp.