USMCrebel

Navi is cast iron yes. if you wanted you could pay 15-25k for an actual FGT motor, but i don't recommend it...as that is 2 mach 1's

Fobra

I dont know why this forum has such a love affair with aluminum, id take iron any day of the week. Aluminum is needed only if your shaving major pounds for bracket racing... and even then most racers would still prefer iron.

boduke0220

i wouldnt go iron block, i'd stay with the 4.6. you can get about 550rwhp out of them all motor. although i think someone got like 615rwhp out of a 5.4 4v. the 4.6 wont have as much torque as the 5.4 though..

Fobra, maybe because its so cheap and so strong? you can get a teskid block for like $300 nowadays, and that blocks capable of holding 900hp i'd rather have that light,yet strong, piece of aluminum for my motor. If you havent noticed alot of terminator guys have switched to aluminum blocks

USMCrebel

no replacement for displacement...
you can get a complete navi motor for ~500, and the bloc for 300 as well.

the teksid is good to 1500hp...550 is the max for a 4.6 well closer to say 561rwhp and still able to street drive it. the 5.4 i can make the same thing less effort and due to the torque it will get better mpg, and the weight will be negligible

http://www.fordracingparts.com/parts...tKeyField=8447

5.4 239 lbs
4.6 178.00 lbs

60lb difference is a lot but look at how much more you can do.

http://www.fordracingparts.com/parts...KeyField=10443
^or go that route and it's now 78lbs less than the stock 4.6

Fobra

I believe a few of you are misinformed. You may be confused with old 5.0 iron block which would split at around 500whp. The modular GT iron block holds just as much power as the teksid. But you are also forgetting how much more expensive machine work is on an aluminum block. Also, there is a reason that Ford and GM switch to iron blocks for boosted apps., the reason is longevity. Aluminum blocks get there strength from being cycled through heat treatments. Once the block is finished and in use, going through heat cycles weakens the blocks over time. For a daily driver this is not an issue, however once you start drag racing it and producing alot of power it will. That said, imo the teksid is not going to fail on you, however it is more expensive and not just in purchasing the block itself. You would be better off taking the extra $ and getting a better FI system or suspension.

Fobra

If you want to get the best, buy the 6L big bore 5.4.

Stone629

I know what you're saying and you are correct. I think aluminum is still more appealing to the masses though, since more people DD their cars and hit the tracks on the weekend versus running weekend only cars. With that said, a more well rounded car works better for most, one that is better balanced, etc. New Edge GTs and Machs are pretty front heavy with the aluminum block (relatively speaking), so an extra 60lbs or so up front doesn't help. If I were going to build a mostly track only/weekend +600rwhp car, then I would go with a cast block for durability.

USMCrebel

they also have a 6.2l stroker for the 5.4l

ranebowcyxx

Correct

Unless something comes up while sourcing the supporting parts the 4.6 is a go. It is a teksid block and was built with the intention of running 20+ pounds of boost.

I am old school so I am having a hard time giving up those 50 cubes. But the flow characteristics and the plug location of the 4 valve head I think will compensate for it. And the 60 or 70 pound weight savings is significant.

This is really a street/strip car, not daily driven but not a track only car either.

Fobra

Adding stroke to a 5.4 would be unwise, its already on the edge of what most would consider for a motor that turns substantial rpms.