Key word there is STOCK... the stock blocks handle alot more power than 700, its the factory pistons and rods that let go. Plenty of 1k hp cobras out there on the stock block

 

I thought that the '03-'04 Cobra shortblocks were putting down well into the 1000 hp range on average before letting go. What's up with them letting go at 700?

Is it the tune? If so, you can break an all billet Dart IE windsor with the best custom pistons at 500 hp with a bad tune.

Chris

 

The best choice for a big power modular build is a teksid aluminum block. The iron blocks are garbage, ask John Mihovetz. He throws em in the trash. Search for his posts on modularfords, he discusses why the iron blocks are junk and that they are failure prone.

 

I was just going to mention John Mihovetz. He's had bad experience with the later aluminum blocks, and also says the Cobra cast iron blocks are no good over 800 hp. He's tested several of them and everyone of them have had problems over 800 hp. Said something about them distorting at that power level. This isn't hearsay either, this was during a conversation I personally had with him before building my motor for my '03 (bought some rods from him).

I'm running a .020 Teksid with Manley rods (arp 2000 bolts), and CP pistons.

The Teksid block was used in all 4V applications until mid/early '01 (except lincoln Continental).

 

Any Modular, SBF, SBC, SBM is going to distort at 800hp. Whatever you choose, iron or aluminum (pick aluminum), you're going to want a competent shop do the machine work and have the block half-filled with hardblock.

 

Ok well now I am geting scared i have the turbo kit picked out and i dont like what i am hearing now i think we are going with a cobra block bc they have bin prooven and ppl have made huge power with them but by we i mean my motor builder and i have talked about what we are to do and he is now thinking of doing a 10 to 20 over cobra block that he has bc it is seasond and doing a cobra crank that has bin polished and gone over with all the trick shit done to it and then useing olliver rods and a set of custom pistons that are better than 4340 forged pistons i dont rember what they are called tho they arre 20 somthing i think he wants to build the motor for 1500 hp and go for 600 that way i can steep up later to close to 1000 for some show but it is not what i want he is going for big numbers at my expence but he is going to pay if it brakes lol i just want some 10's and maby some 9 sec passes lol gona be hard but i hop to see ,,,,,, but cant aney one hear come to a true and strate anser about what block is a good block bc it sounds like u cant ........ more info on blocks please

o and Big Top GT.. thanks for the sights to check out........

Kirs.....

 

But, no matter how you look at it, you'll still be doing worlds better with any production 4.6L block than you would with a production 302 block. lol

Mark

 

Sounds like you need to make a few calls to some of the seasoned modular engine builders/racers. Get their actual experience with each block. Tell them your realistic goals (1500 hp, really?), and go with what they say. That will be far more valuable than anything you'll get here. Get it right from the guys who build them and race them and break them.

Al Papitto, John Mihovetz, and a few others.

 

so true

 

.......

 

Im not going for 1500 my motor builder wants to build for that and push no further than 900 1000 but i am only looking for 600 -750hp and i might drop that down if i ccant hook on the street with slicks or some d,r, but i think we are going to use a cobra block,,

one thing tho he said about building aa 5.4 to me the outher day, but i think i will stay with a 4.6...........

 

Linteck..............................


k well i think i may have a change in plans bc of goles i wanted my motor builder said somthing about a navagator motor what is the blocks like on the 5.4 nave and they are a 4v right.????????????????????????????

 

Do you know LinkMustang?

Mark

 

You're getting way in over your head. Build a damn motor out of the block you have and forget about it. You want 600-700 hp, Any 4.6 block can take that power all day long without a worry. You throw a Navi motor (Yes it's a 4V) into the mix, and it'll put your project (realistically, your engine builders project) that much further down the road.

KISS... Keep It Simple Stupid. This applies in many applications, this one included. Keep it simple, and you'll be blasting down the road in no time. Don't let huge HP goals blur your mind. You'll end up spending thousands on a project that'll never get finished.

 

No i dont know linkmustang ...who is it?

and bc i want room to grow that is why the 5.4 was brought up and he said its not that bad to put in.. just need a diff headers i think and a new hood ......the reason is it is a 4v and not a 2v more flow for a later hp gole,,, thats why he brought it up......

so u think it is a bad idea ,,,i think i may go with the kiss idea then if it wont work.....

thanks kris

 

IMO, a 5.4 is a terrible idea. It will be nothing but a pain in the ass. Build a 4v 4.6 and be done with it. Use any aluminum block(whether it's an early Teksid, late Teksid, or Explorer really doesn't matter a bit), a set of "C" or even 03-04 Cobra heads, a stock cobra crank, billet rods, good pistons and that is all you'll need. Realistically, that's an honest 1200 hp engine. That's also a relatively low budget build for that amount of horsepower, too. Above 1200hp you're getting into race stuff that you're not ready for.

 

I was thinking the exact same thing.

 

hey i got a 5.4 dohc motor and dont think i will be needing it ne wone want to buy it its up for sail........

 

p.s. crank is locked up bc of lack of oil but all els is fine

 

well thanks for the help ! the 4.6 block is in the shop geting all spiced up and a 5.0 stroker willl pop out fresh and new , no more 5.4 biz too mouch work!!!!!!!!!!! lol