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351 vs 4.6 vs 5.4


nemesis500548

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OK, I'm looking to make 500 HP. I'm asessing my options on a stroked 351 (to ~ 454 cu), a stroked 4.6, or a stroked 5.4. Before everyone throws the save your wallet bible at me, I realize that 351s are everywhere and can be done for about 1/3 the cost. But they have also been done to death:beatdeadh , just like the chevy 350. My main concern is driveability and longevity, because who wants to spend 5-10K on something you're going to break in a year or two. I don't want to use any power adders, NOS is just plain lame, and why spend a lot of money to build a strong block and then spend another 5k on a roots supercharger.

 

Yes a 351 will be cheaper and easier, but money isn't that big of an issue for me (I pissed off 10K souping up my 240Z with forged pistons, ARP rod bolts, fully balanced, racing cam, racing ignition, triple Weber carbs, and probably some other crap I don't wish to remember).

 

How do all 3 motors compare in size, as this is obviosly an issue. Weight doesn't matter because, well the car itself could be used as a kite anyway, so 200 lbs difference in motor weight ain't gonna bother me.

 

You can call me crazy:bonk: , but I like the idea of the 3 valve DOHC 5.4L (Over Head Cam, just like my motor:wink: ) but is it as strong as a 351? Which would make the power the easiest?

:willy_nil

Oh, and don't worry about the car being able to take it. It will be equipped with full length frame rails, triangular strut braces, sub frame connectors, ladder bar in the rear, and a custom length 9" solid axle rear end.

 

:puke: Chevy

:rockon:

god I love these things .....:weird:

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351w is the only motor to consider.i work as a ford tech.the late model ohc motors are junk compared to a 351w.example of ohc motor junk-connecting rods made of powdered metal.if you had yout heart set on a ohc motor i would get a motor from a lincoln navigator-5.4 liter with dohc heads.a set of cams and a aftermarkit efi system and it will make some hp.the ohc motors are huge in size because 1/2 of the motor is the heads.the 351w has as much aftermarket support as a sbc.all of the parts are in summit catalog.

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You could get a stock 5.0 motor low miles put a intake manifold throttle body and injectors, and a turbo. This combo will make over 500 at the wheels no problem. Some people put 700hp on the stock short block with no problems thats with the proper tunning but its not hard to make 500hp at the wheels I if you are in the southern cali I could give you hand making a turbo kit for your car.

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Well the Lightning I believe in its last incarnation used the 5.4 supercharged version, and if that thing can propel that tank of a truck to low 11 sec quarter mile times then I think it would be a hell of a motor for the Z.

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351W. Parts are everywhere, and just about everything except for the block is interchangable with the other SBF products (which means easy access to parts). And the modular engine is VERY wide, as well as heavier.

 

Lastly, the reason "they have been done to death just like the Chevy 350" is because they work, plain and simple. I've got a 289 in my Z and would like to see a stroked 351w in it next year.

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Clearly if he is going to be stroking the 351 and going all out, then the crappy rods in the the 5.4 wouldnt be a concern anyway. He will most likely swap them for somethign else. The romeo 5.4 blocks cant take 1300hp with proper prep. There is a guy locally building a TT 5.4 DOHC navi engine, with most of the parts being bought from here http://sullivanperformance.com

 

Sean hyland motorsports also has an alluminum 5.4 block, wich would save on some weights(I know, doesnt matter to you). The stock 351 blocks are good to around 600hp, and with high revs, the will split down the middle. Your only option for a high powered/high revs 351 based engine is to buy an aftermarket block such as the dart block. Be expected to put another $1000 on top of the $2k price tag of the block into machine work since they are not a finished block.

 

The 5.4 DOHC navi engines are probably your best bet for HUGE power without having to get a new block. Both versions of the modular engine blocks are strong, but the romeo is a bit stronger than the windsor. a 4.6 DOHC engine would be more than enough, but hard to come by and would cost quite a bit. Now, from what ive been told, navi(DOHC 5.4) engines are pretty easy to come by, and cost around $5k COMPLETE. throw another $5k at it, and you have one hell of a beast there.

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Sorry, should have specified. I meant longevity of the block. Like Tomscoupe said I'm going to stroking this thing anyway, so stock internals are out of the question. I'd rather pay a little more now and make it bulletproof, than skimp here and there and have it die on me (been there, done that, got the T-shirt).

 

But still, which would stand up better to being stroked and putting out 500 HP day in and day out?

 

And as far as physical size goes, will a 5.4 still fit?

 

By the way, I appreciate all of the turbo and supercharger guys enthusiasm, but like I said, I want this to be all motor, no artificial atmosphere.

 

Furthermore, how much stroke would I need to easily and reliably attain my 500 HP benchmark? I've seen guys online selling 351s bored and stroked to 454 cu in. But will 383 be enough?

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There is no way you would be able to stroke/bore a stock 351w block to 454. If you want that kind of a stroke/bore, an aftermarket block is the only way. Im not to sure what would be the "max" bore/stroke on the stock 351w block. IMO, if you are going to be spending the money to have your stock 351w block machined anyway(which you will), why not spend an extra $200 on machining with an aftermarket block? You could do a 393 stroker with a Dart block(4 bolt mains, siamese bore), and that block will be DEAD reliable with 500hp(rated for 1100+ hp or somethign stupid like that). In your original post, you said you want to spend 5-10k. With 10k(probably less), you could have a 393 stroker with a dart block. And you would most definatly see 500hp, or atleast VERY close to it. Dont forget the GOBS of torque. Relaible power cost money. Someone posted this on here a while back...

 

Fast

Cheap

Reliable

 

You may only pick 2...

 

 

I HIGHLY doubt that the 5.4 will fit. It's not only taller, but wider. And from what ive been told, the 4.6 will barely fit.

 

BTW, are you wanting to go carbed or EFI?

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If you do use a Modular Engine be sure to use a DOHC Cam Engine don't bother with a SOHC. The good thing about the DOHCs are that the heads flow very well from the factory and you will not have to worry about any porting or aftermarket valvetrain as they are all designed to take 7k rpms from the factory.

 

Everyone says 351/302 windors this windsor that. But if u want a street friendly engine a nice DOHC 4.6/5.4 with a Stock block ( aftermarket rods/pistons ) , Stock Heads and Stock Computer and the world is the limit.

 

A large turbo or Nice Blower and you could have a very high hp street friendly car.

 

My vote is modular

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If you do use a Modular Engine be sure to use a DOHC Cam Engine don't bother with a SOHC. The good thing about the DOHCs are that the heads flow very well from the factory and you will not have to worry about any porting or aftermarket valvetrain as they are all designed to take 7k rpms from the factory.

 

Everyone says 351/302 windors this windsor that. But if u want a street friendly engine a nice DOHC 4.6/5.4 with a Stock block ( aftermarket rods/pistons ) ' date=' Stock Heads and Stock Computer and the world is the limit.

 

A large turbo or Nice Blower and you could have a very high hp street friendly car.

 

My vote is modular[/quote']

Yes, but it would cost 10k just for a 4.6 DOHC engine. That leaves him no money to upgrade.

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Yes, but it would cost 10k just for a 4.6 DOHC engine. That leaves him no money to upgrade.

 

You can get a 4V DOHC 4.6 out of the junkyard for less than 1k$

 

They come in all Lincoln MarkVIIIs 92-93 and up

 

Getting and OBDII version would be best or you would need an EEC-V Harness from another vehicles 96+ Cobra possibly.

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You can get a 4V DOHC 4.6 out of the junkyard for less than 1k$

 

They come in all Lincoln MarkVIIIs 92-93 and up

 

Getting and OBDII version would be best or you would need an EEC-V Harness from another vehicles 96+ Cobra possibly.

Good point, didnt think about those engines. I was only thinking about the 03-04 cobra engines.

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I ain't skeered to use no aftermarket block. Since I'm in the habit of dropping wads of cash into this car, why not.

 

Has anyone already checked to see if a modular engine will fit? I know they're bigger, but whether by an inch or a foot I need to know for sure.

 

I wanted to go with EFI, but a carb is soooo much easier (you don't need a 4 year degree in computer programming to tune a carb).

 

I don't want to use a big block because with all the hacking I'm going to be doing to make this thing more stable, I don't want to have to worry about cutting fender wells and firewalls.

 

Guys, let me say this, I ain't afraid to spend money on what I want, no matter how much. If I'm going to do this I'm going all the way. No junkyard parts, no potentially weaker stock components, no skimping anywhere. So if I have to spend an extra $2,000 on just one part that will make my car better, safer, faster, stronger, I won't hesitate. After all, why else do I go to work? It certainly ain't because I enjoy it or because I enjoy the company of my co-workers.

 

By the way, sorry I don't check in that often. My work schedule is psycotic and I don't really have a life outside of it. For example, I just got back from a 1 week road trip to do a job out of town, am off for today, go back to work tomorrow, and won't have another day off for at least another week. So bear with me if I don't reply right away.

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http://sullivanperformance.com/YVS450/tech/tech1.htm

 

scroll about half way down the page for the info. It has the full measurements of the 4.6 and 5.4. So you could take those, measure up your engine bay and hopefully that will answer you questions on fitment.

 

You know, SHM(sean Hyland motorsports) makes all alluminum 4.6 and 5.4 blocks now. SMH and Sullivan performance have a lot of great parts for the mod engines. The only reason to get an alluminum mod engine would be weight savings though, because the stock DOHC 5.4 will hold 1300+hp with proper prep.

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All the DOHC 4.6s are Aluminum Block Except for the 03+ Cobra Motor.

 

Junkyard parts are not skimping you will just want to build the motor ( rods and pistons ) before making any serious horsepower. With stock 6 bolt mains and a stock crank these motors can make well over 1000whp before hurting anything engine related. A big step up from the old 5 liter stuff.

 

As far as the computer goes if you do get an EEC-V swap 96 and newer. I can do the Computer Tuning for you remotely - Can email you files back and forth.

 

And for it fitting - Not sure I was going to try it but I came a cross a crackhead deal on an LS1 so thats what I'm working with now. If it is a tight fit you could always tube the front end.. haha.

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