Im not sure anyone was hating on Ford stuff...I think we were talking more about the 4.6's, seeing as there were only 300 Cobra R's made in 2000. Its not like you can go on ebay and buy a 5.4 L DOHC out of a cobra r and swap it in somethin. But what I think he is trying to say is why make the 4.6 modular ohc motor with less cubes with out a lot of power(net or gross or whatever), yet still a big motor(in dimensional terms). I also question why Ford went to OHC, i mean it is a more complex type of motor, yet is not making any real power without boost. And it is not like power cant be made with pushrod motors, look around this site...Im not bashing ford Im just curious what was their reasoning??

 

The 5.4 DOHC motors went into more than just Cobra Rs. I believe that Navigators also get them. And of course the Ford GT.


OHC motors are less complex and have fewer moving parts in the valvetrain. Fewer parts = less friction = more power (and you can't bend a pushrod). It's just that Chevy kept improving on the old tech and now makes more power. The reason why every Mustang has a blower: replacing heads with two cams in each is $$$. Much more than doing an H/C job on a pushrod motor.

 

Didnt know it was the same motor as the Navigators, but none the less not as common a motor as the 4.6 which i think most people think about when talking about modular, at least thats what I think about...


Good info...I guess a pushrod engine seems simpler because thats what I am used to talking about and working on. But it still seems that Ford could have saved money on the modular design if they just kept improving their pushrod engines. I wouldnt be so skeptical if the 4.6's were a more powerful engine NA.

 

In terms of design, it's difficult to imagine how engineers came up with pushrods and rockers when the camshaft could easily have sat over the valves. Either way it just doesn't seem practical except to say "look what I did."

Just as it doesn't seem practical to swap a LS1 into a 03-04 cobra just for ***** & giglges.

 

IIRC, that is what the Lightnings have.

 

umm, really when did they get a DOHC ??????????

Ryan

 

Lightnings have a 2 valve, and always have. Even the ol' first gens had 2 valves... and pushrods

Navigators have had a 5.4 4 valve since 1999. Since there are VASTLY more Navigators than 1996-2004 Cobras, Mach 1s, Marauders, and Aviators, there are also vastly more 4 valve 5.4s than 4.6s. Now that there are a couple of readily available intakes to facilitate the swap, there are tons of folks putting them in Mustangs and street rods.

I definately agree that the LSx is the pinnacle of production car pushrod technology. I also agree that it's cheaper to manufacture the ford mod motor family.

 

>>it's cheaper to manufacture the ford mod motor family.

That was always the reason, but I would like to see some numbers from Ford and Chevy to compare just how much cheaper if at all.

 

I think the main reason why everybody thinks the Ford modular motors suck is that their heads don't flow near as well as an LS1. If it wasn't for the heads the LS1 would hardly be an improvement over the LT1. That's the main advantage.

 

4 valve heads flow well

Ryan.

 

16 push rods = $20

3 more cams, bearings, springs, etc plus the gigantic heads to mount them on = lots more cash.

 

Stock 4.6 4V heads flow 260 cfm intake and 201 cfm exhaust @ .550" and 5.4 4V heads probably flow 8-10% better due to a much larger intake port. I dunno what stock LS1 heads flow, but I figured this info might be useful for adding fuel to the fire.

 

Actually, depending on which version of the 4.6 head you are talking about, stock for stock the flow #'s are very similar. Go to TEA's website and compare a stage 3 ls6 head to a 4v stg. 3 and you will find that the ls6 will peak out better but the 4v has better flow under peak lift. The DOHC cylinder head is a Godsend for Ford guys, simply put, its probably the best set of heads that Ford Motor company has put out since the muscle car era. It just so happens that Ford has something against cubic inches in the stangs. If they had combined the 5.4 engine with the DOHC heads, they would have been NASTY from the factory. I remember seeing the z06-CobraR-Viper shootout on Car&Driver years ago and they chassis dyno'd all the car and the CobraR put down 360-370. Ford could have detuned that and still had a stout street motor for mass production.
But as is typical w/ford they didn't. Now, me myself, I'm not particularly a fan of the ohc set up. Cost alot more to modify and you cannot get the cubes out of a modular engine that you can out of our engines due to the limitations of the block.

In 5.0-Superford magazine this month on page 16, the editor of the magazine addresses this very topic in his column. The name of the article is IMAGINE THIS.

I know with an OHC engine your deleting pushrods and heavy lifters, BUT your gaining 3 more cams, 16 more valves, 16 more SPRINGS and 3 more chains(2 that are quite large). It seems to me that although this setup would provide better high rpm valvetrain stability, it would also increase the parasitic drag on the engine.

 

The flow data for the different heads is on mach-1.org. I actually didn't see any of them (b-series, 99-01 tumbleport etc...) that flowed 260. Coarse the flow figures are only listed to .500 on this chart. 99-01@.500 was 225, 03-04@.500 was 247. I noticed you figures say .550. I just didn't think they would pick up that much in .050 when they only gained 4cfm from .450 to .550. Not disputing or flaming just curious

 

I got those numbers from Fox Lake, and they are using a 03-04 head.

 

Obviously must just be a difference in the fixtures or setup. Hey, by the way, we still plan on coming to FFW@commerce so maybe we will meet there.

 

Actually if you already had the motor this would be doable as long as you didn't mind completely redesigning the front suspension. Also, a stock cobra motor can make 500 RWHP for less thant he cost of a cam swap on an LS1, so your comparison isn't a good one.

 

Rock 'n roll. I'll be there and at FFW in Bowling Green too.