V10

Hate to nit pick, but:

1. The difference in the 5.4 stroke to our hypothetical 5.0L, 3.81" stroke is .355 not .335"

2. When changing the stroke on an engine, the crankshaft journal position is moved by 1/2 the difference in stroke, not the full stroke length.

Therefore if the 5.4 rods were used on our hypothetical 5.0L, the piston height would need to be increased by .1775" not .335" (nor .355). Or as you said, the same pistons but longer rods could be used (again .1775" longer).

It would probably come down to cost, which is cheaper, special pistons or special rods for the 5.0?

Although I understand your point about rod R/S ratios, the problem with a tall block and long rods (or tall pistons) is that it adds to the reciprocating mass which is not good for a high reving engine. Which is why most high performance engines usually have a lower R/S ratio.

V10

I tend to agree with you, the 4V DOHC heads sound nice on paper, but in reality they are not that much better. They add 70 lbs to the engine in a bad place, high up in the engine compartment. They are also more expensive and physically so much larger that they make working on the engine a lot harder.

The 3V heads can be improved in flow (per one of the rag's articles FF&MM?) and probably provide all the airflow that could be used on a N/A 5.0 engine that would rev to around 6.5 - 7.0K.

This makes the primary advantage with 4V, DOHC heads the ability to independently vary the cam timing between the intake and exhuast cams. This allows variable valve overlap. BMW uses this (Dual VANOS) to help extract the huge amount of HP they get per liter displacement on their engines.

However, Ford has not yet implemented even single VVT on the 4V DOHC heads let alone dual VVT, which reduces the advantage of using the 4V DOHC heads.

Add to that the fact that the 4V Mod Motor heads have had problems since day one and I'd prefer improved air flow 3V heads.

bob

Was that valve stem problems? Seems to I remeber waaay back that there were issues with the valve guides and valves stems????? But that was awhile ago, did they suffer from other problems?

I concur, on an improved 3v head.

As for the piston/rod assy on this hyothetical motor, wouldn't it be best to add the length into the rod, rather than the piston? I would assume that since the piston is farther away from the crank pin than some distance along the rod any weight gain at the end of the rod or extreme end of the piston would be more detrimental.

softbatch

If they make a Boss 302 with a Destroked Cast Iron 5.4 count me out :notnice:

That would take the whole heritage of the boss and toss it.

Just call it a Boss add some FRPP higher flow heads, higher RPM Camshaft and springs. FRPP headers, intake, exhaust, springs, shocks, and anti roll bars and call it a day, maybe some light weight wheels too.

Rampant

Umm, pardon my ignorance, but... how so?

softbatch

Seems to me if you want a good handling high performance car which is what the Boss was then you wouldn't load the front end up with weight by using cast iron.

rhumb

I think most of the 5.4 blocks now, with the exception of the GT500 block, are aluminum, so the actual weight increase over the short block would be fairly nominal. But to get to 5.0 liters, which seems to be some fixation for some, it would be a qood question whether to go with the "Cammer" approach using a bored short block but getting a bit thin in cylinder wall thickness or to a destroked tall block, which would weigh a touch more and, with the longer stroke, be that much less ammenable to being a high revver (though the longer rods and resultant decreased thrust angles would serve up some longevity and smoothness benefits).

But I do strongly agree that the focus of a Boss should be very stongly on overall vehicle dynamics rather than just being another big-motored, one-trick-pony strip car -- save that approach for a Mach I.

softbatch

My friend's 2005 F150 still has a cast iron 5.4, the only vehicle I know of with an aluminium 5.4 is the GT. I know the old Navigators had a 5.4 4V but I am not sure of the engine block material. The lastest Navi's have the 3V 5.4 just like the f150s

MustangFanatic

I'll agree, the mod motor was not designed to be a high RPM piece. However, I do believe Ford could engineer a mod motor that would redline at 7K and still maintain durability. Premium components would be necessary and expected in such an application but again, it isn't outside the realm of possibility.

I know many here believe that any Boss Ford produces should displace 5.0L. While I agree, I would prefer that from a nostalgic perspective, I would rather Ford engineer the best possible engine for the Boss with a goal of 350 - 400 NA horsepower, regardless of engine size. I know we would all love to see a Cammer under the hood but that isn't a reality unless we are running Grand Am. As long as the goal is met, I'm not wedded to a single approach to get there. Just build it, we will buy!!!

softbatch

What about the Cammer Crate Motor T50? That is not built the same as the R50 Grand Am Cammer.

GTJOHN

I am crossing my fingers that they have a prototype or at least more info on an SE or Boss at the Detroit Auto Show.

Last year at the Cleveland Auto Show, a Ford Marketing Rep. told me an SE Stang would be out in 07 or 08. Well, its starting to look that way isn't it?
This guy was right on the money about the Shelby, so I am taking his word on the SE.

I am sooo sick of waiting! Please Team Mustang - HURRY UP!
How about a MY2007 BOSS next September? PLEEEAAASSSSE

MustangFanatic

I don't think the T50 engine will pass emissions or Ford's durability requirements given the very thin cylinder walls.

V10

Besides the valve problems, there have been persistant overheating problems with the heads. One cylinder inparticular (I think rear passeger's side) is prone to overheating.

Yes, if the objective was to let the engine safely rev higher, longer rods would be better then a tall piston.

I'm not holding my breath, but I still think a mid height block would be better for a 5.0, even with it's lower R/S ratio. To me reducing the reciprocating mass is more important.

As far as the block goes, I belive the old Navigator 4V, 5.4 engine used the same iron truck block. One way of looking at it is an iron block 5.4 (or destroked 5.0) with the 3V heads would only weigh a few pounds more than an aluminum block 4.6 with the 4V heads. As I said before, those 4V heads are massive and heavy. Each 4V head weights about 35 lb more than the 3V heads (fully assembled with cams & valves).

Hollywood_North GT

HTT's exact words were: "We're hoping for a Boss 302 and a 5.0 LX. I believe that there is room between a Mustang GT and a Shelby Cobra GT 500 in terms of product positioning and market positioning. We will take your input under advisement."

The quote can be found in this article: http://mustang50magazine.com/eventcoverage...1w_50questions/

MustangFanatic

I would definitely agree with that statement, that their is room in the model line-up for both a Boss 302 and a 5.0L LX. Let's hope HTT honors that statement.

mach1fever

There is nothing wrong with the 4valve heads. They were offered on both the current mach 1 and cobra. Both of which are the best flowing heads on any mustang that have yet been offered. The problem with the "overheating" occured because the channels were not properly designed and they have a redesigned replacement head to eliminate the problem... This is the infamous "TICK". Either way the three valves only saving grace is the VVT . If the newly designed head would not include the VVT it would be nonsensical to include it and it currently does not provide for the higher rpm as the mod motors do. My car redlines at 6800 rpm which is pretty current with what we are looking at. If I were the designer I would make an aluminum block 5.4 liter do to tooling specificity. If the 5.4 is not used I would definately consider waiting on a possible mach 1 or buying the shelby. As far as the 5.0 is concerned I could definately see a varaiant of the 4.6 taking over that niche.

Roger

GTJOHN

The next SE is going to be between the Mustang GT and the Shelby - both in performance and price. So, I wouldn't get too radical with your thoughts!
I am expecting a car that will have between 350-400hp, and priced around $32k-$34k. So, expect a 4.6L or 5.4L.

With the way the automotive industry is right now, plus the economy and the high price of gas, I don't expect Ford to invest a lot of money into tooling for this project.

If we get a "poor mans" Shelby out of this deal, consider yourself lucky!

05-1947

my question is you guys don't think that they will ride the shelby wagon and make a GT350? 350 not meaning the ci but the hp, consequently the original thoughts with the presumed 500hp Shelbe GT500.

GTJOHN

Yes, it makes sense, but it appears that the Boss is ahead of any SE at this time. But, you never know?
350hp wouldn't surprise me either. Ford is known for cutting corners and being cheap. If they give us something in the 365-400hp range I'll be surprised! But I am still hoping!

As long as the next SE can beat the GTO, I'll be happy!

MustangFanatic

I agree with GTJohn, I think the Boss is probably ahead of the GT350 but I'm not opposed to either. Both cars share the same theme, lighter weight, nimble handlers with a strong naturally aspirated engine.

As long as the next SE provides a strong balance of handling, braking, power and style (and can beat a GTO), I don't care what they call it!!