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Why doesn't Ford add 2 cylinders to the Duratec 35???

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Old 12/19/06, 07:41 AM
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Why doesn't Ford add 2 cylinders to the Duratec 35???

They would end up with a lightweight 60 degree, DOHC V8 with 4.6L and 350+ HP(w/DI they could get even more) that would fit almost any engine bay.
Old 12/19/06, 08:14 AM
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I don't think its that simple...

I'm pretty sure the druatec 3.5 is a 60 degree V6. The cylinder angle would have to go to 90 degress for a v8 or you'll get horrible vibration. Its possible the Boss motor could have many of the lessons learned from this engine program.
Old 12/19/06, 09:06 AM
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Originally Posted by Galaxie
I don't think its that simple...

I'm pretty sure the druatec 3.5 is a 60 degree V6. The cylinder angle would have to go to 90 degress for a v8 or you'll get horrible vibration. Its possible the Boss motor could have many of the lessons learned from this engine program.
That's correct. They did that with the '96-'99 SHO V8. It was a Duratec 2.5L with two cylinders added. They had to add balance shafts to it to keep vibration down.
Old 12/19/06, 11:49 AM
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Or two cylinders to the new 3.5, like they did with the Duratec to come up with the SHO V8, now the Volvo V8.

Yeah, it's a 60 degree motor, not ideal for a V8, but balance shafts can quell the vibes.

Interesting idea, but I think Ford simply needs a bigger V8 architecture in general to go up to the 6-7 liter class for their truck lines. The current Mod motor is constrained itself by its FWD roots, wouldn't make much sense to replicate that mistake, especially since Ford already has a tight 60 degree V8 available over at Volvo.
Old 12/19/06, 12:20 PM
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One size does not fit all. New and ever tightening regs on emissions and crash safety mean that focused powerplants(size, performance, emissions and economy) are the way of the future.

The D35 looks to have much room for growth, and for a change, those additions are planned, not band aids. The boss will handle other duties and the diesel for the F-150 is sure to be a focused solution as well.

The perception of the Mods never really matched the elegance of the concept(although the engine in various forms was and is a sparkling JEWEL), and perception spread via the media is everything now...and there is the little matter of trying to make room for the various alternative powerplants that consumers might or might not demand(as opposed to various special interest groups).

Oh yes, there is a rumour about a possible twin turbo version of said D35 out there if enough people insist...?

I insist. Twin Turbo V6 VariableValveTrain GasDirectInjection Fusion SVT with All Wheel Drive? 30-33k? Beyond Bold!!! Call it the Winner!
Old 12/22/06, 12:23 PM
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Originally Posted by rhumb
Or two cylinders to the new 3.5, like they did with the Duratec to come up with the SHO V8, now the Volvo V8.

Yeah, it's a 60 degree motor, not ideal for a V8, but balance shafts can quell the vibes.

Interesting idea, but I think Ford simply needs a bigger V8 architecture in general to go up to the 6-7 liter class for their truck lines. The current Mod motor is constrained itself by its FWD roots, wouldn't make much sense to replicate that mistake, especially since Ford already has a tight 60 degree V8 available over at Volvo.
The original SHO motor and the Volvo V8 were designed by Yamaha. They are not at all related to any other Ford engine.
Old 12/22/06, 01:41 PM
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Originally Posted by AWmustang
The original SHO motor and the Volvo V8 were designed by Yamaha. They are not at all related to any other Ford engine.
I'm not certain which amazes me more, that rumours like these are created in the first place or that people actually believe them. The SHO V-6 is absolutely based on Vulcan V-6 architecture. Worth mentioning is that bore spacing, crank centerline, and virtually every other critical dimension are identical between the two motors. That said even more amazing than the wonders pointed out above is that SHO devotees will still argue that their V-6 is not Vulcan-based even when presented with the above. This argument ranks right up there with the earth being flat and the U.S faking the lunar landing.

As for the Yamaha V-8 not being SHO V-8 derived, a motor which was itself based on the Duratec V-6....the relation is less obvious than was the SHO V-6's relationship to the Vulcan, but it exists nontheless.
Old 12/22/06, 03:27 PM
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So you're saying the Yamaha V8 was not designed by Yamaha, but based on a Ford design??
Old 12/22/06, 03:46 PM
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Originally Posted by theedge67
So you're saying the Yamaha V8 was not designed by Yamaha, but based on a Ford design??
Yes and no. Ford and Yamaha effectively co-developed the SHO, which was based on the Duratec V-6, with Ford largely developing and producing the 3.4L SHO V-8's engine block. The Yamaha/Volvo V-8 may be larger, but it is still loosely based on the older SHO V-8 design.
Old 12/22/06, 04:51 PM
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I'm not a SHO expert, but you guys need to verify the history of the 1st SHO engine. My recollection is that it started out as Yamaha heads on a Ford block.

I'm not a fan of 60 degree V8s. Too much clap trap has to be added on to make them run smooth. A 90 deg V8 is inherently balanced and is a better design choice for most vehicle applications.

V6 or V12 are best @ 60 deg, 120 deg or best 180 deg.
V8 = 90 deg or 180 deg

180 deg is probably the best, but creates lots of packaging problems.
Old 12/22/06, 05:57 PM
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Originally Posted by V10
I'm not a SHO expert, but you guys need to verify the history of the 1st SHO engine. My recollection is that it started out as Yamaha heads on a Ford block.

I'm not a fan of 60 degree V8s. Too much clap trap has to be added on to make them run smooth. A 90 deg V8 is inherently balanced and is a better design choice for most vehicle applications.

V6 or V12 are best @ 60 deg, 120 deg or best 180 deg.
V8 = 90 deg or 180 deg

180 deg is probably the best, but creates lots of packaging problems.
You are not far off really. The original SHO V-6 utilized a Yamaha developed top end on a bespoke aluminum, Vulcan based block.

Regarding the other portion of your post. It's worth mentioning that a 60-degree V-12 is better balanced than a 60-degree V-6. 120 degrees is the ideal choice for a V-6 as you indicate, but the same is obviously not practical for obvious reasons.

If Ford were ever to consider building a narrow angle V-8 I'd rather see them consider a 45-degree vee architecture with a 90-degree crank. The same should work about as well as a 60-degree V-6, and likely even better, for many of the same reasons the 60-degree V-6 pulls it off.

The advantage to 45 degree architecture is obvious, it would be very narrow and would facilitate fitment in many different chassis designs. Another benefit would be the ability to build a super-compact 45-degree V-4 from the same basic design. Even if the four required balance shafts this would be a minor issue since I-4's are hardly well-balanced designs in their own right and often employ balance shafts to solve this problem. And, without question, a 45-degree V-4 would be ridiculously compact.
Old 12/23/06, 10:55 AM
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Originally Posted by jsaylor
I'm not certain which amazes me more, that rumours like these are created in the first place or that people actually believe them. The SHO V-6 is absolutely based on Vulcan V-6 architecture. Worth mentioning is that bore spacing, crank centerline, and virtually every other critical dimension are identical between the two motors. That said even more amazing than the wonders pointed out above is that SHO devotees will still argue that their V-6 is not Vulcan-based even when presented with the above. This argument ranks right up there with the earth being flat and the U.S faking the lunar landing.

As for the Yamaha V-8 not being SHO V-8 derived, a motor which was itself based on the Duratec V-6....the relation is less obvious than was the SHO V-6's relationship to the Vulcan, but it exists nontheless.
So I may have exagerated a bit when I said they were not at all related to any other Ford engines. However I don't think the relationship is quite as close as you claim either.

http://en.wikipedia.org/wiki/Ford_Yamaha_V8_engine
Old 12/23/06, 12:40 PM
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As a former SHO owner, I'm fairly familiar with the history of the two engines. The story goes like this: Ford approached Yamaha about designing heads for the Vulcan 3.0L. Yamaha started work on it but came back to Ford and said the bottom end wasn't strong enough. Yamaha then designed a new block that shared many of the dimensions with the Vulcan but was much beefier. In regards to the V8, it is a Duratec 2.5L with two more cylinders added. Yamaha designed the heads and intake but the bottom end is pure Duratec.

BTW, don't trust everything you read on Wiki. It isn't an authoritative source of information.
Old 12/23/06, 04:29 PM
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Thanks guys, I thought the original SHO engines were related to the Vulcan. Now I know the whole story.


I'm not so sure about 45 degree V8s and 90 deg cranks though. I don't have the time & energy to check right now, but my memory is that they are not as straight foward as a 90 deg V. Narrow V angles also create problems in intake manifold design as well as height issues.
Old 12/24/06, 06:32 PM
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Originally Posted by V10
I'm not so sure about 45 degree V8s and 90 deg cranks though. I don't have the time & energy to check right now, but my memory is that they are not as straight foward as a 90 deg V. Narrow V angles also create problems in intake manifold design as well as height issues.

Y'know, I was thinking the same thing, the V between the cylinders would be narrow indeed (I'm guess about half what a 90 degree V8 would be), just look at a 302 (compared to a 351), and the taller height overall. To get a 45 degree V8 to package nicely, I think it would have to be a very big bore with a very short stroke. The rods would need to be chopped down to the bare minimum as well as the pistons, jamming the rings right up toward the top. To get any sort of decent intake runner length, more than likely, the intake would have to run over the cam/valve covers. Although you could just swap the intake and exhaust with the intakes running from the outside and the exhuast exiting from the V.
Old 12/25/06, 06:02 PM
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Originally Posted by bob
Although you could just swap the intake and exhaust with the intakes running from the outside and the exhuast exiting from the V.
This creates another set of problems putting all that exhaust heat on top of the engine and right under the hood Plus you still have to somehow route the exhaust down to the bottom of the car. To meet emissions regs. the cats need to be as close as possible to the exhaust manifolds, which would mean they'd have to be under the hood. Anyone out the who'd like burned hood paint & melted wiring?
Old 12/28/06, 06:40 PM
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Originally Posted by V10
I'm not so sure about 45 degree V8s and 90 deg cranks though. I don't have the time & energy to check right now, but my memory is that they are not as straight foward as a 90 deg V. Narrow V angles also create problems in intake manifold design as well as height issues.
It ain't a slam dunk by any stretch, but it wouldn't be as problematic to develop and refine as a 60-degree V-8 as best as I can tell (frankly, this wouldn't be too difficult since a 60-degree V-8 is hardly ideal) To my knowledge no truly comprehensive production effort has been made to develop a 45-degree V-8 since before the Cross Plane 90-degree V-8 design was implemented, which is to say a very long time.

Height problems shouldn't be much of an issue since the vehicles this would likely be most useful for regularly employ relatively tall I-4 designs. Intake manifold design would be an issue as well but it should be far less problematic than VW's 'VR' engine family to be sure.

And I agree with Bob that this should be an over-square design ideally speaking, but not for the issues he indicates. An over-square design would further help to minimize vibration which is, of course, desirable. In fact, if executed correctly, I think a 45-degree V-8 would prove easier to balance than a 60-degree V-6.
Old 12/28/06, 08:55 PM
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Why stop at 2 cylinders? Add another 6 cylinders - that'd be real interesting to see (and hear)!
Old 12/29/06, 06:24 AM
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Originally Posted by hi5.0
Why stop at 2 cylinders? Add another 6 cylinders - that'd be real interesting to see (and hear)!
Isn't that an AM V12 IIRC, it seems to me that at one time Aston Martin was or is using what is essentially 2 duratec V6 motors mashed together for thier V12?
Old 12/29/06, 11:48 AM
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Originally Posted by bob
Isn't that an AM V12 IIRC, it seems to me that at one time Aston Martin was or is using what is essentially 2 duratec V6 motors mashed together for thier V12?
Yes, I believe that is correct.


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