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So we threw the baby out with the bath water?

 

Those 3V combustion chambers and intake valve locations were a patented Jim Feuling design purposefully crafted like they were.

That chamber is inefficient compared to the standard 4V chamber, from a perspective of flow and knock resistance.

 

Those 4.6 3V's created a better torque curve than a big 460 from just a decade before.

.

 

The 5.4 3V made decent torque, but so did the 2V. The 3V wasn't a inherently torquey setup, they made some small mid-range improvement for the simple fact they had the ability to advance the ICL 40° over park.

 

With phaser lockouts, the 4.6 3V is fairly gutless down low.

 

I'm skeptical when you say that the single exhaust vslve and port arrangement wasn't up to the job. For Pete's sake it's a decent sized valve/port with a nice shape that is short and direct like a Chrysler Hemi!

I'm not saying it wasn't up to the job, (they are 230/170 cfm heads) what I'm saying it didn't do as good of a job as the 4V parts Ford already had on the shelf.

 

My original point about the 3V's was that they were underutilized. If I were in charge there would be 3V 6.2's right from the get go.

Why stop at 3-valves per cylinder? Honda has had some success with SOHC 4-valve arrangements if cost is a concern. But since DOHC offers significant advantages in VVT, as it allows variable valve overlap, I just can't see a reason for the 3-valves existence.

 

Most manufacturers that dabbled in 3-valves per cylinder have since moved on back the 4-valves.

 

This "valve curtain" business well I'd like to study just what Jim Feuling was doing when he spread the intake valves out like that.

The 3V intake port is a tumble port just like the 4Vs. They aren't swirl chambers. Ford moved away from the 3V valve intake valve placement and the Coyote top end provides more power/torque across the curve given similar displacement and compression.

 

Aren't the 3V V10's reliable? Every single person I have spoken with that owns and operates a V10 Ford likes it and says it's a pulling beast. Everyone.

The 3V V10 do not have cam phasers, and they are low rpm applications do not expose the 3V's valve-train weaknesses.

 

I would say the V10 was the only successful variation of the 3V, once they got the spark plug revision.

Edited by White99GT
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DAMB has been the "grail" of OHC valvetrain designers for years. Fewer parts (lower cost), lower overall height, what is not to like ! It is hard to believe that with modern lubes that wear was/is an issue, especially since some manufacturers are still using it. Besides frictional losses, DAMB has a very high repair cost if the customer complains of valvetrain noise during the warranty period.

You just named a few reasons not like it.

Higher frictional losses, higher wear rates, higher replacement costs.

 

Ford RFF use hydraulic lash adjusters, so I did not think there was anyway to "adjust" the pre-load.

Lash adjuster pre-load set by the relationship between valve stem length, follower and camshaft base circle. Lash adjuster pre-load is entirely adjustable. You can shim lash adjusters, alter camshaft base circle, alter valve stem length, etc.

 

Getting the pre-load tight enough to prevent pump up but not tight enough to wipe the follower off of the valve isn't that hard, Ford has it close to perfect from the factory.

 

I've seen stock GT500 followers and lash adjuster withstand repeated 9500-10000 rpm beatings. This is why I don't see a reason for DAMB in passenger car apps, their reason for existence is to combat hydraulic lash adjuster pump up in extremely high rpm situations and packaging.

 

Leave DAMB to the crotch rockets.

Edited by White99GT
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With all do respect an intake valve in relative close proximity to the cylinder wall is not a true tumble port design. Logic tells me there was some effort to get the cylinder walls to deflect the mixture thus creating a bit of turbulence and effecting a better homogenized charge.

 

I don't know this as fact but using basic logic here.

 

I don't see the apparent failures of the RFF's as a problem

that couldn't be fixed.

 

I don't see the variable cam timing issues as be

insurmountable either.

 

I have a 5.4 3 valve in my fleet. It's in an F250 service truck. Except for having a lazy "tip in" tune on the accelerator pedal the engine performs very well. It has been very reliable to date and it has about 150,000 on the ODO.

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With all do respect an intake valve in relative close proximity to the cylinder wall is not a true tumble port design. Logic tells me there was some effort to get the cylinder walls to deflect the mixture thus creating a bit of turbulence and effecting a better homogenized charge.

The 3V port and intake valve angle is similar to the 4V, the air tumbles into the cylinder as opposed to swirl.

 

 

I don't see the apparent failures of the RFF's as a problem

that couldn't be fixed.

It could be, sure. I am speaking strictly in regards to the 3V arrangement Ford delivered.

 

I don't see the variable cam timing issues as be

insurmountable either.

Ford could have adopted CTA phasers, but it still doesn't allow variable valve overlap like a TiVCT DOHC setup would, unless they went to a 2-piece camshaft that would introduce another set of problems.

 

I have a 5.4 3 valve in my fleet. It's in an F250 service truck. Except for having a lazy "tip in" tune on the accelerator pedal the engine performs very well. It has been very reliable to date and it has about 150,000 on the ODO.

Some 3-valves have lived for decent spans, but I'm confident in the assessment that the 3-valve is overall the least reliable variation of the Mod. Edited by White99GT
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The Coyote has always been RFF, it's the Cyclones (2017 Gen 2 3.5 EB) that are switching from DAMB

to RFF.

 

Some of the early 3.5 Cyclones had issues with bucket/tappet wear that was addressed in the first year or two of production.

Ah yes, thank you I got mixed up with the Cyclone upgrades on the new EB 3.5 and 3.3.

 

 

I personally prefer RFF as it's just a lower friction, lower wearing setup. Frictional losses are probably the reason Ford seems to be moving away from DAMB in the EcoBoosts.

 

The RFF valvetrain, with the proper lash adjuster pre-load, has no issues with 9000-plus rpm operation (with OEM lash adjusters and followers at that). I honestly don't see a reason for DAMB in car/truck applications, except for perhaps reduced exterior dimensions in the cam cover area.

Yeah, it's like the case for DAMB has passed in all but extreme racing conditions,

the RFF also leaves open the possibility of ctlinder deactivation if Ford was ever inclined.

 

 

Just on 3V, I think the big disadvantage is that it can't support dual independent VCT,

the ability to separate inlet and exhaust cam phasing is a lot more important these days.

I do like the idea of the 6.2 gaining 3V heads, it would even out the port flow, especially

with charge motion plates one of the two small inlet ports to operate at lower speeds.

Edited by jpd80
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I will say the 6.2 head is a serious piece. It's a textbook case on how to do a 2-valve right.

 

That engine just needs more cam and compression to make big power. I would love to see a high compression, DI, aluminum block version of the 6.2 in a new Mach 1 or Boss.

Edited by White99GT
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The 3V used oil pressure actuated (OPA) cam phasers, the 5.0/EB/6.2 use cam torque actuated (CTA) cam phasers.

Interesting. I don't have a Ford service manual, but AllData describes the Coyote's TiVCT cam phasers as being hydraulically actuated (at least for my '13 F-150). I've not had call to tear into my engine, so I can't say from experience.

Edited by SoonerLS
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Interesting. I don't have a Ford service manual, but AllData describes the Coyote's TiVCT cam phasers as being hydraulically actuated (at least for my '13 F-150). I've not had call to tear into my engine, so I can't say from experience.

CTA phasers still have a hydraulic function, but they don't use oil pump produced pressure to actually advance and retard the cam in the way the 3V phasers did. CTA phasers don't require nearly as much oil volume/pressure to operate.

 

This is a decent write up:http://www.caranddriver.com/features/cam-torque-actuated-variable-valve-timing-system-feature

Edited by White99GT
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I will say the 6.2 head is a serious piece. It's a textbook case on how to do a 2-valve right.

 

That engine just needs more cam and compression to make big power. I would love to see a high compression, DI, aluminum block version of the 6.2 in a new Mach 1 or Boss.

I'm a little puzzled as to why Ford would develop a giant 2V head with huge ports that flow like sewer pipes

and then expect it to work in a truck where bottom end torque is everything, I just see either a 3V or 4V

head as being more appropriate to Super Duty application.....

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I'm a little puzzled as to why Ford would develop a giant 2V head with huge ports that flow like sewer pipes

and then expect it to work in a truck where bottom end torque is everything, I just see either a 3V or 4V

head as being more appropriate to Super Duty application.....

Wouldn't a 2-valve design have less parasitic loss of energy at low RPM due to fewer moving parts?

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Wouldn't a 2-valve design have less parasitic loss of energy at low RPM due to fewer moving parts?

Those savings pale into comparison to the loss in low end torque due to those huge sewer pipe ports,

Today's engines use a lot more roller followers and the OHC and DOHCs are lightly sprung so those

parasitic losses are a lot smaller than they used to be.

 

Smaller ports afforded by a 3V or 4V head and the use of charge motion valves increases low end torque

over the large ports on the 6.2 Boss...

 

The example I gave earlier in this thread, 6.2 2V versus 6.8 3V - at 2000 rpm the 6.8 is something

like 100 lb ft ahead of the 6.2 thanks in part to added capacity but also better port size at low speed.

Edited by jpd80
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"Why stop at 3-valves per cylinder? Honda has had some success with SOHC 4-valve arrangements if cost is a concern. But since DOHC offers significant advantages in VVT, as it allows variable valve overlap, I just can't see a reason for the 3-valves existence.

Most manufacturers that dabbled in 3-valves per cylinder have since moved on back the 4-valves. "

 

Exactly, if 3 valves were so great Mercedes would still be using them.

 

To go further, is 5 valves were so great Yamaha and Audi would still be using them.

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BTW people gotta be careful with numbers. Like if 4 is good 5 must be better etc.

 

Yamaha did dabble in 5 valves. They worked in the narrow application that they were intended for. They didn't however work well enough to be practical in large scale production use.

 

You guys seem to be saying that there is no place for a 3 valve engine when arguably one of the best engines Ford has in their cache' is a 3 valve engine, the V10.

 

Let me remind you that GM and Mopar are still peddling ancient 2 valve pushrods.

 

I'm simply saying that Ford now has a fully mature OHC engine portfolio. Yes there are some weak spots that should never have happened but I'm sure they've learned from them.

 

I still say that a cheaper and simpler 4.6 - 5.2 SOHC 3 valve would be a dynamite engine for more common uses.

 

Let's not forget here that almost 15 years after they were introduced the Modular family is still incredibly bore limited.

 

This single ONLY reason that GM and Mopar are even in the same universe that Ford is with their V8's is due to the limits on available displacement.

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BTW people gotta be careful with numbers. Like if 4 is good 5 must be better etc.

 

Yamaha did dabble in 5 valves. They worked in the narrow application that they were intended for. They didn't however work well enough to be practical in large scale production use.

 

You guys seem to be saying that there is no place for a 3 valve engine when arguably one of the best engines Ford has in their cache' is a 3 valve engine, the V10.

 

Let me remind you that GM and Mopar are still peddling ancient 2 valve pushrods.

 

I'm simply saying that Ford now has a fully mature OHC engine portfolio. Yes there are some weak spots that should never have happened but I'm sure they've learned from them.

 

I still say that a cheaper and simpler 4.6 - 5.2 SOHC 3 valve would be a dynamite engine for more common uses.

 

Let's not forget here that almost 15 years after they were introduced the Modular family is still incredibly bore limited.

 

This single ONLY reason that GM and Mopar are even in the same universe that Ford is with their V8's is due to the limits on available displacement.

How do you know 4 valve V10 would't be better?

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Just move the balance shaft down next to the crank like in the 4.0 SOHC cologne V6. That would free up the cam sprockets for TiVCT.

 

I'm just slightly bitter that Ford actually developed a V10 and then couldn't be bothered to do a performance version. I guess lugging around big trucks is better than no V10 at all, but only Ford would design an engine with such potential and then abandon it to trucks only.

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I don't think 4V engines are cost prohibitive from a mass production standpoint.

 

Keep in mind that almost every manufacturer that offers a a V6 or V8 today are almost solely producing DOHC 4-valve versions, GM and Chrysler are the oddballs in this respect.

 

The V10 with the Coyote truck style top end package would be a monster from idle to 6500 rpm.

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I'm a little puzzled as to why Ford would develop a giant 2V head with huge ports that flow like sewer pipes

and then expect it to work in a truck where bottom end torque is everything, ...

I was around Engine Engineering when development on that engine restarted. I never worked on it, but the designers sat at the other end of the building. At that time, they would have informal design reviews. Basically all of the parts laid out on tables so that everyone from all departments of Engine Engineering could walk by and comment/ask questions.

 

You have to remember this program was halted once (twice ?) and then restarted. Management wanted a pushrod engine (because that was what GM had) and then wanted some kind of "displacement on demand" (I actually worked on that program before it was canceled in the early 1980s. TRW sold the actuator to Cadillac when Ford backed out.What a disaster !!). Luckily, the engineers talked them out of both of those !

 

I recall having a conversation about the 2 (enormous) valve head with a guy from the program. Again, management did not want to pay for the third valve. I always thought that 2 plugs was not a good idea, but because they could not get the plug near the center and accommodate those 2 "sewer pipes" they had to put it off to the side. The second plug is, obviously, to reduce "flame travel" time.

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We may find that putting 4V heads. VCT and PFDI onto the 6.2 and perhaps the larger (7.0?) V8 coming

would achieve so much more on continuing engines without the complication of a V10 and balancer shaft issues.

I predict DI will be dying off because of cost and particulate emission regulations. I heard that the new 3.5L EcoBoost with PFDI run less than 25% of the fuel through DI. The rest goes in the port injectors.

 

I that statement is correct, the 25% of the fuel is an awfully expensive "marketing" gimmick, although it seems to be working !

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