6 litre Pushrod Motor...Anyone ????

[vztrt]

Originally Posted by gmhdriver

Sigh... _ Some people really need to get their facts straight. DOHC has been around for just as long as pushrods.
http://en.wikipedia.org/wiki/Double_overhead_cam

It's just DOHC is a more efficient motor. If they could reduce the weight of the motor it would give the car a better power to weight and not be considered the show car (as some members have stated).

[gmhdriver]

Originally Posted by vztrt

It's just DOHC is a more efficient motor.

Yes and no. Not in every instance. The LS1/2 engines are a good example of that. GM's engineering has done away with most of the limitations/negative aspects of pushrod engines, giving them the characteristics of a multivalve engine while retaining all the benifits of pushrods.
The 6700 rpm rev limit and fuel efficiency are proof of this.

[4Vman]

Originally Posted by gmhdriver

Yes and no. Not in every instance. The LS1/2 engines are a good example of that. GM's engineering has done away with most of the limitations/negative aspects of pushrod engines, giving them the characteristics of a multivalve engine while retaining all the benifits of pushrods.
The 6700 rpm rev limit and fuel efficiency are proof of this.

Terry Sainty would disagree, his DOHC Topfuel engine is banned in the states because it made too much HP....
Seriously though DOHC is better technology, its pointless to argue otherwise, sure there are very good pushrod engines but to meausre KW/L with engines taken to the extreme a DOHC engine will come out on top every time.
But as HSE2 pointed out, your brain doesn't care what's causing the smile...

[parawolf]

Blah wake me when Ford is producing electronically actuated soleniod motors, rather than an engine with cam timing chains, cam shafts, etc.

Yes it might end up being a 'bigger' motor, but would certainly suit a boxer style engine

[Bossxr8]

Originally Posted by gmhdriver

Yes and no. Not in every instance. The LS1/2 engines are a good example of that. GM's engineering has done away with most of the limitations/negative aspects of pushrod engines, giving them the characteristics of a multivalve engine while retaining all the benifits of pushrods.
The 6700 rpm rev limit and fuel efficiency are proof of this.

Because it has all its power up high in the rev range its suddenly has "the characteristics of a multi valve engine". WTF. Fuel efficiency is only because of the lighter weight of the Commodore and extra tall gearing in the manuals, and any pushrod engine can be made to rev to 6700. Boss 302 Mustangs revved to 7000 and P3 GTHO's could go that far as well with the electric rev limiter removed and thats more than 30 years ago.

[vztrt]

Originally Posted by gmhdriver

Yes and no. Not in every instance. The LS1/2 engines are a good example of that. GM's engineering has done away with most of the limitations/negative aspects of pushrod engines, giving them the characteristics of a multivalve engine while retaining all the benifits of pushrods.
The 6700 rpm rev limit and fuel efficiency are proof of this.

I was thinking that it was more efficient because it produced the same amount of power from a smaller motor. But I would like to see the BOSS get VCT and see how it performs.

[4Vman]

Originally Posted by Bossxr8

Because it has all its power up high in the rev range its suddenly has "the characteristics of a multi valve engine". WTF. Fuel efficiency is only because of the lighter weight of the Commodore and extra tall gearing in the manuals, and any pushrod engine can be made to rev to 6700. Boss 302 Mustangs revved to 7000 and P3 GTHO's could go that far as well with the electric rev limiter removed and thats more than 30 years ago.

Id be interested to see what people say about a 6L LS2 powered car if you used lead and placed the weight difference between the Falc and Com on the top of the engine and then measured its drivability, performance figures and fuel economy.... VERY Different story id suggest.
On another note The Boss motor has specific limitations that anyone with any engine technical nouse will immidiately identify ie: long stroke, small bore motors are traditionally "unexciting" compared to short stroke wide bore engines, the "BOSS's" personality has more to do with this than any short comings a DOHC might bring, in fact DOHC probably gives a bit back over a similar spec pushrod engine..
Id like to see a shorter stroke, wider bore version of the 5.4 boss engine for starters.....

[Bossxr8]

Originally Posted by 4Vman

Id be interested to see what people say about a 6L LS2 powered car if you used lead and placed the weight difference between the Falc and Com on the top of the engine and then measured its drivability, performance figures and fuel economy.... VERY Different story id suggest.
On another note The Boss motor has specific limitations that anyone with any engine technical nouse will immidiately identify ie: long stroke, small bore motors are traditionally "unexciting" compared to short stroke wide bore engines, the "BOSS's" personality has more to do with this than any short comings a DOHC might bring, in fact DOHC probably gives a bit back over a similar spec pushrod engine..
Id like to see a shorter stroke, wider bore version of the 5.4 boss engine for starters.....

If only FPV would use the Carillo rods used in the Cobra R and the 7000 rpm limiter, then played around with the cams, and it would be the ducks guts.

[AnthonyQLD]

Originally Posted by ltd

Wouldn't happen. Cost of making new moulds $$$$$$$$$$$$$$$.

Losing their enviro friendly appeal $$$$$$$$$$$$$$$$$$

Losing their trust in the marketplace after telling everyone ohc was better than pushrod $$$$$$$$$$$$$$$$$$$$$$

Keeping on and developing an already proven stable engine Priceless.

Thats just about sums it up

[Lukeyson]

although the boss in 6L would be near 30kw more than the LS2, but isnt the boss like 90kg heavier than LS2 ?

[4Vman]

Originally Posted by XR8fella

although the boss in 6L would be near 30kw more than the LS2, but isnt the boss like 90kg heavier than LS2 ?

about 40kgs i think, most of the current weight difference between VZ and BF will be dumped into the VE, expect a different playing field once the VE weighs the same as the BF..

[all4ford]

Originally Posted by 4Vman

Id be interested to see what people say about a 6L LS2 powered car if you used lead and placed the weight difference between the Falc and Com on the top of the engine and then measured its drivability, performance figures and fuel economy.... VERY Different story id suggest.
On another note The Boss motor has specific limitations that anyone with any engine technical nouse will immidiately identify ie: long stroke, small bore motors are traditionally "unexciting" compared to short stroke wide bore engines, the "BOSS's" personality has more to do with this than any short comings a DOHC might bring, in fact DOHC probably gives a bit back over a similar spec pushrod engine..
Id like to see a shorter stroke, wider bore version of the 5.4 boss engine for starters.....

I agree, the main problem with the boss is its weight. If the boss was all alloy like the LS2, I think the cars would perform a whole lot better...Of course im not ignoring the problem of the long stroke, but the cars don't need to be revving past 6000RPM from factory. power can be found in other areas.

[gmhdriver]

Apart from weight, there is also the fact that a DOHC engine has more moving parts, which means there is more that can go wrong, not to mention that it is much more complex and expensive to repair.

[Psycho Chicken]

More moving parts? Eh?

OHV - Timing chain, cam, lifters, pushrod, rocker, valve.
DOHC - Timing chain, cam, cam follower, valve.

[phillyc]

According to the latest Motor (pretty sure) it said the weight of the Gen4 was 183kg.

Here is a link with the dimensions and weight of the modular motors.

http://www.mustangandfords.com/techa...ap/index4.html

On the above site, they have the 5.4L DOHC at 540lb which is 245kg
The alloy block is 90lbs (41kg) lighter when factoring in the weight penalty of the 4V heads versus 2 or 3V heads!

Alloy block would make a great improvement to the handling,
reduce overall mass of vehicle by 2.5%
reduce fuel usage by a similar amount
Improve power to weight ie 0-100 improved by about 0.15s as well.

Great gains could be made if they put the VCT technology on the BOSS.
They have it (i'm pretty sure on the single cam 3V Barra 220)
VCT would dramatically improve power, torque spread, fuel consumption and emissions too.

C'mon FORD! Please, please, please!!!

PS Maybe time the release to upset the VE launch? Smash their new performance'' models... he he he...

[banarcus]

Honestly people, who really cares what actuates the valves? I dont, I have a VY SV8 and a windsor 5.0L and I've tried the new mod motors. Theres too many people that really have their blinkers shut.

All I can say is Ford motors sound like fair dinkum V8s.

[brodfloyd]

in the states, they have the 5.0 litre "cammer" engine. it has a wider bore 3.7* or something ,than the 4.6 litre mod engine, but the same deck height as the 4.6. NOW, if they could get this engines bore, but with the deck height of the 5.6, in alloy, with dual VCT, some quality pistons and rods. HMMMM, that would be sweet. Rev to 7000k, prob be about 6 litres in capacity. I'm gonna pour some moulds in my shed tonight, anyone good with auto cad? i'll go u halves. Who wants one?

[SpoolMan]

The States have already done away with there 4 valve 4 cam motors.
Using a push-rod motor will save them $2000 App an engine thats a huge saving when you look at how many are pumped out.
Push-rod motors have served GM Chev very well and you look at there Performance of the recent LS1's and the new LS2 once again a V8 performance winner.
With fuel costs only going up, i cant see company's spending to much on hi tech V8's anymore.
Its all about dollars and cents..

[ltd]

Three specific problems remain with pushrod engines:

Limited rpm - Pushrod engines have more rotational mass, suffer more easily from valve "float", and exhibit a tendency for the pushrods themselves to flex or snap at high rpm. Therefore, conventional wisdom says that a pushrod engine cannot rev as high as an OHC design. Modern pushrod engines generally rev to 6,000 rpm. Compare this to modern OHC engines that rev to 7,000 rpm in the case of ordinary engines, to 9,000 rpm in the case of high-performance engines like the one used in the Honda S2000, and even past 10,000 rpm in specialty engines. However, high-rpm pushrod engines have also been developed — in 1969, Chevrolet offered a Camaro Z28 with a pushrod V8 that revs to 8,000 rpm. Volvo B18 and B20 engines can rev to more than 7000 rpm, and still last for hundreds of thousands of miles. The 2006 Chevrolet Corvette features a 7.0 L LS7 engine capable of revving to 7000 rpm.
Because overall power is a computed by multiplying torque by revolution speed (HP = (RPM x LB-FT) / 5252), an engine capable of revving higher will produce more power from the same amount of torque than one incapable of revving. A pushrod engine needs to have a larger displacement than a similarly powered OHC engine. Higher engine RPMs results in more power overall. A good comparison would be the 3.8L GM 3800 Engine to the 3.0L Honda J-series V6. The smaller (in displacement) Honda Engine produces approximately 40 more horsepower, while requiring less torque (work) to do so.

So far as driving dynamics go, an OHC engine will have power that seems to build as you push higher and higher into the RPM range. A pushrod engine, with torque peaking out very early, will feel strong at low speeds, but seem to run out of steam when pushed to any significant degree.

Difficulty in using crossflow cylinder heads in straight engine configurations - A few straight pushrod engines have been manufactured with crossflow heads, such as the six cylinder Humber Super Snipe. These engines combined much of the performance of the overhead camshaft with the ease of service of the pushrod, but were more expensive to manufacture than either competing design.
Limited valve flexibility - The biggest benefit of an OHC design is the use of multiple intake and exhaust valves and variable valve timing. Most modern pushrod engines have two valves per cylinder, while many OHC engines use three, four or even five valves per cylinder to achieve greater efficiency and power. Recently, however, GM has begun offering a pushrod V6 with VVT, and Cummins' ISB is a 3-valve pushrod straight-6. For the 2006 model year, General Motors will introduce the Vortec 6200. This is the first mass-produced pushrod engine to feature variable valve timing. The system adjusts both intake and exhaust timing between two settings.

[philstoj]

Originally Posted by ltd

Three specific problems remain with pushrod engines:

Limited rpm - Pushrod engines have more rotational mass, suffer more easily from valve "float", and exhibit a tendency for the pushrods themselves to flex or snap at high rpm. Therefore, conventional wisdom says that a pushrod engine cannot rev as high as an OHC design. Modern pushrod engines generally rev to 6,000 rpm. Compare this to modern OHC engines that rev to 7,000 rpm in the case of ordinary engines, to 9,000 rpm in the case of high-performance engines like the one used in the Honda S2000, and even past 10,000 rpm in specialty engines. However, high-rpm pushrod engines have also been developed — in 1969, Chevrolet offered a Camaro Z28 with a pushrod V8 that revs to 8,000 rpm. Volvo B18 and B20 engines can rev to more than 7000 rpm, and still last for hundreds of thousands of miles. The 2006 Chevrolet Corvette features a 7.0 L LS7 engine capable of revving to 7000 rpm.

you forgot to mention that the pushrod engines in nascar sustain 9000+ rpm!
not bad for a ИИИИ design that isnt supposed to rev...

[Perana]

I personally hope it doesnt happen. I am a big fan of 4cam Large capacity V8's.

Look at the ( nearly 10 year old ) BMW S62 V8. 4941cc 294kw @ 6600 rpm and 500Nm @ 3800 rpm and does a Mid/High 13 1/4 in a 1900kg car... Comparing that to the 6.0L Holden/Chev LS2 ( which is much "newer" ) 297kw @ 6000rpm 530 Nm @ 4400 rpm that does a Mid 13 in a sub 1700kg car.. Given they both have 6 Speed manuals with similar overall ratios you can plainly see which is more efficient even though its a much "older" engine..

[brenx]

I don't own one but one day I will. A v8 DOHC that is. I'd prefer OHC. Pushrod engines are simple but look at the import v8's etc running the OHC setup. They make good power and go fast. Ford's issue is they make the cars too fat.

Alloy blocks may sound good but they have their own pros/cons too. Cast iron blocks are better durability wise. Alloy's main benefit is weight and heat transfer.

Just makes me want to buy a late model import V8 or an XR6T as they're fairly sorted performance wise. From what I see on this forum and others is the current ford v8 motors failing. Whether it be due to harmonics or oil pump failures due to poor design. Maybe some are just lemons? It happens.

My own personal opinion Ford need to remain competative on the track. If I pull up in my 250rwkw BF for example? I want to atleast be on par with the same year Holden/Chev. I don't want to watch their tail lights. Although Chris from Bluepower seems to be showing everyone how it's done.

[ltd]

Originally Posted by philstoj

you forgot to mention that the pushrod engines in nascar sustain 9000+ rpm!
not bad for a ИИИИ design that isnt supposed to rev...

Hey, I just copied and pasted from that wikipedea site that someone else posted before. Personally, I couldn't give a rats ИИИИ about pushrod or DOHC. Whatever floats your boat.

[brodfloyd]

Originally Posted by SpoolMan

The States have already done away with there 4 valve 4 cam motors.
Using a push-rod motor will save them $2000 App an engine thats a huge saving when you look at how many are pumped out.
Push-rod motors have served GM Chev very well and you look at there Performance of the recent LS1's and the new LS2 once again a V8 performance winner.
With fuel costs only going up, i cant see company's spending to much on hi tech V8's anymore.
Its all about dollars and cents..

what "states" are you talking about??? Last time i checked every ford car that comes with a v8 over there is a mod V8. Eg, GT, Mustang.

As for "dollars and cents" regarding fuel economy, it has already been covered about how a OHC engine of the same capacity as a pushrod engine has an inherant power and economy advantage due to the use of overhead cams. So i dont see your point as bang for buck the OHC will come out on top.

yes it may cost more to build, but that is what better products usually do. and the consumer for the most part wants the "edge". Better, more powerfull, more economic engine even at a slightly higher cost.

last time i checked, ford and gm US was up the ИИИИter financially, and chrysler had to merge to stay afloat, mainly for having backwards unwanted products that were unwanted in the local marketplace and were being increasingly shunned in favour "high tech" imports like toyota (no pushrods there im afraid) why would ford want to seem more backwards by reverting to (as has also been covered, a less High-tech technology in pushrods)? would this not only further harm their market position. And why build a cheaper car if you cant sell it because the marketplace see's it as "low tech"

Never mind the costs of designing, developing and building this new pushrod v8, it just doesnt make any sense. Would they use the windor as a base? would it be a clean slate? either way, it will cost a lot of money they dont have.

OH, and move away from high tech motors??? yeah i can see ferrari, mercedes, toyota, bmw all moving back to pushrod engines, cant u??? As most if not all european and asian car manufacturers who are financially secure use overhead cam technology, i do not think this is a coincidence. do u think that the ford would want to look even more backward on the world scene than they are already for the most part? The only thing giving them technical credability on the world scene at the moment is the GT, powered by an all alloy DOHC V8.

and incase you havent read any reviews on the hot corvette with the LS7, all of the journo's say "gee its a good car, even with that old boat anchor, based on an engine from 1955 of an engine" even tho it isnt entirely that way, but the conception is that pushrods are a less high tech option and that it is an incarnation of an 1955 engine is still there, and will always be an excuse for people to disregard an otherwise excellent product and choose or recomend a higher tech and more expensive rival.

that is just the start of the reasons why i think this is rubbish and that ford will not stop with the modular engine program, its a point of difference at the moment with the other US manufacturers, and is the hero engine in the F series trucks, which is the highest selling auto there.

[gmhdriver]

Originally Posted by ltd

Three specific problems remain with pushrod engines:

Limited rpm - Pushrod engines have more rotational mass, suffer more easily from valve "float", and exhibit a tendency for the pushrods themselves to flex or snap at high rpm. Therefore, conventional wisdom says that a pushrod engine cannot rev as high as an OHC design. Modern pushrod engines generally rev to 6,000 rpm. Compare this to modern OHC engines that rev to 7,000 rpm in the case of ordinary engines, to 9,000 rpm in the case of high-performance engines like the one used in the Honda S2000, and even past 10,000 rpm in specialty engines. However, high-rpm pushrod engines have also been developed — in 1969, Chevrolet offered a Camaro Z28 with a pushrod V8 that revs to 8,000 rpm. Volvo B18 and B20 engines can rev to more than 7000 rpm, and still last for hundreds of thousands of miles. The 2006 Chevrolet Corvette features a 7.0 L LS7 engine capable of revving to 7000 rpm.
Because overall power is a computed by multiplying torque by revolution speed (HP = (RPM x LB-FT) / 5252), an engine capable of revving higher will produce more power from the same amount of torque than one incapable of revving. A pushrod engine needs to have a larger displacement than a similarly powered OHC engine. Higher engine RPMs results in more power overall. A good comparison would be the 3.8L GM 3800 Engine to the 3.0L Honda J-series V6. The smaller (in displacement) Honda Engine produces approximately 40 more horsepower, while requiring less torque (work) to do so.

So far as driving dynamics go, an OHC engine will have power that seems to build as you push higher and higher into the RPM range. A pushrod engine, with torque peaking out very early, will feel strong at low speeds, but seem to run out of steam when pushed to any significant degree.

Difficulty in using crossflow cylinder heads in straight engine configurations - A few straight pushrod engines have been manufactured with crossflow heads, such as the six cylinder Humber Super Snipe. These engines combined much of the performance of the overhead camshaft with the ease of service of the pushrod, but were more expensive to manufacture than either competing design.
Limited valve flexibility - The biggest benefit of an OHC design is the use of multiple intake and exhaust valves and variable valve timing. Most modern pushrod engines have two valves per cylinder, while many OHC engines use three, four or even five valves per cylinder to achieve greater efficiency and power. Recently, however, GM has begun offering a pushrod V6 with VVT, and Cummins' ISB is a 3-valve pushrod straight-6. For the 2006 model year, General Motors will introduce the Vortec 6200. This is the first mass-produced pushrod engine to feature variable valve timing. The system adjusts both intake and exhaust timing between two settings.

Nice cut and paste there mate..
http://en.wikipedia.org/wiki/Pushrod

[Citric GT]

Bring on the push rod 6 litre. I'd buy one if it sounded good and went good. Who wants technology if it doesn't achieve anything?

[gmhdriver]

Originally Posted by Psycho Chicken

More moving parts? Eh?

OHV - Timing chain, cam, lifters, pushrod, rocker, valve.
DOHC - Timing chain, cam, cam follower, valve.

Umm let me see...

OHV - Timing chain x1 DOHC - Timing chain x2
OHV - Cam x1 DOHC - Cam x4
OHV - Valve x16 DOHC - Valve x32

Need I go on...............?

[Psycho Chicken]

Alright, we'll play that game then.

OHV - 16 pushrods DOHC - none
OHV - 16 rockers DOHC - none

That makes more moving parts by your way of counting it.

[Pieoter]

Originally Posted by philstoj

you forgot to mention that the pushrod engines in nascar sustain 9000+ rpm!
not bad for a ИИИИ design that isnt supposed to rev...

In the case of looking at race engines the new V8 f1 engines have revved to over 22,000 RPM in testing.

[SpoolMan]

Originally Posted by brodfloyd

what "states" are you talking about??? Last time i checked every ford car that comes with a v8 over there is a mod V8. Eg, GT, Mustang.

.

Hi brodfloyd, there a 4.6L 3 valve, 2 cam engine...much better for low down torque, ask Craig from ACE about low down torque on the 3 valve Modular.