4.6 quad cam Ford into RF40 - does go !!!!!

Robert Logan

Defunct Manufactuer - Old RF Company
Malcome,

Beans and chilly eh !!!!

I heard that cows farting causes more emmissions that anything else.

Just to clear up things with people, I intend to continue building the SB GT40 as my standard package and this I doubt will change. I to am a traditionalist and I to love the original SB GT40 and this is what I drive. I also believe that the "noose" is tightening and that an emmissions legal engine is going to be the stumbling block for many companies. I am just geting fore armed as I have been fore warned !!!!

You guys in the US are off the hook anyway looking at the thread from Lynn Larson.

Best wishes,

Robert
 
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Guest

Guest
Robert,
I thought Australia had a few more freedoms than that, I doubt if replica cars would do much damage in a large country with a small population. They must be regulation mad to worry about the replica car trade. I would much prefare the LS1 engine to the 4.6 monster and its light and small. These engines are taken hold in England and are used in the GD T70 and ultima with the porsche box. They can be set low in the chassis and look better in my opinion.
 
A few questions from the other side of the pond:
Is the 4.6 taller due to it's sump height, deck height or just the heads?
And if the heads flow well, what are the power limitations- some mechanical bits that have not been designed with modification in mind? I have seen rods etc advertised, for example.
The next assumption is that the 300 ish from the stock motor is not enough: we should be clear about road cars versus race.
After all, 850 hp was not enough for Mark Donohue, but many people would be better served with less.
And an RF40 with 320 hp would match a Viper in acceleration, probably the fastest real production car about.

 

Ron Earp

Admin
I've seen more build ups of these motors locally and in MM&FF than I care to remember. They're expensive to build up, do not make near as much power regardless of theory, and don't seem to hold up under serious abuse. They're also heavy and big.

I do agree with what was written above - they do seem to respond well to forced induction. The four valve heads also flow very well in this application.

In my opinion GM made the right decision to redesign the SB V8 and stick with a pushrod design. The Z06 motors are really good, 405hp and are emissions friendly. And, they can do much better with stroking, blowing, etc.

Ford decided to ditch the pushrod designs (at least in North America) and go OHC. What we ended up with are small displacement V8s with more cams than necessary (really, an OHC 2 valve V8 with 6000 RPM redline, what is the point? Stock it makes/made less than a good old 5.0L).

It is interesting that RF has one in a GT40, particularily if emissions etc. are something to worry about in Australia. Will be here as well for a company to sell modern emissions legal turnkeys. But, I think the pushrod SBs are still going to clean house on them at the strip and track. Maybe one will prove me wrong, but I'll wait for that.


Ron
 

Ron Earp

Admin
RF,

Some of us in the States are okay. Each State creates its' own set of rules regarding the cars. Lynn and I live in North Carolina and after writing some letters we've been able to clear the matter up in our State. Others are not nearly as lucky, having restrictions and what not, and still others are even better off.

As for a couple of the posts on the motor I don't think it is a matter of 320hp being not enough. It is just that given the fact these are large, heavy, and complex DOHC V8s they ought to make more power than an antiquated and quaint pushrod engine. But they don't, they're hard pressed to match them. And 7500 RPM and higher pushrod engines are available, just call your favorite (good) engine builder.

Malcolm, Chevy (wash out my mouth) V8s in a GT40?

And wasn't it a Mercedes engine in some team car in the 94 or 95 Indy race that won with a pushrod design?

Ron

[ June 02, 2002: Message edited by: R. Earp ]
 
quote:Originally posted by R. Earp:
RF,

And wasn't it a Mercedes engine in some team car in the 94 or 95 Indy race that won with a pushrod design?

Ron

[ June 02, 2002: Message edited by: R. Earp ]


it was a mercedes, definately somewhere from 93-95. using some very ingenious design work they made a pushrod v8 which could rev to 10000. this was still at a serious disadvantage against the sohc and dohc engines that populated indy, but the rules allowed pushrod engines to be 3.4L instead of 2.6L, and allowed the turbocharger to run at higher boost on these engines as well. power output was 1025bhp at 9700rpm.

this is all from my memory, so could be wrong
 
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Guest

Guest
Ron,
Robert needs a little help with the smog boys in australia, if the Ls1 will do the trick we can always put a ford name on the vave covers and the problem is solved. I bet it will go in there with no trouble, lets keep it quiet I dont want anyone to get upset. Its a push rod engine, and if you want more cubes use the truck motor.
 

Ron Earp

Admin
LS1's are good motors and they're small!

I took a look at one in a local street rod and the front dress design was ingenious. Don't know if it was particular to this rod, but the water pump is very small and nestles the rotor into a cavity on the block it appeared.

Still, just a shame that Ford abandoned the motors. GM managed to squeeze a LOT more life out of their series, Ford could have done the same.

Ron
 
I am not sure if you all (or y'all from the south) saw the 2003 Mustang SVT Cobra article in Car and Driver this month. They are offering a 4.6L DOHC with Eaton blower and air to water intercooler. It is 390 HP, 390 ft-lb of torque.

They went back to cast iron block for strength and thus this motor combo increased weight by ~150 lb (exact figure mentioned in article, but not in front of me now). Thus the car now has ~56.5 % front weight bias and overall weight is ~3738 lbs (WOW).

In my opinion this is way to heavy and way to front heavy, BUT the test drivers loved the power, balance, and overall handling of the car.

As the blower fits nicely in between the valve covers this could be an option for the GT40 Mk II. Would love to know the overall engine weight.

Does anyone know if the new GT40 has a cast iron or alum. block?
 
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Guest

Guest
I heard within the last year that Ford was not going to continue the modular motor. But, I have not heard the rumor again, nor what the replacement was going to be. Anyone else heard anything along these lines?

Here is a neat little piece for the 4.6 DOHC from Kinsler fuel injection:



[ June 03, 2002: Message edited by: Lynn Larsen ]
 
GM isn't playing catch up. The Northstar V8
is actually had pretty solid beginning back in 92.
Available in stock trim as 300HP/295 lbs ft
or 275HP/300 lbs ft. They've been supercharged
to 420HP.

ALso the Evoq and Imaj concept cars had
Northstars with supercahrger integrated with
the intake manifold, intercooler and rotor,
as well as variable valve timing -- 425/400!

Then there's the twin turbo LMP - 600HP and
revs to 7200.

Ian
 
Ford had a 2003 Cobra at Carlisle this weekend. This months issue of Muscle Mustangs
also ran a nice article on the car.

GOD is that motor massive! If you want to impress someone, it's certainly an impresive
sight. But for HP per dollar, the Windsor
still has it beat. I'll bet the 302 weighs less. And I'll bet with the added weight of the supercharger, it weighs more than the 351 also.

MikeDD
 
quote:Originally posted by CCX33911:
I am not sure if you all (or y'all from the south) saw the 2003 Mustang SVT Cobra article in Car and Driver this month. They are offering a 4.6L DOHC with Eaton blower and air to water intercooler. It is 390 HP, 390 ft-lb of torque.

They went back to cast iron block for strength and thus this motor combo increased weight by ~150 lb (exact figure mentioned in article, but not in front of me now). Thus the car now has ~56.5 % front weight bias and overall weight is ~3738 lbs (WOW).

In my opinion this is way to heavy and way to front heavy, BUT the test drivers loved the power, balance, and overall handling of the car.

As the blower fits nicely in between the valve covers this could be an option for the GT40 Mk II. Would love to know the overall engine weight.

Does anyone know if the new GT40 has a cast iron or alum. block?


thats a huge hunk of metal for only 390hp.
 

Ron Earp

Admin
I don't think anyone here thinks GM is playing catch up. If anyone, it appears to be Ford.

In my opinion they've not had any really interesting motors in quite sometime. During that period GM brought out the LS1 and their excellent inline DOHC six that appears in their trucks/SUVs.

Ron
 
Obviously the people in the States have the benefit of being able to experience the latest Ford & GM engines first hand and have a better feel for them so I will gladly bow to their opinions of the current engines.

However, I didn't suggest that GM are currently playing catchup. Rather that if they didn't follow the trend of mutli cam engines, then they would be playing catchup in the not too distant future given that Ford have now taken the first steps. I personaly would find it difficult to understand how a multicam engine, in concept at least, can not have far more potential than a pushrod.

Also, there was a question asked on an earlier post on this thread that I am still curious about... What is fundamentally wrong with the quad-cam 4.6 that makes it unreliable, and why can't it be rectified with aftermarket parts?
 
quote:Originally posted by Chris Liokos:
I personaly would find it difficult to understand how a multicam engine, in concept at least, can not have far more potential than a pushrod.

Also, there was a question asked on an earlier post on this thread that I am still curious about... What is fundamentally wrong with the quad-cam 4.6 that makes it unreliable, and why can't it be rectified with aftermarket parts?



To respond to your first question, and in regards to the Ford modular 4.6 in particular, its biggest limitation is bore spacing. The modular engines were originally designed for wrong-wheel drive cars, and the bore spacing was minimized for packaging reasons. This means that in order to get good power, they have to turn high revs, which causes reliability problems, or they have to have an absurd bore/stroke ration to make better displacement, which causes yet another set of reliability concerns.

Regarding specific reliability issues of the 4.6 DOHC, and what can be done to overcome them, here are a few I'm aware of:

The hydraulic chain tensioner over-extends at high rpm, and actually advances cam timing. SHM has a simple yet absurdly expensive fix for this. Interestingly, the tensioner also tensions the wrong side of the timing chain.

DOHCs are prone to oil starvation. One fix is to use seven quarts in the pan along with an Accusump; I wouldn't open track a DOHC without an Accusump. Another fix is to drill out the oil return passages in the heads because at high rpm oil can't getr out of the heads fast enough. There are also windage issues with the DOHC. Finally, anyone who has an investment in a DOHC would be well advised to upgrade the pot metal oil pump gears and the crank position senor to billet. SHM and Accufab offer these.

DOHCs are prone to oil consumption. The only solution I know of is to have the heads rebuilt and use high-quality valve guides and seals.

Ford uses cheap fasteners, in the mechanical sense, and error-prone fasteners in the human sense. The 4.6 DOHC is hand-built at Ford's Romeo plant, but I'm not sure that's such a good thing. My second DOHC developed a coolant leak, which I eventually traced to the fact that two of the head bolts were only finger tight from the factory.
My first DOHC spun the cam sprocket and grenaded the engine, and several others have experienced this exact failure. I'm not sure if the fastener was bad or if it was improperly torqued, or maybe both. Ford extensively uses crappy torque-to-yield fasteners, and I've been told that tolerances can change drastically depending on applied torque value. The solution is to use ARP fasteners throughout the engine and build it yourself.
[/list]

Regards,
Mark
 
Chris

To answer your question of pushrod vs multi-cam...

The cost of gasoline in the US has always been low compared to the rest of the world.
Therefore there was never incentive to replace large displacement pushrod engines
with smaller displacement, more efficient
designs(overhead cam, multi-valve, multi-cam, etc).

The US Government (not market pressures) has forced US car makers to make that change in
order to improve over all fuel efficiency.

However the cheapest way to make BIG horsepower remains a large displacement
pushrod motor. That's why GM still installs
them in Corvettes, and why Ford should still
be installing them in Mustangs (long story).

So if your tastes gravitate towards using
current technology, a 4.6 GT40 is neat.
But the pushrod motor is more authentic,
and will make more power at less cost.

That's why 99% of street rods in the US
are pushrod powered.

MikeDD
 
Robert, Since I did not say it in my last post, good for you for taking on this project. Let's face it, many GT40 'replica' builders (buyers) want to add their own signature to the auto, something that makes it their ideal and be their personal ideal. I can imagine that fitting the larger 4.6 was a more than a bit of a challenge. Your undertaking this shows why you and your company are one of the builders at the top. Any time consumers have more choices, they benefit. It may be also that a part of the powerplant decision ia age based. Most of us 'older' guys remember the '40 when it was in competition, and drove and even raced smallblocks in different areas of competition. Younger guys may be more shaped by the newer mustang and its OHC powerplant. Lucky for us that everyone has a choice. As for me, I have a 'soft spot' for the pushrod engine, and will slip a Gurney head engine into my '40 chassis. That is the realization of the picture I see in my mind of my '40. Kudos to Robert for expanding the envelope.

Roger D.
 
Hi all
So it seems that Ford made a mess of it's dohc v8!
So sometimes it is not assembled correctly, and some of the engineering is dodgy.
(What a shame Honda didn't build it for them...but they have an agreement to "exchange technology" with GM)
But even Mazda build some great DOHC motors- for example their 2.5l v6- so Ford did not use knowledge in their house. Or, the bean counters decided the engineering.
At least now most of the dramas are known, and can apparently be fixed.
Congratulations to Roaring Forties for taking the effort to build a DOHC RF40....all to often high quality workshops only do things one way.
 
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