Ford 4.6 liter in a GT40

Bill Bayard · 09-09-03, 07:26 PM

Some have asked whether a 4.6L will fit in a GT40.
Here's a DRB with a 4.6L engine installed.
The primary tubes look like they'll be a bit close to the rear clip. [img]/ubbthreads/images/graemlins/shocked.gif[/img]

Bigend · 09-09-03, 07:52 PM

Wizard bit of plumbing!

Clayton · 09-10-03, 02:08 AM

Heres a few more of the plumbing
regards

Clayton

Clayton · 09-10-03, 02:12 AM

And here

Mark Worthington · 09-10-03, 09:38 AM

I bet it sounds great.

Just hope the owner doesn't suffer from windage/oiling problems, exploding cam sprockets, chain over-tensioning, or any other afflictions of the DOHC 4.6.

Lynn · 09-11-03, 06:37 PM

Clayton, I tried to send you an email at the ozmail.com.au address and it bounced back. Email me, if you'd like, and I will reply to it.

thanks,
Lynn

Clayton · 09-11-03, 09:16 PM

Lynn
You have mail.
regards

Clayton

Craig · 09-23-03, 03:01 AM

[ QUOTE ]
I bet it sounds great.

Just hope the owner doesn't suffer from windage/oiling problems, exploding cam sprockets, chain over-tensioning, or any other afflictions of the DOHC 4.6.

[/ QUOTE ]

Mark - this car has the single OHC 4.6, not the DOHC. Wow - I didn't realise the Cobra motors had such problems!!! Are they going back under warranty, or is this happening after the warranty has expired?

Rick Muck- Mark IV · 09-23-03, 09:03 AM

Is that the power steering reservoir I see in the picture?

Does this car have PS or is the pump used for some other purpose?

Inquiring (OK, simple) minds want to know!

Rick [img]/ubbthreads/images/graemlins/confused.gif[/img]

Mark Worthington · 09-23-03, 10:46 PM

[ QUOTE ]
Mark - this car has the single OHC 4.6, not the DOHC. Wow - I didn't realise the Cobra motors had such problems!!! Are they going back under warranty, or is this happening after the warranty has expired?

[/ QUOTE ]

Doh...I should've noticed that the valve covers looked too small for that engine to be a 32 valve. Many have gone back under warranty, many have been within the warranty period but were denied warranty coverage, and others have had problems after the warranty expired. Mine threw a cam sprocket at 15,000 miles, and I know of at least five other people who experienced the same exact problem. I think the 4.6 DOHC is a good engine (although it's dimensionally huge and heavy for its displacement) for a stock vehicle, and the 03s are stronger than the 01s which are stronger than the 99s (Ford skipped Cobra production in 00 and 02...guess why?)

Craig · 09-24-03, 08:34 PM

Does the DOHC bend valves when the sprocket fails? That could be an expensive little exercise....

ChrisL · 10-02-03, 09:29 AM

Hard as I tried, I couldn't get the Ford Performance Vehicles development engineer to admit that there was anything fundamentally wrong with the quad-cam 5.4ltr Boss engine (other than its weight). This version of the modular engine is used in the Australian-built Ford Falcon GT and develops 290kw (400+hp) and 520 Newton-Meters of torque. He insisted that it was well within its design limits at 6000rpm and could probably run all day at that. Admittedly, he has a vested interest in supporting the engine and I would normally have dismissed it and left it at that... except that this particular engineer is a friend and I ask the question as a friend.

I know that this is a very untechnical support of the engine and just my say-so, but Ford Australia has an awful lot of its credibility riding on the success of this engine. If it falls on its face, then so probably will the Australian market for an Australian Built Ford.

Ford Falcon GT

Gary Gibbs · 10-02-03, 11:29 AM

The funny thing is that if you are limiting the RPM (for other reasons like long stroke and bad bore to stroke ratio) to 6000 then why have the weight and size of overhead cams (lightweight valvetrain). You can make a cast iron block stroker 351 with 600 HP on pump gas (93 Octane) with a hyd. roller cam. It is good to 6300 - 6500 RPMs, is much smaller and lighter (at 465 lbs). With Alum block it would weigh ~365 lbs.

Chris,
Ask your friend the total weight of the 5.4L engine ready to drop in. I have wondered this, but have no data. I suspect ~600 lbs.

Thanks
Gary

Ron Earp · 10-02-03, 11:59 AM

That has been one of my beefs too Gary. Why have a DOHC design and limit RPM to a low level? I like the blown 4.6 in the Cobra, it seems to be damn strong under high boost, but revving it ain't. And they are heavy, you can search the forum and find some neat comparions in size and weight. If I recall an aluminum headed 385 (460inches and up) block was about the same weight and slightly smaller.

R

ChrisL · 10-03-03, 12:01 PM

I've shot off an email to my friend with regards to the weight and I'll let you all know when I know.

Ford Australia was forced to dump the 302W in favour of the modular on the grounds of emissions requirements, so the replacement choices were the single-cam or the quad-cam modular. Given those two choices, the quad-cam would always come up on top. As I understand it, quad-cam does not mean rev advantage, it means flow advantage, which usually allows itself to be used with high revs. But if the high revs can’t be met for other reasons, that does not mean that the flow advantage can’t be used in other ways. In this case the advantage was lots of (environmentaly) clean horsepower, something they could never achieve with the 302W. Fundamentally, the 302W was a very dirty engine and that is why it suffered in the horsepower stakes in modern production cars.

Steve Toner · 10-04-03, 01:03 PM

[ QUOTE ]
Fundamentally, the 302W was a very dirty engine

[/ QUOTE ]

Is this just a statement that pushrod engines are less efficient than OHC, or is there something else going on here? I'm sure a lot of the decision was driven from corporate HQ in the US (or does Australia have its own casting facilities?), and these were probably driven more by cost considerations (and the way Ford measures internal "efficiency" of their product groups) and US gummint-mandated Corporate Average Fuel Economy (CAFE) requirements than emissions requirements.

ChrisL · 10-05-03, 08:55 AM

Steve,

The comment about the "dirty 302" was not a general comment about pushrod engines. I've read several articles where Ford Australia had been struggling to match the horsepower of its main rival (GMH Commodore using the Chev Gen II and Gen III engine - also a pushrod engine) using the 302W, solely because they couldn’t meet the emissions requirements with it (according to Australian laws). This wasn't due to the engine being incapable of producing the sort of power needed, but that it came at a cost of legally unacceptable emission levels. Now new more stringent emissions standards are about to be introduced, I understand that the 302W would not pass in any state of tune.

Incidentally, on the race track in our Ford verses GM category where emission levels are not a concern, the general understanding has been that the 302 is capable of producing slightly more horsepower than the Chev.

Just for the record, my opinion is that the 302W is probably the best engine that Ford have produced so far, but I don’t have to worry about the new emissions laws (yet).

Steve Toner · 10-05-03, 12:09 PM

So is it a matter of head design then? Seems like the bottom end is just pistons & cylinders, and I can't imagine that something like the bore/stroke ratio has a significant impact on emissions (or does it?).

Ron Earp · 10-05-03, 12:10 PM

I'm not sure I buy the line "cannot meet emissions requirements". I would buy the line "we don't want to invest the time and $$ to meet emissions requirements".

There is no fundamental difference between the GM and Ford pushrod engines. GM has just invested the time and money into designing heads that can meet emissions requirements along with redesigning the latest generation SB GM cooling systems. Add modern OBDII engine controls and they've got it covered.

I would think that if Ford wanted to completely redesign the heads etc. they could do it too. But I don't think the rotating assembly is not responsable for meeting or not meeting emissions requirements. Both engines are basically the same in this respect.

R

ChrisL · 10-06-03, 10:34 AM

Steve and Ron,
Very good point. You’re probably correct in saying that it’s primarily a financial consideration. I suppose that creating totally new heads, or for that matter redesigning existing heads, just to meet local requirements is simply not financially viable. Especially for an engine that sells in limited numbers and has a limited life expectancy. Development was probably limited to cams, induction and exhaust. The last Windsor engines on the production lines had off-the-shelf heads - GT40Ys I think.

PS. Got a response with regards to the weight of the 5.4. The word was "VERY HEAVY" [img]/ubbthreads/images/graemlins/laugh.gif[/img] He's getting back to me with the exact figure.