what year 4.6s...

[99LS1]

are better for running boost, sc or turbo? I thought a good tech thread would be a breakdown of the various years 4.6 engines and why some are better starting platforms for sc or turbo.

[joker]

03-04 cobra eninges or coarse, because they come with forged goodies. Aside from that I would say the newer mach 5 speeds or 99+ cobras, because they have high flowing heads and a a forged crank. Next I would say 99+ gt's because the heads and intake out flow the 96-98. 96-98 would ahve to come last because, well basically the heads, intake, and cams suck.

dont know about 05's because I havent heard alot about them, but they make good stock power :shrug:

[TheJeanyus]

Obviously any of the 4Vs should respond better to boost. The '03 Cobra motor is a great longblock, but unless someone gives you one or you steal one from a warehouse, there are better alternatives for what it costs.

I think a '99/'01 aluminum block with '03/'04 heads, aftermarket cams or '03/'04 cams, forged internals, and a '99/'01 intake would make a great forced induction motor. But if we're talking about stock motors, I'd say either an '01 Cobra or '03/'04 Mach 1 motor would be the best bet.

As for 2Vs, I've heard a ported set of '96-'98 heads will actually outflow a set of ported PI heads. I'd replace the intake on either motor just because that plastic intake makes me nervous. The PI motor has much better cams though.

I think the 3V is going to be a great forced induction motor. Supposed to make torque like a 2V on the low end and scream on the top end like a 4V, and I would think that would only multiply once you add boost.

[Wicked]

Aside from that I would say the newer mach 5 speeds...

Actually, I have heard of some early failures of S/C and turboed Mach 1 motors.

I am not sure on the actual internal differences say to the 99/01 Cobras.

Obviously the crank and block are good to nearly 1000hp on Cobras. The rods and pistons are the weak point on 99/01 Cobras as well as all 2V's.

[TheJeanyus]

Actually, I have heard of some early failures of S/C and turboed Mach 1 motors.

I am not sure on the actual internal differences say to the 99/01 Cobras.

Obviously the crank and block are good to nearly 1000hp on Cobras. The rods and pistons are the weak point on 99/01 Cobras as well as all 2V's.
I'm pretty sure the Mach 1 has a higher compression ratio. Might be a downfall if you planned to run much boost.

[QWKSNKE]

If I am not mistaken, only the 5-speed machs come with a forged crank. Don't know of any other structural differences between them and the 99-01 cobra shortblock

[TheJeanyus]

If I am not mistaken, only the 5-speed machs come with a forged crank.
:yup: There isn't a flexplate to bolt up to the Cobra crank, so the autos come with a GT crank. That's why the 5 spd cars have a 6800 rpm redline while the autos are closer to 5800. In all the comparisons I've seen, the 5 spds ran about .5 sec faster in the quarter.

[banditmwp]

As for 2Vs, I've heard a ported set of '96-'98 heads will actually outflow a set of ported PI heads. I'd replace the intake on either motor just because that plastic intake makes me nervous. The PI motor has much better cams though.



:yup:

Also I have heard a set of PI heads/cams on a 96-98 block will have signifcantly higher compression than a PI longblock.

[Sendero]

03-04 Cobras: Excellent
99-01 Cobras: OK. Rods and Pistons are the weak link. Windsor blocks used in some of the Cobras are a little weak.
96-98 Cobras: OK. Rods and Pistons are the weak link. Heads love Turbos or Centrifiguals.
Mach 1: See 99-01 Cobra except for Auto's

[TheJeanyus]

:yup:

Also I have heard a set of PI heads/cams on a 96-98 block will have signifcantly higher compression than a PI longblock.
The pre-PI pistons aren't dished as much, so coupled with the smaller combustion chambers of the PI heads, you get a higher compression ratio.

[coupe]

Did a '99 GT come with an automatic? If so; then there's a flexplate for 8-bolt cranks. '99 GT's had a "Windsor" 8-bolt crank. Not to be confused with a Cobra crank though...just the GT crank w/ 8-bolt in '99. I cannot think the Mach w/ an automatic would have a different crank than a 5-speed. It's a Cobra engine isn't it?! :shrug:

I remember when the 96 GT 4.6 came out: weaker than the 5.0, but more responsive to a Vortech. Any mod-motor is a good platform for unnatural-aspiration...just be judicious with boost pressure. And watch out for lean condition on the jug...that's the killer on pistons.

[TheJeanyus]

Did a '99 GT come with an automatic? If so; then there's a flexplate for 8-bolt cranks. '99 GT's had a "Windsor" 8-bolt crank. Not to be confused with a Cobra crank though...just the GT crank w/ 8-bolt in '99. I cannot think the Mach w/ an automatic would have a different crank than a 5-speed.
I'm just telling you what I've read - and I've read it in quite a few different places.

It's a Cobra engine isn't it?! :shrug:
No. The heads, cams, and intake are all unique to the Mach 1.

[Italian LX]

I cannot think the Mach w/ an automatic would have a different crank than a 5-speed. It's a Cobra engine isn't it?! :shrug:
Think what you like... but it's true; the automatic Machs have a 6-bolt cast crank.

[coupe]

Good Grief!!! I read about it. What a disaster. :shake:
And it's got a 99 Cobra intake, 5.4L truck intake cams, and one-off exhaust cams.

[QWKSNKE]

Did a '99 GT come with an automatic? If so; then there's a flexplate for 8-bolt cranks. '99 GT's had a "Windsor" 8-bolt crank. Not to be confused with a Cobra crank though...just the GT crank w/ 8-bolt in '99. I cannot think the Mach w/ an automatic would have a different crank than a 5-speed. It's a Cobra engine isn't it?! :shrug:



I would be willing to bet that the 'windsors' were not automatic

[joker]

Yep, the mach autos had a cast crank. I didnt know about the compression ratio being higher.

I have heard of early failures in supercharged gt's as well. Comes down to the tune really.

[EZ SPEED]

Yep, the mach autos had a cast crank. I didnt know about the compression ratio being higher.

I have heard of early failures in supercharged gt's as well. Comes down to the tune really.

True about the cranks and the compression. ;)

[Evil_Capri]

Most people running superchargers on Mach's seem to be fine running a good tune and anything under 9-10psi. From the research I've done on M1R, and some other sites.

[Sendero]

No. The heads, cams, and intake are all unique to the Mach 1.

Huh?

Heads are the rectangular style DOHC's (like the Navi's), Intake is the 99-01 Cobra piece, Cams are Navigator intake and 99-01 Exhaust.

[Italian LX]

No. The heads, cams, and intake are all unique to the Mach 1.
And it's got a 99 Cobra intake, 5.4L truck intake cams, and one-off exhaust cams.
Heads are the rectangular style DOHC's (like the Navi's), Intake is the 99-01 Cobra piece, Cams are Navigator intake and 99-01 Exhaust.
:confused:

Let's see if we can get a few more guesses in here... sooner or later someone's bound to get it right. :rolleyes:


:jester:

[Scothew]

My 00 GT motor was a windsor motor and was an automatic and to the best of my knowledge was a 8bolt crank.

[Sendero]

:confused:

Let's see if we can get a few more guesses in here... sooner or later someone's bound to get it right. :rolleyes:


:jester:

Mine and Matt's answers match with about 90% accuracy. :popcorn:

[Scothew]

I agree with Nathan on the mach1 components.

[EZ SPEED]

I agree with Nathan on the mach1 components.


Yes, Nathan is correct.

[TheJeanyus]

I read they were unique in MM&FF. :shrug:

[Wicked]

99-01 Cobras: OK. Rods and Pistons are the weak link. Windsor blocks used in some of the Cobras are a little weak.


...if you call 800+ hp a "little weak". That's what I've heard they were good for. Sean Hyland reports using them for 600hp engines.

It is referred to as a WAP(Windsor Auto Plant?) block and most 01's have them. The 99 and some early 01's have the Teksid block which was cast in Italy I think and is good for more HP. The teksid block is supposedly good to well over 1000hp.

[banditmwp]

:confused:

Let's see if we can get a few more guesses in here... sooner or later someone's bound to get it right. :rolleyes:


:jester:

Heads are leftovers from the days of 4.9L I-6 engines, custom cut and ground to fit the 4.6. Cams come from 2.3 Tempo/Topaz engines, and the intake is from the Cobra R.


:jester:

[TheJeanyus]

Heads are leftovers from the days of 4.9L I-6 engines, custom cut and ground to fit the 4.6. Cams come from 2.3 Tempo/Topaz engines, and the intake is from the Cobra R.


:jester:
That's a '95 Cobra R, retro-fitted to a 4.6L. :jester:

[Sendero]

...if you call 800+ hp a "little weak". That's what I've heard they were good for. Sean Hyland reports using them for 600hp engines.


The powdered metal rods and hyperpathetic pistons can make 800+ HP, but the first time you rattle them, BOOM! Ringland failures are the most common issues. Its not what they can make, its how long they can make it.


It is referred to as a WAP(Windsor Auto Plant?) block and most 01's have them. The 99 and some early 01's have the Teksid block which was cast in Italy I think and is good for more HP. The teksid block is supposedly good to well over 1000hp.

:yup: Teksid block was cast in Italy. All 99, 00, and the early 01's recieved the block. The blocks have been used to well over 1200 HP without any issues.

[joker]

Hum that is cool. I have done work for Teksid. They cast blocks, heads, and intakes here in Alabama.