what year 4.6s...

99LS1 · 06-29-2005, 07:14 PM

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 · 06-29-2005, 07:18 PM

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

TheJeanyus · 06-29-2005, 07:55 PM

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 · 06-29-2005, 08:01 PM

Quote:

Originally Posted by joker

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 · 06-29-2005, 08:05 PM

Quote:

Originally Posted by Wicked

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 · 06-29-2005, 08:14 PM

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 · 06-29-2005, 08:16 PM

Quote:

Originally Posted by QWKSNKE

If I am not mistaken, only the 5-speed machs come with a forged crank.

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 · 06-29-2005, 08:21 PM

Quote:

Originally Posted by TheJeanyus

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.

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 · 06-29-2005, 08:22 PM

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 · 06-29-2005, 08:37 PM

Quote:

Originally Posted by banditmwp

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.

06-29-2005, 07:14 PM	#1
99LS1 WWIP Saving for Evo XXI Join Date: Dec 2004 Location: You like my biodata. B-i-o-d-a-t-a! Posts: 1,693	what year 4.6s... 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. __________________ 08 cbr 1000 73 mach 1

06-29-2005, 07:18 PM	#2
joker Friends Join Date: Dec 2004 Location: Southern Colorado Posts: 2,452	Re: what year 4.6s... 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

06-29-2005, 07:55 PM	#3
TheJeanyus Administrator Join Date: Dec 2004 Location: Huntsville, AL Posts: 14,774	Re: what year 4.6s... 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. __________________ 1998 Mustang GT Coupe - World's Slowest Racecar 2005 Toyota 4Runner SR5 V8 2013 Volkswagen Jetta Sportwagen TDI

06-29-2005, 08:14 PM	#6
QWKSNKE 3v's are slow Join Date: Dec 2004 Location: Here and There Posts: 17,152	Re: what year 4.6s... 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 __________________ 2009 Porsche Carrera S 2008 ///AMG C63.. Eurocharge Tune. RIP 2019 AMG GLC43..wife's 03 F250 SD.. Edge Evo, AFE Stage 1 CAI 08 GT. JBA axle back, FRPP springs, FRPP swaybars.. daughter's 01 Cobra vert... wife's I need a new toy

06-29-2005, 08:22 PM	#9
Sendero Im gonna show her my... Join Date: Dec 2004 Location: Somewhere providing FREE tech support. Posts: 4,269	Re: what year 4.6s... 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 __________________ I heard it on the internet, so it must be true. "I believe that a person's moral compass can be determined by how he references free men the right to defend themselves." T. Nugent "An armed society is a polite society. Manners are good when one may have to back up his acts with his life." R. Heinlein "Never argue with an idiot. They drag you down to their level, then beat you with experience." -Unknown