GMAN
Dedicated LVC Member
What is the difference between the two. I know one is single and one is double, but that is all that I know. I was watching Motorweek this morning, and they were showcasing the Roush Stage 3 Mustang. A 4.6L SOHC.
Sohc Vs Dohc
- Thread starter GMAN
- Start date
I thought the mustangs were all DOHC's?
2004:http://www.internetautoguide.com/car-specifications/09-int/2004/ford/mustang/index.html
2001:http://www.internetautoguide.com/car-specifications/09-int/2001/ford/mustang/index.html
2006:http://www.moddedmustangs.com/2006-ford-mustang-review-and-specs.html
What year are we talking about? the 2006 is the only one I saw with SOHC's surprisingly
2004:http://www.internetautoguide.com/car-specifications/09-int/2004/ford/mustang/index.html
2001:http://www.internetautoguide.com/car-specifications/09-int/2001/ford/mustang/index.html
2006:http://www.moddedmustangs.com/2006-ford-mustang-review-and-specs.html
What year are we talking about? the 2006 is the only one I saw with SOHC's surprisingly
GMAN
Dedicated LVC Member
Dern Humpus
Dedicated LVC Member
More valves let air flow easier. We have 4 valves per cylinder, SOHC's have 2.
1993_M75
Active LVC Member
KainDTE said:
No, only the Cobra & the Mach 1 were ever DOHC, the GT is SOHC.
MediumD
Dedicated LVC Member
KainDTE said:
All 96+ Mustang COBRAs are 4 valve per cyl DOHC (the Mach 1 as well.) 96-04 Mustang GTs were 2 valve per cyl SOHC. 95 and earlier are pushrod/OHV. The 05+ GTs are 3 valve/cyl SOHC.
GMAN
Dedicated LVC Member
So which is better?
94m5
Dmaup's Daddy
I hear the 3V heads flow really well. But give me the terminator heads anyday.
04SSHD
Dedicated LVC Member
both my 99 Crown Victoria Police Interceptor and my 96 Mustang GT had the 4.6 SOHC. Not a bad motor but not very fast.
formerknown
Dedicated LVC Member
GMAN said:
The DOHC. No contest.
I'll compare 1999 SOHC and 1999 DOHC differences off the top of my head:
Block: 2V are iron, 4V are aluminum (Some 99-01 blocks were leftover Teksid- most are the newer, lighter Windsor Aluminum Plant [WAP blocks]). Lincoln Continental got its own FWD aluminum block.
Heads: Both aluminum, 2V get 16 valves, 4V gets 32 valves.
Intake: 2V got a plastic intake (that usually cracks) and the 4v gets an all-aluminum intake.
Internals: 2V gets cast pistons (except 99' Lightning), 4V gets hypereutectic pistons. 2V gets cast standard rods, 4V gets special I-beam powdercoated rods (that typically suck). The 2V gets cast crank while the 4V gets a forged crank.
Compression: 2V heads have a 42cc combustion chamber that yield about 9.2:1 compression with the stock pistons (3cc dish IIRC). The 4V heads have a about a 52cc combustion chamber that yield a 9.85:1 compression with its stock pistons.
04SSHD
Dedicated LVC Member
evillally said:
oh god, bad memories with this one. My plastic intake cracked on my 96 GT and was leaking coolant into the #2 cylinder. That damn intake is expensive and hard to change.
turborich
Dedicated LVC Member
The owner of silver state motorsports here in las vegas is a ford enthusiest for sure! He fabs up custom turbo set-ups for lightnings and stangs. He told me that the 2 valve engines actully have the potential to make much more horse power than the 4 valve when it comes time to build a race engine. I love my 4 valve and all but the 2 valve engines do have many more parts availible for them.
formerknown
Dedicated LVC Member
04SSHD said:
My crack wasn't too bad. It was a hairline crack on the thermostat housing cup. The leak wasn't bad and only happened after heat up. I slowed the leak with some high-temp silicone sealer. I replaced it myself with a kit from Ford for about $300 and three hours. My car was relatively new at the time, so the bolts and nuts came off with ease...
rmac694203
Dedicated LVC Member
I'm no car genius, but the thought of a plastic intake just sounds like a really bad idea to me. You would think that the engineers would have at least thought of this... Well, I'm sure they did. They probably just figured the savings from making it out of plastic would outweigh the cost of having to fix the problems associated with it. Kinda like in Fight Club.
formerknown
Dedicated LVC Member
rmac694203 said:
It's debateable. On one hand you're correct: plastic is cheaper to make in vast quantities. But it also has advantages; such as lower weight and lower heat transfer properties than metal- thus improving performance, economy, etc. And of course, it also has it's drawbacks. Plastic can crack; it has a lower melt temperature than some metals; durability is questionable if you abuse it.
So it's pretty much another one of those "damned-if-you do..." things.
rmac694203
Dedicated LVC Member
You're probably right. But how much do weight and heat transfer affect a normal everyday driver? It seems that they were more concerned about cost than actual gains from using plastic.
formerknown
Dedicated LVC Member
rmac694203 said:
You're right; cost is a factor. And when it comes to the whole weight and heat transfer thing- it does make a difference. Every little bit counts...
rmac694203
Dedicated LVC Member
Yeah. I guess that's why they decided to use a fiberglass hood on what is an otherwise boat of a car. Every little bit counts.
MediumD
Dedicated LVC Member
evillally said:
Our Mark VIII 4Vs don't get a forged crank do they? At least we have the teksid block.
formerknown
Dedicated LVC Member
MediumD said:
Nope, no forged crank for the Mark. They get the same "standard" cast crank as the automatic 6-bolt 2V. The 8-bolt forged crank pretty much only appears in 4V Cobras- at least in stock form, anyways...
I should also add that SVT Cobra engines are hand-built and blueprinted on the Romeo, MI Niche line by two-man teams. You can see their names stamped onto the valve cover decals. All other 2V and 4V engines are assembled via machine assembly lines in Romeo or Windsor. Their origin can be traced via VIN number...
chicken
SHEOOOOOOOOT
amd the worst part of the plastic intake is when runnin nitrous it can pool in the lower half of the intake and blow the lower half off (check tccoa, nothin but probs)
vr4
Dedicated LVC Member
Dr. Paul said:OHV.
You only need one cam to make power!!
not making much power on that stock 302 block.
i cant understand how a cracked plastic intake got coolant in a cyl. the plastic coolant runner is seperate from any intake runners and EVERY time ive seen 1 cracked it was along the front between the banks.
powdered metal rods not powdercoated
A 2V race engine has more potential than a 4V? The fastest 4V makes close to 2000hp and runs in the mid 6's in the 1/4 mile... no way a 2V 4.6 can come close to that. All though the new 3V SOHC engines are very good that's why the new Navi's have the 3V 5.4 instead of the 4V, they perform equally as good as stock power levels.
MonsterMark
Dedicated LVC Member
MediumD said:
Nope, we are blessed with the lighter weight 'cast' crank. Forged cranks usually feature polished journals, knife-edged counter-balancers, and cross drilled/chamfered oilers. All good reasons to get a forged crank no doubt.
However, I have yet to see a cast crank fail. The lighter weight, if properly balanced, will rev alot faster than the forged steel crank. You are talking around 50 lbs for the forged vs 30 lbs for the cast, rough numbers.
As far as the comment about the 2V heads making more power, I had to laugh. The better the flow, the more power you will make, NA or forced. Period. You have more flow, you make more power.
Here are some numbers comparing the INTAKE AIR-FLOW of the 2V heads, '96 and '01 years vs the 4V heads... imho the Mark 'B' heads are the best heads and the heads everyone seem to adore, the '93 terminator heads.
................2V Heads.....4V Heads
Model.......'96...'01........'B'...'Term'
Lift .100.....46....54.......79......88
Lift .200.....85....98.....144.....151
Lift .300...121..135......207....201
Lift .400...147..156......217....221
Lift .500...170..166......231....233
Hope these FACTS help.