Head differences
 

Can someone give me the short and sweet differences between:

03/04 Mach1 Heads

03/04 Cobra Heads

FR500 4.6L Heads

Re: Head differences
 

There is no difference between the Mach and Cobra heads that you listed. The FR500 heads flow better(some think the 03/04 heads flow just as good), and benifit by changing the cam's, valves, and springs.

Re: Head differences
 

I think there was an early production issue with the 03 heads (both Mach and Cobra) and this issue was fixed in later part of 03 and did not affect 04's. I am not sure if it was the guides, but it dealt with head tick. Also I have read something about 04 heads have a improved cooling, but I have no idea how.

Re: Head differences
 

I saw the same thing over on stangnet. Just trying to get some info. My next big move might be PP heads with F500 valve train or Crower S2s.

Re: Head differences
 

I believe your correct about the head ticking, my friend works for a dealer and they replaced alot of heads that way, also BP I think your correct about the cooling on the early heads, they did come out with revised one's I beleive.

BP I'm just using gt cams, upgraded springs and oversized valves for my build with pp heads. Looking back, I should have just bought the FR500 vt, because it comes with everything.............LOL

Re: Head differences
 

So our heads with F500 package. Does PP the heads help as well?

Re: Head differences
 

Don't get me lying, I only assume better flow would improve the heads a bunch, Jester has Al Papito heads with the FR 500 vt, he might be your best bet for knowledge, Birdman941 would be a good source as well.

Re: Head differences
 

Yes. PP= more airflow= more HP. Using aftermarket cams,valves and springs, PP intake, PP heads, and full exaust makes for a wicked combo.

Re: Head differences
 

5.0 Magazine did a flow test of our heads vs others back in their December '04 issue. The FR500 heads are superior to '03/'04 DOHC heads out of the box. But when ported (by the same shop @ Houston Performance), the '03/'04 DOHC heads outflowed the ported FR heads on both intake and exhaust (especially exhaust).

So to answer, our Machs and Cobras share identical heads. And when ported are the best in the business...

Re: Head differences
 

Here is the difference



02-03 mach 1 and cobra heads
this was the first run of the mach1 and cobra heads, after a million complaints about excessive noise in the valve train on the drivers side ford figured they had to do something so they revised the drivers head. When the car came on to the service drive the first thing the service writer does is run TSBs to find any open complaints and the drivers head had a TSB for noise so ford started replacing them well about 2-3 months in to this they found out that they were redoing some of the cars that had already been don’t so the change the head by having then painted with a blue strip. Now this has no reworking other than some different valve guides but in fords attempt to keep the technicians from double dipping they painted the service head blue so the service writer knows if the TSB had been done or not. This head was the first head and only has 4 spark plug threads


mid 03 to end of 03 cobra and mach 1 heads

This is the 4V head that has been painted with a blue strip to show this is what ford though would take care of the excessive noise from the valve train (little did ford know that the piston slap was the cause for this noise) way to go ford !!!
This head also possesses 4 sparkplug threads




11/15/2003- 4/2004
This was the first 9 thread head
this was the 2004 cobra and the mach 1 head for 2004 this head was completely different. This was the last revision head also known as the FR500 replacement head. This head was issued some time after 11/15/2004 I have confirmed this with every 2004 cobra and mach 1 I have ever touched (approximately 50-60 cobras and 20-30 mach1s ) this head has improved ports also the coolant passages have also been changed. The only way to tell what head you have is by the thread count in the head. 9 thread signifies you have the 2004 heads and 4 thread signifies you have the 2003 heads (while nonpainted 2003 heads notes early 2003 heads) Now there is an easy test to see what heads you have seeing as how all of the threads are at the bottom coming up you can perform a simple thread count test. Start from the tight position and count the number of turns it takes to remove the sparkplug 4-5 turns means you have 4 thread and 8-9 turns means you have the 9 thread heads. if you are buying heads keep this in mind or simply contact me to buy new heads 9 thread with the improved passages 1500 a set complete new



FR500 heads

Now these heads are a little different, the installed “FR500heads” the ones that are on the 2004 cobra and the mach are from the ford line , Ford racing has came up with there own FR500 line that uses longer valve stems, different cams and different followers as well these were only available from the ford racing catalogue. (They are some nice heads but not worth the money when you can take a set of 04 heads and port them with 1mm over size valves to achieve better results) if you get a ford racing catalogue you can buy the entire FR500 kit so that you may too change your stock heads to FR500 heads it comes with all of the followers, all of the valves, springs and cams, along with everything needed to make the swap and that goes for 1700.00- 1800.00







Now the facts

I have been in heated discussion after discussion about this. And please bear in mind I have done my home work, so much that I was able to prove LDC the cooling mod people that they were wrong when they tried to say there was no 9 thread heads ever on the 4v motor from the factory. All I tell you is do a simple thread count test that I have listed above and you too will find out that I am correct in this matter. So here are the facts all of the 4v heads built 2002-2004 are all good heads and produce good power, If you are looking to buy heads used or new the 2004 heads are worth more than the 2003 heads however I can get you new ones (2004 9 thread complete heads) for 1500.00 plus shipping. If you figure a valve job is 800.00 on the DOHC heads and if you buy a used set for 800.00 that means you just paid 1600.00 for a set of used heads when you could have had brand new ones. Just a little heads up

Re: Head differences
 

Cool,my build date is 3/31/04 I should have the 9 threads, Im gonna check that out this weekend

Re: Head differences
 

yes sir 8-9 turns FTW

Re: Head differences
 

Looky like dis...w/out the intake valve damage of course :3amin:
http://www.alienmind.com/dale/heads_teardown_003.jpg

Re: Head differences
 

Wow, Dans writeup should be a sticky for sure. I am educated now. I know I do not have the 9 thread head.

Re: Head differences
 

That means that I have one of each. Funny that my late build 2004 has had the heads replaced. We haven't driven the early build [2003] Mach yet for it to have an issue. Maybe we should start driving that one now and get it fixed. Hmm...

Re: Head differences
 

Are you saying that the "tick" is actually piston slap or is this valve train noise mention above something else? Seems to me that piston slap sounds nothing like the tick plus I can see the Cobra's experiencing a good amount of piston slap because of the forged pistons but the mach's have hypercraps which don't tend to slap. Just wondering

Re: Head differences
 

The ticking sound was coming from the valve guides.

Jerome

Re: Head differences
 

Agreed, most people's ticks can be isolated to valve train noise, and then it's further isolated to a worn valve guide, which is why Ford replaced entire heads( cheaper than tearing down a head and pressing in new guides i suppose)

Re: Head differences
 

good info! im glad i got the improved heads

Re: Head differences
 

My build date was 11/03 But the Car is an 04 and I have the 9 thread heads.:3amin:Thanks for info Dan!

Re: Head differences
 

So if machs were built in early 03, like in January, would they still have the head tick issue? My mach has a blue stripe on the head, so was curious.

Re: Head differences
 

Production date on my 2004 is 2/04 on the drivers jam sticker, So maybe I got the better heads? It's got 40,000 and some change on her I'll check the thread count soon when I change the plugs.

Re: Head differences
 

Blue stripe heads fixed the cooling issue, not necessarily the ticking issue.

Re: Head differences
 

So are the 03-04 cobra/mach heads the only ones from Ford that have had the ticking issue or the overheating issues?

Re: Head differences
 

I think the 99-01 heads also had the same cooling issues on #7 and #8

Re: Head differences
 

i was under the impression only the 05 aviator 4.6 had the better 7/8 cooling passages.

Re: Head differences
 

There was never a head tick issue. Originally it was though to be a lifter tick and they had came up with the head fix by replacing the head however the actual noise is a result of collapse piston skirts on the piston its self. Due to excessive piston to wall clearance. The cylinder is actual cone shaped and the largest being at the top when the piston comes to the top of the cylinder the piston starts to rock back and forth when the cylinder fires rattling all the way down the cylinder.


Also the aviator head is different from the 03-04 head just for the record. And the fact that they were the only coolant improved head was a miss conception as well. As was the rumor of no production heads came with 9 thread

Re: Head differences
 

Aviator cylinder head part numbers cross reference with Cobra, Mach, and Marauder heads. They are all they same, rather they all benefitted from the same upgrades and refits at the same times.

Re: Head differences
 

So given all this then need some discussion concerning the cooling and the cooling mods that help flow coolant at #7 & #8. Is this still an issue? I did the LFP cooling mod so mute point for me.

Re: Head differences
 

Well I have a 2004 and have not and will not ever use a cooling head modification. I have not seen the need for that modification yet. However it cant hurt to be safe

Re: Head differences
 

OK, I'm probably beating a dead horse here, but I have heard repeatedly that the 7/8 cooling issue caused valve guide galling and subsequently a ticking valve sound.

So, this is not the case then?

That would mean if one doesn't already have "the tick", they will likely never experience it at all, since piston slap tends to be a tolerance issue from day 1?

Re: Head differences
 

if a skirt collapse you will hear it as a tick

Re: Head differences
 

soo..people took their cars to ford with a "ticking" sound and ford replaced everyones heads. if it was a piston, it would still tick afterwards. seems like a lot of people would have said something about this by now.

Re: Head differences
 

uhm I worked for for as a master tech for over 9 years and yes that is what WE did because that is what ford wanted to do!!!!!! you would be suprized how much money they saved because a lot of the car fell out of warranty or blew up

Re: Head differences
 

Thanks for the info. Still not fully comprehending though.

Haven't the vast majority of these cases been isolated to the rear driver's side area (7&8)? Wouldn't that still suggest a (cooling?) problem in this area?

Also, it is my understanding that cylinders are honed straight, but that pistons are somewhat cone shaped (larger at the top) to accommodate heat expansion. Is this not the case?

Has this been affecting all pistons/cylinders?

Re: Head differences
 

really? cuz there are a few hundred Cobra owners on SVTp that had their head replaced and have had no problems since.....

Re: Head differences
 

I don't understand how a head replacement (which cures the tick) stops a piston rattle problem. It seems to me if it were the pistons, then there would still be a tick even after the heads were replaced.

Re: Head differences
 

I have March 03 built car. So I'm assumming I have the original 4 thread spark plug hole heads. I don't see any blue paint either head. Is the blue stripe obvious or is it hidden under the valve covers? Just one more thing to worry about as I prepare to put the car on the open track.

Re: Head differences
 

You can't see it from above the engine bay. You have to jack up the car and look from underneath. Its right above the exhaust manifold.
http://i133.photobucket.com/albums/q...1/fa5fc9c9.jpg

I borrowed this image from EPIKMACH, sorry I just needed a quick pic. Credit for the pic goes to him!

Re: Head differences
 

Blue Blurr32V thanks for the info. The next time I crawl under my car I'll take a look.


Mark

Re: Head differences
 

Yea ok I guess adding more cylinder pressure would not stabilize the piston either …. What ever

Re: Head differences
 

I do not claim to be correct and I am sure most people are not as knowledgeable as you appear to be on this subject, so with out adding more negative coments to your post, can you please dumb this down for me and explain this a little further? You mention that that Ford increased cylinder pressure to stop the piston clatter, how? Did Ford change the chamber size? I am not trying to be a smart ***, I just would like to know how things work.

Re: Head differences
 

I was able to stop the ticking by simply replacing the stock guides with bronze ones.

Jerome

Re: Head differences
 

Look not trying to sound like an Richard but here are the facts!!!!!!

This is wrong!!!! Just to state the obvious here when you removed your heads and had bronze guides installed the machine shop also did a valve job to insure that the valve sealed after the new guides, when they tore in to the heads the also milled the bottom ( also known as the deck surface) in order to make it smooth enough for a MLS gasket to reseal when you mill a head you are making more cylinder pressured because the combustion part of the head is closer to the piston thus means less square area in turn adds more pressure to the piston thus stabilizing the piston to one side or the other (it Dampens to noise). The noise is actually still there it is just that you cant hear it due to added pressure. On a cobra it gets real bad because of the cylinder pressure they have due to the supercharger that is why it is more prone when idle and not under high boost. there is already enormous pressure on top of the piston so the clearance on a forced induction would have to be enormous for you to hear when the car is pullied and under pressure. That is why you hear it loudly when at idle due to less pressure

Re: Head differences
 

What you are saying makes sense. However, when the guides were changed, a valve job was done, the deck was milled, and the chambers were tampered with. The static presure remained roughly the same at about 190psi.

It would be interesting to do an experiment by simply changing the guides and seeing what that does.

Jerome

Re: Head differences
 

:crazy:

Re: Head differences
 

So I just went downstairs and double checked and my 03 Mach heads have this same blue paint. So this means its a ford fixed head (different valve guides) and still 4 thread spark plug holes right.

Re: Head differences
 

Wondering this 2, my mach has a built date of 11/02.. but has the blue paint does this mean ford fixed the ticking noise on it and do i have the 4 thread or 9 thread spark plug holes?

Re: Head differences
 

According to Dan it means the heads have replacement guides and are 4 thread.

Re: Head differences
 

mine has april 03 build date,and blue on driverside head only.i have 30,000 klms on it and have no tick or cooling problems so am i just lucky/ or is problem yet to come