03-04 heads on a 99 cobra? Price?

[Westcoast]

Thinking of installing 03 heads on my 99 cobra with a 2.1 kb. Just curious if they will bolt up to the kb intake, and if so are they worth upgrading to over my 99 heads? Their is a set available local to me with only 12k on them for $550.00 seems like a reasonable deal?. Thanks for any suggestions

 

[01yellercobra]

If you were planning on pulling the motor for any reason, I'd say go for it. But if you're doing it just to do it, I wouldn't bother.

 

[99riocobra]

i agree, there's no real reason to do this unless you're already planning on building another motor...or maybe if they're the revised heads that have the 9 spark plug threads. to answer your question though, the 99/01 and 03/04 heads all have the same intake ports so any intake will bolt to either set of heads.

 

[Westcoast]

Thanks for info! I forgot to state that the short block in the car presently is an aluminator with 30k on it, and the drivers side head has excessive leak down thru the exhaust(valves). And yes I plan on adding more boost. I can also purchase a set of crowler stage 2 cams with springs from the same seller, so Im thinking i will pick everything up.

 

[quikcobra]

Yes everything will bolt up, And that is pretty cheap. I say go for it. 4 hrs of fun get rid of your problem and with the cams gain another 50 hp. Make sure you dial them in.

 

[01yellercobra]

Thanks for info! I forgot to state that the short block in the car presently is an aluminator with 30k on it, and the drivers side head has excessive leak down thru the exhaust(valves). And yes I plan on adding more boost. I can also purchase a set of crowler stage 2 cams with springs from the same seller, so Im thinking i will pick everything up.

In that case I say go for it.

 

[SlowSVT]

i agree, there's no real reason to do this unless you're already planning on building another motor...or maybe if they're the revised heads that have the 9 spark plug threads. to answer your question though, the 99/01 and 03/04 heads all have the same intake ports so any intake will bolt to either set of heads.

Nick

The shape of the ports on 03/04 heads are different and flow more then the 4V tumble port heads used on the 99-01 Cobra's. The late 04 heads also have the 9 thread spark plug holes. The 05 update heads have a revised water jacket to address the overheated exhaust valve issue and are about $2500 a pair from Tousley complete with valve gear and the same cams used on the Terminator which are pretty good.

I understand what you were getting at that they will physically bolt on the 99/01 intake but I just thought I would elaborate.

Russ

 

[Westcoast]

This site is great I'm glad I've joined, awesome info, thanks again guys. I will be doing the job in the new year. Any tips on motor removal? It looks like dropping the k-frame with the engine and trans attached is the way most do it?

 

[SlowSVT]

This site is great I'm glad I've joined, awesome info, thanks again guys. I will be doing the job in the new year. Any tips on motor removal? It looks like dropping the k-frame with the engine and trans attached is the way most do it?

yea, A 6' breaker bar with a 6 point impact socket on the harmonic balancer bolt BEFORE you remove the engine, "in" 6th gear, parking brake set wit wheel chocks. If I recall my 1/2" impact driver wouldn't even "faze" the thing :cuss:

Don't remember if it's a right hand thread or not :??:

 

[01yellercobra]

yea, A 6' breaker bar with a 6 point impact socket on the harmonic balancer bolt BEFORE you remove the engine, "in" 6th gear, parking brake set wit wheel chocks. If I recall my 1/2" impact driver wouldn't even "faze" the thing :cuss:

Don't remember if it's a right hand thread or not :??:

Your's must have been really bad. My impact made short work of the original bolt. It's a right hand thread.

 

[SlowSVT]

Your's must have been really bad. My impact made short work of the original bolt.

That's putting it mildly.

It brought the Ingersoll Rand on 125 psi to its knees :nonono:

This was on a Terminator engine but I don't think that matters. Torque to 250 ft. bs. if I remember correctly.

 

[na svt]

The shape of the ports on 03/04 heads are different and flow more then the 4V tumble port heads used on the 99-01 Cobra's.

Terminator which are pretty good.

There is no difference in shape of the intake ports on the 03/04s and the 99/01s. The exhaust ports are are different but any header will work.

Terminator intake cams are terrible, use the 99/01s (16 degrees more duration).

 

[SlowSVT]

There is no difference in shape of the intake ports on the 03/04s and the 99/01s. The exhaust ports are are different but any header will work.

Terminator intake cams are terrible, use the 99/01s (16 degrees more duration).

:nono:

NOT TRUE!

The Terminator heads are different then the 99/01. No, the ports are not the same.

No one said the Terminator cams should be used in an NA Cobra. The Terminator cams are very good right out of the box........for a blown application which is what the PO is looking to do. An NA engine needs more duration and overlap so in that respect you are correct.

 

[na svt]

:nono:

NOT TRUE!

The Terminator heads are different then the 99/01. No, the ports are not the same.

No one said the Terminator cams should be used in an NA Cobra. The Terminator cams are very good right out of the box........for a blown application which is what the PO is looking to do. An NA engine needs more duration and overlap so in that respect you are correct.

Please get your facts correct before you post any more info. The 03/04 heads have a better short turn radius but the but they use the same intake gaskets and the same manifolds. I know, I port the damn things.

Also, the early cobra cams will work better than the 03/04s for FI and n/a. I've done the cams swaps on both centri and 03/04 combos and the early cams make more power. As for the overlap, there is none on either set because their durations are so low.

 

[SlowSVT]

Please get your facts correct before you post any more info. The 03/04 heads have a better short turn radius but the but they use the same intake gaskets and the same manifolds. I know, I port the damn things.

Also, the early cobra cams will work better than the 03/04s for FI and n/a. I've done the cams swaps on both centri and 03/04 combos and the early cams make more power. As for the overlap, there is none on either set because their durations are so low.

Good grief

You mean to tell me the fact they share the same intake gasket is what matters?

The stock 03/04 cams work pretty good and very few Terminator owners run aftermarket cams. Guys are making upward of 800+ hp running stock cams yet you call that "terrible". If the OP feels he needs more power then they can deliver he can run aftermarket cams or even early Cobra cams, his call. But I doubt it will make much difference. A few guys even swapped out for Ford GT cams and were disappointed with the results. Anything over that and your running into problems passing emissions if that matters.

BTW: The overlap on the Terminator cams is 38 degrees.

 

[olgreydog7]

Having seen both heads, the ports are the same as nasvt said. Also, guys make "800" hp with more boost. It has nothing to do with the cams. They run stock cams cause pulleys and a port job on the Eaton are cheaper and MUCH easier to install. Even upgrading to a Whipple or KB is cheaper in the long run in hp/$. The 03 cams are not blower specific by any means. BTW, they are the same grinds as in the Mach and some of the other late 4 valves. More duration equals more power, to a certain extent anyway.

To the OP, I say go for it. If the heads have as few miles on them as the seller says, you would probably spend more freshening up your heads than buying those. Jump on them. If he is giving you a good deal on the Crowers, then you can forgive the bickering over the stock cams :burnout:

 

[na svt]

The stock 03/04 cams work pretty good and very few Terminator owners run aftermarket cams. Guys are making upward of 800+ hp running stock cams yet you call that "terrible".

BTW: The overlap on the Terminator cams is 38 degrees.

The 96-98 cams will offer some free power since he alreasdy has them.

Anyone can make 800 with an 03/04 with a lot of boost. Add the longer duration intake cams and that same power is made with less boost.

The amount of overlap under .050" doesn't have a great affect on performance. Once again, I've done the swaps and there has always been a power gain.

The 03/04 head has a better short turn radius and larger exhaust ports, but the gains they offer over the 99/01 heads is minimal on boosted engines,

 

[99riocobra]

Good grief

You mean to tell me the fact they share the same intake gasket is what matters?

The stock 03/04 cams work pretty good and very few Terminator owners run aftermarket cams. Guys are making upward of 800+ hp running stock cams yet you call that "terrible". If the OP feels he needs more power then they can deliver he can run aftermarket cams or even early Cobra cams, his call. But I doubt it will make much difference. A few guys even swapped out for Ford GT cams and were disappointed with the results. Anything over that and your running into problems passing emissions if that matters.

BTW: The overlap on the Terminator cams is 38 degrees.

i know you know more than me on the subject. when i said the ports are the same between the two heads, i was referring to the port inlet shape on the head. so in this case, sharing the same gasket is what matters. i fully understand that the actual ports are different after the opening.

 

[SlowSVT]

i know you know more than me on the subject. when i said the ports are the same between the two heads, i was referring to the port inlet shape on the head. so in this case, sharing the same gasket is what matters. i fully understand that the actual ports are different after the opening.

Nick

I wouldn't be so sure of that. You don't own the number and variety of cars you have and not learn a thing or two.

On a blown engines cams and heads really aren't a big factor. My heads are on the bench right now waiting for the die grinder but it won't be nothing more then cleaning up the pockets (all 32 of them :bored, unshrouding the intake for the Boss block and polishing the exhaust ports. I figure all that will be good for 20 hp :dw:

Russ :beer:

 

[na svt]

My heads are on the bench right now waiting for the die grinder but it won't be nothing more then cleaning up the pockets (all 32 of them :bored, unshrouding the intake for the Boss block and polishing the exhaust ports. I figure all that will be good for 20 hp :dw:

The absolute best thing you can do to your heads is install 38mm intake valves and open the seats up to 90% of the valve diameter, 1.496. At a minumum open up the seats to 90% of the stock valve diameter (if using stock valves) which is 1.45669". These heads suffer from undersize seats and by opening them up you will get significantly more flow.

As for the combustion chamber, enlarge it to the size of the BB head gasket. This will unshroud the valves (a little) and also remove any sharp edges and pockets that inhibit flame travel and lead to detonation.