Headgames/Cosworth Heads - Comparisons?
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Joined: Jun 2005
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From: SA
Originally Posted by BrianLG35C
Just so I'm clear, "FI Gods"...why wouldn't you spend the budgeted amount for a build on new heads with L-19 or 1/2" studs instead of sleeves? You can run much lower psi for the same whp which lessens motor stress/headlift risk, right? What's the downside?
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Joined: Jan 2006
Posts: 97
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From: Ewing,NJ
the differences in our heads start with the fact that we can custom taylor a head to your application...there is not a one size fits all in our opinion.
And when it comes to size, we offer both size valves..(stock, 1mm over) but however in most applications we believe that the stock size valve head will out perform, making more torque in the low to mid range, which makes for alot more fun when you plant your foot onto the loud pedal and feel what you just spent your money on. We know from experience that you can make in upwards of 1000 rwhp with a stock size valve..we have made 700 with a Honda, 1100 with a Supra, and 900 with a mitzu all with stock size valves...could you have it if you want it though? Sure..but we just don't recommend it just so you can say you have a bigger valve to your buddy and gloat to your buddy's about the flow chart. It might flow better, but we are not racing flow benches..so I would rather worry about what works on the car then the bench.
Our heads also do not use the stock cast iron guide (cosworth does) that can become briddle and break the tip off (FI exhaust most common) and has poor heat resistance compared to the Maganese bronze(intake) and copper alloy(exhaust) valve guides we use that are specifically designed to withstand anything you can dish at them and they also take heat away from the valve!
We also use a custom made exhaust valve made for us by Ferrea made from the material pyromint, which is the same material used in Top Fuel!
they are the differences I could see, hope this helps.
And when it comes to size, we offer both size valves..(stock, 1mm over) but however in most applications we believe that the stock size valve head will out perform, making more torque in the low to mid range, which makes for alot more fun when you plant your foot onto the loud pedal and feel what you just spent your money on. We know from experience that you can make in upwards of 1000 rwhp with a stock size valve..we have made 700 with a Honda, 1100 with a Supra, and 900 with a mitzu all with stock size valves...could you have it if you want it though? Sure..but we just don't recommend it just so you can say you have a bigger valve to your buddy and gloat to your buddy's about the flow chart. It might flow better, but we are not racing flow benches..so I would rather worry about what works on the car then the bench.
Our heads also do not use the stock cast iron guide (cosworth does) that can become briddle and break the tip off (FI exhaust most common) and has poor heat resistance compared to the Maganese bronze(intake) and copper alloy(exhaust) valve guides we use that are specifically designed to withstand anything you can dish at them and they also take heat away from the valve!
We also use a custom made exhaust valve made for us by Ferrea made from the material pyromint, which is the same material used in Top Fuel!
they are the differences I could see, hope this helps.
Originally Posted by BrianLG35C
Right, why sleeve when you can get this much power/torque at such a lower psi.
because you will have greatly improved cooling capacity= longevity of the bottom end, also, you can up the power later when the 350z modding sickness continues to infect, without having to rebuild the bottom end...
good ported and polished heads are also a must (IMO)... the differences between all of the different heads is going to be minimal, but understand that a true port and polish is a time consuming, expensive process... the know how and experience allows these guys to achieve better results
another head to enter into the competition; GT motorsports heads...
I'll post some charts soon...
-TODD
I understand Todd but I'm looking for the safest way to make the most power at the least cost. If that even makes sense.
I seriously don't think I'lll ever want to go over 500-550whp in this car, especially with the lack of traction and required mechanical knowledge to keep a car of that whp running reliably. I just want to drive the car and enjoy it with the least amount of hassle possible. So that leaves how much I'm willing to spend. For added safety I'm willing to spend more for the best pistons, rods and head stud kit. To me it seems I'll get better results per dollar with heads because I'll be staying with the Unichip for now (which maxes out at 12psi or so) and will provide a higher whp number at the same amount of boost. Which means it will cost me less $/whp.
I seriously don't think I'lll ever want to go over 500-550whp in this car, especially with the lack of traction and required mechanical knowledge to keep a car of that whp running reliably. I just want to drive the car and enjoy it with the least amount of hassle possible. So that leaves how much I'm willing to spend. For added safety I'm willing to spend more for the best pistons, rods and head stud kit. To me it seems I'll get better results per dollar with heads because I'll be staying with the Unichip for now (which maxes out at 12psi or so) and will provide a higher whp number at the same amount of boost. Which means it will cost me less $/whp.
Originally Posted by HeadGames
the differences in our heads start with the fact that we can custom taylor a head to your application...there is not a one size fits all in our opinion.
And when it comes to size, we offer both size valves..(stock, 1mm over) but however in most applications we believe that the stock size valve head will out perform, making more torque in the low to mid range, which makes for alot more fun when you plant your foot onto the loud pedal and feel what you just spent your money on. We know from experience that you can make in upwards of 1000 rwhp with a stock size valve..we have made 700 with a Honda, 1100 with a Supra, and 900 with a mitzu all with stock size valves...could you have it if you want it though? Sure..but we just don't recommend it just so you can say you have a bigger valve to your buddy and gloat to your buddy's about the flow chart. It might flow better, but we are not racing flow benches..so I would rather worry about what works on the car then the bench.
Our heads also do not use the stock cast iron guide (cosworth does) that can become briddle and break the tip off (FI exhaust most common) and has poor heat resistance compared to the Maganese bronze(intake) and copper alloy(exhaust) valve guides we use that are specifically designed to withstand anything you can dish at them and they also take heat away from the valve!
We also use a custom made exhaust valve made for us by Ferrea made from the material pyromint, which is the same material used in Top Fuel!
they are the differences I could see, hope this helps.
And when it comes to size, we offer both size valves..(stock, 1mm over) but however in most applications we believe that the stock size valve head will out perform, making more torque in the low to mid range, which makes for alot more fun when you plant your foot onto the loud pedal and feel what you just spent your money on. We know from experience that you can make in upwards of 1000 rwhp with a stock size valve..we have made 700 with a Honda, 1100 with a Supra, and 900 with a mitzu all with stock size valves...could you have it if you want it though? Sure..but we just don't recommend it just so you can say you have a bigger valve to your buddy and gloat to your buddy's about the flow chart. It might flow better, but we are not racing flow benches..so I would rather worry about what works on the car then the bench.
Our heads also do not use the stock cast iron guide (cosworth does) that can become briddle and break the tip off (FI exhaust most common) and has poor heat resistance compared to the Maganese bronze(intake) and copper alloy(exhaust) valve guides we use that are specifically designed to withstand anything you can dish at them and they also take heat away from the valve!
We also use a custom made exhaust valve made for us by Ferrea made from the material pyromint, which is the same material used in Top Fuel!
they are the differences I could see, hope this helps.
Originally Posted by BrianLG35C
So I understand, you're porting and polishing my stock heads?
i think the question would have made more sense if you asked something like ...."so you use the stock sized valves?", ... or something like that....
he states pretty clear that he replaces components and talors the heads to what your needs are:
Originally Posted by HeadGames
the differences in our heads start with the fact that we can custom taylor a head to your application...there is not a one size fits all in our opinion.
And when it comes to size, we offer both size valves..(stock, 1mm over) but however in most applications we believe that the stock size valve head will out perform, making more torque in the low to mid range, which makes for alot more fun when you plant your foot onto the loud pedal and feel what you just spent your money on. We know from experience that you can make in upwards of 1000 rwhp with a stock size valve..we have made 700 with a Honda, 1100 with a Supra, and 900 with a mitzu all with stock size valves...could you have it if you want it though? Sure..but we just don't recommend it just so you can say you have a bigger valve to your buddy and gloat to your buddy's about the flow chart. It might flow better, but we are not racing flow benches..so I would rather worry about what works on the car then the bench.
Our heads also do not use the stock cast iron guide (cosworth does) that can become briddle and break the tip off (FI exhaust most common) and has poor heat resistance compared to the Maganese bronze(intake) and copper alloy(exhaust) valve guides we use that are specifically designed to withstand anything you can dish at them and they also take heat away from the valve!
We also use a custom made exhaust valve made for us by Ferrea made from the material pyromint, which is the same material used in Top Fuel!
they are the differences I could see, hope this helps.
And when it comes to size, we offer both size valves..(stock, 1mm over) but however in most applications we believe that the stock size valve head will out perform, making more torque in the low to mid range, which makes for alot more fun when you plant your foot onto the loud pedal and feel what you just spent your money on. We know from experience that you can make in upwards of 1000 rwhp with a stock size valve..we have made 700 with a Honda, 1100 with a Supra, and 900 with a mitzu all with stock size valves...could you have it if you want it though? Sure..but we just don't recommend it just so you can say you have a bigger valve to your buddy and gloat to your buddy's about the flow chart. It might flow better, but we are not racing flow benches..so I would rather worry about what works on the car then the bench.
Our heads also do not use the stock cast iron guide (cosworth does) that can become briddle and break the tip off (FI exhaust most common) and has poor heat resistance compared to the Maganese bronze(intake) and copper alloy(exhaust) valve guides we use that are specifically designed to withstand anything you can dish at them and they also take heat away from the valve!
We also use a custom made exhaust valve made for us by Ferrea made from the material pyromint, which is the same material used in Top Fuel!
they are the differences I could see, hope this helps.
Originally Posted by NoLimit
rgr, ... maybe he was asking if you need his stock heads to do the work, as in he can't just buy new ones out-right or something......
Originally Posted by BrianLG35C
I did read his post and was just trying to clearly understand if I would be using my stock heads or not. My knowledge is very limited on this and I'm just trying to decide if this mod would be cost effective for my build. Sorry to get everyone confused.
Good luck with your build! 
I think that the idea of the headwork being matched with your 'setup' sounds like a sure fire way to safely [safer] acheive the HP numbers everyone is looking for these days....
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Joined: Jan 2006
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From: Ewing,NJ
Thanks Brian for clearing that up...in my opinion, if I were you..I would rebulid the bottom end using the stock sleeves and put a good rod and piston in there..and top it off with a head package if you want, depending on your horsepower goals..the problem lays in you if you just purchase the heads the power that they will produce with the power you are already making will make a nice little(or big) hole not only in the block but your wallet as well when the rods let loose if you leave the stock rod in there.. The recipe mentioned above with the right size turbo's would produce safely 600rwhp or 550 or so on pump..and drive it everywhere..
As far as your head question, I have heads here so there would just need to be an exchange. There are no aftermarket heads available if that was what you were wondering..
And since you mentioned you were not real knowledgeable on the subject feel free to ask a question..I am sure there is others out there wondering the same thing.
As far as your head question, I have heads here so there would just need to be an exchange. There are no aftermarket heads available if that was what you were wondering..
And since you mentioned you were not real knowledgeable on the subject feel free to ask a question..I am sure there is others out there wondering the same thing.
Originally Posted by HeadGames
Thanks Brian for clearing that up...in my opinion, if I were you..I would rebulid the bottom end using the stock sleeves and put a good rod and piston in there..and top it off with a head package if you want, depending on your horsepower goals..the problem lays in you if you just purchase the heads the power that they will produce with the power you are already making will make a nice little(or big) hole not only in the block but your wallet as well when the rods let loose if you leave the stock rod in there.. The recipe mentioned above with the right size turbo's would produce safely 600rwhp or 550 or so on pump..and drive it everywhere..
As far as your head question, I have heads here so there would just need to be an exchange. There are no aftermarket heads available if that was what you were wondering..
And since you mentioned you were not real knowledgeable on the subject feel free to ask a question..I am sure there is others out there wondering the same thing.
As far as your head question, I have heads here so there would just need to be an exchange. There are no aftermarket heads available if that was what you were wondering..
And since you mentioned you were not real knowledgeable on the subject feel free to ask a question..I am sure there is others out there wondering the same thing.
I'm in the process of planning my build and figuring cost/value before I proceed. My plans already include Arias ED/Pauter Rods type quality pistons and rods, cams and L-19 head studs. I'm weighing going with sleeves or heads as the final upgrade for safety and efficiency. Trying to figure what will give me the most bang per buck including safety and whp. What would be best If I had to go with either sleeves or heads.
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Joined: Jan 2006
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From: Ewing,NJ
Well, if it were a question of either, or..I would go with a head. The reason I say this is because you had stated earlier that you were looking for bang for the buck, although I think the combo of a sleeved block and a good head is the best combination because by going with the sleeved block you have the advantages that Todd had mentioned earlier but also you now have the opprotunity to go with a larger bore which creates a little more horsepower and added strength but you can not fully take advantage of that because of your cylinder head being stock..if you are going to go with a stock bore size, you did nothing but add strength to the block..and we already know it will make 700+with out cracking a sleeve as long as it is tuned correctly. And you would not be able to pick up 70+hp from going to a bigger bore like you would with a head.
If you reuse the stock valves, the material they are made of will not bend if something happens and the piston comes in contact with the valve, they break which I am sure you are now aware of..it could be catastrophic by skimping there. If you put a valve in it, you have to machine the head for the valves and you should put guides in it at that point to.
The valve job, if done correctly could yield close to 20-30cfm which would help you in your case of doing something with the block, but in my opinion it would not be advantagious to do the block and not do the head, but you can do a head without doing the block as long as you are putting a good rod in the motor.
If you reuse the stock valves, the material they are made of will not bend if something happens and the piston comes in contact with the valve, they break which I am sure you are now aware of..it could be catastrophic by skimping there. If you put a valve in it, you have to machine the head for the valves and you should put guides in it at that point to.
The valve job, if done correctly could yield close to 20-30cfm which would help you in your case of doing something with the block, but in my opinion it would not be advantagious to do the block and not do the head, but you can do a head without doing the block as long as you are putting a good rod in the motor.
Last edited by HeadGames; Jul 22, 2006 at 11:42 AM.
Originally Posted by HeadGames
Well, if it were a question of either, or..I would go with a head. The reason I say this is because you had stated earlier that you were looking for bang for the buck, although I think the combo of a sleeved block and a good head is the best combination because by going with the sleeved block you have the advantages that Todd had mentioned earlier but also you now have the opprotunity to go with a larger bore which creates a little more horsepower and added strength but you can not fully take advantage of that because of your cylinder head being stock..if you are going to go with a stock bore size, you did nothing but add strength to the block..and we already know it will make 700+with out cracking a sleeve as long as it is tuned correctly. And you would not be able to pick up 70+hp from going to a bigger bore like you would with a head.
If you reuse the stock valves, the material they are made of will not bend if something happens and the piston comes in contact with the valve, they break which I am sure you are now aware of..it could be catastrophic by skimping there. If you put a valve in it, you have to machine the head for the valves and you should put guides in it at that point to.
The valve job, if done correctly could yield close to 20-30cfm which would help you in your case of doing something with the block, but in my opinion it would not be advantagious to do the block and not do the head, but you can do a head without doing the block as long as you are putting a good rod in the motor.
If you reuse the stock valves, the material they are made of will not bend if something happens and the piston comes in contact with the valve, they break which I am sure you are now aware of..it could be catastrophic by skimping there. If you put a valve in it, you have to machine the head for the valves and you should put guides in it at that point to.
The valve job, if done correctly could yield close to 20-30cfm which would help you in your case of doing something with the block, but in my opinion it would not be advantagious to do the block and not do the head, but you can do a head without doing the block as long as you are putting a good rod in the motor.
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