Performance Heads?

[~JM~]

Looking for info on what all is available in the bolt on performance cylinder head department.

I've done some searching & it sounds like there are basically 2 players in this market. TA & Champion. I've seen some reference to problems with the aluminum heads but wasn't able to determine what the issues were. How well do our engines respond to aluminum heads vs. iron heads? Is there an aftermarket iron head, or are they tricked out OEM iron heads?

Please educate me.

Thank you
~JM~

 

[~JM~]

I've also read a few posts that mention M&A heads? What's the story on these heads?

Thanks again
~JM~

 

[turbofabricator]

The only available aluminum heads are the TA and Champion. The M&A heads are no longer in production. The TA heads are made more robust to resist cracking. THe early Champion GN1 heads were crack prone. They "supposedly" have fixed the problem. If you are mostly a street driver, then a set of ported stock castings are the way to go, in my opinion. Not alot of gain going aluminum on a mid ten second car or slower. High output full race. My choice is TA or go with a real StageII cylinder head. There are lots of StageII (Buick Motorsports) available used. They will support over 1500 HP properly ported. They will require aftermarker headers, intake, camshaft (port configuration is symetrical, so a production cam shaft blank will not work) What are your goals? That will help to detirmine which direction. Want is your budget, that is also needed.

 

[turbo nasty]

Ported irons will knock out tens all day. As mention by turbofab whats your goal

 

[~JM~]

I'm more accustomed to how naturally aspirated engines respond to the addition of bolt on aluminum heads. There are usually substancial gains along with the benefit of weight reduction. Are the factory heads a fairly good design to begin with?

I don't have any 1/4 mile goals. I see my car as more of an open road car that is fast & also handles well.

Thank you
~JM~

 

[big reazon]

Its not the aluminum that helps naturally aspirated motors its the flow of the heads. Typically aluminum heads are machined and ported for better performance because they are easier to do. It is supposedly easier to cast a high performance aluminum head while a cast iron one is not so easy. But listen to turbo fabricator he knows his stuff he is walking me threw my set up, porting my heads, and doing all the supporting mods I need for a consistent low 11 car high 10 potential.

 

[wickedtt]

If you are leaning towards Aluminum heads I would have them fully ported and polish to really benefit over the ported irons. With the Aluminums you will make the same power with less boost and have the cool bling factor your looking for. Im not sure if anyone here has ever really done back to back testing on the Aluminum ported vs Iron ported heads debate. Then again like many have said the ported irons are consistently in the 10's all day long. The big question is always how fast do you want to go and thats answered by how deep your pockets are?

 

[Nick Micale]

Looking for info on what all is available in the bolt on performance cylinder head department................. How well do our engines respond to aluminum heads vs. iron heads? ............~JM~

Aluminum heads out-of-the-box will outflow by far a set of max ported iron heads. One simple reason for this is that alum heads use larger intake and exhaust valves.

Another advantage of alum heads is that they transfer heat better, so higher boost or compression can be used vs. iron.

If you crack an iron head, it is then a boat anchor, not worth the $$$ to repair, better off just porting another one. The alum head is usually easily and inexpensive to repair.

Alum heads are, of course, more expensive than ported irons, and they do require specific roller rockers. Since the larger valves are spaced further apart, stock rockers will not fit and work properly.

 

[~JM~]

Forgot to mention a goal. I want to run the best that I'm able to on 92 octane without the benefit of alcohol injection. My thoughts are improved more efficiant breathing & the coolest charge temperature as possible will allow me to run more boost. I will most likely be installing a large FMIC to achieve the most charge cooling. I usually like to build on the overkill side with components that will provide the most reliability & require the least amount of maintenance.

My closest local TR Guru is a strong believer of using iron heads vs aluminum.

Thank you
~JM~

 

[big reazon]

For the most on 92 only aluminum would seem like the way to go.

 

[~JM~]

Anybody have anything else they'd like to add?

Could someone please explain to me the bolt pattern differences? I've seen reference to 14 bolt heads, etc. What does the OEM block require?

Thank you
~JM~

 

[~JM~]

...THe early Champion GN1 heads were crack prone. They "supposedly" have fixed the problem....

Any idea when the problems were fixed? Is there a certain date or time frame that I should avoid? Is there any way to determine wether or not the heads I'm looking at have been improved or are an older design?

Thank you
~JM~

 

[bison]

Any idea when the problems were fixed? Is there a certain date or time frame that I should avoid? Is there any way to determine wether or not the heads I'm looking at have been improved or are an older design?

Thank you
~JM~

Anything from 07 up has been gtg from what ive seen. Earlier castings may have been crack prone but not in typical street applications making less than 700hp. The later castings have a flat with the GN1 logo machined on the spark plug side side and also on the front/back of the head. The earlier castings have the i.d. cast in the side on a non machined surface. Any of them that arent bastardized will serve your purpose with little fear of cracking. For the most part the iron heads are easier to deal with. The 14 bolt versions require rocker arms also. The stock rockers could be used on the 8 bolt but i wouldnt bother.

 

[Street Lethal]

If you crack an iron head, it is then a boat anchor, not worth the $$$ to repair, better off just porting another one. The alum head is usually easily and inexpensive to repair...

I used to feel that way, but brazing iron is extremely easy to do (and cheap), and VERY strong to boot...