Do I need GN1's?

[GangsterMD]

I'm in a rebuild. I've gone with stock crank, k1 rods, forged pistons, billet mains, 210/215 hyraulic roller cam, GT6765BB, SLIC, 60#ers, 3200 Conv, stage II tranny. I've can't decide what I should do for heads. I'm thinking if I'm going to spend money cleaning up my heads or on a different set of iron heads, why not go with the best Champion aluminums. Also I don't want to have to upgrade later - and spend the money twice. Goals right now are low 11's or high 10's. But that could change - but with the stock crank??? Any advice would be appreciated.

 

[dlafont]

You can probably get into the 11's without excessive boost (>25lbs) with stock heads however it starts to get a little harder to get into the 10's with stock unmodified heads.

If you want to get into the 10's a little less expensively get some Champion ported irons. They get you most of the way into the 10's without excessive boost (like 30lbs).

D

 

[jasjamz]

No you dont "need" them. Cars in the nines on steels.

 

[bison]

Stock bottom end=no need for more than ported stock heads.

 

[krom]

You do not need them but they sure make a difference. Remember you will need rockers and pushrods which will add lots of extra cash. When I put them on a car with a stock bottom end I went from 12.1 to 11.7. I run my signature with ported irons.

 

[GangsterMD]

So when does a bottom end not become stock? I guess what I'm missing is a girdle and forged crank right? I went with the billet caps instead because I've heard girdles have a tendancy to leak? Right or wrong? As for Champions, if you go with the 14 bolt alums with scorpion rockers, vs the irons with rockers I thought there's only a few hundred bucks different. What am I missing?

 

[callmeebryan]

If your goals are low 11's-high 10's, aluminum heads would be silly. Like others have said, there are guys in the 9's with a great set of ported irons. I think the money would be better spent making your car hook better (control arms, sway bar, shocks and springs, poly mounts,etc), but its your money not mine . You'll pick up a good .3-.5 (easy) in the quarter with a great launch.

 

[GangsterMD]

That make sense guys - the money would be better spent elsewhere. Ok so sticking with irons, are roller rockers any help? And what all should be done to the heads and roughly how much should it cost?
Thanks again.

 

[kingots2004]

man if you want champion gn1s get them. i got a set for a good deal and put them on a bone stock bottom end motor last year with no plans to do anymore to the car and now im building a 250 cube stroker and dont have to buy another set of heads. yeah i couldve done it deferent but i like to buy stuff once just like turbos get one that will support past your goals then you dont have to run it till the tounges hanging out to get the performance you want. if ya want a mid 10 car build it for mid nines and you dont have to work on it all the time

 

[bison]

man if you want champion gn1s get them. i got a set for a good deal and put them on a bone stock bottom end motor last year with no plans to do anymore to the car and now im building a 250 cube stroker and dont have to buy another set of heads. yeah i couldve done it deferent but i like to buy stuff once just like turbos get one that will support past your goals then you dont have to run it till the tounges hanging out to get the performance you want. if ya want a mid 10 car build it for mid nines and you dont have to work on it all the time

The difference between mid 10's and mid 9's could be $15k. Most on here dont have $ like that to throw at an engine

 

[Pronto]

Most on here dont have $ like that to throw at an engine

That's the truth!

 

[WSLN 6]

OH Come on now Bison! Be realistic! There is no way that it costs that much to get to the 9's.
Look you take 3 rebuilds, add forged parts add 10,000 carry the 5000....oh my bad. :biggrin:

 

[Rell87]

Buy the aluminum Gn1's. If u don't after someone blows the doors off u, u'll be shopping for some.

 

[kingots2004]

The difference between mid 10's and mid 9's could be $15k. Most on here dont have $ like that to throw at an engine

thats my point why pay 1200 for ported irons when he can pay 1600 and get gn1 aluminums nonported that flow more than the irons with room to grow? 1200 for maxed out heads then when he wants to step up he has to sell those or put them on the shelve and pay 1600 later.dont make sense to me to buy the same parts 2 or 3 times unless im vendor that needs to sell parts constantly. it would be like you tellin him to buy 42 lb injectors when 60 work just as good with room to grow. with my stroker motor thats 1600 i just save because ive already got the heads

 

[Grumpy]

go with the aluminum's. thats what you NEED .. ok I said it

 

[bison]

thats my point why pay 1200 for ported irons when he can pay 1600 and get gn1 aluminums nonported that flow more than the irons with room to grow? 1200 for maxed out heads then when he wants to step up he has to sell those or put them on the shelve and pay 1600 later.dont make sense to me to buy the same parts 2 or 3 times unless im vendor that needs to sell parts constantly. it would be like you tellin him to buy 42 lb injectors when 60 work just as good with room to grow. with my stroker motor thats 1600 i just save because ive already got the heads

Your missing the point of having a tight combo. If you want to have a fast car you buy parts that work the best together. If you want to go fast with GN1's you will be spending more than $1600. Dont be fooled. You wont make much more power with them vs good irons in a small hydraulic application at low rpm with a small turbo. You dont grow into turbos either. You buy a turbo that will work for you rpm range/limit. Of all the posts i see on here i am appalled at some of the times i see for the given parts. Most of the money is better off spent on tuning and datalogging devices since 90% of the numbers i see on here arent even close to what i would consider ok. There i said it. Not to many on this board know how to tune a car very well. If he planned on running slower than 120 in the quarter i would tell him to buy whatever injector was cheaper 42's or 60's. You think you can grow into injectors easily with a stock ecm too? Not really unless you get re-burns to add fuel as rpm and hp goes up. Try running a chip for a stock headed/cam car that was burned for a 400hp application with 60's in your 700hp application and see if you are able to get it to work. Last i knew chips werent free. Neither was my down time waiting for one to come back. Be sure to post your combo and times with your GN1 headed stroker when you run it. Should go 9.80's@137-140mph without even breaking a sweat the first time out if a few if a few of us are going nearly that fast on iron heads and stock stroke with hydraulic cams and small turbos:biggrin:

 

[Sweet6]

A lot of guys go 9s and 10s on the ported irons. They are proven and do not have any issues. Pretty much plug and play. The GN1s weigh I think about 30-40lbs less and they do flow better out of the box. They cost a little more but may have some issues with sealing(depending on gaskets used), cracks(I heard new castings are much better) at least from what I have read.

It seems like the irons are pretty much dummy proof and the GN1 could be a little extra work. As far as need, irons will get the job done for low 10s high 9s for sure. Just depends on if you want to spend the extra cash and take any chances on the install taking some time. When I say install meaning getting a good seal on the head. I thought that was more so with the cometic gaskets. Maybe someone can chime in on that.

 

[GangsterMD]

Ok, well it looks like 3 or 4 nays and 3 or 4 yays - imagine that It's either do my irons up, or aluminum GN1's. Champion irons are out. Could I get some answers to the following?
-Are there drawbacks to aluminum such as cracking?
-Do the aluminums need much work or do you just bolt them on?
-When should you go to roller rockers on irons?
-How much should it cost to get my irons ready - valve job, hyr cam work like exhaust guides, exhaust valves etc?

With this information I think I can feel good about the decision.
Thanks fellas.

 

[Sweet6]

I thought if you did your irons up they would end up costing about the same as the Champion irons. But since you are starting from scratch the cost could vary from $600 to $1000. Just depends on how far you want to go. Just to give you an example I know a guy that was trying to save a little money and had his stock heads work. He ended up not being happy for whatever reason and ended up getting Champion irons. So it ended up costing him more in the long run. There are other good head porters out there. I think Russ Merrit did Grumpy's irons and his turned out good. I would go with someone who has a proven track record with the Buicks. The ones I know offhand are Champion, DLS, and Russ. But I know there are others out there. Just have to do some research and make a choice.

 

[Grumpy]

you can grow into the Aluminum's.. I would suggest a cam like this to go with them
http://www.turbobuick.com/forums/parts-sale/277750-erson-solid-billet-roller-cam.html