which head??

I am planning for a 8:1 compression 350 with a 72cc head with nice wild cam fully built rockers etc.. and twin turbos...

do u guys think I shoudl use the dart aluminum heads or the dart cast iron heads... I dont want the crazy high priced 1200.00 heads.. so either the aluminum head or the cast iron "platinum" series

which do u guy think

I was thinking cast iron due to the fact that the manifod will be VERY hot due to the turbos and I dont want to have a problem with warping in the head surface


Dave

You want to run twin turbo's but you are worried about a $1,200 set of heads.I don't get it.

yeah I dont feel I NEED the 1200.00 set of heads first off plus those heads only come in 68cc and I need 72cc so in that respect I need to get wither the aluminum ones or the cast iron platinum ones..

besides IME aluminum is NOT what u want when running turbos due to the EXTREME heat.. thats myw orry I would think cast would be the way to go

Dave

Why turbos?? Just punch it out to a 383 stroker with afr heads and you can make an easy 450 hp and have it be reliable and smokin fast.

nope... I want turbos

Dave

If you want Dart heads, call their tech line and get some advice. Keep in mind that horsepower primarily resides in the heads because flow is everything. IMO, you ware making a mistake trying to skimp on heads. You should be running the best flowing heads you can find for this engine if you want it to perform effectively. Building a great engine means choosing a combination of parts that work together as a unit. The most common mistakes novice builders make are choosing cams that are too big, carbs that are too big, and heads that don't flow enough air or heads that flow too much air. Then they wonder why their new engine runs like a dog. Just make sure you do your home work and make a lot of calls to get the opinions of experts. You are pouring a lot of money into this engine so you don't want to screw up. Just my two cents worth . . .

so yoru telling me that the cnc ported aluminum head at 64cc will flow better then the cast head at 72cc??

I planned to work the heads and port etc.. however I need the 72cc heads for the lower compression.. so my choice on that in dart is either the aluminum 72cc platinum series head or the cast head at 72cc

the 64cc/68cc (which ever it be) I cant use that will make my compression to high.. I cant match the pistons good enought o make the compression low enough with that head

Dave

[QUOTE]Originally posted by SpooledupRacing
[B]so yoru telling me that the cnc ported aluminum head at 64cc will flow better then the cast head at 72cc??

I planned to work the heads and port etc.. however I need the 72cc heads for the lower compression.. so my choice on that in dart is either the aluminum 72cc platinum series head or the cast head at 72cc

the 64cc/68cc (which ever it be) I cant use that will make my compression to high.. I cant match the pistons good enought o make the compression low enough with that head The size of the combustion chamber has nothing to do with flow rates in the intake or exhaust ports.

What I was trying to say is the size of the cumbustion chamber has nothing to do with flow through the intake or exhaust port.

ah o... well I called Dart and the supplier I am buying the heads from.. I plan to use the Pro 1 Aluminum Dart heads.. they are

200cc intake ports
72cc chamber
2.02/1.60 int/exh valves

thats the stock info on the heads...

here is th ekey.. I am running twin turbos but they will be small turbos and this car is not being built for serious racing just look, sound and run nice and get the AWW factor.. I would be happy with a 12 sec pass or so

it is soemthing for me and my wife to do together and something I have always wanted to do.. just for fun and thats it..


Dave

You'll always want more than one opinion, even if they are experts. Now, call Brodix and see what they recommend. Compare the two and go with what you think works best for your application and your wallet.

One trick I have learned over the years is to have the smallest port voulme with the highest flow numbers.

well here is what there website says abotu dart heads

200cc intake port
72cc Chamber volume
2.02/1.60" intake/exhaust valves

Street performance, exellent replacement for stock heads, 6000 rpm, 327/383 ci

OR

180cc intake port
72cc chamber volume
2.02/1.60" intake/exhaust valves

Excellent street or marine upgrade, maximum torque & throttle response through low/midrange 305/383 ci



in reading those what do u guys think???

Dave

If it were me, I'd go 200cc because you are going to be forcing a lot of air through them. You might give up a little torque at lower rpm's but you will see a lot more power at mid and upper rpm ranges. With the power you are going to be generating, you are not going to be hurting for torque when you drive at low rpm's. What does Dart say? Do you have access to flow numbers for comparison purposes? AFR 195 heads work great on 350's and 383's so I don't think 5cc's will make that much difference.

or there is

215cc intake port
72cc Chamber volume
2.05/1.60" intake/exhaust valves

Serious street perfornmance, Bracket Racing, restricted Oval Track 7000 rpm, 350/400 ci

ok here is the actual page to the heads I have mentioned each one has a clkickable link for the info

im looking at the pro 1 72cc heads

http://www.dartheads.com/sbchpro1.aspx

no I want whats best for my setup.. I was just posting what I read on there for u guys to help me decifer the differences

Dave

Denny,L.O.L. 230 CC, talk about poor throtle responce.You are really trying to start things now.I would run these heads if you had 434 small block and you turned to 7,500 r.p.m.s.Denny,I am glad you have a good sense of humor.:LOL:

lol I saw that and my eyes about popped out of my head.. lol.. I think the 180cc or 200cc would be best.. u guys agree.. fi so which should I choose??

Dave

I think I will go the 180cc then.. this will mainly be a weekend warrior for show and crusin.. maybe on nice summer days drive to work etc.. but I would like to hit the track with it as well atleast a few times...

Dave

If I were building a naturally aspirated motor, I'd be concerned about intake runner size and matching it to the rpm range where I'd be operating the motor. With artificial aspiration where I'd have positive manifold pressure, it wouldn't matter much if I overdid the size of the intake runners. If I were going to size the housings to make boost from....say....3,000 to 7,000, I'd just use a looser torque converter and a cam and springs to allow the higher revs.

I wouldn't limit myself to a certain combustion chamber size either, because I could dial in the c.r. with the dish size in the pistons.

and to ad.. the pistons I am getting will limit me to a 72cc head in order to run 8:1 compression

I will be using SRP JE's

Dave

yeah I knew TT was better then supercharged... its funny to see he runs a water to air cooler lol....

great article thx for that....

to bad it dont help with head info ;) lol

Dave

gottcha...now I was thinking this will prolly require injection setup instead of carbs.. regardless of head.. u agree

Dave

well it looks like the dart pro 1 180cc heads will be hard to get...

but the 200cc heads are quite available

do u think I will notice or loose a signifigant amount to matter

Dave

I think it's more than a "what head?"-question. It's also more than a "I will be using these pistons"-statement. Instead of starting off with things you want to have you should start off with the question: "what performance do I want to get out of my engine?"
What counts most is what the engine wants, not what you want. If the engine says it would prefer other pistons and would run better and faster with them, then that's the way to go. If you're planning to put twin turbos in you seem not to be very limited in terms of money. So you can get not only good stuff which has a name and sounds cool, but you can get down and look for parts that GO TOGETHER WELL. That includes things like optimizing your combustion chamber shape. Don't use pistons that mask the spark plug too much. Go for heads with little squish. Try to get a nice combustion shape when the piston is at TDC so that the flame front can run trough the chamber quickly and uniformly but not too quickly.
Remember: Heads are more than flow-numbers and port sizes. With a blower you shouldn't be too worried about port sizes, but you should always be worried about port shape, you will get the flow from the turbos. But you want swirl to get the mixture homogeneous so that it burns well. You can always build an engine with 400 HP. Everybody can do that, it's not difficult if you have the money. But with the same amount of money and parts that harmonize nicely you could get 500 HP out of the same displacement. I wouldn't necessarily stick with Dart, I would shop around a see what's best FOR YOUR ENGINE.
And for performance you won't see much difference between carb and injection as long as you don't go and dish out 2k for sequential electronic injection with loads of whatnot nobody understands. For those systems you have to be a computer expert, not an engine builder. Go with carbs, maybe dual. That would be my guess.
That's just my opinion and I'm no real judge on engine building, I'm also just getting started on the subject. But I started by reading some good books on engine building, there's quite a lot you can learn without having to make all the mistakes yourself :LOL:
Hope i could help,
Max

thx max... what all heads do u guys recomend then.. the only reason I went with dart is cause a local shop around here sells them and my cost is LOW due to buying them through my work...

what other heads are good quality IYO

Dave

so in other wards... 180cc is what I shoudl aim for

Dave

well with the 180 72cc iron eagle dart head I can get (not aluminum) cost on those bar is 265.00 each.. so shoudl I just go with those.. they have heart shape combustion chambers to if that matters

ok so cast iron would'nt be bad...

now do u youirself perfer one brand head over another???

remember I am from the import world so this is all new to me...

Dave

Talk with the tech staff at AFR and Brodix. See what they have to say and what they recommend. Like I said previously, and I can't say it enough times, "Do your homework!" You cannot make an informed choice without it. Have you called any turbocharger manufacturers to see what they recommend? Do that, too.

it appears that afr dont have a 72cc head... only a 74cc head.. that would lower my compression lower then 8:1 which IMO only gets better for forced induction.. ill all them

Dave

I agree with rumrumm. you should check out the AFR heads. They have some of the best flowing heads in the business. usually the smaller the port size the faster the velocity of the incoming air. You might get more air with the bigger ports but it wont be coming in as fast. sooooo what does this mean? A smaller amount of air but it will be coming into the engine faster. Usually you will get more flow until you get into the 4500 plus rpm range then the big port heads will really shine. It is knid of hard to explain without going in engineering terms. Just a couple questions. What stall speed will your converter flash at? What rpm will you be launching at? If you have not thought about it, you should call ATI and tell them what you will be running, they can build you a converter to match your application. Hope this gives you something to think about.

As I say, I'm no judge when it comes to engine building. But I have learnt one thing: Do it right now or do it again soon. It always pays to get info first. I didn't say the Dart heads are bad. Dart is certainly one of the best firms yround for aftermarket heads. But I was just trying to say that maybe for a twin turbo 350 those Dart heads might not be best choice. Almost every firm has heads in the 72cc region. But you might consider getting 76cc heads with a better chamber shape and have them machined down to get 73cc or so.
With a turbo you'll be seeing higher cylinder pressures so you wouldn't want heads that are known to be crack-prone. There are some castings that are quite heavy, but have thick castings and they won't brake. I think aluminum isn't a good choice, it isn't as strong as iron and might not survive the higher burning temperatures without warping soon. But that depends on how much boost you want to run later on. And on whether you want to use an intercooler and which one...
You see what I mean? Your first step has to be finding out what you want to do with the engine, what setup your planning for and whether you want a full blown racer or a daily driver which sees the strip now and then. Sketch out possible engine combos on a piece of paper and note what specialities you have to look out for.
You see? There's more to successful engine building than a set of good heads when everything else is already fixed. If your starting from scratch on this engine (except maybe for the short block), then do it right and find out FIRST what goal you want to achieve. Then find out what numbers you're aiming at (like 8:1 CR, 350 ci, 180cc intake runners with good bias...). Then see what parts that fit in this project you can get hold of. Then go and build the engine, drive that car into the 11s and have a lot of fun with it for years to come.
Or you buy everything YOU want. Then assemble the engine. Then find out it only puts out 300 HP. Then fiddle around, idle is crappy and power is low, engine doesn't turn higher than 5000 RPM and you loose every race :LOL:
I hope you get what I'm trying to say. Make a sketch of the complete setup you want (this will prove more difficult than you think). Then make a list of brands to chose from. Then make a list of parts within those brands... Don't forget the small things like valve springs, retainers, rods (6 inch or 5,75 inch?)...
I can't give you any direct advice on your heads though, because I've never built anything not normally aspirated.
Hope I could help,
Max

I called AFR and Jason was a big help.. I told him what I felt I wanted to do with the engine..

mainly weekend warrior streetable with the ability to hit the track and have fun and get soem good pull up to about 6500rpm then shifting

he recomended the 195cc heads with 74cc chamber, says they will be there if I end up boring the block bigger they will flow great with the twin turbos, and not be to much in order to not run a crazy cam ..

he also recomended I upgraded the valves and springs with a upgrade package to suit the forced induction properly..

1500.00 for the set.. more then the darts but atleas tthis guy seemed alot more knowledgable and gave me the truth behind what I have been told by the local shops here..

Dave

ok I have done this with AFR and dart.. ill call brodix later

Dave

I am partial to AFR because they worked great for me and lived up to all expectations. My 383 (which has their 190 heads) with a relatively mild CC Magnum 280 hydraulic cam made 450 hp and 468 ft. lbs. of torque on the dyno, and it is so streetable my wife could drive it (if she wanted and if I let her). LOL! I have no problems with Brodix, Canfield or Dart. They have great parts, too. I chose AFR because they have the best flow numbers and a lot of guys on another Chevy website think very highly of them.

thx for you opinion I will keep collecting info from others as well

Dave

ok well after some conversations with brodix and some other place.. cant emember off hand.. I think AFR will be the best choice..

so there 195cc @ 74cc head will be what I will go for and I will get the upgraded spring/valve package with it..

I just ordered pistons today so once they arrive a few more things the the block gets worked, balanced, and assemebled then to heads :)

Dave

If you order AFR heads, buy them direct from AFR. That way you can be sure to get what you talked about. Keep in mind that they make up a set heads on a per order basis, and they do not have any pre-assembled sets on hand. That is why it will take about five weeks before you get them.