aluminum head recommendations
 

looking for advice on replacing the original GM iron heads with aluminum ones to go under some whipple chargers on a couple 502’s. i know dustin recommends dart pro one heads, what is everyone else’s opinion? i would like to reduce the compression ratio to about 8.2:1. any recommendations on who could put something like this together? looking for a builder who has good experience with blown applications, that won’t charge me an arm and a leg.

I have ordered some AFR 335CNC's. Going to put on procharged 540 when they get here. They had the best numbers when I ran them on desktop dyno with my setup. We will see.

My friend, JpClear of OSO, has ordered a pair of Canfields for his 540. Same thing that Keith Eickert uses on his engines.

Dean, you'll get a ton of answers on this one, and they'll all probably be correct. I just did a Whipple with the 2000 CFM throttle body on a 454 Magnum with mildly worked Brodix BB1 heads, a mild cam and high performance exhaust. It made 789 hp on the dyno at 5500 RPM. I think the Pro 1's are the best right out of the box. The more important thing is to get the correct runner size and chamber size to fit your application. I run ported BB2+ heads on my NA 555 and it makes over 600 HP with MPI and a very mild cam. I've also heard good things about the Canfield heads. Whatever you go with, make sure you have them assembled by a good shop to marine specs and get the inconel valves.

Bob

Edelbrocks CNC Victor marine heads are worth a look.

Dart Pro 1's are tough to beat for the $$$.

While were talking about this.

I have 96 502mpi with a Whipple on it.

It has zero gap rings, crane HP gold roller rockers.

Can the stock MPI intake flow enough air to feed the Pro 1's?

If not what ,modifications would need to take place?
If it can flow enough would the stock injectors be big enough to flow enough fuel to the engine or would I have to buy bigger ones?

How much are the heads?

I'm looking to maybe spend a little money this winter.

Thanks:D

I think that the AFR probably builds the very best but as is usually the case with the very best, you must pay. I would call Dave Kubert there, 818-890-0490. He is extremely easy to talk to and knowledgable and accomodating. Tell him what you have and they can custom build them for you. I would also contact Ken at Canfield Heads, 330-533-7092. He is very good too. Canfields have flow #'s that are close to AFR's for considerably less $. To see the #'s yourself, check Chevy High Performance magazine website @ www.chevyhiperformance.com Good hunting. --- Jer

Before I ordered the AFR I researched all of the heads. From what I was being told was after I bought some other heads I would need to take to someone & have them port them so they would really flow. I was getting prices from $600-$900 to port them. I could not get a solid number. So by the time I bought them from AFR I was not spending any more $ that if I had them ported. Once the hassel factor is added by messing with someone that can screw up your heads I thought the price for the AFR were about equal.

If I had to pick a head for the 700-800hp level, supercharged, best bang for the buck I feel are the Dart Pro Ones, 325 intake runner, 119 combustion chamber. I think they run just above $2000 from Summit fully assembled. The CNC 335's are incredible and are still worth the money, but there quite more. Brodix makes awesome heads as well, but are more expensive, more room for porting though. I've only heard about the AFR's, I know the small block heads work really well, I have to imagine the BB's work well too, but can't say from experiance. Never tried the Canfields so I can't say. If your looking for some people to do these mods on your motor, try GT Performance, 909.982.8391 or Paul Phaff Racing Engines, 714.894.7573.

29Scarab, no problem feeding the heads on your engine. You'll need a bit more fuel on top and a smaller pulley to increase airflow to see the gain, but it will be fun, especially torque, acceleration is unreal. Typically, for this application, I would get the out of the box Pro 1's (119/325), run a 3/8" smaller pulley, will have about 8lbs. of boost and should pickup another 75-90hp. Stock injectors are fine, would raise fuel pressure 2-4lbs. with an adjustable regulator and leave intake as is. You can cut the runners off to increase flow, but seriously, they'll flow plenty as is.

I'm interested in what anybody finds out on the heads though, would love to hear some numbers from some who have run the AFR heads. I would stay away from the Edelbrock heads for either of these applications, I've never had any big numbers from those.

Thanks,
Dustin

Hard to imagine that high perf heads cost less than exhaust manifolds.

Chris,
It is all that extra machining that goes into exhaust manifolds. Ya, right....

Can you say marine parts.

Rick

Can anyone tell me the best application as fas a aluminum or cast iron head?


I do run in salt water, but flush the HELL out of it when I'm through.

Thanks!

Any input on the Dart Iron Eagles?
I would think that the castings are close the same as the Pro1s only much less $$$.
Dave

Dave,
I heard that the Iron Eagles and Pro1's were the same casting only difference was iron vs aluminum. If you get the flow numbers from Dart they should match.

But I think for blower application you are better off with aluminum as they conduct the heat away from the chamber faster and prevent detonation in this application.

Shoot me an email when you get a chance, I would like to hear how the project is going. Have you started yet.

Rick

Shawn/29Scarab,

Go to the thread titled; "Headers" by "88 Mach 1" in Technical Q & A. We went into some detail there that you might be interested in.

Dean,

I have used the Dart Pro ones 310-325cc with great success. I believe either port volume will work well for your app. If your going to have the heads ported I would start with the 310s with a 2.300 valve. The final airflow numbers will be the same, with a little less volume with the 310 head. The exhaust ports on the Darts out flow the canfields up to I believe .600 lift. Unfortunatly a chamber port will not get your compression down enough to achieve your desired compression ratio. You may want to look at the 320 Darts the are capable of 130+ cc's after a chamber port and valve grind. The 320's have a much thicker deck than the Pro Ones. This could save you from buying new pistons. As with any head, porting will increase flow and hp. I would recommend a full chamber and exhaust port minimum.

As far as price the Pro Ones are $1570.00 bare. I include seat blending in that price. My assembled price is more expensive because of the hardware in them. Be careful about the quality of the parts in the Jip Joints assembled heads.

jim v
 

what cc’s are the stock heads on a new 502 gm crate motor (435hp, 8.75cr)?

what would the cr be with the 320 Darts after a chamber port and valve grind if the chamber = 130 cc's?

what would you charge for a job like this on 2 sets of aluminum heads with Ferrea Super Duty exhaust valves installed?

I will install brodix bb2 rect.
479-394-1075.brodix team

Dean

The head volume should be 119cc. A 130 chamber would be 8.2:1. I believe the most volume I got out of the pro one heads was 126cc which would be 8.43:1. I may be able to squeek a couple more cc's out of the pro ones.

320 Dart Heads......1,825.00
Exhaust valves..........264.00
Intake valves.............160.00
Titanium Retainers.....140.00
spring locators.............40.00
valve seals..................20.00
Keepers 16 -.050........50.00
springs.......................170.00 hydraulic roller/ 320.00 mech roller
Chamber port ...........250.00
full Exhaust port........450.00
Bowl port intake........150.00
valve grind................120.00
hone guides.................60.00
assemble N/C
Total.........................3,699.00 per pair

cut heads (if needed)100.00

We have had really good luck with the Canfield heads. They flow great #'s when ported correctly, and make great power. They also seem to be good against corrosion. They are also very inexpensive. We can offer you a complete set, with Manley severe duty Inconel exhaust valves, and Stainless Intake Valves. These heads are full ported and polished, with CNC chambers. They will be complete and custom built for your engine. All you'll have to do is bolt them on. For about $2500.00 Feel free to call me if you need anything.

Stephen

hp confusion-cylinder heads
we all know that horsepower is directly related to airflow (cfm).I dont understand something why dont we just put a 400+cylinder head and receive more hp. why use dart 310's or 330's
isnt bigger better when it comes to heads?!?
why?
I know some heads suggest hi-comp(why?) like bb2xtra brodix;but they also work perfect with lower comps?

Just call Dave at AFR. (818) 890-0616 ex.111. He will give you the #'s and send you the test sheets. If you don't like the price; look elsewhere. ---- Jer

It's called "volumemetric efficiency". Sometimes bigger is better and sometimes faster is better. The right combination of big and fast makes the most power. Talk to "The Man Who Flows, Knows" !! --- Jer

The heads are just fine.
 

Dean,
When dealing with a supercharger the size of the intake ports becomes a minor consideration.
A naturally aspirated engine needs to have the intake ports matched perfectly to the camshaft and exhaust system.
As long as you have large ports, and the stock rectangle port heads are large, the performance increase from changing to a larger port is almost nil with a supercharger. If you want more power you just increase the boost. Don't waste your money, install blower pistons (or simply install flat top pistons) to lower your compression. The stock heads are good!
Sincerely
Dennis Moore
FAMILY AND PERFORMANCE BOATING MAGAZINE

Simply raising the boost will work fine for a short amount of time, but this will not account for inefficient heads. We engine builders wouldn't spend countless hours porting and flowing heads if it wasn't very effective in producing RELIABLE HP. The whole point in having cylinder heads that flow high volume correctly is to increase the engines efficiency, thus creating more HP at a lower boost. This increases engine life.

We had a set of fully CNC ed AFR small block Chevy heads I remember getting about 30 more CFM out of them and maybe increasing volume about 2 cc.

Kaama- Only one problem with your post. When I ordered the AFR's I was told it would be 8 weeks before I got them. I thought I was told about 2 weeks when I had called before asking all kinds of questions. The extra time might be because they are not installing the regular valves & springs they normally do.

No offence but you have to look at the exhaust ports on the gm iron heads as well. Overlooking the fact that the left intake port flows considerably less than the right and the ports are overall ineffiecent as far as volume v/s airflow, the exhaust ports are turds at best out of the box. By compairson a small block aftermarket head ported (1.6 valve)
will outflow a stock or slightly modified (1.88 valve) big block head. With extensive porting the airflow can be increased substantually, but not enough to match a ported aftermarket head. First hand experience is by increasing airflow (big port or small, I prefer small) the hp will remain close to the same. The boost will drop depending on the airflow increase.

Mark

Does that 1380.00 include the the port work from the previous year too?

Exactly how much experience do you have with cnc'd heads other than what you have heard or read? Did you do a A/B compairson? Maybe you can buy a couple of sets and post the results.

I believe the nascar teams tweek their heads after the cnc process. When I did a set of heads for Melling/ Bill Elliot six years back, they told me to charge them $2,500.00 just for port work. I heard rumors of pro stock heads for $4,000.00 and up for labor. Quit Winning

I knew this thread was going to develop into something. So here's my two cents worth. As usual everybody's right, but the problem is multi-faceted.

Dennis Moore is right, if you already have big intakes, the supercharger will be happy, but since much of the resistance to air flow occurs around the valve, I would think that close attention should be paid to porting in this area and the chamber.

JimV is right, if it can't get out, it ain't goin' in. The stock exhaust ports in an iron head are a problem. And if you reduce resistance in the heads, but don't change pulleys (on a positive displacement blower) the HP will stay the same, at a lower boost.

totalmp is right, increasing blower speed does increase air flow, but that also increases the temperature of the charge air and puts you closer to detonation and other bad things.

Every engine project has a power/reliablilty/$$$ goal. I could make 700 HP many ways with a blower:

- restrictive intake path and 11 psi boost
- lower resistance path and 8 psi boost
- best flowing intake path, 5 psi boost.

Changing pulleys is easy and has almost no additional cost, but for lower temperatures and reliability the high flow cylinder heads are the answer.

Of course, none of you guys would leave the high flow combination at only 5 psi boost, would you?;)

"Of course, none of you guys would leave the high flow combination at only 5 psi boost, would you?"

I think JimV would agree with me here but a set of fully CNC ed heads just wont out flow a hand massaged set.

Turbo2256- I would not queston your statment, I would guess there is more there after CNC'ed. The real question is at what cost of $, time, & frustration dealing with the head massuse.

29scarab, if you flush your motor out a lot, the aluminum heads will be fine. Many engine builders use the aluminum and in blower applications, are a major necessity.

Lowering the compression lowers your effective compression ratio and hence, can lower the engery/power of combustion. One thing you have to remember when looking at power, as many have touched on, power is directly related to the amount of airflow into the engine. Of course you need the proper fuel, timing, etc. to make power, but most never realize, boost is just a measurement of what is left outside the valves, thats' not telling you whats entering the cylinder or being combusted. So cam, head flow, head porting all matter. Just lowering the compression with flat tops in a 500 HP EFI is pretty much a waste of time for the cost vs. benefits. Running more boost on pump gas will blow the head gaskets because of detonation, you can run better grade gas and more boost, but it comes down to detonation. How much air and fuel you can fire in the cylinder before it detonates or pre-ignites. So when you get a chance to increase air flow while able to tolerate more air and fuel.

Thanks,
Dustin

I think JimV would agree with me here but a set of fully CNC ed heads just wont out flow a hand massaged set.

I agree 100%

Another thing to consider the cnc head that their selling you is the same program their selling to the drag racers for their drag race motors. They are selling airflow numbers that work with camshafts at .800 lift. Write this down Mark so you can baffle someone else in your future posts. Most all the drag race ports are designed to flow air at higher lifts. To achieve this the venturi area or the throat of the port below the valve seat has to be enlarged and the short turn radius has to be laid back. When this done the numbers in the mid lift suffer. The result from this will decrease torque substantially at low rpms. 4000 rpms is low for a drag motor, it's where most of us boaters cruise and we need the torque. Also the back angle on the valve cannot be too wide or it will cause turbulance in the port at the higher lifts. The right back angle will gain 4-6 percent from .2 up to .6 lift. In a marine motor the ports need to be small and flow a lot of air. This port pictured has a volume of 318cc's and mates to a 572 twin turbo motor that made I believe 1300hp.

We had bad luck using standard CNC heads. This is the reason we use Canfields so much. They CNC chambers, and Valve seats, and Port match, then we can come in and full port the heads for optimum flow, while keeping wall thickness at a comfortable level. We're in salt water here, so we try not to thin the walls excessively. We can do all of this complete with the best Manley Valves for around $2500.00.

Also I forgot to mention the valve seat widths. The out of the box Dart has a seat width of 30-40 thousands intake about 60 exhaust. For cooling and longevity a marine motor seat widths need to be 60 -70 intake 80-90 exhaust. One more thing is the seats are rarely square with the guide and need to be ground. If the guide clearance is .002 and there is .008 runout in the seat the stem can seize or wear prematurly.

How much to correct that? Another $500 ???


Looking it from your consumers point of view, even at $500.00 dollars for a valve grind is cheaper than rebuilding a destroyed motor. I get consumers in my shop that will whine about how much money their spending and they cant offord my services but will show up three days later with a set of cool guy rocker arms with no needle bearings that cost $1,100.00 dollars when there was nothing wrong with his original rockers. Or the guy that we just completed his 700 hp 540 motor that wanted to change the cams because there was soot in the exhaust port. Meantime this guy has more aeroquip on his boat than the space shuttle and he is beating me up because he thinks I am charging him too much for my labor. Should I go on? Its impossible to deal with a customer that believes that what glitters is gold.

Oh yes if you reread my post the point was that marine ported heads are different than non marine ported heads. The volumes, seats, venturi area are different. A .650 lift cam doesn't care what a port is flowing at .800 lift. And yes the difference between a good combination and bad could be 50+ hp

JimV ,

Thats cuz were just selling them more air... how do you show that off at the Tuesday night car show behind the bar?