Which will flow better? Unported Eddy heads or Gessler level 3 ported Iron Stage1's?

Re: Which will flow better? Unported Eddy heads or Gessler level 3 ported Iron Stage1

A word of caution on time slip comparisons.

To be valid, weather considerations have to be eliminated.

All times must be converted to standard conditions, and any wind or traction issues have to be noted.

Fairly easy to do these days, just list the date and time of each pass, and what track was run. There is a comprehensive database available for this now.



JW

 

Re: Which will flow better? Unported Eddy heads or Gessler level 3 ported Iron Stage1

Ok here are the results of the iron swap-out to aluminum.

The OP Joe Medrano's hunch, earlier in this thread, looks like he was right: "I'm thinking that the ported iron heads probably flow better then the stock Eddy heads and the only gain would be the weight savings."

Iron ported heads: 10.67 @ 123
Unported Eddys: 10.74 @ 120

Note: The Eddys also had the benefit of 1.65 ratio rockers vs. 1.55 for the ported iron Stage 1s. JW -I did not get the track conditions, but the numbers were so close it could have been a factor.

My own take from this:

1) Unported aluminum Stage 1 style heads will typically not out perform (well) ported Stage 1 iron heads.
2) Based on this one example, and possible track condition differences, you could argue the two heads are about the same, less than 1/10th apart.
3) Coming from ported Stage 1s, plan to have the aluminum heads ported and you will be happier.
4) If the goal of Edelbrock was to achieve the power of "the best" ported iron heads right off the shelf, they did it.

The car belongs to Brent Earp. BTW Brent is planning to have the Eddys ported now.

For these particular iron heads, the original ported flow numbers were lost. I now own these iron heads, and I am in the process of getting flow numbers. I will post them in this thread when I do.

Meanwhile, does anyone know the flow numbers for stock Edelbrocks?

 

Re: Which will flow better? Unported Eddy heads or Gessler level 3 ported Iron Stage1

Thats some interesting info, thanks for posting Dean. That is pretty close (obviously depending on similar track conditions). I'll be interested to see what the car picks up after the aluminum heads are ported. Please keep us posted!

 

Re: Which will flow better? Unported Eddy heads or Gessler level 3 ported Iron Stage1

Another consideration before swapping to aluminum heads is when the intake valve closes. I have Gessler Level 5 heads on my 10:1 stock appearing engine. I had thought about switching to aluminum S1 TA but my compression ratio stopped me as I thought at best the performance would be the same but probably less. My current set up closes the intake valve late and on bad air days at the track my car is handicapped more than other combos I've run. I lose about 0.10 in 60'. If I ever did change to Aluminum heads without changing my shortblock, I'd for sure also change the camshaft.

 

Re: Which will flow better? Unported Eddy heads or Gessler level 3 ported Iron Stage1

I had the ported Stage 1 heads flowed. Here is the head flow comparison with the Edelbrock. See results in next post.

 

Re: Which will flow better? Unported Eddy heads or Gessler level 3 ported Iron Stage1

I had the ported Stage 1 heads flowed. Here is the head flow comparison with the Edelbrock.

Image is small so you need to click on it.

The Edelbrock is clearly superior at all lift points for both Intake and Exhaust. Interesting that it did not beat the ported iron Stage 1s at the track.

S1 = Ported Stage 1 Heads
Eddy = Edelbrock Heads
Int = Intake port
Ex = Exhaust port



Source for Edelbrock flow numbers: Edelbrock

 

Re: Which will flow better? Unported Eddy heads or Gessler level 3 ported Iron Stage1

Here are some pics of one of the intake ports on the iron Stage 1 heads. You can get an idea of the level of porting work that was done in order to get closer to the flow numbers of an Edelbrock aluminum head. It was a substantial amount of porting.

The first pic is looking straight into the valve pocket. The red stuff is machinist ink since from just getting a valve job.

The 2nd pic is looking straight into the runner from the intake manifold side, you can see the flashlight in the valve area.

 

Re: Which will flow better? Unported Eddy heads or Gessler level 3 ported Iron Stage1

After reading all the post in this thread, I'm wondering how many of you really know about wet flow compared ti air flow? There is a huge difference between both of them. On the flow bench, not wet flow. The air can move quit easily but you can not see the liquid swirl in the combustion chamber nor the bore. Now looking in a ultraviolet lighted wet flow, you can see everything that makes a world of difference in designs of heads. That includes aluminum and cast iron. By running aluminum heads doesnt mean you need to up your compression ratio, if the head is designed properly, it will out shine the O.E.M. ported heads any day of the week. Look at any other engine brand and their factory NHRA direct replacement head. They out flow, wet flow, and better perform any factory head. Even a aluminum version of the exact head. For an example, AFR 160 head for the sbc, it makes more power on a factory sbc then any factory head could and thats aluminum. Why you ask? Simple, better designed...

 

Re: Which will flow better? Unported Eddy heads or Gessler level 3 ported Iron Stage1

Very interesting. Thanks for posting the results.

 

Re: Which will flow better? Unported Eddy heads or Gessler level 3 ported Iron Stage1

So what your saying is a guy could do fine with a little less compression and well ported iron heads over the cost of the Eddy's and the cost of raising the compression or porting the Eddy's. Ok guys that are going aluminum start selling those awful iron heads

 

Re: Which will flow better? Unported Eddy heads or Gessler level 3 ported Iron Stage1

Good info but it lacks some perspective.

Sure, if you've invested huge expense and time in iron Stage 1 heads, you may be slightly better off than out of the box Edelbrock heads.

However, if you have a stock small valve motor then the Edelbrock heads are a huge step forward for very little effort. If you do anything at all to the Edelbrock heads, you just blew past where the iron heads can never go.

It all depends on what you have and what you want to accomplish.

 

Re: Which will flow better? Unported Eddy heads or Gessler level 3 ported Iron Stage1

I think this is an excellent example of the fact that street/strip port iron heads will perform right with "out of the box" aluminums.

Slight flow advantages are offset by a decrease in thermal efficiency.

Cost-wise, with the Edelbrocks up over 1K each now, they aren't the "low price option" they once were.

But if we consider the costs of the two heads involved, from core status small valve iron heads, rebuilt and ported, will cost approximately the same as as TA or E heads, out of the box.

The difference really is that the aluminum heads allow for a greater evolution of your combo, over time. I see this all the time, and do 470 Builds with existing aluminum heads that we "fluff up" to enhance performance.

That "fluff money" goes a lot farther with the aluminums, than with irons.

The best value for the mid price- mid performance (450-525HP) Buick big block is still previously ported iron heads, and will continue to be.

JW

 

Re: Which will flow better? Unported Eddy heads or Gessler level 3 ported Iron Stage1

Based on the experience found in this forum, I believe this is the pecking order of 455 heads:

1 - stock small valve
2 - stock unported Stage 1
3 - ported small valve
4 - tie: ported Stage 1 and unported aluminum (either support well over 500 HP)
6 - mildly ported aluminum
7 - fully ported aluminum

Remember this is the Street/Strip forum.

Not sure where to put Stage 2-3-4 heads, but if you need those you already need aluminum anyway unless you need to qualify for a racing class that requires iron.

I realize there are exceptions. Gessler level 4 max effort Stage 1 port for iron will flow equal to mildly ported aluminum. You wouldn't spend that kind of money on iron unless you were racing in a class that called for iron heads. Also, 500 HP has been done with ported small valve and unported Stage 1.

 

Re: Which will flow better? Unported Eddy heads or Gessler level 3 ported Iron Stage1

Larry, what happened to your iron Stage 1 heads. Asking for a friend

 

Re: Which will flow better? Unported Eddy heads or Gessler level 3 ported Iron Stage1

Thanks Larry. I forgot you swapped out engines.

 

Re: Which will flow better? Unported Eddy heads or Gessler level 3 ported Iron Stage1

So, if I decided to buy eddy heads and decided to have the combustion chamber coated to retain heat for under a hundred bucks, I still come out on top of any cast iron head? Yes thermo barriers can be bought and applied by your self for under $100.00. That just sums up this case real quick. Aluminum heads still out do any ported head period, no matter what. A simple home valve bowel job on any aluminum heads, will beat a best of the best ported iron head. Apples to apples folks not some weird thinking stuff. Its like saying high silcon pistons can hang with forged? Not...