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

I have some Gessler ported iron heads on my car and I was wondering if I would gain any performance by putting on my unported Edelbrock heads.
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.
I have the SPX intake with TA 1.6 rollers as well.

 

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

I run a set of the Gessler Level 3 iron heads my numbers are intake 254 @ .500 & exhaust 187 @.500. does any body have flow numbers for a set of untouched Eddys ?

 

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

There are TWO keys to making power: Breathing and Burning.

What does the combustion chamber of the Edelbrock heads look like compared to the iron stockers.

 

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

For a few hundred dollars, you can get some bowl work done to the Eddies that would really wake them up. That is a lot of bang for the buck. Also remember that if the heads came from Edelbrock assembled, they need to come apart and checked anyway.

 

The Edelbrock heads have a more modern heart shaped combustion chamber compared to the identical to stock TA head. Ditto on having them disassembled, inspected and blue printed. The unported E heads are comparable to most ported iron heads. I believe that was the intent of the design.

 

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

Call Greg and ask him which will work better.

 

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

Thanks fellas for all your input. I think I'll just keep the ported irons on for now and just wait until I send out the Eddy's to get ported.
Seems like the difference isn't big enough for the hassle.

Thanks again Joe

 

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

If you go Aluminum why not go TA heads since you already have the roller rockers. You will need to buy the Chevy style rockers for the Eddy heads.

 

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

I have may some recent info in this topic. A member here had a set of full port job Stage 1 heads (professionally converted from small valve).

The car with these heads ran a last pass of 10.67 @ 123 mph. He took them off and bolted on a set of off the shelf Edelbrock aluminum heads. He then went to the track and ran the quarter mile with the Edelbrocks.There was a difference in the results.

I will ask his permission to report what the performance difference was.To answer some questions about the quality of the port work on the iron heads, they were ported by Les Schmader, who is one of the most experienced head porters in the country for a variety of types of heads. It's all he does. The point is that this was not a DIY best guess port job. They heads were fully ported from intake to valve seat, but were not an all out " full race" max port.

I think most would agree that actual qtr. mile drag strip time comparison is a better indication of the power produced vs. flow numbers, chassis dyno numbers etc. Hope to get back soon with the Edelbrock ET and MPH.

Anyone care to guess what the difference will be?

 

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

My guess is 10.28 @ 128 mph. Based on nothing but a WAG and being 50lbs lighter.

 

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

I think you it's a good idea to consider the proof being in the time slips.
The raw CFM #'s are far less important than matching the CSA and velocities to your desired TQ and power peaks along with the velocity profile being better with a well ported head over an as cast OOTB head.
Whatever fits your combo and goals better and take seriously the aspect of heat rejection.

 

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

Larry, you make a good point on the compression ratio. Aluminum heads will need up to a full point more than iron to take full advantage of them. But it is also valuable to know the difference in just replacing iron with aluminum. Not everyone that considers aluminum is going to want to add the time and expense to replace pistons, deck the block, mill the new heads etc. So this is a true "bolt on and go" before and after.

No use having the argument like "if he raised the compression the aluminum would have done even better". That argument is more for those who can design their build from the start around the aluminum heads. Plus for an iron-headed engine already built or up and running, it drastically changes the economics for aluminum heads from being a $2,500 decision to more like a $3,000 and (way) up decision.

I believe lots of guys are looking at a plain swap-out replacement if there is enough benefit to change.

As for the compression ratio before and after, it was about 11 to 1. So the only impact would be a bit higher compression, favoring the Eddy's, based on going from 71cc iron heads to 68cc Eddy heads. Keep in mind that the higher the compression ratio, even small changes make a huge difference.

 

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

Larry, kinda off topic but I am curious what your quench distance is.

 

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

With the Eddie's the time will be 11.50,as compared to the steel heads,this with the direct swap.Bruno.

 

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

I believe you mean 10.50, Bruno.

With the aluminum heads you can run 4 deg more timing which doesn't make it imperative to raise compression while at the same time take that 4 deg away and it will be more pump gas friendly.