Need head advice, #12s vs aluminum D-ports
 

I just purchased a Comp hydraulic roller cam spec'd by Butler. It's 224/230 with .501/.510 lift w/1.50 rockers. I'll be using it with 1.65s, so that's closer to 0.551/.561. LSA is 114.

It was spec'ed for my GP with a 428+030 and 3.08 rear and planned #12 heads (I told them I was considering better heads). I was told it should be run with 9:1 to 10:1 compression. My next step is deciding if I want to proceed with #12s or not.

I have a set of #12s I always intended to use. In the earlier days of E-heads, I wondered about trying those. Then I decided "I don't want round ports. I'll just port my #12s."

Then I was told "some restorer may want those #12s for a Judge or T/A restoration depending on their date code." I don't know what they will fetch, but that seems to be worth considering. I've known KRE D-ports were on the market for years, and I had them in the back of my mind. Now I see Edelbrock makes D-ports for us, too.

The GP is to be "a cruiser more than can be a bruiser." It won't be a regular at the track, so max HP is not my goal, but throwing away power due to lackluster head flow isn't anything I want do either.

My biggest concern is ending up with an engine that pings because I went with iron heads and the CR calculations weren't 100% correct.

Or is that 114 LSA forgiving enough that ported cast iron heads are fine? How many CCs can the measurements be off and detonation rear its ugly head?

My cheap side says "Port what you got or get Butler's ported factory D-ports." The devil on the other shoulder says get the ported Edelbrock D-ports and run higher compression or minimize detonation risks with a conservative CR.

With my cam in mind, any thoughts on ported iron vs Edelbrock D-ports or even KRE D-ports is appreciated.

Unless you're class racing and are required to use a factory iron head I wouldn't spend the money to have one ported. (buying a used set of ported iron heads would be an option though)

A valve job and minor clean up on your 12's, or choose a set of aluminum heads that fit your goals and budget. Personally I'd call Butler back and let them match your goals and needs.

Thanks for the input David. I am trying to educate myself, so I can ask them all of the right questions. Butler has been EXCELLENT.

I haven't been reading Pontiac stuff much the last few years. I understand those Edelbrock D-ports are rather new on the market. As desirable as their round port brothers are, I suspect they are a good product, too. That is what I am leaning towards at the moment.

No problem, that's what we're here for. Ask away.

David and Rodney Butler won't steer you wrong.

The Butlers are a class act.

Agree with the esteemed David H in that it really isn't worth having iron heads ported when the aluminums have so much more potential. Even out-of-the-box KREs or E-brocks will generally outperform mildly modified iron heads.
Go alum !!

Jim

I agree with those that say the Aluminum heads have more "potential" than the iron. I am going with iron in my case. With a zero decked block and properly cammed engine running a good tune, a few cc here or there are not critical at less than 10:1scr. I wanted to have that stealth look on my daily driver and as crisp a throttle response as possible at light part throttle highway driving speeds. I also KNOW that 500hp is the absolute maximum I will ever want in this Daily Driver that will not be raced. So in my case the "potential" would remain unrealized with the aluminum and Iron was my best choice. This tech tip at SD Performance helped me decide: http://sdperformance.com/moreTech.php?newsID=37
I'm also using more cam than you are so if you are sure you will not get more power hungry later I would say use the iron. I'm no expert just offering up my thought process. I also would figure in what those #12 heads are worth to a restorer....If you can sell them for enough money to buy the aluminum you should seriously consider that also.....

Karl

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Thanks for the added comments everyone.

Karl,

What is your combo? What are your cam specs? I don't want over 500 hp either. I thought my cam was pretty big (the lift still surprises me!), but you saying your cam is bigger has my curiosity up. What kind of work will you have done on your cast iron heads? Do you have a particular CFM target in mind?

Also, when you say "as crisp a throttle response as possible at light part throttle highway driving speeds" how is that related to the heads?

What condition are the 12`s in? Are they set up for that HR cam and have new, non stock valves? Dish piston in that 428?

Do you want the stock look when you open the hood?

On the throttle response, the intake port size, shape and charge velocity at lower and mid lifts have the most effect on how responsive it is. The intake manifold is also a major player here. You would need to email Dave at SD Performance to get his technical explanation on this as I am NOT any kind of expert on this. His email is techsupport@sdperformance.com .
The engine that I am building is as follows: 400 block bored .030" over, zero decked, Racetec 7cc flat top forged pistons, RPM Ultra-light 6.625" floating pin forged rods, RPM cast 3" main 4" stroke crank for 433ci. The heads are 6x-4 milled to achieve 87cc chambers and ported by SD Performance http://sdperformance.com/viewProduct.php?productID=583 (Their 265@.600 lift package). The intake is a Pontiac cast iron http://sdperformance.com/viewProduct.php?productID=1727 modified by SD Performance modeled after Cliff Ruggles' intake. The cam is SD Performance's "Stump Puller HR" http://sdperformance.com/viewProduct.php?productID=1815 which specs out to 286/289 adv. 108ICL 112LSA .567"/.578" lift 230/236 dur @ .050" lift. RARE 2.5" RA manifolds into 2.5" H-Pipe magnaflow exhaust. I am going to get a TH 350 from http://www.jakesperformance.com/TH350.html probably the "stage 1". The torque converter will come from http://www.ctconverters.com/ and the rear gears will be 2.78:1 with the stock size 14" wheels.

As far as cam size goes, the Hydraulic Roller cams will act like a comparable Hydraulic flat tappet cam of around 10* smaller size as far as idle quality from what I understand. So if you think your engine would provide the idle quality you desire with 220* intake duration using a HFT cam then a 230* intake duration HR cam would be of similar idle quality using the same specs of overlap, LSA, and so on.

Karl

:usflag:

Agree 100% with not dropping coin to get iron heads ported. I had the Butlers do a set of 62's years ago - pretty much 1200++ dollars and went to KRE dports on that motor w/in a year or two anyway. I like the KRE's - the Ehead dport are basically same head. Not sure why they brought those to the market.

A .030 over 428 w/ 230/236 HR, aluminum dports/ good flowing intake and headers would make for a nice (still very streetable) motor.

With what else I purchased from Butler yesterday, I think the underhood stock look went out the window. ;) I opted for the EZ-EFI multiport setup with Torker II intake.

The #12s are supposedly untouched. I'm going to send photos of them to Butler to get their thoughts. They are assembled with regular springs/etc. I actually bought them back in '97 or '98. I always planned to have them rebuilt no matter what route I took. In those early days, I was like, "Ooooo, I got RAIII heads!" All these years later, I realize, "Oh, I have another set of plain ole D-ports with high compression chambers. Whoopeedoo."

I know if I stick with the #12s, dished pistons are going to be a necessity. I know some say that's not ideal. I need to read more about "quench."

Lou, Karl, thank you for your comments. I will check out what SD has to offer. I have friends that have used them.

Well then, that`s easy. Go with KRE or Eddy. D`s. Get the chambers to get you to 10 to 10.5 with the piston you have.

Sell the 12`s to someone that`s looking for them. 12`s are harder to find than the 13`s in 1970.

I love Butler to death, but SD Performance has a nice menu of CNC ported heads. Ebrocks as well cast iron. You heads or theirs. The Eheads ported with 1.77" exhaust are only a tad more than straight out of the box. Hard to argue the logic! Don't forget aluminum heads will tolerate a little more compression than cast iron. Your car would probably run a little cooler as well cause the aluminum shed heat better. IMHO

Thanks Punch and Frankie!

Edit: I was about to google "Eddy D." wondering who the heck is that builder. Oh, I bet that's Edelbrock D-ports! Long day... LOL

You can use the money from the 12`s to take some of the sting out of buying the alum. heads. Someone, somewhere, needs those 12`s to complete a higher dollar resto.

Do you think listing them for sale here be sufficient? I hate the idea of dealing with Ebay. Surely someone in need will look for Pontiac forums... <shrug>

Iv`e sold 3 sets of heads here in the past. 62`s, 96`s and 87cc Edelbrocks. So, yeah, you can sell them here without the drama.

Read over in the race section the other day that the smaller 72cc edelbrocks with a dished piston makes a more efficient combustion chamber than the 87cc with a flat top.

Here is the link and a few quotes from the thread.
http://forums.maxperformanceinc.com/...=728252&page=2