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Old 01-27-2020, 12:09 AM
JEC3039 JEC3039 is offline
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Default When are Out-of-the-Box E-heads Good Enough?

Looking for forum input regarding when out-of-the-box Edelbrock heads are good enough for street use versus requiring additional port work to make them "better" than as-shipped. This conversation is specific to the 72cc round port version.

Engine is a 461 Butler rotating assy with dished Ross pistons where the dish is machined fully round and leaves only ¼" of the flat top remaining. The pistons are a terrible mismatch for my current RAII closed-chamber iron heads, hence I'm considering a change to the open-chamber E-heads.

Car is a 4-speed, 3.73 rear. Cam is a HR 224/224 @ .050, 114 LS.

I know porting can further enhance mid-range and upper-end HP, but what I'm interested in is low-end to mid-range grunt. For a pure street car that will never be raced and will rarely see 5500 shifts, is the flow of the as-shipped E-heads good enough?

Thanks.

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Old 01-27-2020, 12:34 AM
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They’re always going to be good enough out of the box. What’s more of a question is what your goal for your car is.

Baes on your post of just using this as a street car that will never be raced, unless you just have to have that extra power, there’s not a ton of reason to go further with those heads.

I went with as cast KRE’s and it was a great upgrade. I don’t regret it in the least. And if you’re ever left wanting, pull them off and send them out for porting.

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Old 01-27-2020, 01:43 AM
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From what I've read , it's not the flow rate that's the problem with E-heads. It's said that the valves, springs & machine work can be much improved by having a knowledgeable Pontiac head guy machine & assemble bare heads, using better valves & springs.

https://butlerperformance.com/i-2445...tegory:1234814

Butler seems to indicate that they only sell heads they assemble, with porting included. I assume they would do a set without porting. But, I suppose it's possible that there is not enuff profit in the assembly alone. Don't know.

https://butlerperformance.com/i-2445...tegory:1394343

But, there are probably several members here who will assemble a set for you, without porting.


Last edited by ponyakr; 01-27-2020 at 01:57 AM.
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Old 01-27-2020, 01:54 AM
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for your application the answer is yes....if you use the 87cc ones for street. the 72 ones will require some higher octane.put them on and forget about it....have fun

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Old 01-27-2020, 02:10 AM
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Quote:
Originally Posted by jamaca85 View Post
for your application the answer is yes....if you use the 87cc ones for street. the 72 ones will require some higher octane.put them on and forget about it....have fun
Before saying he wants the 87 cc for the street, I would want to know how many cc's is the dish in his pistons.

Stan

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Old 01-27-2020, 06:24 AM
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They will flow more than enough for the cam and rpm range you are using. I went to Summit Racing bought a set and bolted them right on and improved only about .1 in ET from a Dan Whitmore ported 1968 16 head on a 455 with a mid 240 @.050 sft cam.

Myself I’d keep the RAII heads for the cool factor alone, but I also don’t see a huge performance gain with E heads unless other changes are made.

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Old 01-27-2020, 07:18 AM
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Your question should not be framed by as you posted air flow, but by Intake port volume as it relates to the cylinder heads minimum port area and it's big effect on port air speed, which in the end is what determines how much Torque the motor makes at given rpm.

If your more concerned with drivability then ultimate top end high rpm HP then the Edelbrock D port heads at 188 CCs, or the Kaufman D port heads are what you want to fly with , not the Edelbrock round port heads at 215 CCs.

Just for a example Pontiac iron heads with only 148 CCs of Intake port volume ( even smaller then your current 154 CC iron RAII heads ) have taken cars well into the 12s at the drag strip!

Also your RAII heads ARE open chamber as is, but they are not the better heart shape of some aftermarket heads.

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Old 01-27-2020, 07:22 AM
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Agree with Stan that knowing the dish size in your pistons is useful information.

What is the engine doing/not doing that has you considering changing heads?

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Old 01-27-2020, 07:33 AM
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As others have said, use the chamber volume that suits the type of fuel you intend to run, and they'll be fine unported. The track times in my signature line were with out of the box 87cc version.

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Old 01-27-2020, 08:51 AM
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For a street engine that will see 5500 rpm and will rarely be raced out of the box heads are perfectly fine. As long as you order a set that are over the max valve lift of your cam, a set of preassembled heads from any vendor would be fine.

I just ordered and recieved my edelbrock round port heads from butler last week. I had them do the setup because I'll have around .620 valve length and no out of the box head offers that. As i built my engine, I opted to run dished pistons as well and figured out the compression ratio to 10.5:1 with 72cc heads.

Before you order, I would figure out the exact cc of your dished pistons and see what you need for chamber volume. If you need larger or smaller than 72 butler can make that happen.

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Old 01-27-2020, 09:09 AM
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Presently RA II with dished slugs for 9.0:1.

Been thinking Ported Aluminum Round Ports for the Spare 469; if Roller Cam.
Been thinking about the old pair of 48 D-ports for the Spare 469; likely Flat HYD Cam.

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Old 01-27-2020, 09:11 AM
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I might have interest in those dished pistons...dish volume?

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Old 01-27-2020, 09:44 AM
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Quote:
Originally Posted by Stan Weiss View Post
Before saying he wants the 87 cc for the street, I would want to know how many cc's is the dish in his pistons.

Stan
And the fact that the E heads are aluminum...which means you need an extra point of compression vs. using iron heads...

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Old 01-27-2020, 09:51 AM
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I don't understand why the op would spend $1500 on new heads because of a round dish in the piston. What issue is being solved by doing this?

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Old 01-27-2020, 10:18 AM
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I had a round dish in my old SpeedPro pistons, and ran right at 10.0:1 compression with iron heads on pump 93 octane. That motor was built back in the 90's, and I recently learned it is STILL running fine. That is the motor mentioned in my signature, for the 67 Firebird.


Also, about 20 years ago, I built a 455 with out of the box Edelbrock heads. The cam used was a Crane 228/228 on a 112, and used 1.65 HS rockers to get the lift higher. I tested it on a chassis dyno locally, with a Q-jet and stock intake, and it made 356 at the wheels. (graph attached)

The owner lived outside Dallas, and had it retested there - recording the same results. He later switched to a Performer RPM and an 830 Barry Grant. He retested it, and it picked up another 30rwhp. Oh, I still talk with that guy periodically, and that motor is also still running great.
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Old 01-27-2020, 10:36 AM
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Quote:
Originally Posted by ShortyWashburn View Post
Looking for forum input regarding when out-of-the-box Edelbrock heads are good enough for street use versus requiring additional port work to make them "better" than as-shipped. This conversation is specific to the 72cc round port version.

Engine is a 461 Butler rotating assy with dished Ross pistons where the dish is machined fully round and leaves only ¼" of the flat top remaining. The pistons are a terrible mismatch for my current RAII closed-chamber iron heads, hence I'm considering a change to the open-chamber E-heads.

Car is a 4-speed, 3.73 rear. Cam is a HR 224/224 @ .050, 114 LS.

I know porting can further enhance mid-range and upper-end HP, but what I'm interested in is low-end to mid-range grunt. For a pure street car that will never be raced and will rarely see 5500 shifts, is the flow of the as-shipped E-heads good enough?

Thanks.
they are plenty good for what you described & better than almost any factory head.... but a bit overkill for the purpose you described.

i have the round port 72cc e-heads on a 467 pump gas motor with a factory intake (ported) & q-jet & the same dished ross pistons at 10.7:1. its more than what the street tires can handle even at 1/2-3/4 throttle & low 5000rpm shifts & runs excellent in all situations. from city to highway cruising. 3.23 gears & th400 trans.

& just for perspective since you dont plan to race it, my 2nd gen firebird does consistent low 11's at 121+mph launching off idle & traction problems with drag radials using out of the box e-heads with their provided valves.


Last edited by 78w72; 01-27-2020 at 11:12 AM.
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Old 01-27-2020, 11:03 AM
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Quote:
Originally Posted by slowbird View Post
I don't understand why the op would spend $1500 on new heads because of a round dish in the piston. What issue is being solved by doing this?
I was wondering the same thing. I was going to suggest not spending the money on aluminum heads because from what I read from his original post, street car, low rpm cruiser, not raced, I'd leave it alone and drive it as is.

With the round dish piston, quench isn't going to change or get better by swapping heads and from what I gathered from his post, quench seems to be his concern.

I run a round dished piston in mine with about 1/4" of flat quench area left around the parameter of the piston, and use them on stock iron heads. Runs perfectly fine. Matter of fact thanks to the chamber design of the iron head it's already taking advantage of most all the quench the heads have to offer anyway, switching heads would do nothing in that department.

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Old 01-27-2020, 01:12 PM
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will that small cam ping?

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Old 01-27-2020, 01:25 PM
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His Cam may be considered small by some for his cid , but with those 3.73 gears it will be far less likely to ping due to lugging as takes place with under 3.23 gears.

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Old 01-27-2020, 03:18 PM
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Quote:
Originally Posted by slowbird View Post
I don't understand why the op would spend $1500 on new heads because of a round dish in the piston. What issue is being solved by doing this?
This was the gist of my question above. What is driving the desire to change heads? I can't imagine that dish is causing an actual problem.

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