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#1
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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. |
#2
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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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-Jason 1969 Pontiac Firebird |
#3
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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. |
#4
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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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1970 firebird, 468, e heads, |
#5
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Quote:
Stan
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Stan Weiss/World Wide Enterprises Offering Performance Software Since 1987 http://www.magneticlynx.com/carfor/carfor.htm David Vizard & Stan Weiss' IOP / Flow / Induction Optimization - Cam Selection Software http://www.magneticlynx.com/DV Download FREE 14 Trial IOP / Flow Software http://www.magneticlynx.com/DV/Flow_..._Day_Trial.php Pontiac Pump Gas List http://www.magneticlynx.com/carfor/pont_gas.htm Using PMD Block and Heads List http://www.magneticlynx.com/carfor/pont_pmd.htm |
The Following User Says Thank You to Stan Weiss For This Useful Post: | ||
#6
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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.
__________________
68 GTO,3860# Stock Original 400/M-20 Muncie,3.55’s 13.86 @ 100 Old combo: 462 10.75 CR,,SD 330CFM Round Port E's,Old Faithful cam,Jim Hand Continental,3.42's. 1968 Pontiac GTO : 11.114 @ 120.130 MPH New combo: 517 MR-1,10.8 CR,SD 350CFM E's,QFT 950/Northwind,246/252 HR,9.5” 4000 stall,3.42's 636HP/654TQ 1.452 10.603 @ 125.09 http://www.dragtimes.com/Pontiac-GTO...lip-31594.html |
The Following 2 Users Say Thank You to TCSGTO For This Useful Post: | ||
#7
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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.
__________________
Wernher Von Braun warned before his retirement from NASA back in 1972, that the next world war would be against the ETs! And he was not talking about 1/8 or 1/4 mile ETs! 1) 1940s 100% silver 4 cup tea server set. Two dry rotted 14 x 10 Micky Thompson slicks. 1) un-mailed in gift coupon from a 1972 box of corn flakes. Two pairs of brown leather flip flops, never seen more then 2 mph. Education is what your left with once you forget things! Last edited by steve25; 01-27-2020 at 07:32 AM. |
The Following User Says Thank You to steve25 For This Useful Post: | ||
#8
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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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---------------------------- '72 Formula 400 Lucerne Blue, Blue Deluxe interior - My first car! '73 Firebird 350/4-speed Black on Black, mix & match. |
#9
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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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'65 Tempest 467 3650# 11.30@120.31 |
#10
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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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1967 GTO, 432 (428+.030), 4-bolt mains, factory Nodular crank, scat rods, icon dished pistons, Lunati HR 243/251@.050, .618/.622 lift, Edelbrock 72cc round port heads, 10.5:1, offy 2-4 intake, Edelbrock 650cfm carbs, Super T10 trans (2.64 first), BOP 10 bolt w/ Eaton posi and 3.36 gears |
#11
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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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12.24/111.6MPH/1.76 60'/28"/3.54:1/SP-TH400/469 R96A/236-244-112LC/1050&TorkerI//3850Lbs//15MPG/89oct Sold 2003: 12.00/112MPH/1.61 60'/26"x3.31:1/10"/469 #48/245-255-110LSA/Q-Jet-Torker/3650Lbs//18MPG 94oct Sold 1994: 11.00/123MPH/1.50 60'/29.5"x4.10:1/10"/469 #48/245-255-110LSA/Dual600s-Wenzler/3250Lbs//94oct |
#12
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I might have interest in those dished pistons...dish volume?
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#13
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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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1977 Black Trans Am 180 HP Auto, essentially base model T/A. I'm the original owner, purchased May 7, 1977. Shut it off Shut it off Buddy, I just shut your Prius down... |
#14
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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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#15
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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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'73 T/A (clone). Low budget stock headed 8.3:1 455, 222/242 116lsa .443/.435 cam. FAST Sportsman EFI, 315rwhp/385rwtq on 87 octane. 13.12 @103.2, 1.91 60'. '67 Firebird [sold], ; 11.27 @ 119.61, 7.167 @ 96.07, with UD 280/280 (108LSA/ 109 ICL)solid cam. [1.537, 7.233 @93.61, 11.46 @ 115.4 w/ old UD 288/296 108 hydraulic cam] Feb '05 HPP, home-ported "16" D-ports, dished pistons (pump gas only), 3.42 gears, 275/60 DR's, 750DP, T2, full exhaust My webpage http://lnlpd.com/home |
#16
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Quote:
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. |
#17
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Quote:
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. |
#18
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will that small cam ping?
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#19
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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.
__________________
Wernher Von Braun warned before his retirement from NASA back in 1972, that the next world war would be against the ETs! And he was not talking about 1/8 or 1/4 mile ETs! 1) 1940s 100% silver 4 cup tea server set. Two dry rotted 14 x 10 Micky Thompson slicks. 1) un-mailed in gift coupon from a 1972 box of corn flakes. Two pairs of brown leather flip flops, never seen more then 2 mph. Education is what your left with once you forget things! |
#20
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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.
__________________
---------------------------- '72 Formula 400 Lucerne Blue, Blue Deluxe interior - My first car! '73 Firebird 350/4-speed Black on Black, mix & match. |
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