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#1
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Speedmaster CNC vs. KRE 290cfm CNC D-ports?
Sorry, another SM head post.
I picked up a set of the Speedmasters during the Black Friday sale. I know they are going to need a little work like removing the tangs, upgrading the valve locks and perhaps a better valve job. With that said and in my case, would these heads be an upgrade for me over my KRE 290cfm 74cc D-ports with no other changes (minus headers)? Can I use my ARP D-port head studs with them?
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Johnny US Army Retired 1978 T/A 463 Pontiac, KRE 74cc 292CFM D-ports, Lunati VooDoo, V-max lifters, TKII, ATM 850 E85 carb, TCI TH-350 race tranny, 3600 converter 3.73 12 bolt 11.63@116.68mph 1981 T/A 4-speed 406 Pontiac, Merrick ported 6X heads, Comp 270S cam, Crosswind intake 750 Street Demon, 3.42 30 spline Eaton posi street car. 1980 Formula 350 Pontiac back burner project 1972 LeMans 350 Pontiac |
#2
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Speed master only makes a round port version of a Pontiac head so you can't do a apples to apples comparison.
In short here's what will happen in my opinion. The speedmasters start off as per there web site at a port volume of 230 CCs, your worked over KRE heads even at flowing 290 cfm are not at 230 CCs. If both heads flowed close to the same amount of air at the same lift then the Speedmaster heads with there greater port volume will hold on to the peak HP number that they make longer before nosing over turn like the KRE heads will. The question then becomes will this effect take place in too high and narrow of a rpm range to be of benefit to you motor combo as it is now. I guess you will find out. I don't know the Cam spec's your running, but here's another guess on my part. I don't think you where running enough valve lift to even make the best usage of those KRE cnc D port heads in terms of what they flow.
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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; 01-03-2024 at 07:21 AM. |
The Following User Says Thank You to steve25 For This Useful Post: | ||
#3
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Quote:
The SD Performance web site lists the 290-295 heads @ 197 cc. https://www.sdperformance.com/listPr...?categoryID=49 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 2 Users Say Thank You to Stan Weiss For This Useful Post: | ||
#4
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2nd gen (2 lengths) Round port eheads head bolts and studs work w speed master. Do not know if k dports use same length studs as e round ports
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1969 carousel red firebird 455, richmond 5 speed 1964 540 gto 1971 lemans sport convertible 1972 Maverick under slow construction |
The Following User Says Thank You to mysticmissle For This Useful Post: | ||
#5
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Thanks gentlemen, here's the cam card of my current camshaft. I'm currently running .580/.584 lift with the VooDoo HFT and Rhoads V-Max lifters.
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Johnny US Army Retired 1978 T/A 463 Pontiac, KRE 74cc 292CFM D-ports, Lunati VooDoo, V-max lifters, TKII, ATM 850 E85 carb, TCI TH-350 race tranny, 3600 converter 3.73 12 bolt 11.63@116.68mph 1981 T/A 4-speed 406 Pontiac, Merrick ported 6X heads, Comp 270S cam, Crosswind intake 750 Street Demon, 3.42 30 spline Eaton posi street car. 1980 Formula 350 Pontiac back burner project 1972 LeMans 350 Pontiac |
#6
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So Johnny, what is your current HP, TQ, 1/4 mile ET/MPH? If you put the SM's on how will you judge the change?
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Tim Corcoran |
#7
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Quote:
This is my only timed 1/8th mile 125 shot nitrous run I have (right lane). I would love to pick up .3 in the quarter on motor if I swap the heads.
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Johnny US Army Retired 1978 T/A 463 Pontiac, KRE 74cc 292CFM D-ports, Lunati VooDoo, V-max lifters, TKII, ATM 850 E85 carb, TCI TH-350 race tranny, 3600 converter 3.73 12 bolt 11.63@116.68mph 1981 T/A 4-speed 406 Pontiac, Merrick ported 6X heads, Comp 270S cam, Crosswind intake 750 Street Demon, 3.42 30 spline Eaton posi street car. 1980 Formula 350 Pontiac back burner project 1972 LeMans 350 Pontiac |
#8
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No data, but I don't think you'll pick up. The SD KRE heads are very efficient. Many of those heads used in combos on this site that make nearly 600hp.
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#9
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I think it's a toss up if you would gain anything by putting the SM heads on. I think you would gain more with a cam change. I think this Ultradyne solid lifter flat tappet cam would wake up that motor some, Adv. 288/296 lift .612/.630, Dur. 255/263 @.050 and 108 LSA. Tim at Bullet Cams could grind one up for you. This is one of Harolds favorites I ran it in a 455 with mild 6X ported heads and it was a screamer. If you were going to run N20 with this cam you would want to have it ground on a 110 LSA. If you wanted to go with a hyd roller you might consider this Voodoo Hydraulic Roller, works with moderate nitrous and small superchargers. Very healthy idle quality. ;Advertised Duration (Int/Exh): 294/302 ;Duration @ .050 (Int/Exh): 243/251 ;Gross Valve Lift (Int/Exh): .560/.565 ;LSA/ICL: 110/106. You may want to run this cam with 1.65's. with the correct springs to go with it. Going with a hyd roller is costly though and you would want to run the Johnson lifters and they are over $800 bucks or run the Comp new Evolution lifters but I would not use any of the others.
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Tim Corcoran |
#10
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If you do swap heads let me know, I'm going to purchase a set of KRE D ports
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1967 GTO 416 5-spd streetcar 11's on HP low 10's 150 shot 1965 GTO 10-71 Littlefield high-helix retro/Bird (untuned) 8.44 @159 3500+lbs 10.5W's SOLD! 1964 421 GP-Sold 6.0 cert. Fiat bodied altered blown alcohol Pontiac IAII-Sold |
#11
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Thanks everybody for your input, I really appreciate it.
Since the SM heads have the bigger runners, I will install those on the 463 with a solid roller Paul Kippens sold me sometime back. I have new Howards Cams 98541 springs and new Comp Cams retainers and locks to go with it. The KRE D-ports along with the Dougs headers I'm running will go to the future 428 for my 81 T/A.
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Johnny US Army Retired 1978 T/A 463 Pontiac, KRE 74cc 292CFM D-ports, Lunati VooDoo, V-max lifters, TKII, ATM 850 E85 carb, TCI TH-350 race tranny, 3600 converter 3.73 12 bolt 11.63@116.68mph 1981 T/A 4-speed 406 Pontiac, Merrick ported 6X heads, Comp 270S cam, Crosswind intake 750 Street Demon, 3.42 30 spline Eaton posi street car. 1980 Formula 350 Pontiac back burner project 1972 LeMans 350 Pontiac Last edited by Johnny406; 01-04-2024 at 06:00 PM. |
#12
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Solid roller in a street car, hmmmmm
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Tim Corcoran |
#13
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Run more valve lift...
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466 Mike Voycey shortblock, 310cfm SD KRE heads, SD "OF 2.0 cam", torker 2 373 gears 3200 Continental Convertor best et 10.679/127.5/1.533 60ft 308 gears best et 10.76/125.64/1.5471 |
#14
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I run the UltraDyne 288 solid roller lobe on the intake side, but with 292 on the exhaust side.
0.4176" lobe lift / 1.65 intake and 1.6 exhaust. Set at .022" lash. With a 110 LSA. 505 CID Peak torque 4400 /4500 RPM average 627-630 ft.lbs. TQ Average peak power at 5750 RPM (depending on the pull 5600-5800 RPM) 625-630 HP .
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'70 TA / 505 cid / same engine but revised ( previous best 10.63 at 127.05 ) Old information here: http://www.hotrod.com/articles/0712p...tiac-trans-am/ Sponsor of the world's fastest Pontiac powered Ford Fairmont (engine) 5.14 at 140 mph (1/8 mile) , true 10.5 tire, stock type suspension https://www.youtube.com/watch?v=qDoJnIP3HgE Last edited by Steve C.; 01-06-2024 at 12:34 AM. |
#15
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Are the D ports forsale?
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#16
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No, they will be going to the street car or a spare motor. THanks for asking.
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Johnny US Army Retired 1978 T/A 463 Pontiac, KRE 74cc 292CFM D-ports, Lunati VooDoo, V-max lifters, TKII, ATM 850 E85 carb, TCI TH-350 race tranny, 3600 converter 3.73 12 bolt 11.63@116.68mph 1981 T/A 4-speed 406 Pontiac, Merrick ported 6X heads, Comp 270S cam, Crosswind intake 750 Street Demon, 3.42 30 spline Eaton posi street car. 1980 Formula 350 Pontiac back burner project 1972 LeMans 350 Pontiac |
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