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#81
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That SD455 on the Facebook marketplace link was cool.
BS meter is running pretty high on the number 16 SD heads that flow 340CFM, especially when it mentions the “mildly worked over heads”. That’s pretty hilarious. That 455SD engine, with the numbers it’s is making sounds more like about 310 -315 cfm on the head flow? Which would be a feat! The dude must have a very CFM friendly flow bench. 6X and 4X have good flow potential. High compression Ping monsters, LOL. I like that… |
#82
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Are those the sheets Pete McCarthy posted in his magazine and Rocky used in his book?
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#83
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Yes they are. Bob also gave me a copy of them. I used the info when I ran the SD 455 in my car.
The best improvements were headers (duh! for a race car) and when I put the 'domed' pistons in for 10.5 CR. That also helped a bunch. Ran a .700 lift roller and the engine was still very docile. But a beast when throttle mashed.
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John Wallace - johnta1 Pontiac Power RULES !!! www.wallaceracing.com Winner of Top Class at Pontiac Nationals, 2004 Cordova Winner of Quick 16 At Ames 2004 Pontiac Tripower Nats KRE's MR-1 - 1st 5 second Pontiac block ever! "Every man has a right to his own opinion, but no man has a right to be wrong in his facts." "People demand freedom of speech to make up for the freedom of thought which they avoid." – Socrates |
#84
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Quote:
A professionally ported SD-455 head flows 285-290 with a basic race port job. 330 max effort with moving the pushrod..... Advertised 340 cfm is probably hurting the chance of a sale but helps the dreamers dream. Last edited by PAUL K; 09-09-2023 at 12:35 PM. |
#85
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Quote:
I ran ported SD heads on my Firebired in the mid 90's. The car went into the nines through the mufflers, weighing 3900 lbs. with a shot of spray. The SD engine are Bad Azz! |
#86
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I knew I had seen/read them somewhere!
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Skip Fix 1978 Trans Am original owner 10.99 @ 124 pump gas 455 E heads, NO Bird ever! 1981 Black SE Trans Am stockish 6X 400ci, turbo 301 on a stand 1965 GTO 4 barrel 3 speed project 2004 GTO Pulse Red stock motor computer tune 13.43@103.4 1964 Impala SS 409/470ci 600 HP stroker project 1979 Camaro IAII Edelbrock head 500" 695 HP 10.33@132 3595lbs |
#87
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Quote:
I am not on Facebook so maybe there are parts of the post that I can not see. But I didn't see the seller say anything about the head flow cfm. I only saw that in GTO-relic's post. Stan PS Does anyone still have a copy of the dyno sheets that they can post?
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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 |
#88
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#89
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Quote:
http://pontiac-power.com/sd-dyno-menu.htm
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John Wallace - johnta1 Pontiac Power RULES !!! www.wallaceracing.com Winner of Top Class at Pontiac Nationals, 2004 Cordova Winner of Quick 16 At Ames 2004 Pontiac Tripower Nats KRE's MR-1 - 1st 5 second Pontiac block ever! "Every man has a right to his own opinion, but no man has a right to be wrong in his facts." "People demand freedom of speech to make up for the freedom of thought which they avoid." – Socrates |
The Following User Says Thank You to johnta1 For This Useful Post: | ||
#90
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Quote:
Thank you very much. Stan
__________________
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 |
#91
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#92
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Each test sheet basically listed what was done to the engine for that test. Then a one page report was sent telling the recommendations. Larger diameter exhaust system was one. I do not have sheets copied to computer just hard copies.
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The Following User Says Thank You to sdbob For This Useful Post: | ||
#93
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flow numbers are only part of the story...
the discharge characteristics of the intake valve/chamber are just as important, Pontiac intake ports 1968-up had the scallops in chambers, to deflect flow in 4 different directions, as the valve opened/closed. to see how it works, the intake port must be pressurized, with the flow bench in exhaust mode, and the chamber faced sideways, and intake valve opened. then epiphany still strike. if heads are only flowed with chamber down, that's only half the picture or less, it's just a number. better than nothing, however, you need to see how chamber side is working too. when the chamber scallops are ground away, and the quench pad opened up like the spark plug side, it completely changes the flow and burn characteristics of the head. Last edited by GTO-relic; 09-13-2023 at 07:32 AM. |
#94
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#95
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Quote:
Stan
__________________
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 |
#96
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Appears the tanker cars in relic's trainwreck are hauling nitro.
Clay |
#97
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factory stock round port head combustion chambers were opened up on quench side of the chamber, right from the factory
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#98
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quench pads, side spark plug Boss 429 head
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#99
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We port a lot of factory iron heads and have made decent power in the past. We spend about as much time as it takes to read this thread on the combustion chambers and a lot of time on the ports and valve job.
We can post pictures stolen from the Internet forever and accomplish very little. Does anyone have before/after track tests or dyno numbers showing results of these chamber modifications? ...asking for a friend |
#100
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The shallow side of the chambers being opened up was done more in response to the tuliped intake valve used in the IV heads then anything else.
Later I will dig out the 1989 article that I think I still have on SD455 motor built for SS with ported heads making 590 hp . I recall that Kip Martin during the dyno session picked up 90 Hp by just tuning changes.
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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! |
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