Re: Engine Build Philosophy: Port Size vs Application
[Re: GTX MATT]
#2416882
12/11/17 06:20 PM
12/11/17 06:20 PM
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Joined: Jan 2003
Posts: 14,506 So. Burlington, Vt.
fast68plymouth
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Victors should be used only by masochists Do you follow Brad's posts on here? Brads Victors were less work than his stage 6's(well, pretty much any non-Chapman stage 6's)......and no more time or labor intensive than a set of 280cfm 906's.
68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123 Dealer for Comp Cams/Indy Heads
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Re: Engine Build Philosophy: Port Size vs Application
[Re: HotRodDave]
#2416922
12/11/17 07:35 PM
12/11/17 07:35 PM
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Joined: Jun 2003
Posts: 52,972 Romeo MI
MR_P_BODY
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It seems to me that a too big of port thing is not as important as it seems at first glance, a stone stock 392 CID GEN III hemi runs great at 2000 RPM with huge ports, next time you drive one with a 6spd try lugging it at low RPM, seems to run just fine, as a matter of fact the eagle 5.7 has almost as big of ports with even less displacement and make plenty of TQ down low and has great throttle response once the DBW crap is tuned right.
Wet flow dynamics is more than just high velocity. These modern engines work so well because the engineers work on improving all aspects like flow, swirl, velocity, cam timing, runner length, ex flow, chamber shape, spark plug placement (find a way to get the plug in the richest mixture part of the chamber), cool intake air (hint... the manifold is a lot more important in keeping the charge cool before entering the chamber than the part the air filter is hiding in).
Bottom line is you can still make big TQ with big efficent ports but you can not make big HP with little ports no matter how "efficent" they are. I got a set of modern cylinder head CNC 302 casting heads and velocity is incredible but even jeff said he had a hard time making 500 hp with em but TQ was great. You just got to find a balance that works for you. Your talking dry flow VS wet.. 2 different worlds I love the power in my 416 W2.. its injected with multi port injection.. it was less power with the carb on the street.. but I did make some changes so its not 100% the same... I did go with a smaller cam for one thing
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Re: Engine Build Philosophy: Port Size vs Application
[Re: BradH]
#2416923
12/11/17 07:37 PM
12/11/17 07:37 PM
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Joined: Jan 2005
Posts: 12,419 Kalispell Mt.
HotRodDave
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HRD - I don't think that's an apples-to-apples comparison. How's a 426 N/A Drag Pak with a 270+ at .050" cam pull at 2000 RPM under a load? And how would it behave if it was also retro-fitted with a carb and old-tech mechanical-advance ignition? The original question was port size vs aplication, this is a very exagerated example of really big ports in both size and flow for the CID but still makes plenty of TQ in the aplication and velocity will be really low at lower RPM yet it works. If you heard of someone putting heavily ported W2s (similar flow to an eagle but smaller cross section) but on a stock 340 short block you would think they were crazy and going to kill there streetability but the Gen III engine seems to defy old school logic. All I am saying is you can not just say you need velocity more than flow, there is a lot more to it and some of the old hard fast theory no longer seems to hold up. Now we have a 485 hp SAE Net 392 with plenty of low end TQ.
I am not causing global warming, I am just trying to hold off a impending Ice Age!
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Re: Engine Build Philosophy: Port Size vs Application
[Re: HotRodDave]
#2416953
12/11/17 08:35 PM
12/11/17 08:35 PM
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Joined: Jan 2003
Posts: 15,439 Val-haul-ass... eventually
BradH
OP
Taking time off to work on my car
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OP
Taking time off to work on my car
Joined: Jan 2003
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Val-haul-ass... eventually
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HRD - I don't think that's an apples-to-apples comparison. How's a 426 N/A Drag Pak with a 270+ at .050" cam pull at 2000 RPM under a load? And how would it behave if it was also retro-fitted with a carb and old-tech mechanical-advance ignition? The original question was port size vs aplication, this is a very exagerated example of really big ports in both size and flow for the CID but still makes plenty of TQ in the aplication... Now we have a 485 hp SAE Net 392 with plenty of low end TQ. True, as it is w/ the GM LS7 "stuff". But what works using current tech doesn't always apply -- much less retro-fit -- to the old sh!t most of us are building on here.
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Re: Engine Build Philosophy: Port Size vs Application
[Re: HotRodDave]
#2417043
12/11/17 10:56 PM
12/11/17 10:56 PM
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Joined: Nov 2010
Posts: 3,696 jersey
Spaceman Spiff
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It seems to me that a too big of port thing is not as important as it seems at first glance, a stone stock 392 CID GEN III hemi runs great at 2000 RPM with huge ports, next time you drive one with a 6spd try lugging it at low RPM, seems to run just fine, as a matter of fact the eagle 5.7 has almost as big of ports with even less displacement and make plenty of TQ down low and has great throttle response once the DBW crap is tuned right.
Wet flow dynamics is more than just high velocity. These modern engines work so well because the engineers work on improving all aspects like flow, swirl, velocity, cam timing, runner length, ex flow, chamber shape, spark plug placement (find a way to get the plug in the richest mixture part of the chamber), cool intake air (hint... the manifold is a lot more important in keeping the charge cool before entering the chamber than the part the air filter is hiding in).
Bottom line is you can still make big TQ with big efficent ports but you can not make big HP with little ports no matter how "efficent" they are. I got a set of modern cylinder head CNC 302 casting heads and velocity is incredible but even jeff said he had a hard time making 500 hp with em but TQ was great. You just got to find a balance that works for you. What do you consider " big HP?" Modified eliminator guys were running in the 9's, under 300 cubic inches, and with stock head castings. and that was 40 years ago.
526 cubes of angry wedge, pushbutton shifted, 9 passenger killer!
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Re: Engine Build Philosophy: Port Size vs Application
[Re: Spaceman Spiff]
#2417177
12/12/17 03:15 AM
12/12/17 03:15 AM
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Joined: Aug 2003
Posts: 43,237 Bend,OR USA
Cab_Burge
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When you discuss the old days in Modified eliminator you have to remember that all those drivers let the clutch out at 8000 + RPM with either 6.17, 5.86 or maybe as tall as 5.57 with a 3.25 low gear and shifted them between 8500 up to 9800 RPM, NO torque what so dang ever They idle at 1500 + RPM, those motors flat scream from when the top bulb came on until they let off on the other end, none of those motors ran in gear below 2500 RPM until they stuck the clutch in to reverse directions or were shutting the motor off
Last edited by Cab_Burge; 12/12/17 03:16 AM.
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
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Re: Engine Build Philosophy: Port Size vs Application
[Re: Cab_Burge]
#2417227
12/12/17 09:30 AM
12/12/17 09:30 AM
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Spaceman Spiff
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When you discuss the old days in Modified eliminator you have to remember that all those drivers let the clutch out at 8000 + RPM with either 6.17, 5.86 or maybe as tall as 5.57 with a 3.25 low gear and shifted them between 8500 up to 9800 RPM, NO torque what so dang ever They idle at 1500 + RPM, those motors flat scream from when the top bulb came on until they let off on the other end, none of those motors ran in gear below 2500 RPM until they stuck the clutch in to reverse directions or were shutting the motor off That was my point. Those cars made big HP, from little cubes, and a production head, with not very large ports( compared to what is available in the aftermarket today).
526 cubes of angry wedge, pushbutton shifted, 9 passenger killer!
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Re: Engine Build Philosophy: Port Size vs Application
[Re: Spaceman Spiff]
#2417392
12/12/17 03:42 PM
12/12/17 03:42 PM
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Cab_Burge
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The smaller the motor the more sensitive it is to port size at WOT below peak torque RPM Did you ever drive a 351 Cleveland powered Mustang or Torino? Talk about port size being over sized for the application They where dogs to me below 5000 RPM
Last edited by Cab_Burge; 12/12/17 03:44 PM.
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
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Re: Engine Build Philosophy: Port Size vs Application
[Re: BradH]
#2417505
12/12/17 06:51 PM
12/12/17 06:51 PM
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Joined: Jan 2005
Posts: 12,419 Kalispell Mt.
HotRodDave
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Glad the cleavland was brought up, it is about 2.9 square inch and the eagle 5.7 is about 3.0 sq inch. One is good at making TQ and one sucks both are good at making HP but one is better.
I am not causing global warming, I am just trying to hold off a impending Ice Age!
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Re: Engine Build Philosophy: Port Size vs Application
[Re: BradH]
#2417578
12/12/17 08:56 PM
12/12/17 08:56 PM
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Joined: Jan 2003
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ZIPPY
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Nice analysis and research, good reading and food for thought as ever.
Is there a timeframe for the ol' E body to come back out with the new bullet in it?
Any changes anticipated to better accommodate the motor?
Rich H.
Esse Quam Videri
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Re: Engine Build Philosophy: Port Size vs Application
[Re: HotRodDave]
#2417716
12/13/17 01:02 AM
12/13/17 01:02 AM
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Joined: May 2003
Posts: 6,566 Downtown Roebuck Ont
Twostick
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Glad the cleavland was brought up, it is about 2.9 square inch and the eagle 5.7 is about 3.0 sq inch. One is good at making TQ and one sucks both are good at making HP but one is better. Put port injection and a fast burn chamber that only needs 25 degrees of timing on the Cleveland and I think the torque gap disappears. Kevin
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Re: Engine Build Philosophy: Port Size vs Application
[Re: Twostick]
#2417718
12/13/17 01:06 AM
12/13/17 01:06 AM
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Joined: Jan 2003
Posts: 9,876 Weddington, N.C.
Streetwize
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Comparing old to new is a bit moot, New motors have either port or dirct chamber fuel injection, the manifold and port only have to move AIR and not carry fuel in suspension. Put a carb manifold on a modern hemi in a 4400 pound car nd watch the torque plummet at low/medium piston speeds.
The cleveland in smaller 2V form still needed a long skinny intake manifold runner just ot make decent torque, and the 4V was a bit soft on the bottom end unless you had steep gears, you basically had a smallblock with a 427 Chevy size intake port , they used to sell port stuffer sheetmetal plates to pick up the velocity in the Cleveland heads which blocked the lower third of the port....but Clevelands still make really stout 408+ " short rod stroker motors.
Last edited by Streetwize; 12/13/17 01:12 AM.
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Re: Engine Build Philosophy: Port Size vs Application
[Re: BradH]
#2417763
12/13/17 02:16 AM
12/13/17 02:16 AM
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Joined: Aug 2011
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CSK
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Newer engines also have variable runner length intake manifolds, this is an OLD Harley engine I built, this is a 94 inch Harley, very old design with heads I ported on the large side for cid, it is also EFI, the blue run on the dyno is with a 8 inch long individual runner length, very gutless down low, the red line is with 22 inch runners, everything else is the same, tie both these power bands together with a Variable runner set up & you will have something that has power all over the place with a HUGE intake port on the cyl head. this is only for a 2 cyl, X the results by 4 for an 8 cyl
Last edited by csk; 12/13/17 02:25 AM.
1968 Charger COLD A/C Hilborn EFI 512ci 9.7 compression, Stealth heads, 4.10 gear A518 ODtrans 4100lb,10.93 full street car trim 2020 T/A 392 Stock 11.79 @ 114.5
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Re: Engine Build Philosophy: Port Size vs Application
[Re: HotRodDave]
#2417852
12/13/17 12:04 PM
12/13/17 12:04 PM
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Joined: Jun 2006
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GTX MATT
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Glad the cleavland was brought up, it is about 2.9 square inch and the eagle 5.7 is about 3.0 sq inch. One is good at making TQ and one sucks both are good at making HP but one is better. Look at the flow out of the box though, the Hemi head flows ~50 CFM more at .300 (190 vs 240) and ~60 CFM more at .600. (270 vs 330).
Now I need to pin those needles, got to feel that heat Hear my motor screamin while I'm tearin up the street
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Re: Engine Build Philosophy: Port Size vs Application
[Re: mopar dave]
#2417927
12/13/17 02:02 PM
12/13/17 02:02 PM
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CSK
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The yamaha r600 has something simular to what you found. The velocity stacks electronically lift off the carbs at a certain rpm for better top end power. Best of both worlds. That 600 red lines at 18000 rpm. If we could just do this with our motors we would really have something. So do most of the gen3 Hemi's, Active Intake Control
Last edited by csk; 12/13/17 02:48 PM.
1968 Charger COLD A/C Hilborn EFI 512ci 9.7 compression, Stealth heads, 4.10 gear A518 ODtrans 4100lb,10.93 full street car trim 2020 T/A 392 Stock 11.79 @ 114.5
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Re: Engine Build Philosophy: Port Size vs Application
[Re: CSK]
#2418019
12/13/17 04:34 PM
12/13/17 04:34 PM
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Joined: Jan 2005
Posts: 12,419 Kalispell Mt.
HotRodDave
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only the trucks have active runners and only on 09 up
Last edited by HotRodDave; 12/13/17 04:34 PM.
I am not causing global warming, I am just trying to hold off a impending Ice Age!
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Re: Engine Build Philosophy: Port Size vs Application
[Re: ZIPPY]
#2418044
12/13/17 05:12 PM
12/13/17 05:12 PM
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Joined: Jan 2003
Posts: 15,439 Val-haul-ass... eventually
BradH
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Val-haul-ass... eventually
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Nice analysis and research, good reading and food for thought as ever.
Thanks. Is there a timeframe for the ol' E body to come back out with the new bullet in it?
2018... or my family will find me swinging by a rope tied around my neck on New Years Eve 2019 Any changes anticipated to better accommodate the motor?
Replaced the 8.75" with a Strange S-60, and the S-60 has CalTrac's reinforced spring perches to take the hit off the line better Went back to 22" front spring segments from the SS-spec 20" while staying w/ CalTracs and their mono-leaf springs Switched from 8" to 10" rims to help spread the footprint of the 275/60R15 drag radials; also going with M&H radial "skinnies" up front that will lower the ride height of the car a tad The Drag-Pack inspired hood mod gives me room for an air cleaner and at least some amount (1/2" or maybe 1") of carb spacer; I wasn't even sure the standard T/A scoop would fit a 3" air cleaner with the Victor heads & a tall intake like a Victor or Trick Flow Maybe some other things that don't come to mind at the moment... Probably need better rear dampers than my old Rancho 5-ways; a nice DA would help getting the rear suspension dialed in
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