I see your question about quench/squish distance. shoot for .040
I suggest you also look into "Singh grooving" by searching this site or seach member name "automotivebreath". Although I would groove the pistons rather than those heads. This process uses a slightly wider squish distance, about .060. This is good for better low rpm combustion and detonation resistence, often drops the octane requirement about 2 points,
and usually results into more feelable torque.
I don't know why they're not more popular - they'll accept square or spreadbore. I guess they don't grace the pages of PHR or Chevy Hi Perf all that often...
The spreadbore manifold also flows differently in the plenum area which can affect booster signal.
AND putting a square bore carb on a spread bore intake causes all kinds of turbulence under the carb that can only slightly be healed by contoured spacers.
Weiand has a balanced plenum volume that Edel does not, which might or might not affect wet flow delivery, atomization and vaporization on a particular application.
All this turns into a "try them all back to back on a dyno" to see what is best,
just give it your best guess as to which looks the prettiest.
Ok, here's some changes in considering. NOTE: ** denotes a change.
1987 caprice, 200-4R tranny, .500 boost valve, billet servo, 5500rpm shift governor. Right now it has a 9" 3000 stall converter(custom built Edge racing converters). It is a lockup converter, Tranny cooler. 3.90 posi rear end. Approx 4000lbs including driver (gathering parts to swap to a T-56 6speed trans)
**-Gen I SBC, 4-bolt splayed mains, 1 piece rear main seal, OE-Roller block, 0.030" Bore, "0" deck.
**-Canfield Aluminum 195cc, 65cc CNC chamber, 2.055/1.60 or considering AFR 195cc Eliminators with 65cc chambers.
-1.6 Ratio Aluminum roller rockers
**-0.039" thick Felpro Permatorque MLS head gasket 4.166" bore
-Scat cast steel 383 stroker crank. 3.750 stroke
-5.7" forged I-beam rods
**-SRP Forged flat top pistons, -5cc dome, 1.285 compression height, approx 10.89 static compression ratio, 8.42 dynamic compression ratio, 445 grams
-Balanced rotating assembly (Internal balance)
-Comp Magnum Hyd Roller 286HR cam, 230/230 dur@50, .596/.596 lift with 1.6 rocker. 110LSA, 106 intake centerline, approx power range 2500-6000.
-Edelbrock performer RPM Q-jet manifold with 3/4" 4 hole spacer. (dual plane intake) 1500-6500rpm range.
-Cliffs Performance built Q-jet 780cfm, 1/8" Heat insulating gaskets used above and below carb spacer creates 1" total spacer height.
-1 3/4 ceramic coated headers (long tube)
-2.5" inlet/outlet 2-chamber Flowmasters
-2.5" Dual exhaust with X-pipe
-Spectre performance Dual cold air intake (carb hat with two 4" air inlets, draws cool air from front of car and traps hot air out of intake.
-Water pump fan delete. Electric fans on 4 core radiator.
-Standard flow oil pump with Milodon 7 Quart oil pan and windage tray.
-Double Roller timing set with 2 piece timing cover for easy cam swaps.
-FBO systems Built HEI distributor with MSD 6-AL ignition box (multi-spark) with 6250rpm rev limiter chip.
-Oil cooler with filter relocation kit (Dual large filters) Makes it about a 9 quart oil system.
Considering the XR288HR cam part number 08-433-8
236/242 @ 50
.555/.576 lift with 1.6 rockers
110 lobe sep
I might have to drop the compression a hair to use this without pinging. Tell me what you think about the cams. Suggest something else? I want to hear. Should I advance the cam a little? Remember this is an all street car that weighs 4000lbs. I would like a decent sounding cam but im more concerned with function. I've thought about going with a 106 lobe sep but i think id have to lower compression more. Im open to ideas.
973kgt's goal for this build is 500/500. I wanted to play around with it with an additional goal of 400 ft/lbs @ 2000 with the lowest possible SCR. I tried upwards of 2 dozen camshaft/SCR combinations to get there. Best results were achieved with a custom grind cam, although a couple of off-the-shelf grinds were close. I tried lobe separation angles from 106 to 112 and settled on 110 for the best numbers between hp and torque. A 106 cam made incredible torque from idle, but never reached the 500 mark and was pretty much all done at 3000. Maybe it's possible to make the 106 cam work and I just don't know how to do it.
Anyway, here's the combo....
383, 10.30:1 static compression ratio. Cylinder volume 783.85 cc's, combustion volume 84.28 cc's, combined volume 868.13 cc's. Heads are 65 cc's, so another 19.28 cc's have to be found between the piston, gasket and piston deck height to reach the 10.30:1 SCR used in this combo. If we shaved the heads for 63 cc chambers, used KB197 pistons with a 12cc dish and a Fel-Pro 1003 gasket (recommended for aluminum heads and iron block) with dimensions of 4.166" X 0.041" and a zero deck, the SCR would work out to 10.31:1 and the squish would work out to 0.041". Sounds pretty close to me. 5.7" rods. (6" rods picked up 3 hp and 2 ft/lbs)
Canfield 195 aluminum heads 2.055"/1.60"
Flow figures: (from 973kgt)
.200 128 103
Intake manifold: Dual plane max flow (RPM or equivalent)
Carb: 780 CFM
Cam: Hydraulic Roller.
Intake & exhaust lift at valve 0.560" (1.6 rockers)
Intake & exhaust lift at cam 0.350"
Primary timing seat to seat (0.006") 31/63/77/29
Duration 274*/286* @ 0.006", 230*/236* @ 0.050".
Intake centerline 106*, exhaust centerline 114*, lobe separation angle 110*, overlap 60*.
Secondary timing (0.050") 9/41/52/4
Installed retarded 1*
True seat to seat timing @ 1* retarded 30/64/76/30, ICA 107*, ECA 113*, LSA 110*, overlap 60*.
Lifter acceleration rate 3.10
RPM HP TQ VE BMEP
1500 102 359 67 141
2000 155 407 74 161
2500 197 415 77 164
3000 253 443 83 175
3500 317 476 89 188
4000 377 495 94 195
4500 432 504 98 199
5000 470 494 100 195
5500 496 474 99 187
6000 501 438 95 173
6500 470 380 89 150
Last edited by techinspector1; 11-11-2008 at 02:32 PM.
Ok. Thanks to many conversations with Tech Inspector I think we have come up with the best build we can without going over on compression ratios.
You can download the build sheet and dyno sheet.
Let me know what you think.
This is using SAE Correction.
Last edited by 973kgt; 11-12-2008 at 12:23 AM.
Strange, this looks completely different on the curves than my DynoSim. I wish I could figure a way to post the graphs that way, but haven't yet. There may be some safeguard built into the software that prevents it.
Either way it works out, it should be one heck of a fun ride with a 6-speed.
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