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sharing my progress - 425 rear wheel hp on pump gas
Getting the "sickness" after a 40 years. Work and life got in the way but, my 1970 C3 purchase 2 yrs ago has awakened the "sickness" Need more of everything. I have a lot of catching up to do, Lots of new stuff to learn, but am asking the right people, taking my time and learning as much as i can. I know many will be happy to critique my direction and all comments are welcome and appreciated. ... Really!
Those rods are not high quality hp did they give you a hp range? To make 425rwhp you have to have over 525 at the crank which requires big heads, cam, and rpm's in I guess a 383
For awhile the 357 in my 6t8 had 411 RWHP, std tranny is approx. 20% hp loss estimated 480 at the crank. Callies crank, Callies 6" rods, Mahle pistons splayed caps. T
For awhile the 357 in my 6t8 had 411 RWHP, std tranny is approx. 20% hp loss estimated 480 at the crank. Callies crank, Callies 6" rods, Mahle pistons splayed caps. T
Cam is not yet figured out. I am using Chuck at C&D engines in Kirkland WA. He is well known in the area and has a great reputation. The engine is a 383 based on a zzz block. My corvette has currently a Tremec TKO 500 wide ratio. Using Eagle steel crank, Scat I-beam rods. ANd oops here on the cost. I had in my spread sheet qty 2 and should have been qty 1 as they are sold as a pair. Cost is really $2000 for the heads. Good catch, feeling a bit red in the face on that one.
Thank you on the rods. Will check on that. For the rotation assy, i have been trusting Chuck to select what is good. He has been doing this for a long time.
Walter, I'm restoring / modding my 79 in Woodinville, so I'll definitely keep track of your build. Great to hear some recommendations for some local area shops. (All the place I've seen recommended in the larger Seattle area are all in the Auburn area so far.)
-I'm also doing a sequential multiport EFI conversion, but using a TPI-style intake and the Holley EFI.
How do you like the Borgeson after starting with manual steering? (I did the Steeroids Rack and Pinion power steering conversion on mine.)
Those rods are not high quality hp did they give you a hp range? To make 425rwhp you have to have over 525 at the crank which requires big heads, cam, and rpm's in I guess a 383
George, with AFR 195cc heads, and a 383, what do you think is the min required cam duration @ 0.050" for a roller cam to make 525 @ the crank? -Just to get a rough idea. Into the 240s or can the mid to high 230s get you there?
Adam, I went borgeson because i had concerns of the geometry of the rack on the steeroids. But know i have read of many that love the steeroids. I had nearly pulled the trigger on buying the sniper efi, but in the end, i felt that the pro-m sequential efi with mass air feature would bring all the modern air / fuel management that a modern engine has yet still have the old school look under the hood. I live in Brier WA , not far from Woodinville, love to see what your doing.
Will follow up on the cam specs as soon as we get them.
I think you're good to hit your 525 crank HP goal with those AFR Heads, open headers, and a modern-style hydraulic roller cam. Those AFR heads are just stupid good.
I modeled a 10.2 CR 383 with AFR 195cc heads, open headers, an 850 CFM throttle body on that single plane intake, and a Lunati Voodoo SBC Hydraulic Roller 282/290 cam and got 540 hp @ 6,500 and 500 ft lbs @ 5,000 RPM (desktop dyno; not a "real" professional dyno software).
Most people would recommend a single pattern cam with the same duration on the intake and exhaust with those AFR heads, especially with your open headers; DesktopDyno never likes single pattern cams for some reason and says 540 hp @ 6,000 and 500 ft lbs @ 5,000. --The single pattern cam gives you a little torque boost down low but move the HP peak down a little bit in RPM. (I think average torque is up from 2,000-6,000 with the single pattern cam.)
[Edit] I @#$@#$#ed up! I had my cam settings in DDYNO stuck on "manual" for lobe acceleration rate so that was calculating with my cam's lobe profile, not the Lunati cam in question. -I get 507 HP @ 6,000 and 489 ft lbs @ 4,500 with that cam.
With a similar accel rate lobe to the Lunati I get 292 degrees seat to seat duration and 241 @ 0.050" w 0.571" intake lift; 0.550" exhaust, 110 Stepping up to the Lunati 294 hyraulic roller (243 @ 0.050" duration) and with 1.6 rockers on the intake with a 10.5:1 static CR (min recommended for this cam) I get 538 HP @ 6,500 and 492 ft lbs @ 5,000. -This is a totally theoretical cam; I was just playing with a "typical" modern hydraulic roller profile and the min duration to crack 525 crank HP just to see where it landed. -It looks like low to mid 240s for the @ 0.050" duration to crack 525 HP.
Adam
Last edited by NewbVetteGuy; 09-20-2018 at 05:30 PM.
Adam I have not seen desk top dyno in many years, but from what I remember can you input the intake CFM at .050 lift increments. Does it have the ability to input duration number not just at .050 but .200 and even .400?
My present 383 cam is 236/242 @ .050, but with solid roller racing ramp lobes might make it equal to a few degrees larger. It runs fine with 91 octane and 10.86 C/R. I have AFR 210 heads with 64 cc chambers and have to use a Team "G" single plane because the intake ports are so big.
Adam I have not seen desk top dyno in many years, but from what I remember can you input the intake CFM at .050 lift increments. Does it have the ability to input duration number not just at .050 but .200 and even .400?
My present 383 cam is 236/242 @ .050, but with solid roller racing ramp lobes might make it equal to a few degrees larger. It runs fine with 91 octane and 10.86 C/R. I have AFR 210 heads with 64 cc chambers and have to use a Team "G" single plane because the intake ports are so big.
You CAN input the lift in .050” increments; the 2003+ versions of DDyno allow you to put in the advertised /0.006” duration and 0.050” only and the type of cam and it then makes assumptions for the duration at the rest of the lifts. (DDyno 2000 only allowed 0.050” OR advertised).
(I'm not sure where you'd even get the duration @ all lifts data; I thought this was the "secret sauce" that none of the cam MFGRs want to give you. You'd have to use one of those "cam doctor" things to calculate this yourself, right?)
Adam
Last edited by NewbVetteGuy; 09-21-2018 at 02:28 PM.
You CAN input the lift in .050” increments; the 2003+ versions of DDyno allow you to put in the advertised /0.006” duration and 0.050” only and the type of cam and it then makes assumptions for the duration at the rest of the lifts. (DDyno 2000 only allowed 0.050” OR advertised).
(I'm not sure where you'd even get the duration @ all lifts data; I thought this was the "secret sauce" that none of the cam MFGRs want to give you. You'd have to use one of those "cam doctor" things to calculate this yourself, right?)
Adam
So your AFR heads give you a CFM at .100 .200.300...……… so you can just figure out the @ numbers for the .050 increments. The more information the more accurate
This is where I pick my roller lobes for custom cams. So if you turn to page 85, TC solid roller for small base circle cams. You could pick the 236 and 240 duration for example and they give the .200 duration numbers for comparison of how steep the rams are.
Or on page 29 the HLO hydraulic roller lobes have really high lift to match the AFR lighter weight valves. You could use a #13779 235 dur and #13781 239 dur and have .644 I and .648 exhaust with 1.6 RR's or on page 28 extreme marine #3474 & 3376 or page 25 and use the high lift QXI lobes
Just something to base your cam choice on.... this engine also made over 400RWHP thru a 700r4 with a 3500 stall. Car runs in the low 11s @121mph on motor and has been low 10s on 125hp nitrous.
So your AFR heads give you a CFM at .100 .200.300...……… so you can just figure out the @ numbers for the .050 increments. The more information the more accurate
This is where I pick my roller lobes for custom cams. So if you turn to page 85, TC solid roller for small base circle cams. You could pick the 236 and 240 duration for example and they give the .200 duration numbers for comparison of how steep the rams are.
Or on page 29 the HLO hydraulic roller lobes have really high lift to match the AFR lighter weight valves. You could use a #13779 235 dur and #13781 239 dur and have .644 I and .648 exhaust with 1.6 RR's or on page 28 extreme marine #3474 & 3376 or page 25 and use the high lift QXI lobes
Thank you. My engine builder spec'd this over my choices because his experience suggested that although the rumble will be less impressive, the car will be more driveable and will still get me great horsepower. I am happy to trade some show for more go.
09-19-2018, 08:24 PM
sharing my progress - 425 rear wheel hp on pump gas
