500" timing

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famous bob

famous bob

mopar misfit
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so what are you guys running for timing on 500-505" engines out of curiosity ?
 
I have a 493" six pack motor with just over .600" lift hydraulic roller cam ground on 110 degree centerline in a 1970 'Cuda with a 5 speed manual transmission. It likes a lot of initial timing and has just under 13 to 1 compression. Yes, it does burn 101 octane unleaded, which is available at the pump out here.

I have it set at 26 initial with 36 total, all in by 2200 rpm. It dynod at 684 hp 682 ft lbs of torque with about .550" lift using 1.5 to1 ratio rocker arms. I've since installed T&D 1.6 to 1 ratio rocker arms, and it really loved those. It was a noticeable performance increase likely pushing it to or slightly over the 700 hp mark at 5500 rpm.

It wants more cam, but I don't want to trade off the torque on the bottom end. It spins out more than 500 ft lbs at 2000 rpm. It's a beast.
 
jbc426 said:
I have a 493" six pack motor with just over .600" lift hydraulic roller cam ground on 110 degree centerline in a 1970 'Cuda with a 5 speed manual transmission. It likes a lot of initial timing and has just under 13 to 1 compression. Yes, it does burn 101 octane unleaded, which is available at the pump out here.

I have it set at 26 initial with 36 total, all in by 2200 rpm. It dynod at 684 hp 682 ft lbs of torque with about .550" lift using 1.5 to1 ratio rocker arms. I've since installed T&D 1.6 to 1 ratio rocker arms, and it really loved those. It was a noticeable performance increase likely pushing it to or slightly over the 700 hp mark at 5500 rpm.

It wants more cam, but I don't want to trade off the torque on the bottom end. It spins out more than 500 ft lbs at 2000 rpm. It's a beast.
Click to expand...

What heads are you using? Just curious.
 
Hughes Super prepped Indy EZ's with Stage 2 porting and a deep port matched aluminum factory style six pack intake.
 
I build tight quench engines for pump gas. The last two were:
505" RB, RPMS, solid flat tappet, total 32°, initial is 18°. Estimated 580hp, 600+ tq.
496 B, Stealths, solid flat tappet, stock appearing, total 32°, intial is 18°. Chassis dyno'd 440hp, 450tq at the tires

Typically I'd say start at 32° and work backwards 2° at a time. You may find it likes less.
 
moper said:
I build tight quench engines for pump gas. The last two were:
505" RB, RPMS, solid flat tappet, total 32°, initial is 18°. Estimated 580hp, 600+ tq.
496 B, Stealths, solid flat tappet, stock appearing, total 32°, intial is 18°. Chassis dyno'd 440hp, 450tq at the tires

Typically I'd say start at 32° and work backwards 2° at a time. You may find it likes less.
Click to expand...

I`ve got the initial set at 19, all in at 3000. if I remember right, the 505 is as responsive as my sbc`s were, really surprised at it. maybe the fast 2.0 ???
 
501
.572 lift on solid roller
11.8:1
M Demon 850
18 to 32 deg full on around 3k
Purrrrs like a kitten till you stomp on the tail.
 
famous bob said:
I`ve got the initial set at 19, all in at 3000. if I remember right, the 505 is as responsive as my sbc`s were, really surprised at it. maybe the fast 2.0 ???
Click to expand...

While I don't think it hurts, I don't think the efi is solely responsible for it...lol. These big engines are very responsive because it's kind of hard to over carb (or cfm in your case) them.
 
500" RB - Solid Flat tappet cam with EZ heads. 763hp and 680tq on pump gas. We lock the timing at 38 degrees on the MSD dist.
 
440dartsport said:
500" RB - Solid Flat tappet cam with EZ heads. 763hp and 680tq on pump gas. We lock the timing at 38 degrees on the MSD dist.
Click to expand...

thanks for the replies. what head flow do u guys have on the hi h.p. engines mentioned here? mines 352 @.600 lift, am expecting great things out of it.???????????
 
Mine weren't flow tested. The RPMs were done by me but were basically a clean up after the valve job was corrected. I'd say they flow a few cfm better than advertised. The Stealths were bought by my customer - they were ported by a pro shop and if I had to guess they were around 310-315 at .600.
If the parts are right, and the machining is right, and the assembly is right, it will produce it.
 
Could be. I've a magazine article where the builder claims to be getting, if I remember correctly, 680 HP with a 509 cam and OOTB RPM heads. I'll try to remember to bring the magazine from home and post the numbers and build.

Okay, it was 657 HP, started a new thread about it.
 
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