Camshaft Selection Help Needed

[richiedd]

Looking for some views on a cam recommendation from my engine builder. I am building a stout(ish) street motor and my builder recommends the following comp hydraulic roller cams. Would they work well as a combination (aiming for 600hp/600lb/ft)?

Car is a 77 TA, 462cid, 3700 lbs, 3000 stall converter and 3.23 rear. E heads to flow ~310 - 320 cfm


SERIAL # O 1390-08
> PART # 51-000-9 CAMSHAFT, P8 PONTIAC V8 265-455 1955-81
>
> CORE C51-9C CAMSHAFT BLANK, P8 PONT 265-455, 5160
> GRIND # P8 3115B /3171B HR108.0
>
> DURATION @ .050 INTAKE 246 ROCKER ARM
RATIO
> VALVE ADJ INTAKE .000 DURATION @ .050 EXHAUST 258 INTAKE
1.50
> VALVE ADJ EXHAUST .000 LOBE LIFT INTAKE .4000 EXHAUST
1.50
> VALVE LIFT INTAKE .600 LOBE LIFT EXHAUST .3610
>
> VALVE LIFT EXHAUST .541 LOBE SEPARATION 108.0
>
> DURATION .006 INTAKE C/L 108.0
>
> TAPPET LIFT INTAKE 306 CAM ADVANCE 0
>
> TAPPET LIFT EXHAUST 325 HYDRAULIC Y
>
> VALVE TIMING .050 OVERHEAD CAM N
>
> VALVE OPEN INTAKE 15 JOURNAL DIAMETER STD 1.899
>
> VALVE OPEN EXHAUST 57 RECOMMEND VALVE SPRINGS
>
> VALVE CLOSED INTAKE 51 DEPARTMENT P
>
> VALVE CLOSED EXHAUST 21 SPC INSTR FOR CUSTOMER
>
>
> SERIAL # O 1391-08
> PART # 51-000-9 CAMSHAFT, P8 PONTIAC V8 265-455 1955-81
>
> CORE C51-9C CAMSHAFT BLANK, P8 PONT 265-455, 5160
> GRIND # P8 3115B /3171B HR108.0
>
> DURATION @ .050 INTAKE 246 ROCKER ARM
RATIO
> VALVE ADJ INTAKE .000 DURATION @ .050 EXHAUST 258 INTAKE
1.50
> VALVE ADJ EXHAUST .000 LOBE LIFT INTAKE .4000 EXHAUST
1.50
> VALVE LIFT INTAKE .600 LOBE LIFT EXHAUST .3610
>
> VALVE LIFT EXHAUST .541 LOBE SEPARATION 108.0
>
> DURATION .006 INTAKE C/L 108.0
>
> TAPPET LIFT INTAKE 306 CAM ADVANCE 0
>
> TAPPET LIFT EXHAUST 325 HYDRAULIC Y
>
> VALVE TIMING .050 OVERHEAD CAM N
>
> VALVE OPEN INTAKE 15 JOURNAL DIAMETER STD 1.899
>
> VALVE OPEN EXHAUST 57 RECOMMEND VALVE SPRINGS
>
> VALVE CLOSED INTAKE 51 DEPARTMENT P
>
> VALVE CLOSED EXHAUST 21 SPC INSTR FOR CUSTOMER
>



Thanks,

Rich

[ArtosDracon]

Those cams are compltely identical in every way that matters. As for the power they make, I'll be happy to run the numbers for you once I get my laptop up later this morning, if I forget, just shoot me a pm and I'll be back on later this afternoon.

[richiedd]

Thanks Artos. Appreciate that. If I don't see a post later I will definitely pm you.

Cheers

[Josh]

are you fine with running manual brakes or hydroboost? IE- vacume will be low.

[richiedd]

Josh
vac will be fine - using a vac pump and may install a HB system eventually.

Thanks

Rich

[ArtosDracon]

Lol, I didn't even notice, need compression ratio too, I'll guess at 10.5:1 for now.

I got about 542 ft\lbs at 4500, 558hp at 6000 with a pretty tight exhaust and 10.5:1 with a 780cfm carb. BMEPs were pretty low though.

Bigger carb made no difference, Opening up the exhaust bumped torque to 550 at 4500 and 573hp at 6K.

Going to 11:1 still had 93 octane friendly BMEPs and made 558ft\lbs at 4500 and 584hp at 6K.

I've played with several hundred cams in tiny increments, and I don't know that you're going to find 600hp and 600ft\lbs without a big intake, stepped long tube headers and a custom cam. I had to do a bit of guessing on the heads, but I went a bit optimistic on how quickly the flow came on.

Now, using that cam you had in your post, with as optimistic as I could get on everyting else, did make 595ft\lbs and 650hp,but that was being VERY generous on everything. Being conservative, I think you could make 600hp with that cam and the right porting on the heads, but it's only going to make 560ft\lbs and everything is going to have to be in line to make it. Port matched big single plane intake, 1 7/8 primaries with high flowing mufflers, 800cfm carb and no AC.

[richiedd]

ArtosDragon
Thanks a bunch for your time and efforts - they are well appreciated.

You are dead on with the CR - 10.5! D'ont know what hedders the builder used but the carb he tested with was a 850 Mighty Demon DP. Heads are "worked" E heads that are supposed to make the power "low down". My hedders are the 13/4" Ron Watts Tri Y's for ground clearance (he doesn't currently offer anything bigger). Intake is ported/matched Torker II.

Didn't get a dyno sheet but the builder claims it made "560 hp" and was only short on the 600 mark because the day of the dyno pulls was unbelievably hot (118*) when the testing was done (?). You can tell me how much b/s is in that claim - LOL. No mention was made of the tq numbers.

Rich

[ArtosDracon]

560hp to 580hp is believeable, without knowing at what rpm I would have a hard time commenting on torque, except that it's probably right in the 550 neighborhood. Temperature on dyno day won't usually account for more than 3-5% because the most it will do is a bit of timing and a tiny bit of fuel, and engines will always run hotter in a vehicle than on the dyno, so running the dyno on a hot day is a good way of getting the tune closer to what it'll be like in vehicle. Sounds to me like the engine builder is a pretty straight up guy.

[OLDFLM]

Try this Comp grind Robert and let us know what it does...

Mechanical Roller Cam 248/260 113 lobe # 4875/4877 SR113

[ArtosDracon]

Much smoother power curve, 560ft\lbs at 5K and 590hp at 6K installed straight up. Assuming all else being equal.

You guys should look into a 1462\1465 cam on 112LSA. Similar torque, but holds on longer. 563ft\lbs at 5K, 601hp at 6500. 400hp by 4K, 500fl\lbs from 3600 to 6300.