CAM Selection Discussion for a 505 stroker

[68-440]

CAM Selection Discussion for a 505 stroker, solid flat tappet cam, Edlebrock Perf.RPM Heads, Street Dominator inlet, Proform 950 Carb, TTI 2" Exhaust Headers.

I have read many posts on this Board and the most recommended CAM appears to be the Comp Cams XS290S.
I downloaded Comp Cams Camquest software to see what they recommend and their estimated parameters.
The software recommends 2 cams that have been used by members on this Board.

The XS282S and the XS290S were shown.  I looked at their parameters to see if I could judge which would be a better choice for my needs.

Just to be clear, I have NO practical knowledge on this subject so PLEASE correct my thinking.

The RPM range was 2500-6500 for the XS282S, and 3000-7000 for the XS290S.
The recommended stall for the XS282S is 3000 (2400-3400), and 3500 for XS290S.
The Duration (IN/EX) is 244/252 for XS282S and 252/260 for the XS290S.
The Valve Lift (IN/EX) is .520/.540 for XS282S and .540/.558 for the XS290S.

I then looked at their predicted Average and Peak Torque:
Average Torque of 220 ft-lb for XS282S and 215 ft-lb for the XS290S.
Peak Torque of 599 ft-lb for XS282S and 583 ft-lb for the XS290S, both at 4000 RPM.

One other Comment:  I would probably go with the 112 LSA on the CAM Grind for better vacuum, etc.

NOW for the dumb questions:  PLEASE Comment!!
1.   Using a MSD 6AL Ignition, the Rev Limiter would be 6000 RPM.  This implies, to me, that the XS282S is more in the range of the RPM that I can use and requires a lower stall torque converter (more street friendly)??
2.   The XS282S has Higher Average and Peak Torques (more street friendly)??
3.   With the Rev Limiter, is the engine Over Carb'ed with the Proform 950??

How do you look at the CAM selection and carb selection?

[Mick70RR]

I built and run a 505 stroker with stock RPM heads, Proform 950 and 110 degree XS290S cam but went with the Performer RPM intake. The RPM range quoted by Comp Cams is based on a 383/440 engine but when the same cam is installed in a bigger engine the RPM range is lower. I'd guess about 500 RPM lower for a 505. My engine feels strong from as low as 2000 RPM and pulls hard to over 6000 finally giving up at about 6500. The Proforn 950 is a great carb, I had a little tuning to do to get rid of a light throttle stumble, but now that's sorted it can't be faulted. I use the car as a daily driver and it starts on the button every morning, and by the time it's out of the garage it idles just fine despite having no choke. I've run the car at a few test and tunes and it runs low 12's exactly as I drive it to the strip, best et so far is 12.1 @ 116 and best mph is 118, it's the 60 foot times that let me down, I rarely get below 2 seconds.

[68-440]

Mick: Thank you very much for your reply.  Sounds great.  I hope, when I finish mine, it runs as good as yours.
How much vacuum do you get with the 110 LSA?  Do you still have power breaks?
I was hoping that one of the CAM guys could discuss what to expect from the two cams I compared.  Considering the RPM limiter, the 282 looked stronger and was happy with a lower stall.  But in reality, looks can be deceiving.

[Mick70RR]

10 inches of vacuum at idle (850RPM), enough for power brakes I guess but I don't have them. It's a heavy car, 3800 with me in the drivers seat and I sometimes wonder if a smaller cam like the 282 would have been a better for a daily driver. Having said that, the engine is certainly not overcammed with the 290 but you wouldn't let your wife drive it.

[Blakcharger440]

I built and run a 505 stroker with stock RPM heads, Proform 950 and 110 degree XS290S cam but went with the Performer RPM intake. The RPM range quoted by Comp Cams is based on a 383/440 engine but when the same cam is installed in a bigger engine the RPM range is lower. I'd guess about 500 RPM lower for a 505. My engine feels strong from as low as 2000 RPM and pulls hard to over 6000 finally giving up at about 6500. The Proforn 950 is a great carb, I had a little tuning to do to get rid of a light throttle stumble, but now that's sorted it can't be faulted. I use the car as a daily driver and it starts on the button every morning, and by the time it's out of the garage it idles just fine despite having no choke. I've run the car at a few test and tunes and it runs low 12's exactly as I drive it to the strip, best et so far is 12.1 @ 116 and best mph is 118, it's the 60 foot times that let me down, I rarely get below 2 seconds.

Mick, my engine combo in my 70 Charger is alot like yours. Your mph looks great and says that there is alot of ET left to shave 
AND I also agree that the 950 Proform is an excellent carb. I dynoed my engine with one and it barely required any tuning out of the box. I am sure that I will have to do some more tuning once I hit the streets though.

[Mick70RR]

I built and run a 505 stroker with stock RPM heads, Proform 950 and 110 degree XS290S cam but went with the Performer RPM intake. The RPM range quoted by Comp Cams is based on a 383/440 engine but when the same cam is installed in a bigger engine the RPM range is lower. I'd guess about 500 RPM lower for a 505. My engine feels strong from as low as 2000 RPM and pulls hard to over 6000 finally giving up at about 6500. The Proforn 950 is a great carb, I had a little tuning to do to get rid of a light throttle stumble, but now that's sorted it can't be faulted. I use the car as a daily driver and it starts on the button every morning, and by the time it's out of the garage it idles just fine despite having no choke. I've run the car at a few test and tunes and it runs low 12's exactly as I drive it to the strip, best et so far is 12.1 @ 116 and best mph is 118, it's the 60 foot times that let me down, I rarely get below 2 seconds.

Mick, my engine combo in my 70 Charger is alot like yours. Your mph looks great and says that there is alot of ET left to shave 
AND I also agree that the 950 Proform is an excellent carb. I dynoed my engine with one and it barely required any tuning out of the box. I am sure that I will have to do some more tuning once I hit the streets though.

Just looked up your engine build and it is very similar to mine. I never did dyno my engine but I know I have the horse power to run well into the 11's by the mph. Just need to work on the 60' times before I get that 11 second run, not easy without carting slicks to the strip.

[firefighter3931]

The xs290s is the better choice for a street 500in build, inmo. The 282s is better suited to a smaller displacement build. 



Ron

[68-440]

Thanks everyone.
Ron - I guess I was mis-led by the numbers generated by COMP CAMS CAMQUEST software.  The numbers it generated makes it look like the XS282S would result in the better choice for the 500 in engine, with the components I have shown.

[firefighter3931]

Thanks everyone.
Ron - I guess I was mis-led by the numbers generated by COMP CAMS CAMQUEST software.  The numbers it generated makes it look like the XS282S would result in the better choice for the 500 in engine, with the components I have shown.

Did you plug in 505ci when doing the camquest simulation ? I can tell you from experience that a cam with 244*@.050 will nose over early with a large cube build. You need the added duration to feed the extra displacement. 



Ron

[Challenger340]

IMO,
Unless you have 300 cfm Flow, or over, on the EDDY's, (thats alot of port work), move up to the xs290 for the 500 Inch.

Most 451 stuff I do, which is alot smaller, is pretty much "done" by 5600 rpm, even with the xs282, with ported EDDY's.


Bob out.

[68-440]

Yes Ron. 
I input the 505 cu-in, 10.5 cr, 950 cfm carb, bore and stroke, to match what I knew.
The numbers, that I posted up front were generated by CamQuest6.
To an amature like me, the 282 looked stronger (average and peak torque), operated in a lower rpm range (2500-6500 vs 3200-7000), and required a lower stall (2500 looked better to me than 3200 minimum cam range).
But, I would prefer to go with experience rather than the software estimate.

Bob - If I interpret your input correctly, you are also in favor of the XS290.

[68-440]

 
Just trying to understand.

[firefighter3931]

I'm pretty sure Bob is saying to go with the XS290S Comp grind. 

When sizing a cam you have to consider the displacement....larger motors need larger camshafts with longer duration or they run out of steam early. Here's a good example to illustrate the point effectively ; the dyno sheet below is for Vegas Mike's build that I helped to sort out. The cam profile was my choice because it was originally waay overcammed. There were other issues that needed addressing as well (intake manifold/compression/Carburator)....if you're interested in some good reading see the link below.

http://www.dodgecharger.com/forum/index.php/topic,6000.0.html


Keep in mind that this is a stock stroke 440 bored .055 over and now displaces 451ci. The peak power comes in @5700 rpm so the same cam in a 500in build would be all all done by 5200. These are real dyno numbers....not some simulator program. 



Ron

[Challenger340]

Ron's right on here, and I agree with him 100%.
Go to the 290.
Bigger Engine =  Bigger Cam

With that Big Arm in there, you won't be short for Torque anywhere when ya mash the "loud pedal",
but,
you'll need the added events of the Bigger Cam, to keep feeding the "Bigguy" up higher.

Bob out.