RB Cam Performing Right?

[Road Grabber]

My current cam has 48 degrees overlap and runs about the same or a bit better than the previous cam with 54 degrees overlap.


Andy F. made 550 hp with that cam with manifolds on his 470. Pretty small cam. Probably 0.500” net lift. Probably 230 -232 degrees duration at 0.050” when considering the 0.028” lash.


View attachment 1968850View attachment 1968854View attachment 1968855
500 cu. In.
600 hp -ish
Manifolds
15” idle vacuum
Used a stock stall converter for years
3.23 gear
2 1/2” exhaust
15 years old
Drive it to work. Drove it to both Carlisle and Mopar Nats this year, with track time at both.

Probably not a 50,000 mile motor. With a couple changes, could be. But ask yourself this how: many miles do you really drive your car? You’ve had your car for 30 years. How many miles did you put on it? What does your next 30 years of driving look like?

All that said, based on your comments in this discussion, keep the cam, put headers on it, put it in the car, close the hood and forget about it. It won’t matter if I it makes 450 or 550 hp. You, nor anyone else will know.

If you want to stick with manifolds an explore a better cam, contact someone that has experience and does it for a living. Like PRH

Who is PRH?

The lack of much difference installing the more efficient heads and bigger cam was the reason for inquiring and higher expectations.

Time will tell after the new dyno runs without bent pushrods.

Thanks for replies.

 

[496 polara]

Who is PRH?

The lack of much difference installing the more efficient heads and bigger cam was the reason for inquiring and higher expectations.

Time will tell after the new dyno runs without bent pushrods.

Thanks for replies.

See post #24

 

[Road Grabber]

See post #24

thanks

 

[BSB67]

See post #24

This.

PRHeads - Dwayne Porter, Porter Racing Heads

 

[PRHeads]

Like I stated, I don't subscribe to the proportional relationship. Nor does the Desk-Top dyno, albeit a fairly crude tool. As an example, your analysis would be analogous to saying that if you took all the key components from a 273 that made 1.0 hp/cuin and put them on a 500 cuin engine it too would make 1.0 hp/cuin. This would include valve size and head flow.

Actually, I look at it as taking the top end off a 360 making 400hp, and putting it on a 273 and making 300hp.
(Taking the top end from the bigger engine making more power than is expected out of the smaller engine, and using it on the smaller engine)

I have DD2000.
I gave up on that years ago.

I built a pair of BBM’s, and dyno tested them.
Nearly twins except for the ci.
493 vs 446.
Both were 10:1, and got bowl ported rpm heads, sd/850, 2” headers, SFT cams with 1.5 rockers.
Same lobe family(254/254-110 for the 446, 250/254-112 for the 493).
I don’t recall the exact numbers, but the DD predicted the 446 to make noticeably more Hp than the 493.
DD doesn’t like combos with what it feels are undersized heads.
The real dyno results were quite different, with the 493 making about 45 more hp than the 446.

The actual hp/ci was pretty similar between the two.
446- 1.16
493- 1.14

At that point I figured any program that predicted the opposite of what was really going to happen was something I wasn’t going to spend any more time messing with.

 

[Road Grabber]

Actually, I look at it as taking the top end off a 360 making 400hp, and putting it on a 273 and making 300hp.
(Taking the top end from the bigger engine making more power than is expected out of the smaller engine, and using it on the smaller engine)

I have DD2000.
I gave up on that years ago.

I built a pair of bum’s, and dyno tested them.
Nearly twins except for the ci.
493 vs 446.
Both were 10:1, and got bowl ported rpm heads, sd/850, 2” headers, SFT cams with 1.5 rockers.
Same lobe family(254/254-110 for the 446, 250/254-112 for the 493).
I don’t recall the exact numbers, but the DD predicted the 446 to make noticeably more Hp than the 493.
DD doesn’t like combos with what it feels are undersized heads.
The real dyno results were quite different, with the 493 making about 45 more hp than the 446.

At the point I figured any program that predicted the opposite of what was really going to happen was something I wasn’t going to spend any more time messing with.

I guess you can't argue with cubic inches.

 

[PRHeads]

I don’t ever recall building an engine and after dyno testing it thinking to myself, “I should have made it smaller”.

 

[gtxrt]

what rpm did you shift at with your 484 cam ? when was peak HP and TQ coming in at with this last build.