Check this image out. Just tinkering but.

This old cam I used to run, an SLP 51010. Was 224/230 @ .050, and .502/.510.
(thats 280/288 advertised) . Similar to the comp 503 cam.

The cam I'm running now is the comp 306. 230/245 @ .050, .510/.540 (thats 290/307 advertised).

Oddly enough, until 6k the 51010 according to this graphy in desktop dyno kicks it's ***. after 6,000 the 306 cam is better.

Makes me wonder if I shoulda kept the smaller cam.

Thoughts?

 

Well, what kinda of power band do you want? The comp 306 is a big cam for a 350, and is obviously going to sacrifice low and mid range power for high rpm power.

 

My SLP 51010 that's going in my next engine actually measures 224/232 and 282/294 advertised, just for reference.

 

The 306 cam is carrying you roughly 1000rpm higher, and when it gets to that point, it looks like it's roughly 10hp more. Also the old cam had more torque in it on average too.

So it's up to you, give up that torque and get 1000rpm more, and a slightly higher peak hp, or, a better average horsepower and torque and start to run out of steam after 6500. It looks like each cam's benefits are equally comparable to eachother. If your car can handle the extra rpms, I'd say you should be content with what you have.

Also, it's only desktop dyno, it's not going to be 100% accurate. Best thing to do would get on a real dyno and see how each cam performs. Although I'd be damn curious to see how close to DD your results would be.

 

I'm confused.. Here is an attached cam card from SLP back in '99 when
I bought the cam. Why is yours different??

With those advertised specs, it makes the cams power and torque lines almost identical to 6k.

-- Joe

 

I Dunno. I know the numbers on DD are generally off, but the lines usually are close in regards to comparing things.

I'm curious if for a street car, the 51010 was a better cam. I'm also curious, if the car is being shifted at 6k anyway, if the 306 is the wrong cam..

The rest of the combo is:

10:1 compression, .044" quench
55cc chamber heads, rolled to 22 degrees (angle milled)
-16cc inverse dome pistons, mirroring chamber
H beam rods, 5.850"
steel crank
2800 stall converter, rated at 650hp (realisticly probably 2500 stall on a 450hp car)
3.42:1 rear end, 700R4 transmission, transgo shift kit
26" tires.


The DCR might be a little crazy with the smaller cam though..


-- Joe

 

ttt

 

You are right, I would say for a daily driver, the original cam would have been better. If it were a track car, and you were winding it out constantly to that redline, then you'd probably want the second cam.

And if you are shifting at 6k, then yes, the original cam would have been better. You generally want to shift right after the horsepower peaks, so when the next gear catches, you are in a good spot on the powerband. You aren't even utilizing the potential of the 306 if you aren't shifting at 7 grand.

 

Hrmm. Perhaps I shouldn't have sold the 51010 cam. Maybe this winter I'll do a cam swap.

-- Joe

 

Thats just what it measures. It was bought in 1994. I think the actual cams have varied over the years.

 

Heh. Wonderful.

The comp 503 cam seems similar. I wonder if comp can regrind to the specs I have on my card.

-- Joe

 

The ZZ9 camshaft changed over the years, too. I didnt know my cam was first purchased in 1994!

I had my cam put in a machine and checked, and that is what it measured. I have no idea why yours is different, other than either design changes over the years, or manufacturing tolerances.