cam choice ??

[69chargerR/T]

These two cams look pretty close to me,which cam looks better to you guys,or which one would you pick.
comp XE274H 230/236 dur 488/491 lift 110 cl
lunanti 60303 226/234 dur 494/513 lift 110 cl

440 .30 over
TRW forged flat top pistons
stock 906 heads
eddy rpm intake
holley 750dp
hooker comp 17/8 headers
3" exhaust
TCI converter flash stall 2400/2600
3.91 gear   

looking for good all around performance, that will pull hard. car is a 69 charger.

[Challenger340]

TRW Piston # ?

Is it the L2266F ?
or,
The 2355's ?

No matter,
If L2266's, just make sure you "degree" whatever you choose Cam-Wise, get it up around 105 or so will add some pressure down low.

If L2355's, then you are stuck with degree'ing at 108.

Use a Cloyes "Hex-ajust" Timing Chain & Gearset either way, which will make the Cam degree'ing process much easier !

[Musicman]

I'll run it through my PC and get back to ya.
I'm partial to the VooDoo cams myself, but the other cam is no slacker eirther, so I'll try both.

[69chargerR/T]

TRW Piston # ?

Is it the L2266F ?
or,
The 2355's ?

No matter,
If L2266's, just make sure you "degree" whatever you choose Cam-Wise, get it up around 105 or so will add some pressure down low.

If L2355's, then you are stuck with degree'ing at 108.

Use a Cloyes "Hex-ajust" Timing Chain & Gearset either way, which will make the Cam degree'ing process much easier !

The pistons are older TRW's that aren't made anymore. I think they are similar to the L2355's. If I remember right they were close to o deck ??   The pistons were in the motor when I got it, don't remember the # on the piston. I should have wrote  it down when I freshened the motor up 8 years ago What do you think of these two cams ??  Are these cams pretty equal, I know the comp has more duration and less lift compared to the lunati, but I'm not sure what the performance difference would be      

[Challenger340]

I was only asking about the Pistons, to get a better read on Cylinder Pressure available for the duration @ .050.

If they are "similar to the 2355's they will have 4 "eyebrow" Valve reliefs on the Top.
No matter,
it's just nice to know the Compression ratio for sure,
however,
I suspect either Cam is gonna perform better "advanced a bit", from the Rec'd Installed C-Line, with the heavy Car @ 24-2500 stall.

Are you changing/matching the Valve Springs for whichever Cam you choose ?
or,
trying this on stock Valve Springs ?

The Comp grind is a little "less sensitive" to Spring Pressure and Seat Angles than the Lunati.
The Comp won't matter if it only "sees" 105# to 110# Seat Pressures.
That said,
Understand that the Lunati REQUIRES to Spring Pressures be "right" for that grind.
If they ask for 115# to 120# pressure on the Seat, make sure thats what it gets, and you'll get a few ponies more.

And remember, MAKE SURE TO ADD A ZINC ADDITIVE TO YOUR OIL AND FOLLOW CAM BREAK-IN PROCEDURES !

[69chargerR/T]

Yes, I will be using the recommended valve springs for the cam I pick. And the pistons do have the 4 valve reliefs on them. I'm leaning towards the lunati,but the comp cam looks good too. Thanks for all the info 

[Musicman]

OK... obviously I don't have all of the finer specs of your proposed build, so I input what I new and guessed on some of the other stuff... either way, this graph should do well enough for a cam comparison anyway. The Lunati curves are in Blue... and I ran both cams with a 4 degree advance...
(Remember, this is NOT the predicted output of your build... it's just a similar style generic build for cam comparison)

Six of one, half dozen of the other really as we suspected.... The Lunati makes a little more initial power for greater acceleration, but the CompCam has a slight advantage at the very top. I still like the Lunati better in a street build like this. I would also consider changing your headers if you have not already committed. 1-7/8 is really more than required in this case... 1-3/4 is the max that I would use here. This will beef up your lower end Torque and HP... Sure you'll lose a couple of points at the very top, but this is a street build...  all the fun is in the lower end.

[firefighter3931]

Those cams will be very close. The lunati will have slightly better power down low while the Comp will be a little better up top.

Mike's dyno program illustrates this point quite well. 


Ron

[69chargerR/T]

Thanks for all the info, and taking the time to compare the cams I do like the lunati cam, but the comp cam is nice too. I will most likely get the lunati because it has a little more power down low. I was wondering why you ran the cams 4* advanced ??

[Musicman]

I was wondering why you ran the cams 4* advanced ??

No particular reason really... Many of the Lunati cam specs recommend a 4 degree advance, and as such it is preprogrammed into my basic cam models for those cams. I have the ability to go in and change it of course, I just didn't give it a second thought at the time. I didn't have a premodeled spec for the XE274H, so I input the info over the existing Lunati 60303 model that I was using at the moment.

[69chargerR/T]

thanks again,musicman for all the info I think I'm going with the luntai cam, I always read good things about the voodoo cams everyone seems to like them.

[flyinlow]

I have the Lunati 60303 in my 446 ,similar built except Eddy heads. Happy with it.

Why is the Lunati more sensative to spring pressure? I am using the springs that came with the Eddy heads.

On the graph , the engine makes less power that a stock 440? Where is that power estimated? Rear wheels?

[Musicman]

As I said... This WAS NOT a predicted output for the build in any way shape or form... It was based on my programs model of a pre-existing generic stock style 440 installed in a B-Body with a full stock style exhaust system, and it was only used to illustrate the different characteristics of the 2 cams. The Lunati is always going to make more power up to the peak, but the Comp Cam will carry that power just a little further, and since that is all we needed to illustrate here, I felt it was good enough to post as an illustration. I apologize if I have created any undo confusion.

My program always starts with a basic bottom shelf model as a base, and you build on it from there. However, this is not "DeskTop Dyno" or "Camquest" were talking about here. This program is designed to be an aid and a guide for professional engine builders who need to predict and analyze changes or trends in their work. The program assumes that you are doing custom work, custom modifications and/or building custom components, so it does not contain a library of pre-existing models, and therefore every last little detail has to be measured and input. I have created a few models of my own of course for some of the more common items, Stock 906 heads etc... but in general, it takes quite a lot of time and tweaking to put a build together from scratch. It's not a user friendly program... If I took the time to build a good library of models, it would speed things up, and I could run it more or less like a Desktop Dyno... but I'm not that ambitious If I did it for a living I would, but I don't...

[flyinlow]

Thanks for the information.