Thinking about this cam.. VE's inside
 

Below are the VE's taken from Jrod's VE calculator spreadsheet for a 236/238 .602/.605 114lsa 110icl cam using comp's X-er lobes. This will be going into my current combo in the sig. My pistons are flycut .075 on the intake, but only .010 on the exhaust. I wanted to run the MS3, but my lack of exhaust clearance had me worried. What do you guys think about this cam and do you see any clearance problems on my unmilled heads with 2.05/1.60 valves and the flycuts that I have. And most importantly, what do you think about the cam in the "performance department"

-LIFT___.006____.050____.200
- ID____ 285_____236____157
- ED____287_____238____159
- LCA___114_____114____114
- ICL___ 110_____110____110

- IVO___32.5______8_______-31.5__ BTDC (- indicates ATDC)
- IVC___72.5______48_______8.5 ABDC
- EVO___81.5_____57_______17.5 BBDC
- EVC___ 25.5_____1________-38.5 ATDC (- indicates BTDC)
- ECL___118_____118_______118
Overlap__58_______9________-70 degrees

I'm also hoping that this cam will peak around 6500 to 6600.. what do you think?

Will peak high around there and hold it out for a whiel as long as it can control the valves

Why such a high LSA?

I had a few reasons for the high LSA
1. Better idle (less overlap)
2. More intake clearance
3. Higher peak HP number
4. Broader power range
5. Moving the torque curve up in the RPM band
6. Nitrous friendly

I'm going to be running the new PRC dual springs that are have a little more pressure than the patriot gold duals. I plan on shifting around 6900-7000 normally aspirated.

Gomer,

Tough to figure out what'll work without more info...

Vehicle dynamics and flow figures would help...

Also weight of the valvetrain... The XER lobes are not friendly to heavy valvetrain...

Ed

I don't have flow numbers thru the intake, but the head flow numbers with a pipe are below. The car is light, 3400-3450 with me in it, 4.10 gear and 26 inch tire, 6 speed. The valvetrain is pretty much "standard" stuff. Ferrera 2.05/1.60 valves. Stock diameter dual springs, and Ti retainers... also hardened 7.400 pushrods along with yella terra rockers. Flow numbers were on a SF600 3.90 bore.. standard stuff. I know it sounds silly, but I'm wanting to loose some low end over the cam I have now. I'm wanting my torque curve to come on later in the RPM band and carry further into the upper RPMS. I've also noticed that pretty much any aftermarket H/C setup on these cars have a peak TQ around 4800rpm. I'm guessing that's dictated by the intake runner length more than the characteristics of the camshaft. I want my powerband to be strongest from 4,000 rpm to 7000rpm, peak HP to come around 6500 to 6600. Runner volume on the heads are about 217cc intake and 80cc exhaust.

Lift___int___exh
200___152__117
300___206__166
400___261__202
450___274__210
500___292__219
550___305__225
600___314__229

Hmmmm....

Can your springs handle .625-.635" lift???

Ed

They are good for .650

Id say look at slower opening/closing ramp lobe, prolly what Ed is thinking. Thats a relatively heavy valvetrain with them monstrous valves. Slow lobes seem to be worth a few extra up top due to maintaining valve control a little better, and aggressive stuff worth a few down low/midrange

Are you building it for nitrous? You were looking at a wide lobe for that reason, but is there enough exhaust lobe for a what you plan to run?

Who has a "slow" lobe with high lifts? I'd like to keep the lift up around .600 without having to run a higher ratio rocker.

With that much duration and that wide an LSA I would expect your motor should peak much higher than 6500-6600 your valvetrain can't go that high, but I'd say peak should be north of 7000 with that cam.

There are plenty of non XE-R lobes that can work just fine.

Then why would TSP's MS3 with 237/242 113lsa 113icl peak at around 6600 and not over 7k? I would think the cam above would peak at the same point or sooner than the MS3?? Also, the total duration is smaller than the G5X3 cam isn't it? There are a few of those out there on 114 + 4's peaking in the 6600 area.

I can't tell you here.... :secret2:

Ed what do you think about a relatively small duration, tight lobe cam retarded a couple degrees? Think that may accomplish what hes lookign for NA?
Defintely not optimal for nitrous

What would the idle be like though? I've tried something similar to that before, it really idled like a much larger cam.

Ummm...

Up to a certain point (relative HP) a nitrous specific camshaft design in not really needed. Since he's looking for a certain operating range, and the heads are in a higher Ex/Int ratio, there's going to be more to his specific design than just the "relatively" wide LSA and its resulting intake timing events. I think I'd go as far a stating I'd get more aggressive! Image that...

Basically I'm just looking at the overall combo that Gomer has and what his goals are, and see that the cam profile he's looking at doesn't seem correct. (At least to me anyway) Hey.... but WTF do I know... I only know 5.0's, right? :rolleyes:

Ed

I wasnt questioning you Ed, if thats what you menat with the eyes :)

Just throwing out some ideas

No no no... not you...

Just retorting some comments made by "frequenters".... I'm in a fiesty mood... Just turned 48 and I'm feeling old... :(

...back on topic... sorry...

Ed

Also, I'm not questioning anyone either... if I knew all the answers I would just order a cam and not seek input and advice. Thanks for all the replies so far guys. :cheers: