I would like to have someone with the EA program to run a couple of camshafts w/my combo. 4.030X3.75 461 heads 2.02/1.60 stk ports. 461 intake and 2818 carb. 10.8:1 2 1/2 ramshorns and 2 1/4 sweetthunder side exhaust. I currently have a Comp xe274s cam, and would like to see the numbers for a change to a 30-30 and also the Lt-1 cams. The comp part#12-677-4 Thanks.

 

I use the Dyno 2000 program. The 30 30 cam is still ( mho ) the best street cam. Tied to PM you--you are full. I spent a year running head flows and cam combos. Still stayed with the 30 30. I tried 140 went back to the 30 30. The LT-1 cam is too weak.

Current combo:
400 stock bore and stroke
China Alum heads-- ported by me.
Dual Quad Offy hi rise intake--2 500 performers
Stock Ram Horns--ported by me.
6 inch Scat Rods--good to 750 hp
Flat top pistons --10.95 cr
It's got less than 100 miles -- how does it run -- just one word.....D@MMMMNNNN!

 

what was the differences of the 140 to the 30-30, and if you have any numbers relative to my combo i emptied my box. thanks.

 

The "-140" cam is a slug on a normal street engine, with even less low-end torque than the "30-30"; the "-140" was designed to run at 12:1 with the cross-ram intake on the Trans-Am Camaros, which spent their whole life between 4000-8000 rpm. May sound cool idling at the cruise-in, but it's a lousy street cam.

 

I agree that the 30-30 is the best street cam of the bunch.

a 12 to 1 383 with big headers, intake and carb would probably be a whopper with the 140 cam, but not through those ramshorns.

I'm comtemplating building a 383 for my 69Z using that very build.
12 to 1 383, 140 cam, 1 3/4 headers, ported 186 heads (stock casting for 69Z) and Z28/LT1 intake.

the limiting factor will be the heads/intake... but i want to use the 186castings and the original intake so it looks purely stock other than the headers.,the 186 heads, can be ported to support a 302 with the 140 cam at 7500rpm, but i'm not sure they can support a 383 with the 140 cam.

you have to remember, the more cubes, the smaller the cam acts..

so what acts big in a 302 or 327 becomes alot tamer in a 383 or 400.

i think a 383 with the 30-30 and ported 2.5 ramshorns or headers would be a real street screamer.. and pull hard to 6000 rpm.

The 30-30 is great, and everyone things its is a monstor cam, but both my cars stopped climing at 6600 rpm (302) and 6400 )327)

I'd bet the additional 50 cubes of the 383 would make the peak HP of the 30-30 around 6000rpm.

but you'll need more carb than the 2818 and that 461 intake is gonna choke her up also.

Good luck

A

 

Thanks guys, aaronz28 I seem to remember your 30-30 was a different grind than the speed-pro or crane replacement could you give me the part# and supplier info. Thanks again. PS I'm still interested in anyone who could run the 30-30 against the comp xe274 solid w/my combo.

 

The 140 is a strong runner with open headers and high RPM.

 

I don't know about it running out of power at 6,000. On my 400 (with 041 heads-ported at the time) I was able to go to 6,250 before it STARTED to run out of steam. Generally, with the 041s I used 3,500 to 6,250 as the power band, but did take it to 6,800+ on hard runs.
You are right about the Idle, it is slighty less lopy with the 400 than a 302. But, it still has the 30 30 lope.

BTW- That was with dual 500 performers on a Offy low rise intake.

 

my 30-30 is from

predator cams../midway performance.

look up 30-30 on ebay and you'll find them.,

i stubled across it.

it is a stock grind with 4 degrees ground in..

i used Crane and comp, lunati 30-30 grinds before, and I really think this one performs the best.

thansk

aaron

 

Thanks again guys, I put this engine together last year at the height of the famous Lt-1 cam vs the world and couldn't seem to get any good info so I went with a comp which has always worked very well. The car runs very strong 13.18 @107 on 205/75-15 michelins and a 3.36 gear, but when its next to a 30-30 equiped car i just shut mine off, I can't stand the idle sound. It would be great if the 30-30 outran the comp but low 13s are fine w/me.

 

I'm not sure what you mean, by "30-30 outrun the comp"

but if you are comparing a 30-30 to LT1 in a 383... the 30-30 will pound it all day long.

the LT1 is a smaller cam on a wider lobe seperation angle.... which is great for a small engine.. 302, 327 etc... I still prefer the 30-30 in the smaller engines...

once you come on the cam,, the 30-30 will outpull the LT1 all day long.

the idle quality is not that different between the two though...
and in a 30-30 in a 383 will probably sound as smooth as an LT1 in a 327...

I have an LT1 ground on a 115LSA that I was gonna put in my Z, or put it in a 383, but i'm just so happy with the 30-30 that whatever I build, its gonna get a 30-30

thanks

A

 

aaronz28
i'm just so happy with the 30-30 that whatever I build, its gonna get a 30-30

thanks

A[/QUOTE]

 

The Comp Cam thats installed now is what I was refering to.

 

oh, gotcha.

i would venture to bet that the 30-30 would certainly idle rougher than your current cam, and it would pull much stronger above 4500rpm.

the comp cams guys will disagree, but i've been down this road with modern shafts....

i think modern cam designs are great, but you need the complete package to make use of them, (headers, exhaust, intake)

thanks

A

 

Thanks Aaron, its nice to get a few opinions of real experiences, the Comp cam runs fine, I just hate the sound. We have a all Corvette drag race this sat. so I'll run it this weekend and then pull it on sunday and start the cam swap, I'll check midway performance I also see Comp and crane make 30-30 cams. Crane is supposed to exact replacement.

 

All the discussion here ( from me anyway ) is on a factory spec 30 30 cam. Comp Cams 30 30 is NOT factory GM specs. It is their idea of what the 30 30 should be. The Crane is a factory GM blueprint.

 

Thanks Glenn, Crane will most likely be my 2nd choice once I get more info on the Predator 30-30. Does speed-pro or anyone else sell one? Comp is definitly not a player.

 

Mellings makes a blueprint cam for the 30 30. That's what I have been using for years and years.


BTY; I did advance my cam 2* cam - 4* crank.

 

I have EA and I have entered your motor but I had to guess at a few things and it would help if you can supply complete cam specs as I didn't find the comp cam you gave in the EA library, so I choose one that was close just to set up...the XE274H....but if you could supply all the details for the 30/30 (I Know I should know) and the other cam that would help.

I need lifts and durations at 050, if it is solid I need lash numbers also intake and exhaust centerlines and if you know the open and close points of the valves and lobe seps that helps, also if you want to run any static advance on the cam.

I also had to guess at the carb, 650Vac? and the intake (stock AL?)

more info the better.....here is a summary of my test run assuming 1000CFM exhaust which I have been told is about right if you have oversized chambered pipes.

Peak Tq of 368 at 3500 and Peak HP of 298 at 4500
Average TQ from 2000-6500 296 ft/lbs and Average HP 223

switching to the solid roller XR274R
tQ goes to 384@3500 and HP to 323@5000 with AVGs of 319ft/lbs and 245

 

This will get you close...

The Mellings 30-30 duplicate:

Lift: 0.3235 lobe - 0.485 at valve @ 1.5 rocker ratio

Cam Timing: TAPPET @.050
Opens Closes Max Lift Duration
Intake 15 BTDC 59 ABDC 112 254 °
Exhaust 63 BBDC 11 ATDC 116 254 °

Lash I/E 0.030/0.030




The Predator 30-30 (POML's are advance four degrees from the GM cam at 0.050, but the asymetric GM lobe profile may have more to do with the timing difference than actual open valve sq-in-per degree window area around the POML's):

PREDATOR CAMS

ENGINE 265- 400 CHEVY

CAM GRIND # SBC30/30 DUNTOV

INTAKE EXHAUST

DURATION @.050 254 254

LOBE LIFT .323 .323

LOBE SEPARATION 110 118

SEAT DURATION AT 314 314

GROSS VALVE LIFT .485 .485

VALVE LASH ( HOT) .030 .030