using the numbers provided above and the same basic motor I used for the other numbers...

Mellings 30-30
PK TQ = 364@4000 Pk HP = 316@5000
AVG TQ= 305, HP = 238

Predator 30-30
(assuming the numbers above are centerlines not lobe seps)
PK TQ = 369@4000 Pk HP = 315@5000
AVG TQ= 306, HP = 233

If we assume a bit more agressive ramps on the Predator...
PK TQ = 370@4000 Pk HP = 317@5000
AVG TQ= 308, HP = 238

 

Comp gives the specs @.015 Tappet lift.
Gross valve lift Int-.501/ex-.510
Duration @.015 Int-274 Ex-280
Valve lash- Int/Ex-.016
Installed @106 Int. Centerline
Valve Timing @.015 Int. Open-31 Close-63
Ex-Open-74 Close-26
This is the cam that is currently installed. Thanks.

 

Dyno 2000 puts my 400 with Tri State Racing Heads Flow numbers -unported - gives these figures:
512 HP at 6000 rpms
503 ft lbs at 5000 rpms.
The program shows over 400 ft lbs 2500 to 6500.

This is with open headers. Of couse, with a closed exhaust it will be lower.

I use these programs as a guide line only. But, this 400 does run like the figures stated.

The 346 cam ( 30 30 ) is a very good street cam. What I like is, it is easy on valve train parts. Since 1972, only ONE broken valve spring. That was with a new set of TRW first service cam valve springs ( 110 lbs seat ).

 

I downloaded the Comp Cams catalog and looked up the part number listed in the original post. The specs for the cam are slightly different from those given above but then are also at a more 'normal' .050.

I also found better data for the head given and plugged that in as well so the numbers I give here have been recomputed with the new head data so will be slightly different from before.

So with the Current comp cam part#12-677-4

Peak TQ = 369@3500, Peak HP = 306@5000
Avg. TQ = 305, Avg HP = 233 2000-6500RPM

With the LT1 CAM listed as the Chevy Cam # LT1 3972178 in EA Lib.

Peak TQ = 374@3500, Peak HP = 317@5000
Avg TQ = 313, Avg HP = 241 2000-6500

I want to note that EA shows spark induced knock at lower RPM resulting in backed off ignition timing. I run these sims with 98 octane fuel as I think EA is too conservative and you can get away with out knock at higher compressions numbers than it thinks so adding a few octane points allows the program to be a bit more aggressive and realistic with timing curves.

The program gives tons of info, if you want more let me know, also if you have a specs on the 30-30 you want to use I can run that too. Looking at the curves of the above runs the LT1 is the equal of the CompCam to 3000RPM where the LT starts to climb more steeply.

 

Thanks macdarren, Looks like the Lt-1 is a bit better than the Compcam, I talked to the crane guys today and he recommended a way more radical, at least to my thinking, cam based on the extra cubes in my 383. @.050 Int. opens-21 closes 49 Ex- opens-58 closes-22
Int duration 250 Ex-260 Int lash .026 Ex-.028 Crane#12003
I would still like to see numbers on the Predator 30-30.

 

be careful when taling to tech support guys..

they can read the catalogs with the best of them... and rarely have any real experiance...

they all say "should be no problem with manifolds" but that is rarely the case.

With any exhaust manifold, the 30-30 is about as big as you can go... those manifolds will not allow any more HP to escape.
and opening the lobe seperation on any given cam is not the answer.

As long as you run factory manifolds, run the 30-30 or LT1 cam. those cams were designed on 114 and 116 lsa

ttaking a cam designed on a 106 LSA and opening it up to 112 is not the solution... i've tried this and had poor results several times... proves that the cam tech help line guys really don't have experiance with stock exhaust type experiance.

I've been tossing around this idea of stroking my 327 FI out to 383 and using the Offroad cam, but I know that the exhaust will be the bottleneck.

A

 

numbers for crane 12003...this is an odd cam...alot of overlap, it probably sounds nasty, but is not much of a performer on your setup. If I had to guess it is more for a smaller and even higher compression higher rev motor....ie 327 w/ 14:1 turning 6500?

Peak TQ = 355@3500, Peak HP = 298@5000
Avg. TQ = 293, Avg HP = 225 2000-6500RPM


Predator 30-30
This cam is really similar to the above crane in performance, lots of overlap. It has a bit better performance down low....

Peak TQ = 358@3500, Peak HP = 293@5000
Avg. TQ = 292, Avg HP = 222 2000-6500RPM

If it was me I would look at cams with a bit more duration at 50 maybe and a wider lobe sep.

Starting with the LT1 I played around some, first the heads could use some work but I think if you want a hard running car, and don't might some lope, still decent vacuum, look for something like this.....

IN/EXH DUR@50 230/252 a bit more than you have looked at but ok with wider lobe sep.
InCL/ExCL 115/123 this is wide but not unheard of but with manifolds and mufflers it is ok
Lobe sep is 119

Lobe lift .36/.37 rocker .54/.555 this is high but not too radical should last OK

I mocked this up and got this on your motor:

Peak TQ = 383@3500, Peak HP = 320@5000 Note the meaningless but fun 1ft/lb per cube
Avg. TQ = 320, Avg HP = 246 2000-6500RPM Lots of torq and good HP = fun around town

This thing should pull hard to 5k...it gets my vote, I had something similar in a 400 SBC and
it always impressed until about 5500 then it goes flat fast....I'd come these to what others have
posted and know works





If you want a peaker higher rpm motor this one looses below 4000rpm but wins above.

IN/EXH DUR@50 258/268 a bit more than you have looked at but ok with wider lobe sep.
InCL/ExCL 111/125 this is wide but not unheard of but with manifolds and mufflers it is ok
Lobe sep is 118

Lobe lift .36/.37 rocker .54/.555 this is high but not radical should last OK

Something like this will help with detonation due to high static comp. ratio too.

I mocked this up and got this on your motor:

Peak TQ = 360@3500, Peak HP = 322@5500 Note the raised RPM
Avg. TQ = 307, Avg HP = 242 2000-6500RPM



***Disclaimer, I am an software designer NOT a cam designer so these are strictly opinions not assurances.

 

Yea, be careful, us.....I mean THOSE TECH guys..... may not always have your best interest in mind, but some of us....I mean THEM... give it their best shot.

Like I've said before; The 346 ( 30 30 ) is the BEST solid lifter ( flat tappet ) street cam I've ever used in a SB. I've used it in 327 to 415 ci engines. Now, with open headers, there are other cams that will give you more power. But, with closed exhaust, this cam is very strong and easy on valve train parts.

 

I have to generally agree with glen, on the 30-30, I have only used the factory cut and one other close reproduction and with the 327 with exhaust it is a good cam. I happen to like a bit more lobe sep to clean up the idle and I think widen the power band. I don't know about various so called 30-30s some might be very good others who knows. I also think in general the cam tech guys are decent but some are vastly more knowledgeable than others. Some probably know alot more about a VTECH than a V8, others are very stuck in a rut, but many have real experience too.

I was always partial to UltraDyn cams before they vanished into history... I always felt that at least the one or two guys I talked to knew their stuff (I think that is an advantage to the smaller outfits) and all the cams performed as expected. Key to doing the job right I think is asking all the right questions....if I get a cam tech that is really a sales guy in general he won't want to spend time going over engine, chassis and application information, he will ask a few basic questions and spew out his less than expert opinion. One thing that always amazed me is often I am not asked displacement or for head details....maybe the thought is well all SBCs are 350s. But I like the big small blocks and as mentioned earlier what is radical in a 327 or 350 is not so radical for a 383, or 434 small block.

I personally think I might have made a mistake on my last cam choice but I don't have the motor in yet. They dyno looks good but I think the exhaust will kill me....I should have gone with my own gut instead of giving in to the dyno shop. I have learned alot since then that makes me suspect even my fairly decent exhaust will really hurt those dyno numbers. Oh well live and learn and install 3 inch straight pipes...

 

Just to help out, at 800 rpm - idle - I have 9 inches of Vacuum with the 400 engine. This is with an M20 ( no Auto Trans ). When this cam was in the 327 I had 5 inches of Vacuum. In the 350 I had 6 to 7 inches of Vacuum. The 400 idle still sounds mean , just like any 30 30.

 

OK, it looks like the 30-30 wins I also should have listened to my gut last year when i put this together, I was talked out of the 30-30 for a more modern stick. I know with the torque of the 383 my 205/70R15's don't stand a chance so if the 30-30 kills alittle low end that may help. So now the question is WHICH 30-30? Crane has a blueprint, Melling and Speed Pro and also Predator have cams. I am going to the Corvette drags tommorrow and then pulling the engine on sunday, so I need to order a cam and lifters. Hit me with all of your experience with any of these, I know Arron has great things to say of Predator, any other input is welcome I would like to order tonight so I will have it by tuesday. Thanks again guys, the experiences of your builds really make this forum the best source of info there is.

 

Since you have folks running EA simulations, you might want to try two other cams:

If you plan to run headers the Crower interpretation of the 30-30 works up to ~6600rpm in (383-400) larger displacements. Stock exhaust manifolds and heads do not work as well with this cam (less torque below 3200, compared to a GM 30-30 or LT1) but if the exhaust restriction is reduced it can put out impressive power numbers (just do not expect it to work well with stock exhaust manifolds and side pipes):

Part Number/Work Order Number 00322
Engine Application 262-400 CHEVY
Grind Number 282SF

ADVERTISED CAMSHAFT SPECIFICATIONS:
INTAKE: Duration: 282º Lift: 0.504 Clearence Hot: 0.022
EXHAUST: Duration: 292º Lift: 0.528 Clearence Hot: 0.024

The specifications listed above are based on a rockerarm ratio of 1.5 IN 1.5 EX

RECOMMENDED VALVE SPRING INFORMATION:
Part # 68390-3 Single Dual X Triple
Approximate spring pressure: valve closed: 120/130 LBS.
valve open: 320/330 LBS.

The information below is for degreeing cam only. Correct only at .050" tappet lift.
INTAKE Opens: 16.0 BTDC Closes: 52.0 ABDC
EXHAUST Opens: 62.0 BBDC Closes: 10.0 ATDC

LOBE SEPERATION 112º

Duration at .050" Intake: 248 Exhaust: 252
LOBE LIFT Intake: 0.336 Exhaust: 0.352

If using "Lobe Center" method of degreeing, cam should be installed on an intake centerline of: 108º


With exhaust manifolds (and even stock sidepipes) the Crower intrepretation of the LT1 works to ~6000 rpm in larger displacement engines. It will perform well at higher rpm for the smaller displacements, with porting and headers, but is fairly tractable in 383's and up with manifolds (it can even work well with an automatic trans and a ~2000 rpm stall torque converter):

Part Number/Work Order Number 00321
Engine Application 262-400 CHEVY
Grind Number 274SF

ADVERTISED CAMSHAFT SPECIFICATIONS:
INTAKE: Duration: 274º Lift: 0.482 Clearence Hot: 0.022
EXHAUST: Duration: 282º Lift: 0.504 Clearence Hot: 0.024

The specifications listed above are based on a rockerarm ratio of 1.5 IN 1.5 EX

RECOMMENDED VALVE SPRING INFORMATION:
Part # 68390-3 Single Dual X Triple
Approximate spring pressure: valve closed: 120/130 LBS.
valve open: 320/330 LBS.

The information below is for degreeing cam only. Correct only at .050" tappet lift.
INTAKE Opens: 11.0 BTDC Closes: 51.0 ABDC
EXHAUST Opens: 62.0 BBDC Closes: 6.0 ATDC

LOBE SEPERATION 114º

Duration at .050" Intake: 242 Exhaust: 248
LOBE LIFT Intake: 0.321 Exhaust: 0.336

If using "Lobe Center" method of degreeing, cam should be installed on an intake centerline of: 110º


One aspect of the original GM cams is that they are gentle on the valvetrain (compared to more aggressive moden lobe profiles) and work better than almost everything else if you run stock heads and exhaust manifolds (and sidepipes). If you are not trying to squeeze every bit of higher rpm power out of the engine combination, and are willing to trade a little peak power for durability (and the peace of mind that an occasional over the redline rev will not be catastrophic) the GM profiles are hard to beat for long term wear and durability.

.

 

Get the Crane Blueprint and advance it 4* crank if you want. Just MHO! Just remember, any cam you get is a compromise.
The 346 cam is just a VERY good street cam that is easy to tune and make go-fast ( lawfully ). With a .030 lash you have room to adjust up or down to change the way the engine performs.

 

I agree..

all of the 30-30 clones are good choices... i've had great luck with the predator and will never use another... the crane is an exact GM blueprint, as is the melling. the comp and predator have 4 degrees advance ground in.

the 30-30 likes 4-6 degrees advance especiallly in small engines.

mine runs like crazy in both cars. (302Z28 and 327FI)

i doubt you'd notice any difference between the various vendors unless you had all of them and did multiple dyno pulls with each cam.

most likely, the ones with advance ground in will make a few more ft/lb at a lower rpm, and would fall off a few rpm earlier than the ones wthout the advance ground in... of course you can install it advanced if you like.

either way, the 30-30 is a great cam and while I think you can make considerably more power with a modern cam, you need the rest of the combination to make that power....

modern cams in vintage engines with stock exhaust doesn't cut it.

i'd love to see Super Chevy or Car Craft do some fancy engine builds and dyno pulls using the old grinds just to see how they fair with a set of 220cc AFR heads, victor jr intake, 850 holley, and 1 3/4 supercomp headers.

A

 

Well I'm back from the Corvette Drags, best run of the day was-
60ft---1.984
1/8----8.509
Mph---82.78
1/4---13.229
Mph--105.09
had an absolute blast. So next is to order the Crane Blueprint and install 2 degrees advanced since the crank gear is already @ 2 advanced. The end of the month or the end of july Capitol Raceway has another oldies drag day so we can see how the 30-30 fairs.
Thanks for all of the great advice.