Thanks I was thinking the reverse may also be true using an LT-1 cam in a 327. Well actually a 331.

It may also have better throttle response with the smaller 600cfm carb and slightly more restrictive 461 intake. I will keep my shift points in the 6200 rpm range with an LT-1 cam. I bet the LT-1 heads had bigger intake runners than my 461 heads.

But then again, it's dumping into a 2 1/2 manifolds and exhaust the 30-30 was specifically designed for.

I wonder how valid my above comments are?

 

At this point, that may be the deciding factor. I already have it. I could alway sell it if I go with a different stick.

I may be splitting hairs between the 30-30 and the LT-1

 

There is no splitting hairs between those two cams. Totally different.

There are some here that wouldn't use a LT 1 cam for a door stop!

There's no shortage of opinions on camshafts.

 

too bad 'Duke' isn't around to weigh in...

BILL

 

The most important consideration is compression ratio which must be matched to the cam's inlet valve closing point. No matter what you decide to do, you should first work backwards from about 8.25:1 dynamic compression ratio. Running on 93 PON gas, I wouldn't recommend going any higher than this with iron heads unless you are willing to de-tune the timing curve to quell detonation. This procedure will kill more power than had you built in too low a cylinder pressure to begin with.

You must also specify your measured combustion chamber volume (average), your compressed head gasket thickness, your piston above/below deck volume (actual) in cc's, and your engine's true piston to deck clearance in order to plug into the static compression ratio formula and arrive at your true static compression ratio.

If you don't choose your camshaft based on these principles, then you are wasting your time with pure guesswork, and are risking leaving lots of power on the table! Your engine should finally run just prior to detonation at all times for maximum torque output. Max cylinder pressure is always reached just prior to detonation, which is why "race gas" is needed on track days for engines that have been de-tuned for the street................the addition of advance that was taken out for street running on an already over built engine for pump gas necessitates the additional octane when optimum spark is dialed in for the track.

If you use the LT1, the 30-30, or the L79 cam in that engine, you will be leaving lots of power on the table because those cams can tolerate 11.0 to 11.5 static. Once you calculate your vital statistics, then pick your cam based on its inlet valve closing point in order to arrive at your desired DCR, which, as I said, should be about 8.25:1. You will be better off using a "milder" cam than those three, for optimal cylinder pressure at WOT unless your block's decks have already been milled to boost compression with those flat-tops.

Here is something, albeit inconclusive and idiotic, but which will at least give you some "food for thought":

http://purplesagetradingpost.com/sum...nations-1.html

 

Did he ever get any more than two people to use his super, duper 300 cam?

 

yep!!.....run the 30=30, you have good compression and that cam works well with 10.-12 in a 340 cu in mill
don't be afraid of the cam card, 450 net lift with that duration makes for good power starting at 2000 rpm and actually is not a dog around 1500 for slow cruising before it gets a little lumpy
the 30-30 really likes different lash settings, i have set them at .025 for midrange and top end and as loose as .035 for low end with no valve noise whatsoever
the idle is really bad azz too......

 

Thats for sure.. I find the whole exercise educational. In this case,concensus can be a valuable thing.

What is it about the 097 that makes it your cam of choice?

 

I am not contesting what you say.

But Chevy got pretty good results with an LT-1 cam and 9.5 to 1 flat tops in 71-72. I think I have smaller chambers .64cc than the LT-1 heads also.

 

Given my total engine & exhaust package was designed by chevy for the 30-30 cam, minus .75 in Comp ratio.

I am inclined to do the 30-30. Of course I am still undecided and enjoying the debate.

 

LT-1 Heads and your 461 heads are basically the same configuration, same small port volumes and both 64cc chambers. The LT1 also used 2" exhaust manifolds. I would take 65Tripleblacks information to heart, the 30-30 will run at your compression but not nearly as well as it can at 11.5:1. You asked similar questions before you bought the thumper cam everyone said not to buy. If you just want to replace the thing for now with a good driveable cam use the L-79 and install it advanced 4 degrees for increased torque. Otherwise take it apart and build it around the cam you really want otherwise you'll end up with half *** performance.

 

Apparently, you need more of an education before you make a wise decision. You don't seem to understand anything about post # 45.

Speaking for myself, and MikeM may have a different perspective on it, but from a purely dynamic viewpoint, the "Duntov" cam is much more aggressive than either the 30-30 or the LT1, strictly judging by its required valve lash settings of .012"/.018" for the 283 and .012"/.012" for the 327 in 1962-63. The faster the cam's dynamics, the faster the valve opens/closes which bleeds away less cylinder pressure, and provides greater "area under the curve", or "in-cam lobe degree". This is not to say that the 097 cam is a more high strung cam than the 30-30 or the LT1.......only that its lobes operate the valves much faster per degree cam rotation. The 097 is by far, the most docile/streetable of the three, with 228/230 and .395"/.401" (with true 1.5:1 rocker ratios, and which is not the case with the stock, stamped steel slotted rockers). Far more aggressive is the LT1 with 242/254 and .459"/.485", and still more aggressive is the 30-30 with 254/254 and .485"/.485".

You state: "Chevy got pretty good results with an LT-1 cam and 9.5 to 1 flat tops in 71-72. I think I have smaller chambers .64cc than the LT-1 heads also." First of all, the pistons used for all three years were the same, domed pop-ups; the difference was in the combustion chambers. You failed to understand that the LT1 was running open chambered heads in '71-'72 versus closed chambered heads for 1970. Notwithstanding the increased flow and enhanced power potential of the open chambered heads, the 1971-'72 LT1's output was still 40 (330 versus 370) horsepower lower than the 1970 version. This emphasizes the importance of maximizing compression ratio and properly matching it to the camshaft. If you were to compensate for the better flow from the open chambered heads, and had computed the difference in power between the 1970 and the '71-'72 LT1 based solely on static compression ratio deficit in the later years, the difference amounts to a whopping 60 horsepower. Furthermore, if the 2.02/1.60 valves in your 461 heads were unshrouded either at the factory or by someone else, then the chambers are 66cc, which are exactly the same size as the chambers of the 1970 LT1 with closed chambered heads. The 1971-'72 heads had 76cc chambers.

 

First of all, the only thing I know for sure about aftermarket cams is the ones I've inherited in engines/cars I've bought. The lone exception being a Crane Fireball I bought years ago. I haven't read all about camshaft theory like Joe so I can't tell you how to design one for your needs. I can tell you, all the aftermarket cams I've owned haven't suited me, one way or the other. Most of the other was there was NO low end to them and in some cases,(like you) no top end because the cams were mismatched to the rest of the combination.

I've run all the cams mentioned here in 327's. I absolutely love the 151 cam. Only problem, it won't put out much power above about 5800. Excellent to that point though. The LT1? I don't like the way it idles, don't like the way it pulls and drops off power at higher rpm. The 30-30 is a great street cam if you run headers and want to open them at the track and they'll really come alive. In the meantime, you get a pretty wicked idle and under acceleration, they make your power curve feel like I envision a midyear should feel like.

The 097? Good rumplety bump idle. Sufficient low end to pull down to 1000 rpm and then pull away in high gear. Starts really pulling about 2500 and still going to around 6500, depending on your combination. They'll even be pulling good to 7000 if you want to go that far. That cam will also give you around 14-16" vacuum @ 750 rpm. Again, depending on your combination.

Just thinking about what your original "mission statement" said, I think you'd like the 097 best.

Keep in mind, any of the factory cams are designed with an OEM exhaust system installed. Not so with the aftermarket camshafts.

Other opinions may differ.

 

Mike, curious what you mean by the LT1 cam's power falls off. Check out Mark's dyno, the 327/LT1 cam motor pulls very steady.

http://forums.corvetteforum.com/c1-a...27-lt-1-a.html

 

"Steady" doesn't give me the feel of driving I like.

I have no plans to defend my choice of camshafts. I merely reported what I have experienced in real world driving, not on a dyno. I don't even have a desk top dyno program here.

I believe some sit at their computer running their desk top dyno, making gurgling sounds, mimicing an engine idling and then utter sounds like uddddnnnnnn, udddddddddnnnnnnnnn, uddddddnnnnnnnn while playing with a sawed off broom stick for a gear lever beside their chair.


See the last sentence in my previous post.

 

dunno....

i did try his valve adjustment specs for the LT1 cam and got beat in a drag race by a boy on a bicycle...

Bill

 

Anybody have the specs on the 097 cam?

 

GM 3736097

http://www.cranecams.com/product/car...detail&p=23966

 

I want to thank everyone for responding. I know this subject gets beaten to death. I know it's hard, especially for the old timers to keep responding to the same old subject.

But I feel this is a productive thread. I am learning a lot. I bet I am not the only one.

I think the 30-30 is going to be my choice. It was GMs choice for my motor combination.

Until I have first hand knowledge otherwise. I feel factory cams will give best performance with cast iron exhausts, intake etc..I can always change if it doesn't suit me. According to 427hotrod,I can use my existing springs, I won't be pulling the motor just yet.
If I do? I may go ahead build a cosmetically "correct 427 SB".

 

Hey Mike,

I keep watching and watching this thread, but what seems lacking is a firm statement of your requirements, and they need to be attainable.

Here's a few which the experts will ask...
What is your intended usage?
What is your desired RPM range?
What's your compression ratio?
What kind of idle do you want?
How much vacuum do you need at idle?
How important is mileage?
How much horse power do you want (how quick in the 1/4 mile)?
What is your carb size? Vacuum or mechanical secondaries?
What kind of exhaust system - headers or stock?
Which heads?
Would you modify the heads for 1.45" diameter valve springs?
If stick, what is your first gear ratio? Your rear gear ratio?
If auto, what's the diameter of your torque converter and stall speed?
Are you willing to check valve lash every 6 months or so?
What is you budget?

Nail these down, and you will likely get a rough consensus.