66gutlass

There is indeed such thing as too much camshaft. While it is easy for me to say this, it is not within my scope of knowledge to know what exactly IS too much cam. So here's what I CAN tell you. I have a 1966 330, stock crank, street dominator intake, 10.5:1 pistons, will be getting a brawler 650 full mech carb, will be getting roller rockers and valve work to match new cam, and plan to port and polished heads. Speaking drivetrain, will be matching this motor to a 200r4, still deciding on what rear end and stall converter. Naturally, I am forgetting something. Regardless, my question is, I see how many cam options are out there, and my head starts to spin. I am new to engine building if that wasn't already apparent. So here goes. Hydraulic flat tappet. I present to you 3 random options on the comp cams list I am viewing.
a.(206/212)
b.(212/218)
c.(224/230)
(@0.050 inch lift)
I know roughly what all this means on paper but in practicality I am lost at sea.
Enlighten me my friends!

redoldsman

There are people on here that can probably give you some good advice. I am not one of them. Other things to consider are lift and lobe separation. Rear end and stall speed of the converter are things to consider.

Fun71

“10.5:1 pistons” may not translate to 10.5:1 compression ratio.

Multiple things go into the actual compression ratio.

Piston to deck clearance:
The distance from the top of the piston at TDC to the block surface where the head sits.
- Almost all replacement cast pistons are shorter than factory, some by as much as .020”.
- Most blocks have around .020” deck clearance from the factory.

Head combustion chamber volume:
- Chambers are typically larger than factory spec due to manufacturing tolerances.
- Valve jobs can increase the chamber volume.

Head gasket thickness:
- Factory used steel shim head gaskets that were about .017” thick compared to modern composition gaskets that are .041” thick.


So with all this you have to actually measure everything to calculate what the actual compression ratio will be. You can put “10.5:1 pistons” in an engine and easily have 9:1 actual compression ratio.

Fun71

The more cam you have, the more need for lower rear gears and higher stall converter.

If you plan on power brakes, the cam will need to generate sufficient vacuum. I found 15-16” was needed on my car.

66_Jetstar

"There no such thing as too much cam, you don't have enough motor."

Dream67Olds442

Here are the specs of the Engle hydraulic lifter flat tappet cam in my '67 Old's 400ci.


The duration of my cam @ .050 is very close to your "Option C, 224/230". Here's what I can tell you about the performance in my 400ci. My motor starts well, has a very lopey "muscle car" idle and sound, and runs like a bat out of hell. However, there is NOT enough vacuum to operate front discs without a vacuum collection system. ​​​ My car now has a Comp Cams vacuum collector to power the front discs. Not ideal! I am not the world's best mechanic or engine guy by any stretch of the imagination, but I have read on this forum that all other things being considered equal, the same cam run in a smaller displacement engine like your 330ci vs. my 400ci, will act even more radically. For what it's worth, you might want to consider crossing Option C off your list for better streetability. Just my 2-cents.

olds 307 and 403

I say option two and maybe slightly more. I personally won't spend money on a flat tappet cam again. Unfortunately roller cams and hardware are many $$$. If you do, make sure every precaution is taken for break in. I ran a flat tappet 214/214 cam in a 9 to 1 350. It had good vacuum, 16 inches at idle, which was close to stock. With a 2350 stall, 2004R and 2.78 gears it would do 1/4 block 1 wheel peels and got 16 mpg US on the highway. I assume with the 2004R, you are going to a higher rear gear, like 3.55? What stall range are you wanting? Both those affect cam selection. I went back to the stock TH350 with 1600 stall, it sucked. It would barely spin the tires and just wasn't near as fun. The cam did go flat the next year. Also degree it, so at least you know everything is right where it is supposed to be. Good luck.

BillK

Gutless,
I am going to give you the same advice as I give everyone else when it comes to cams even though I think I am mostly wasting my breath Pick a cam manufacturer and call them and let them tell you which cam to use. I have been doing this for a living for over 30 years and that is still what I do every time.

By the way your three sets of numbers do not mean a thing without the corresponding advertised duration and lobe centerlines etc.

66gutlass

fair enough man, i have no problem making it clear im like a child building an airplane right now, a whole lot of guess work and redundant questions. Thanks for the suggestion though, I will give them a call and see what they think.

66gutlass

if you have a suggestion on roller cam supplier I will take that leap, not sure exactly where to look.

66gutlass

does a larger cam generally create less vacuum? I am completely new to engine building so i dont know even the slightest on this matter.

Fun71

Yes, generally higher duration means more valve overlap and less vacuum. There are other cam parameters that can affect vacuum but that gets very technical.

Koda

There is such a thing as too much cam, but there is not such a thing as too little cam. By this I mean, an engine that could use a bigger cam for its role will still run well with the smaller cam. It won't be perfect, but it will be good. On the other hand, too much cam will make the car be a dog. My project 442 is this way, which is why it was sold to me cheap.

Why are you putting so much money into a 330 when you could put a 455 in there and have much more power yet still have manners? Big cams mean lots of gas consumption, setting idle is a bitch, power brakes and AC are a bitch, and so on. Better to have bigger engine with same power but behaves nicer.

redoldsman

It is very common for folks to overcam an engine. Lots of people want that lumpy idle which is pretty cool. And in an overcammed engine that is where it ends. If it is overcammed it will fall on it's face. Calling the cam manufacturer is a great suggestion.

66gutlass

I suppose so, but at the end of the day, this motor really isnt supposed to be a monster, the car is just going to be a low slow cruiser, that I can stomp the throttle if I want. Besides so far it isnt looking to be costing me a fortune. From the way some guys talk I figured this motor would cost a fortune, but its similar to some mild 350 chevs that have gone in family and friends builds. And as the first sentence implies, indeed I know there is such thing as too much cam, was more a question of what people recommend based on what I envision. Seeing as how I have very little engine rebuild experience.

Koda

Oh, ok, then the cam you want is slightly more aggressive than stock.

Fun71

Based on what you last posted, I would say a cam with around 210 duration @ .050” lift. My engine has a 217 / 221 cam and I think it would perform similarly but be more streetable with a bit smaller cam. Also, I don’t really like those Comp Cam profiles, so maybe check with cutlassefi (Mark) for a recommendation on a cam profile.

OLDSter Ralph

"To much cam", "Overcammed" are terms that usually show up when an automatic transmission is involved. Typically the Torque converter is mismatched......stall speed to low. It can show up almost as quick with a close ratio 4 speed.
Let the cam manufacturer tell you what torque converter stall you need for each cam. Tell them what transmission you'll be using.
Also inquire about vacuum to operate accessories.

olds 307 and 403

You need to nail down compression, stall and gear you want to run.. See what condition the block is in. Another member bought the high compression 330 pistons and he only actually had around 9.3 to 1 instead of 10.5 to 1. It is due to every cast Olds piston being about .040" below deck. Honestly he got decent dyno numbers from and it performed quite well.
https://classicoldsmobile.com/forums...light=330+dyno

67OAI

As "olds 307 and 403" and others have stated, talk with the cam grinder or send a pm to Mark, "cutlassefi". They will need as much info about the car, the transmission, rear end, tire size, and the rest of the engine build to give you a really good recommendation! Some of the cam grinders will have forms on their web site to gather the information needed; take a look at several of these to get an idea of what they want to know. Good luck with your build! Oh yeah, and if you have power brakes they will want that info too so as not to provide you with a cam that won't generate enough vacuum to safely operate the power brake booster!

Dream67Olds442

66gutlass - I responded to your request for info early on in this thread. Other's have already provided great advice, but would like to summarize what other's have said in order for you to have a "Plan" to work.

1. Know what your car currently is - What component's are currently on your car that affect performance including, block, heads, intake, carburetor, exhaust manifolds or headers, exhaust type (duals or single, and diameter), transmission, rear end (ratio, and single or posi), and whether you have vacuum assisted accessories like power disc brakes.

2. Have a clear vision of what you want your car to be, and do, when you're done - ​The final performance of an engine build, and final overall performance of the car, is totally dependent on all the components of the drivetrain being matched to optimize their designed performance.

3. With these "knowns", Private Message (PM) "cutlassefi" (Mark) - Mark is a very reputable engine builder on this site, and he can recommend a camshaft for you, and possibly even sell you what you need. He can also provide additional knowledge and recommendations to help you achieve your vision for what you want your car to be when it's finished.

Just my 2-cents, well, more like a $1.50.

66gutlass

clear and concise. thank you!

Dream67Olds442

You're very welcome, and best of luck with your build! Keep us updated if you have time going forward.

cutlassefi

Pm me anytime. I’ll give you the whole story on cam selection.

Tony72Cutlass'S'

So here’s a question:

do you pick your camshaft for your current configuration, or where you want your car to go?

for instance, I’ve got a pretty bone stock setup, 350 4bbl carb, edelbrock intake, single exhaust. 2.73 diff

i would love to put dual exhaust on the car, just isint in the cards yet. I will likely leave the rearend as it is because it’s never given me an issue.

curious what you guys think! Is it worth putting a cam in now, or waiting until I install dual exhaust.

redoldsman

Do the dual exhaust. With those 2.73 gears you will not be able to do much of a cam. Putting a new camshaft with single exhaust would be a waste of money.

olds 307 and 403

What year 350? I assume it is a 8 to 1 350 in your 72 Cutlass? I wouldn't bother with a low compression 350, especially with the stock converter. Even a mild cam benefits a lot from the factory 1600 stall. The stock Olds crossover from to manifold is a very restrictive set up, do dual exhaust first.

Andy

OP, this guy is a wizard on this subject, PM him if you want solid guidance