I have a '65 Olds Cutlass with the original 330ci v8. The engine is stock for the exception of a Holly 600cfm carb(don't know the model #), and a MSD 6A ignition and a MSD Blaster coil. The factory spec compression ratio is 10.25-1 and the HP is supposed to be 315.  (I haven't been able to find out the cam specs..) The "problem" is that it it runs like a top on 87 octane gas.. I don't get it.. No ignition knock no mater how I drive it. And, it has gotten as high as 24MPG on the highway at an average speed of 80.  It usually gets about 16-18MPG around town and will run 15 flat at 95 in the 1/4.. My question is WHY? I have talked to dozens of people about this and nobody can seem to tell me why it runs like it does. I have owned the car for almost 10 years, and have never even adjusted the timing because i'm afraid to mess with a thing.. The only thing I do is change tho oil and filter. I changed the points, cap and rotor once, but never adjusted the timing. And the thing will still still burn the right rear tire to the rim. (with the brake of course) Can anyone help?

If this thing is capable of this kind of performance in "stock" trim, on 87 octane, what would this thing be capable of with a bit of tuning.. and 115 octane...  

I'm not an expert by any means but a couple of guesses on my part. You're assuming it is a TRUE 10.25:1 because the factory says so but what is it really? It needs to me measured to really find out. Your cam timing plays a big part as well for your actual cranking compression. The cam specs with that advertised compression might bleed off enough pressure to operate on 87. Next up is the combustion chamber. It may be fairly efficient allowing it. The unleaded gas and modern lubricants. years ago you'd get build up of carbon that that would glow and ignite the charge prematurly causing detonation. The gearing in your car may also help easing the car off the line. Last, maybe the Gods are smiling on you!  

I wouldn't be worried if it runs fine and there is no signs of detonation.

Husky has a point, with poor factory tolerances the static compression could be much less than advertised. Larger than normal chamber volumes and taller than normal decks are actually very common and will start to dwindle away compression pretty quickly, but my only correction is I wouldn't call the combustion chamber on this engine "efficient."

Why are you asking why when you are getting everything you want? Save the "Why's" when nothing works.

My stone stock (I did switch the Qjet to a 750 Holley)70 LS4 454 with 10.25 compression runs on 87 octane as well. I was fully expecting having to put 93 plus octane boost in it when I bought it. In summer I run 89 to keep it from knocking when I run the A/C.

Pharside, back in the mid 70's a co-worker of mine had a '70 396 Chevelle. It had a mild hydraulic marine cam that Chevy sold at the time along with headers, Edelbrock intake with a 780 Holley along with a 4 speed. His car use to run just fine on regular gas of that time. He found that out when he couldn't afford premium!  

It's not that there's a problem, the car runs great. It's just that I'm the inquisitive type, and I'd like to know WHY it runs like it does... If this basically stock, carburated 330ci engine built with 60's technology, running through stock cast iron manifolds and a 2 1/2 in dual exhaust,  in a 4000lb car, can get 24mpg at an average speed of 80, (I checked this on the interstate from Columbus OH, to Pittsburgh PA), how can I incorporate the same 'tricks' into another engine? My dad's 78 El Camino with the stock 350 manages a best of 13-14mpg in town, and 16 tops on the highway.. If we're lucky.. What is it that makes this "antiquated" 330 run so well? (and run circles around any stock 350 chevy I've ever come across, as well as my dad's 73 T-Bird with a 429) That El Camino weighes a good 500lb less than my Cutlass and still sucks gas like a bulldozer.. not to mention, is completely guttless. Damn thing will barely spin 'em on dirt.. But it is a rather unique car around these parts, (northwestern PA), and is very comfortable and a pleasure to drive. I just wish it got better mileage, and had enough power to get out of it's own way. I realize it's a low compression 70's 'smog' motor, but there's got to be more to it than that.. Both the Cutlass and the Elky have the same tranny, a TH350..

What do I have to do, throw an Olds engine in it to make it run? It seems to me that whatever it is that makes that 330 run so well could be incorporated into other engines. I'd really like to find out the head flow data and cam specs for the 330.. but I can't seem to find any info anywhere.. and I've been searching the internet for a couple years now.. I'd like to run the numbers through Dyno2000 (it's the only engine sim I have..) and see where I can make improvements.. Adding the MSD 6A and coil made a world of diference, but I'd like to see what cam or intake changes could do without having to dish out the cash and experiment.. I think the 600cfm Holly is a good carb for it based on displacement and top engine speed (I never run it over about 5 grand, but I don't have a tach in this car yet, so I'm just guessing this by ear.. and I've been told by a few sources that stock Olds engines shouldn't be run over 5k anyway because they make all their power at lower rpms, and the valve train isn't really made to handle much more than that.) But I really need the cam and head specs to get a good baseline with a simulator. I just don't have the finances to take it to a shop and have it blueprinted and dyno'd.. I know the simulator isn't 100% acurate, but at least it would give me an idea of what I'm working with..

I've talked to dozens of people about this including engine builders, car nuts, gearheads, and auto parts store weenies, and I'm still left with more questions than answers.. CC has flow specs for Olds heads on the site, but there's no mention of what ci and year the flow specs are for..

If anyone could give me some info, I'd really appreciate it.

P.S, I was told by the prevoius owner that the rear gear is 3.08.. I kinda have my doubts about it though.. at 80mph, the thing seems to be spinning pretty fast.. But 15 flat @95 in the 1/4 ain't too shabby for a basically stock 330.. The curb weight on this thing is supposed to be 4030lb.. And if that's true, with me and a tank of gas, it's probably closer to 4400lb.. I've driven everything from econo-boxes with 4 bangers to trucks with 502's and this is the all-around best performing car I've ever owned, I'd just like to know why. And besides, what kind of gearhead would I be if I didn't try to improve what I've got?

I know a little about Oldsmobiles.  I have a '67 Cutlass with a modified 330 in it and as you say, they are a little different animal.  The rear end gears in your car probably are 3.08s.  That was the standard that came on those cars unless otherwise ordered.  There were a few options, but most of the heavier stuff came on the 442s and wagons.  Compression ratio of your engine is going to be close to 10:1 as this was pretty much the standard for the time.  Unless the engine was rebuilt with dished pistons, advertized compression ratio should be pretty close.  Compression ratio is going to be a big part of why your Olds is both quick and economical.  Between the highway gears and the higher compression, both combined will give you considerably better gas mileage. 

As for the engine itself, there are several unique things about the 330.  They came from the factory with forged cranks and rods.  They are tough engines, but I agree with the notion that they are not good for high RPMs.  They tend to be torque monsters making most of it within the 2500 to 3500 RPM range.  Not that they can't be made to go higher than 5 grand, it just isn't normally the case with a mild build up.  I suppose if you put in main studs and a girdle in the lower end it could be pushed more, but to what end?  They make good power in the low and mid range anyways.  If you are interested I can tell you about my build up via Email.  I've posted it before but don't want to bore people with it again.  The one out of the ordinary thing I've done with mine is I am running Big Block heads off of a '70 W-30 442. 

The combination you have on your Cutlass is a good one for both power and economy.  It's pretty much how they were designed.

Bowser

The answer is simple. The cam has these specs:278/282 seat to seat duration, 222/226 @ .050 lift,114 LDA, .430/.432 lift. The compression ratio is really 10.1:1. Now, with that big of a cam your dynamic compression ratio is 7.5:1. To run into detonation with iron heads on 87 octane you would need a DCR of around 8:1 and even then it is possible to run without detonation if tuned correctly. Another reason for it running on 87 is that the timing curve came in very slow on the older cars. Usually all in by 4000rpm and only providing a total of 30-35 degrees.In the long run you can expect 300 hp at the crank and 320 torque.Also the reason why you shouldn't rev your Olds over 5000 rpm is, for one the cast pistons don't like it, and the oil drainbacks are not very good, leaving the oil up in the valve covers and not in the bottom end where it is needed. Although that is more of a problem with the big block Olds because they have very big main bearings along with lifter priority oiling. Old ladys didn't like lifter noise on a cold morning.  

Well, if that's true, than there's one problem.. Given the car's weight with driver and gas (which comes out to around 4400lb if the curb weight info I have is correct) and the 1/4 mile time and trap speed, (15 @ 95) than the thing is putting out somewhere around 325+hp.. The factory rating is 315hp, and with the addition of the MSD ignition and coil, 325 would make sense.. Another problem is that this thing came from the dealer with a tag hanging from the rear view mirror specifying premimum fuel only.. and in '65, that was quite a but above what we've got now at the pump.. This thing shouldn't be making any where near what it does on the 87 octane crap I run in it.. If I was running "race" gas at 110 or higher octane I could understand it.. especially with the MSD goodies I've added..  Don't get me wrong, I absolutely LOVE the way this thing runs, and I'm forever sold on old Oldsmobiles, but how can I incorporate the same technology into other engines?? This thing make mountains of low end torque, and gives incredible mileage if I baby it. What is it about the heads, cam, compression, intake (lousy and very low profile as it is) that makes this engine run so well??? I would love to put someting like a Edelbrock Air-Gap on it but it simply wouldn't fit under the hood. The previous owner told me he had a Malory ignition on it and it ran 9.9 in the 1/8.. He called it the "one wheel wonder".. It'd burn the right tire to the rim..  (Which it easily does with the MSD stuff I've installed) He said it routinely ate mustangs and camaros for lunch.. I don't have quite as much to compare it to because, to be honest, it's a 41 year old car, and I'm just afraid of blowing the engine.. It's a numbers matching original.. If I'm gonna start drag racing the thing, I'd throw in a junk yard 455 or something (if I could find one, and 330's are even less common..) I do lean on it from time to time and she's managed to dust a mitsu eclips and a chevy z71.. (and got savagely beaten by a '69 442.. but I try to baby it for the most part..
Does anyone know where I can find head flow specs for a '65 330 so I can run it through a simulator? I just want to find out why it runs so well. I'm 29 years old and have been working on cars since i was 10. I've been reading CC and Hot Rod since I was old enough to read. I know there's no voodoo to these things. Every component of the engine works together to produce an outcome. I just want to figure out why this thing works like it does. And not just theories, but mathmatical figures. I guess what I really want to know is how I can make a chevy (or any other engine for that matter) run this good. My dad has has a 78 el camino that frankly runs like crap. I already changed engines in it once.. It's now got a 350 out of a '76 Impala, and still runs like a slug.  And I have another late 70's 350 that needs rebuilt as well.. what can I do with a 350 to make it run as well as this "antiquated" old 330 Olds engine? What type, model, or brand of head, & what cam can I put in a 350 to make it run as well as this old Olds 330? Did Chevy ever put anyting on a production engine that is comparable to these Olds heads? Am I supposed to believe that Chevy never built anything of comparible size that could compete with an Olds? I love this Olds engine, but there just aren't too many around any more.. Chevy's are a dime a dozen.. 
I have a '53 Olds 98 with the stock 303 (with a forged botom end also) that I would like to make a daily driver also. This shouldn't be rocket science, (no pun intended) and I can't believe i'm the first to pose the question. Given the crazy fluctuations in gas prices, we should all be looking for ways to get more power on less gas. This 41 year old Olds proves it is possible. I want to know the science behind it. I'd love to see a CC article on this. I don't have a huge bank roll to work with, like most other CC readers, and I'd like to know know how to piece something together from junk yard parts that would run well for a daily driver and not break the bank when passing gas stations..  

Ok, well I gave you the math. And that car only weighs about 3400-3500 lbs. The reason why the 76 chevy doesn't run is because it has very low compression, smog heads and intake that are very restrictive along with the tiny smog cam. Your 330 is a high compression engine (relatively). With you and a tank of gas, figure 3700lbs and 300 hp at the crank and it comes out to be 95 MPH trap speed. And, you should be running mid-low 14's at that speed. 15 flat is not that great. I have an 80 T/A that runs 12.50's at 108 MPH and gets 20-22 MPG. It has 3.42 gears and a 2004R overdrive tranny (2200 stall) with a mild 400 Pontiac. By mild I mean the cam is a Crane with 216/228 duration. It pulls 18 inches of vacuum at idle. I am running 11:1 compression with aluminum heads.That is the key for good power. Pushing the DCR to the limit and tune the engine perfectly to get it to run on 93 octane. As far as head flow, I don't have flow numbers for the #4 heads but they flow pretty good. Close to # 5 heads which is the flow numbers I used on my software.Your looking at 200cfm on intake and 160cfm on exhaust @ 25 inches.