elguapo

hi all,


as I am waiting for my car passing the inspection, maybe a strange question:


I rode a pre-71 cutlass once, and was very impressed about the torque and his power in first gear.
now i bought a cutlass myself, and I am a bit disappointed about the lesser power my car gets.


is it really such a difference, or can I have other failures on my car that cause this feeling I got?


please consider I am new here AND Belgian

70cutty

That pre-71 might have been a 455 powered.

elguapo

70cutty, can be indeed, so much difference with a 350?


I really have the impression the car lost much hp, but on the other hand I am used to drive cars with high torque

70cutty

It's a pretty big difference especially torque wise. 455 is a torque monster.

Fun71

The car you rode in may have had a lower rear gear, which totally changes the feel. My car has had 2.56, 3.08, 3.23, and 3.55 gears over the years. I ca tell you that changing from 2.56 to 3.08 felt liek the car had a new engine with a lot more horsepower, then changing from 3.08 to 3.55 again felt like a new engine with more power.

There's not that much difference in "feel" between a '70 and a '71 350-4bbl, assuming all else is equal.
Back in the late '70s I had a 1970 Cutlass Supreme with a 350-4bbl and a school friend of mine had a 1971 Cutlass Supreme with a 350-4bbl. Both cars had 2.56 rear end gears and in drag races the would perform very similarly: off the line they would run side-by-side and I would pull ahead of him at the top of 1st gear (~50 mph with the 2.56 gears).

So I would suggest that you determine what rear gear ratio your car has and if you want a more powerful feel, install a lower gear ratio.

Koda

Guapo,

You can have many things that cause this.

1. He may have had a 455.
2. He had higher compression.
3. He may have had a lower gear ratio than you.
4. He may have had aggressive cam shaft.
5. He may have better tune-up condition.

Often, gear ratio is really what makes the car feel fast in first gear.

The good news, you can fix 2 through 5 easily.

jpc647

Rear end gear is most likely it. It's a cheap thing to change and it'll feel faster, stop light to stop light. My car with a 3.23 rear end and a350 is nothing to write home about, I can't imagine an Abody 350 cutlass with 2.56 or a 3.08 rear end. No disrespect to anyone, but wow, can a car be any slower?

Top of 1st gear at 50!? Wow.

BlackGold

I'm sorry, but if your Olds 350, especially with a 3.23 rear, feels slow, you've got to learn how to tune it. Something's wrong.

Fun71

Actually, yes. You would be surprised how many cars I beat in the '80s with the 2.56 and 3.08 rears under my car. Corvettes, IROC Z-28s, Supra turbos, Porsche 944, a '70 Toronado that the kids driving thought couldn't lose to anything because it had a 455, to name a few.

oldcutlass

Whats your ignition timing set to? Is yours a 2 or 4v carb?

joe_padavano

I'd argue that you can fix #1 more easily than 2, 3, or 4. At least, I'd rather swap the engine than pull the cam in the car.

Koda

Time or money, I suppose.

joe_padavano

Yup, and these days, time is what I don't have...

Of course, fixing #1 can also fix 2 and 4 at the same time.

jpc647

The only one on this list i'm really surprised by are the Corvette's. The IROCs, okay, the measly 305 ehh.. The 944 was never anything special and the surpa's of the 80's bleh. But taking vette's, wow that 355 must really be something!


Slow I guess is relative. My DD cranks of 325hp and just shy of 300tq at the wheels, and has blistering throttle response all the way t0 7300rpms, so when I get into the stock 350, it feels slow.

Are you good with carbs? I'm happy to go through my setup with you, but I've gone through almost the entire tuning chart for the 1405 edelbrock with minimal gains. CopperCutlass ran 13.3 on a 1405 carb(not sure what number on the chart). Now my everyday car will run right about that, and my cutlass is way way slower. I don't expect my stock 350 to run 13.3 but it shouldn't be running lean I guess is my point. I shouldn't be almost all the way rich on the calibration to get anything out of it.

elguapo

the car is a 2 barrel.


considering the carbs changing into 4 barrels,


woudl that be a huge difference, or is it just better to change to higher gear?


grtzz

oldcutlass

The gear change would be the most bang, going from a 2v to 4v will give a small improvement with dual exhaust.

grampy

Stock 70-72 350 cutless are slow they run into high 16 if your lucky.I agree rear gear is the biggest bang to start with,then headders,exhaust after that a quadrajet.a 3.42 gear will still be OK for freeway driving.but a 3.90 to 4.11 is more optimal .because as you upgrade the RPM and MPH usually follow.

joe_padavano

In that case you might be able to catch a glimpse of the emblem on the front fender.

captjim

I don't think you can include 1970 models in that blanket statement, I bet'cha a high comp 350 doesn't feel "slow" and will run a mid 15 pretty easily.

GEARMAN69

Remember some folks don't know how much that "stock" 195 degree T stat and especially a closed stock snorkel air cleaner totally kills all performance even on a big engine.

coppercutlass

Jpc yes I ran a box stock 1405 on my set up. Now my good friend has a 72 post copue 442 with a 350 and a 4 speed with 3.42 gears. You better belive it is a fun little street car with what it has. Its never been restored . I was impressed when I took it for a spin. Now my dads car with a very mild 350 a 1405 and 3.08 gears is plenty peppy for such a tank of a car (late 70's b body ) but its not a tire scorcher like my car used to be with that engine.

johnnyjaws

my old 1970 cutlass s 350 4bl with headers did 14s over and over

captjim

Huh??

MDchanic

Glad you said it. I'd have gotten in trouble.

- Eric

captjim

Yeah, we both get in trouble for "arguing" when we disagree with a post.

joe_padavano

x3...

Fun71

Yep, my '70 Supreme (350-4bbl, dual exhaust, TH350) ran ~15.5, even with the 2.56 rearend.

GEARMAN69

I only said this oh so basic thing for some that have not experienced the difference on a old car . Their are some folks out there that may buy or drive a car and never flipped over the lid or stuck a nice open element air cleaner on and the drastic difference it usually makes. Just saying the "Pre 71" ride could also been breathing well and the "Post 70" low compression car besides gear could also have been a closed snorkel and stock hot thermostat. It would just make it all more drastic of a difference. Just like a 8.5:1 72 with a recurve kit, a Moroso air cleaner and 160 stat could whip a 70 that had higher compression but was running the 195 stat and the closed breather and stock distributer springs with gear being equal between them.

captjim

I am certainly not the smartest guy on the planet, but this makes NO sense to me. Flipping over the air cleaner lid makes a "drastic" difference? Really? Also, please explain how a cooler thermostat makes MORE power. Heat is energy, a higher stat usually results in higher cylinder pressures, better fuel atomization, better ring seating, etc. As long as it isn't TOO hot.

You stated,
"Just like a 8.5:1 72 with a recurve kit, a Moroso air cleaner and 160 stat could whip a 70 that had higher compression but was running the 195 stat and the closed breather and stock distributer springs with gear being equal between them."

I disagree completely. A cooler stat and re-curve kit (I won't even address the "Moroso air cleaner" remark ) will NOT make up the difference in slightly better heads AND the higher compression ratio. Compression=torque. IMHO.

GEARMAN69

Well Jim we will just have to disagree then. It does make a big difference. Go try it. All iron engines (intake and heads specifically) lose torque and HP when they get hot (over 180 degrees) , drive off the highway pull up to the starting line with no cool down, versus parking it for a few hours then taking it to the starting line. Then immediately hot lap it and run it 2 more times with no cool down. The better ET will be after warm up the longer cool down . A stock car with a 15 second road test with stock single air cleaner closed becomes a 14 second car as soon as its removed. Even late model stuff, Turbo cars etc. Most run quicker with a cool down for the intake charge density, the only exception can be some all aluminum and plastic engines that have a cooler 180 or 160 stat then they can run good off the highway since the heat is less a factor. Recently was talking online with a guy that seemed disappointed with lack of power on a stock survivor 68 350 HO 4speed 320 hp LeMans and only after repeating myself numerous times, he finally removed the stock closed snorkel and ran with out it and he came back with a "Holy Sh**" improvement smoking tires until he let off. The same stuff I figured out as teenager messing with the old cars in the 80's. Its just uber basic stuff. Like when I was messing with a four door boat 69 Bonneville 400 that didn't spin the tires from a dead stop when I floored it but then only changed the distributer springs to some light ones and then it would smoke the tire instead. Same stuff man, can't believe you man. A lot of Quadrajets on the muscle cars are tuned for cool unrestricted air and they get fat and lazy when ever the air available is reduced and also when the temps are up on the engine like sitting in summer traffic and or the closed breather and a hot engine. To be clear I am talking about full throttle response and pull afterwards. A lean carb can cruise good at light throttle with hot air that's what its made for but its not going to be the quickest and fastest tune when it time to hammer down.

oldcutlass

Optimum power and efficiency with the least wear on our older cast iron engines has always been between 175 and 185/190 deg F. This has been the rule of thumb for street engines since I can remember. Newer engines run 200+, mostly for emissions.

In my opinion, engine temp is really not the issue for power, it's more of an issue of oil life and how it disposes of contaminants combined with engine wear. A lot of people will argue that a cooler 160 at the track is optimum and some will argue the higher temp works better. I guess it all depends on how the engine was built and what it likes. I like a 190 degree engine and a cooler fuel charge.

GEARMAN69

When I bought a 2000 Silverado ex cab 1500 5.3 new , I raced it stock but cooled down and got to the starting line before the engine warmed up and cut my best times in the 1/8 (9.8-9.9) when it was fully warmed up with the 195 stat it would only run 10.1-10.3 in the 1/8th , I put a 160 stat in it then I could run 9.9 or better every time easily and that was late model alum head and plastic intake. My iron intake iron head stuff at the track mind you runs strongest at 140-160 degrees as far as water temp after a cool down so the oil is still warm from running to full temp earlier. Yeah wear may be reduced at 180 and up as is MPG on EFI is better with warmer T Stat but was just talking flat out performance, street or strip it works. The bigger factor is the open air cleaner versus the restrictive closed one regardless of T stat , the air is still cooler and un restricted + big gains unless you have lean POS carb tune.

oldcutlass

Your not comparing apples to apples with a 2000 Silverado vs an old cast iron carbureted non CC'd engine. I agree with flipping the air breather cover on a non CC'd engine, but on the 80's engines with ECU's it had the opposite effect due to the programming.

GEARMAN69

Well switching back to old car examples, I was playing with my 68 GTO when I first got it going a few years back and had a 455 in it that had cast iron intake , iron heads and iron exhaust manifolds. The quadrajet ran really strong when the engine was warm but not hot. I didn't block the heat risers on the intake at that time and would run the car when the intake hadn't got hot yet and it would have max torque and run 12.6 with 2.93 gears and stock converter. On a hot lap the iron was too hot and it would slow to 13.0-13.1 from heat alone. Cool it down it picks back up. For an Olds example a combination of problems, 85-86 Cutlass 307 smogger and some Buick big car that had the same motor. The leanest most ridiculous thick secondary metering rods I ever ran across. Did the air cleaner lid flip but still not quite right, found the hideous thick rods and swapped them to a normal looking set from the older days gone by and combined with the lid flipped.. great response and strong as could be expected pull but much quicker. It does seem the Olds uses a really lean Qjet for most applications but a lot to be gained just waiting.

oldcutlass

2.93 gears and a 12.6...in the 1/4 with a stock 455?

GEARMAN69

224/234 @050 112 LSA cam, HO iron exhaust manifolds, iron Qjet intake, , good compression was main factor 10.5:1 , '77 800 Trans AM Quadrajet, stock carter mech fuel pump for mid 70's AC application, stock Th400 stall (max 1700 foot braking a twisting up car) 5000 rpm shift. Full stock interior, steel Rally wheels etc. RW 3900#

captjim

You are mixing things up. You are mixing engines operating temperatures with underhood temperatures which affects the temp/density of the air coming in. IMO, the engine coolant temp (which is what you stated, referring to the thermostat) does not reduce power or torque.

Removing the air cleaner lid results in a second drop in ET? Nope, not buying that, not at all.

GEARMAN69

Don't care , what ever. Yes air temperature, intake manifold temperature, coolant temp and oil temp are different but all tied in. Under hood temps are lower if the fan is not blowing back as hot of air at the air cleaner too. The biggest single difference is cooler air going in carb AND the availability of it (volume) without restriction. Lower intake manifold temps help on the density and spike in torque too.

captjim

Still no real answer, just a bunch of anecdotal stuff. My 9 to 1 355 ran .15 quicker when I went from a 160 stat to a 180.

GEARMAN69

Sounds like a lean carb to me and the bigger difference as I repeated is a stock breather car getting turned loose to real breathing (assuming not a less than optimal lean carb)