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Discussion Starter #1
I have a '65 el camino with a 283(casting number 3849852). It has power-pack heads from 1966-1967, 1.72/1.50 int/exh valves, 60.530cc combustion chanbers (casting number 3884520) rated at 195-220hp. The intake manifold is casting number 3844457 from 1964 rated at 220hp for the 283. I have a 600cfm edelbrock carb, flowtech long tube headers, msd hei distributor/wires, dual 2.25 exhaust with flowmaster super 44's, all already installed and running. It runs great, but i want more. i already have an edelbrock performer eps 2701 manifold waiting in my garage to put on. MY QUESTION IS THIS: Will edelbrock aluminum heads benefit my motor? I want the E-street #5089 with 64cc chambers, 185/60cc int/exh port volume, 2.02/1.60" int/exh valves. Will these heads work for my motor? Are the valves too big to clear the cylinder walls? And will the increased combustion chamber size (64cc,edelbrock vs. 60.5cc,stock) decrease my compresstion ratio and cause a loss of horsepower? The edelbrock heads are only $910 assembled for a pair, so they are relatively affordable. Any advice anyone has would be greatly appreciated. I really like this little 283, and just want to make it as hot as i can and still be reliable. Anyone knowledgeable in 283's? [email protected] if you want to E-mentor me. Thank you
 

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The hot ticket back when the 283 was new, was a 283 HP 283. The 270 HP was a dual quad set-up if remember right. As far as the aluminum heads combustion chamber being a bit bigger, yes, it would have a slight power drop-off. I don't know what the parts situation is for 283s these days, but some domed pistons to bring the CR up would be one way. The valve to block clearance issue is a question that may be answered by having a 283 head gasket to lay on a 350 head with big valves, which I would think would show a bore versus valve picture. The 2.02 intake valves on performance heads may be a problem for clearance in the bore (?)
You didn't mention a cam change. Are you thinking about that also ? Cam duration, if it's quite a bit, will also affect the useful CR.
In the old days, we used the Duntov 30-30 solid lifter cams in the 283 & 265. Copies of that cam are available, but who wants to fool with adjusting valves there says !
If you do think about a cam change, you could call Competition Cams, and get the right information. And they may even know about the head swap and valve issues.
 

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Discussion Starter #3
yes, forgot about the cam. Definately one of the main things i want to do,

The edelbrock heads were actually a result of looking up cam options, and reading that all the cams i am interested in need aftermarked heads capable of higher lift, and better valve springs and hardened pushrods etc etc. Any experience with the comp thupr lineup? i do like that rough/choppy idle, with street-ability. Whats the difference between single pattern and dual pattern cams?
 

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The edelbrock heads were actually a result of looking up cam options, and reading that all the cams i am interested in need aftermarked heads capable of higher lift, and better valve springs and hardened pushrods etc etc. Any experience with the comp thupr lineup? i do like that rough/choppy idle, with street-ability. Whats the difference between single pattern and dual pattern cams?
A single pattern camshaft shares the same duration on the intake and exhaust side. Example: 252/252 duration @ 0.050. Meaning the intake valve and the exhaust valve with stay open for the same amount of time.

A dual pattern camshaft shares different durations on the intake and exhaust. Example: 250/260 duration @ 0.050. Meaning the exhaust valve will stay open longer than the intake valve.

IMO, when dual pattern cams really become necessary is in forced induction engines. In a naturally aspirated engnie, the intake valve opens, the piston goes down and sucks in as much air as the engine is capable of sucking in. Example: A 350 chevy small block cylinder will suck in about 44 ci of air per cylinder and have to exit 44 ci of air out of the exhaust valve.

On a forced inducted Chevy 350 as soon as the intake valve opens, there is lets say 20 pounds of boost blowing by the valve and rushing into the cylinder. That 44 ci small block chevy cylinder is probably being filled with as much air as a cylinder on a 540 ci Big Block (example), well now all that air needs to be able to exit the cylinder out of the exhaust valve and exhaust valves are usually smaller than intake valves. So, you install a "dual pattern" camshaft in the engine that allows the exhaust valve to hang open longer than the intake valve and allow all that hot exhaust air to exit the engine.

Basically, you don't want to have any airflow restrictions in an engine and if you've got a huge carburetor, intake manifold and cylinder heads that are allowing the engine to take in lots of air, but you cant get that air out of the engine because the wrong camshaft is in it then its not going to perform as well.

I hope this is helpful. You should be able to get 1hp per ci with ease.

Mario
 

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In addition to forced induction you have to take into account the relative efficiencies of the ports, the small block chevy benefits from loger duration on the exhaust side because the flow has to make a sharp near 180 degree bend coming out of the valve, this sharp turn reduces flow, so a longer duration on the exhause side is of benefit.

The amount of exhaust gases is exactly as you describe, but forced induction or not, it takes it a bit longer to get out of the chamber than it took to get into the chamber and thus the advantage of a dual pattern cam.
 

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the 283 has a small bore and small cumbustion chambers.the 64 cc heads will lower your compression and the valves may hit your cylinder walls from what i can remember i havent even seen a 283 in 35 years, i think the biggest valve you could safely run was 1.94 and 1.60. the bore spaceing is the same on all small blocks but the 2.02 valves come so close to the walls that depending on the head and valve spacingmay actually strike it or at the least shroud it so badly it impeedes flow to the point it hurts performance. i have a ser of the 186 heads from an original lt1 in the shop i will measure the outside of the valve set to see for sure. the 186 head was the later version of the power pack heads with the accesory holes and iether 1.94 or 2.02 valves depending on thier application
 

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i just plugged in the 283 into my desk top dyno and came up with 413 hp at 6500, now the amzeing thing was at 6000 rpm it made 400 hp,350 ft lbs torque and was at 98.8 volumetric efficiency. 11 to 1, 194 &160 valves,hi flow duel plane intake and a 660 cfm carb,small tube headers and mufflers,mild performance cam.you can make big power but the torque is always low on these small motors. look at the 302 chevy it made around 500 hp on the dino around 8000 rpm but had around 320 ft lbs of torque.work great in 4 or 5 speed cars with a lot of gear.but in average drivers they always seem underpowered untill twisted into thier sweet spot then hang on. trying to build big power from the little motors is possible but really how many time during its life will it reach its true potential.how many of you really drive with your motors in the 4500 to 6500 rpm range?
 

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To quote the father of one of my T bucket friends when he wanted to hop up the 283 in his bucket: "You could do that, but when you're done, what you'll have is a 283 and an empty wallet. "

You can get a brand new GM 350 for $1500.
 

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well that is true but you put that 1500$ crate 350 up against a 1500$ 283 and the 350 will loose on most aspects except torque and torque is what moves most cars in the real world. i grew up with the 283 s and 327 s they were nothing to sneez at unless you had a really big dog chained up under the hood. i have seen many 301 s run away from big fords and chryslers. but it was in a nova or camaro,4 speeds and a lot of gear
 

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the 2.02 valves are within 70 thou of the cylender wall. way too close to do any good. 3 in 701 thou in a 3.875 bore.:beer:
 

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Two years ago, I gave a friend a Corvette 283, which had big valves, but I didn't measure them. More than likely 1.94 & 1.5. It was (is) a '61 'Vette engine from a boat I had. Owens Yachts used Corvette engines with a Flagship marine conversion. I had just over 300 hours on it from new when I pulled it. Lots of bigger boat engines rarely got a lot of time on them in the Great Lakes.
Anyway, it had no ridges in the bores, and the crank looked new. I went to a 327 in place of it.
 

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Flatblack,
Does your car have a standard or automatic transmission? I don't know how much trouble you want to go to but your 283 will easily make 1 hp per cu in. My first real hot rod was a '56 Chevy that started out with a stock power pack 265 and a power glide trans (I bought it from my Mother with 42k miles on it). As soon as i got it (in 1962) I pulled the engine and had it bored to 283. I used Chevy domed pistons and a Melling cam that a local short track racer at the machine shop recommended. I don't remember the specs for the cam but it had a very rough idle and pulled real hard to 7500rpm. While the short block was in the machine shop I ported the heads just mainly opening up the valve pockets and port matching everything. I had a set of quads off a 270 hp Corvette and a set of headers built by a local guy. I got rid of the powerglide and installed a 3 speed standard trans, and 4.56 gears. I never got outrun in this car. I outran a '56 Ford with a 406 in it and a '62 Chevy 409 among many others. I really liked to mess with the rich kids around here with their fuel injected Corvettes. If I built the same engine today i would probably use a set of World Product 305 heads with 58CC combustion chambers (I'd port them) or a set of Trick Flow heads (if they're still around). I'd also use an Edelrock Victor Jr. intake with a Holley carb. I'm sure there are much better cams around today than I had to chose from back then.

Good luck with your 283!
 

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Discussion Starter #14
Wow! I lost this thread and just found it during and advanced search!

So, its now August. I've had my Elco for 5 months now, and i've done some significant work to my '65 with that little 283. I LOVE THIS MOTOR!!! And i havent even gotten deep into the motor. It was totally stock when i got it(rated at 220hp/295tq), and since then, i've done this to it: Flow tech long tube headers, Edelbrock performer eps alum. intake. Re tuned the edelbrock 600 carb with bigger jets, and smaller rods, better accellerator pump. K&N 14" filter, MSD HEI full distributor, MSD wires, Dual exhaust with Flowmaster super 44's. Removed the stock belt driven fan, installed and electric set-up. My exhaust shop is a small privately owned place and has a dyno, wich they let their friends use for free (awesome!) and they gave me a few pulls. 307.6hp/351.3tq!!!!!!! I mean....I knew that my motor was strong, but man! I love driving my '65 every day. As soon as i get home from work around 4pm, i hop in it and drive around town. There's a big import crowd here, and one by one are being humbled by my 47 year old, primer black rocket. Being that i only weigh a smidge over 3000Lbs, i'm pretty light. There are plenty of american V-8's in town too, both old and new, and especially all the mustang gt's are finding out too, what my tail gate looks like as i rev my little 283 well above 5000 rpm while pulling away from them. My last victim was a 2000-something Trans Am just a week ago. I dont get reckless though, just beligerent. My dad told me when he went with me to look at my '65 the day i bought it, that a 283 was a "good little motor"(he had a 283 in his 55 chevy back in his high school days and a couple others here and there). I had my doubts, but those doubts didnt last long. My next modification will be a strong cam-lifter-spring-pushrod set, and a rear gearing change to get more accelleration still using my TH350 trans, since i dont really do any highway driving. but don't want to get into that till summer is over. Anyway, Thank you all for all your imput. I actually lost this thread, and just found it again, not knowing that i had had soo many replies.
 

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Lov'n the 283!!! My first brand new car was a '65 Biscayne with a 283/3-speed stick. I installed the Impala 327/300hp dual exhaust (the only change I remember making). It would get 24mpg on the highway too!

Doug
 

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283 power

My 2nd ride was a '56 210 Chevy. Lost the 265ci for a 283 with power pack heads, Vette dual point distributor, Carter AFB 4 bbl carb(re-jetted), headman headers, 24inch glaspacks mufflers, deep groove vette pulleys, #098 Duntov solid lifter cam( love that thump, thump, thump sound), 6 qt modified oil pan, oil cooler(fm my uncle's dirt track car). Close ratio 3 spd trans (fm '58 vette) and a 4:56 posi rear end. You could twist it to 8K all day long. A great little engine with lots of power and torque.
 

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Discussion Starter #18
yeah! It gets GREAT gas mileage for a V-8. I have a really heavy foot driving this thing, and i only run around town, gassing away from every stoplight, and i still only have to put about 5 gallons of regular generic gas in it a week. Its my in-town-looking-for-a-fight-car...."fight" being a bit of a race, of course. I probably will not change this motor out for a few years. Save some money up, piece together a summit/jegs catalog dart/world 383, and use my existing intake, carb, headers, distributor, and exhaust, only going new on the heads, cam, block and rotating assembly. I WILL definately miss the good gas mileage though, so, i'm not too much in a hurry to do all that....
 

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i grew up with the 283 s and 327 s they were nothing to sneez at unless you had a really big dog chained up under the hood.
Totally agree , most people do not realize the performance these engines achieved , I would take a 283 or 327 over most 350s , the 283 was one of the first engines to achieve 1hp per cubic inch , a feat easy to do today but still pretty impressive when you consider most of the v-8 engines in the mid 70s-early 90s didn't even come close to this ratio
 

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283....Now you are running down my street....
Forget those "Crate" motors...Boooooring!

With that 3" stroke, it likes to run around upstairs on your tach:nanawrench:
Over Bore it to 4" (The blocks with the Dish bottom cylinder webbing will go out that far...Sonic test to make sure) and make a "******* 302" out of it...Give it lots of Solid Lifter Cam, as much compression as you dare, Big Carb, and 202 Heads and some Good Rods...it will be a dog arround town, but when you put your foot in it she will scream from 3,500 RPM on...Above 5,000 it is orgasmic...

This is the "Biker Chick" of GM Power...Nothing else has the throttle response or the Bad Attitude of this one...Sure lots of Cubes will make more power...Crates are less expensive....But this will put a smile on your face every time you have the balls to stand on the throttle and see the RPM scream into the Twilight Zone....

Raced in Cubic inch to weight Brackets back in the 70's...Beat lots of Big Blocks with a light car and one (Read Several) of these motors....Going to build one for my 69 this time around...

Go Wild with this one!
 
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