I was wondering if the 283 Crank would fit in the 87-92 Roller Cam block? This was the formula of the original 302s and was wondering if I could recreat it. I am not happy about using a 'classic' small block.

If this wouldn't work, do you guys think that a 377 would be cool for a 3rdgen?

 

Becasue the mains on a 283 crank are smaller that the mains on a 350.


Why do you want to loose 50 cubic inches, if I may ask?


377 - standard bore 350 with a crank or the 400 with a 350 crank?

 

loss of cubes but the short stroke/big bore of the 302 makes for high-rpm torque/HP. Nice motor, a screamer if built correctly, balancing VERY VERY important... Nostalgic...

 

377 = 4.155" bore x 3.48" stroke
or...
377 = 400 block with 350 crank

 

It was the 283 crank in a 327 block to get a 302

 

rjmcgee's right. It's a 327 block with a 283 crank. It's gotta be the small journal 327 block though.

 

Just have a 3" stroke 1-piece rear main seal crank made for you and use 302 pistons in it.

FWIW, I had a .060"-over small journal 327 block with a 283 crank (steel) with 12.5:1 pop-top 302 pistons about 20 years ago. LT1 solid lifter cam (the "original" LT1), 2.02/1.60 valve, angle plug heads, Torquer intake & Holley carb. No power whatsoever below 2500 rpms. After that, hang on!

What are your plans for this 302 or 377? If TPI, figure on major mods.

A 350 or 400 would make more street-usable power than the shorter stroke engines you propose.

 

You can use a 302 crank from the 68-69 block. That had the 2.1/2.45 journals like the 350. BTW, the 327 had the same large journals in 68 & 69 and a 4" bore like the 350 does.

Your gonna need custom pistons. 1.8" comp. height. They will cost you $$$.

In order to use one of those cranks in a 1pc. rear main block, your gonna need one of those adapters. I dunno how good those things are though. You may want to check into that. They cost about $40.

Don't try and pass it off and sell it as a original 302. Someone will royally kick your A$$!!!!!

AJ

 

350 bolcks and 327 blocks are the same, they just have a different crankshaft. (and the LT1 blocks have 327 casted on the side, not 350, even though they are 350's, just some food for thought)

 

I like the idea of having an engine no one else has, but that isn't the only reason that I would do it. I am trying to go over the rules of the Grand Turing Sedan race that features only 5 litre Mustangs and Third gens. I want to creat a car to run against them competively, and a good street performer wit ha few mods.

I am thinking of Accel SuperRam, but if it is only good in high Rpms, I would need something with much longer runners. Why is it so hot on top? I would think that the big valves would be good for low lift flow and eventually torque.

What would be the need for the custom pistons?

 

By the way, the theme of the SC is G Machine, and a engine that spools up quickly is very important to me. But If it needs custom pistons that rules out the light pistons that I was looking into.

 

If you want to make a factory roller block 302 then use the 265ci crank and rods out of a 94 Impala or Caprice. The 265 had a 3" strock and 5.95" PM rods. You can then use standard 350 pistons of your choice. With the long rods the piston pin location is the same as a 350. You will also benifit from the rod to stroke ratio, This along with some good heads, LT4 Hot Cam and a LT1 intake will make a killer combo for the track or the street. If you use aluminum heads (Fast Burn would do nicely) you can even run 11.0/1 to 11.5/1 on pump gas without fear of detonation if tuned properly.

 

GreenPS, did you read my post? You can use 350 oistons there by keeping the cost down. If you find a 265 baby LT1 in a bone yard you won't have that much in the bottom end either.

Steve

 

Thank you.

I knew there was a crank that would work, but couldn't remember the engine it was in.

BTW, the 94 Impala only came with the iron head LT1, so you'd have to find a dead Caprice. Or order the crank from GM. Can you say megga bucks???!!!!!

AJ

 

AJ_92RS, you are really trying to talk me out of this engine. Is it just eh price?

I have deciding on the intake: If the engine is so hot up top then I am going with a Miny Ram, instead of the Superram. Is this is a good choice? I was thinking of using the Vortech, with the Snoogy Diggin base, but if the engine will support high compression, some ported L98s would probably be better.

This is a long term thing, and will eventually make it's way into my Camaro, so I am going to save for the long block while I dig up the short block pieces. Thanks for your help!

 

is the crank in these cars a 1-year-only crank?

 

I think it will last a little longer than that , maybe 18mo's to two years. J/K I 'm not sure but I think they made them a little longer than that. Three or four years probably. I'd say the easist place to find a cheap one would be in a bone yard out of an old taxi cab.

 

Just browsing through and now im stuck-
That is, i happened to note that somone was thinking of a 302.
"hybrid block" is what my friend calls it. He owns one, has had it in his 71' chevelle, then back into his 69 Clone Z-28 camaro.
I have been there since day1 when he got the block, a 327 Bore, then installed a 283 Crank etc etc etc.... i can go on for days.


It was such a custom job, in fact, the engine weighs a mere 380 Lbs. Before oil / carb / water. Everything, including crank, Rods, pistons, Heads, Rockers are Aluminum. He has receipts with over $22,000 in engine componenets, INCLUDING A <b> Custom Hybrid Turbo </b>

From the time it takes to mash the gas to the time it takes to follow the RPM guage your ears have already popped, hurt, and bled. It revvs up Soooooo damn fast, then that LOUD blow-off valve opens and makes your head hurt sooooo bad. O *** it screams race me.

I can sit and tell you how he pulls left front tire everytime he hits second, or how the 15" wide tires nearly fry off the rims, or how the car makes you choke when it leaves the line. did i forget to mention its almost In-Audible (that is, impossible to hear) at an idle? The cam is as follows if i remember correctly:
Solid Roller: 256/266 @ .050 .612 / .626 lift, 106 LCA
Triple Valve Springs in use here... <b>600</b> Lbs of Pressure required for max lift.
As you can imagine, the need for an 8" 4500 RPM Stall converter is necessary, along with a Super-Bullet proof TH400.


His shift lite comes on at around... <b>8200 RPMS</b>
Although he hates putting it past 8000 (he says its "hard" on the motor)
Usually races it with a 8K rpm limiter on his MSD 7 Digital box.

'Nuf said?
Ohhhh yeah it runs a 7.77 in a 3600 Lb. Chevelle SS

Check out the pic :-)

 

He must run in Super Street. Does he?

 

Thanks for all the help!!!

 

I was reading the current GM Hi-Tech Performance and they have an interview with Trans Am racer Lou Gigliotti. His Corvette runs a 310 ci small block Chevy, which is just a .060 overbored 302, and it pulls 690 hp!!!

It will go over 200 mph on the track

He says in the quarter mile it would be in the 9 second range

That is NOT fuel injected--ONLY A SINGLE HOLLEY 830 FOUR BBL

Who says 302s are yesterday's news?

They won the Trans Am series in 1968 and 1969, and Gigliotti won the Trans Am race at Long Beach, CA, this year--2001

Sounds pretty darned current to me!

 

Well considering that Trans Am has a 5.0 liter limit, that pretty much rules out any of those guys using a 350. They have little choice but to build the hottest 5.0 liter engine the rules allow. Those numbers, while impressive enough in and of themselves, don't mean that for your street build, smallifying your motor will make you go faster. If you built an otherwise identical 350, I'd bet you'd get just about exactly 350/302 times the horsepower. In fact Winston Cup cars get just about 800 HP out of a somewhat similarly prepared 358, which would probably do 225-230 MPH laps at Talladega using that same Holley 830 (their rules too) if it weren't for restrictor plates.

 

I am interested in this since I am considering a motor change for my 5 speed...

If I have learned correctly (and anybody can correct me if I am wrong), then there are 3 ways to make more power...pump more air, reduce friction, and turn higher rpm. Now...I partially understand the complexities and efficiencies of the engine and how it all works together at different rpms. Is it correct to say that the 302 will turn a higher rpm, and with less overall stress on the motor than a longer stroke, equal bore motor??? Is that not a good thing...then the only concern would be pumping more air!?! A lot, not all, of people say more cubes is better...but can somebody give me some data, or mathematical theory or law behind all of this??? Obviously a 350 is better than a 305...but I question the validity of a 350 over a 327 or 302. A 350 would be set up differently than a 327 and vice versa (right?)...so all things are not equal. My extinct tells me that the 302 or 327 can turn a higher rpm than a 350. Can it then pump more air at that higher rpm than a 350 at a lower rpm, thereby making more power?

I also disagree with a motor like this not being streetable...as some of you say. There are plenty of low torque motors out there moving cars effectively below 2500 rpm...such as my 85 LG4 back in high school.

 

That brings up another point RB, IF the 302 was so hot, wouldn't you expect to see people in Nascar running it instead of a 358?

Also, as RB said, that 302 would NOT be very streetable. I highly doubt Gigliotti is using 23* heads, which really is the main bottleneck on getting really high HPs. You can't compare a race engine with heads that have 18* valve angles (or less) to maximize flow at high rpm (along with compression ratios that you'd never be able to get gas for) to a street engine using 23* heads that promote lower TQ at the cost of high rpm power, running 9.5:1 CR.

 

That is half the beauty of the 302! With the big 4.00 bore it get's air in an out more quickly. This and the less reticulating mass makes it a monster!

 

Having had an "old world" 302 (283 crank in a 327 block), I can say it can be an awesome engine.

But, what RB and Glenn are trying to get through to your thick skulls is, it's not the fact that it's a 302 that makes it powerful, it's what is in and on it!

That was exactly the case with my 302: Original LT1 solid lifter cam, 2.02/1.60 angle plug heads, Torquer intake, 12.5:1 pistons, Holley carb. Yes, it would go like the perverbal bat, but the same parts on/in a 327 or 350 would have been even faster!

Horsepower is torque times rotating speed times a constant. Torque is force times length of lever arm. Force is cylinder pressure times area of the piston.

The rotating mass of a 350 isn't going to be any more than that of a 302. Things such as piston speed (which translates to acceleration in stopping the piston at each end of the stroke) and friction will be slightly different, but in the whole minor actors (especially in a street engine).

Take all the factors in the last two paragraphs, and the biggest difference between a 302 and a 350 is going to be the length of the lever arm, and there the 350 is the clear winner.

 

five7 and Glenn made part of the rest of my point.

If you take a 350, and set it up exactly the same as a 302, it will out power the 302 every time. Period. I can't imagine where you guys are getting the idea that you can take an otherwise identical motor, remove some of its cubes, and make it produce more power. It defies all logic, not to mention practical experience. Power comes from burning gasoline: there is no other source. So, the more gasoline you burn, the more power you get. It's so simple and obvious and trivial that maybe it's easy to outsmart yourself and convince yourself that there must be some mysterious 60s magic at work somewhere. Well, there isn't! In the 70s, when 350s became widely available to rebuild, we all quit buiding 302s and 327s! Wanna know why? It's because they were getting beat by 350s!!!

More fuel = more power. Remember that. Now we all know it takes air to burn fuel, right? OK, more fuel and air = more power. Now we all know that air takes up space, right? More volume = more air & fuel = more power. How much simpler can it be?

If you really want to be "different", go downsize your motor. Yes, you can make a fast small one, no doubt about it. Yes you will beat some larger motors in a lesser state of prep, no doubt about that either. But the flip side of the coin is, there is also no doubt that you will get beat by a larger motor in an equal state of prep. Every time. No questions asked. There's almost no point in running the race, except to see who drives without making a mistake, and whether something is going to break. Yes, you can be "different" from most people who win races; you can be the kind of person we call a "loser". That's how we refer to people who make bad decisions.

Take five7's 302, pull those heads and cam and put them on an otherwise identically prepped 350, and it will make more power than the otherwise identical 302. The laws of physics don't change for people who want to be "different". I know, I had a motor just like the one he's describing, and it ran like a bat out of Hell too; but when I built all that stuff into a 400.... I never looked back at a 302 or a 327, I can guarantee you that. But not all of us can get a 400 as cheap as we can get a 350, so maybe that isn't the best possible answer for everybody.

But do you want to get the most for your money, like most normal sensible people do? Then spend it on a motor with as many cubic inches as possible!!! Think of displacement as "leverage" for your money. Speed is all about economics. It costs money. Most of us have a finite, exhaustible supply of it, beyond which we cannot go. If you want to go as fast as possible on whatever money you have available to spend, spend it on the bigger motor. Don't handicap yourself unless you plan in participating in a class with cubic inch rules, either a fixed limit like Trans Am at 5.0 liters or Nascar at 5.8, or a weight-to-inch class like alot of the econo dragster classes and such. (There's that word, "econo".... hmmm.... wonder how that got into the name of that class......) Otherwise, for the street or for bracket racing, you will go faster easier and cheaper with the largest cheap motor, which happens to be a 350 if you're building a Chevrolet.

 

Someone told me that a magazine (CHP?) did a comparison build up between a 377 (400 destroked), and a 383 (stroked 350).
Anybody have that article?

It is obvious that what is in it or on it is what makes it powerful.

It seems to me that a shorter stroke can rev quicker and higher...and make horsepower and torque up high. Isn't that more desirable than torque and horsepower down low? Are you saying its easier to do that with a 350 than a 327 or 302? Is it easier to do that with a 383 than a 350? Wouldn't making more stroke in a 383 defeat the purpose of attaining power at higher rpms like you can in a 327 or even a 350? Would boreing the motor bigger make better power than stroking?
As far as CI restrictions for Trans Am racing...which is better...the Chevy 305 or a Chevy 302??? All things being equal, what wins out....the bigger bore, or the bigger stroke?

I think I'll put my dad's 632 Cubic Inch Caterpillar into my car and see how fast that makes it with all of that low end torque. Would that be awesome, or insanely stupid??? It's not about Cubic Inches...correct? Isn't it about making power in a way that can be taken advantage of for the purpose involved.

I personally would rather have a quick reving motor with power up high and high ratio gears and a close ratio manual... The gears allows for streetable use and awesome 60' times and quarter times. Lower ratio rear would allow for autocrossing.
As far as street usable power...I woudn't want a motor built lkike that just so I can drive 55 to and from work...I'll just leave my good old 305 in it for that...good "street torque" and good mpg if that's what I wanted.

If I'm wrong, let me know now...cause that's where I'm headed with my 5 speed car...a 327 out of an old wrecker that I plan to rebuild for high reving power...
Or is the best thing to stroke it with a 3.48 crank to a 350 for more torque? Can I still make it rev up high 7-8grand?????


How is the NASCAR motor set up bore and stroke wise?

 

Gotta call you on that. Any pics of the 3600 pound beast and can you post a couple of the time tickets?

 

This is tough stuff to get across to someone who may not have built many (or any) motors before. Not meant as an insult or a flame. It's just that there are certian things that are more important than others in making power. I'll try to keep this simple without missing anything important.

The #1 starting point is diplacement. Take 2 "identical" motors, one a 302 and one a 350. The 350's gonna make more torque and power than the 302 EVERYWHERE in the RPM range. Period.

The 302 will have one minor advantage- you can rev it higher before the bottom end of the motor blows up. Becuase the shorter stroke puts less strain on the bottom end parts moving the rod and piston assy. up and down in the bore- it doesn't have to move them as far or as fast as the 350 does.

So you can rev the 302 higher? Yes, if all else is held constant. Doesn't that mean more power? Yes, but NOT ENOUGH TO MAKE UP FOR THE SMALLER DISPLACEMENT.

Also consider this: Cost. There are many redily available parts for the 350. Wann build a bulletproof 8000 RPM 350 bottom end? No problem. Reasonable easy and cheap to do. In fact, probably NO additional cost to build a high revving 350 bottom end than a 302.

Same RPM potential for the same money but the 350 makes more power everywhere. Which motor would you choose?

 

Don't get me wrong, I LOVE when people do something different. 350s are as boring and common as cow turds. 302s have a little "flair" to them. But if what you are after is bang for the buck, the bigger motor is always the way to go.

 

Would 383 and 350 be considered "identical"?
More power EVERYWHERE in RPM range???

What about the bigger bore or bigger stroke issue?
377 vs 383 a 305 stroked to a 334 vs a 327?

I too would like to see some hard numbers on any of this!

 

I've built many 350s and several 383s. If I set them up the same way the 383 will clobber the 350 every time.

383 versus 377 is gonna be a close call. The larger bore 377 might have a slight head flow advantage due to the larger bore undshrouding the valves some. Never built a 377, though. If I had a 400 block I'd build a 400, never destroke it.

334 versus 327 I'd give to the 327 becuase it can use big valve heads where the tiny little bore on the 334 is gonna limit the size of valves that can be used and, therefore, limit the head's flow potential.

 

I'm gonna have to agree completely with Damon. For much less $$ you can build a high rev 350, and have better results. It doesnt make sense to me that you would want to remove displacement to see some high rpm hp gains. We all know that if you can make an engine spin to 8 grand it will make more hp simply because the engine is doing more work (torque X rpm/5252=hp). Look at honda's 2.0L 4 that sits under the s2000's hood. Sure it makes 240hp at 8000rpm, but when the revs are in a normal range the car feels as though it is powered by a small 4 cylinder engine (less torque). Also remember that by using a rev happy engine you will need a intake system that will not limit the airflow, good heads, one hell of a cam, and an insane torque converter. Now realize that if the 350 can make it to 8000rpm and also is set up for it, the result will be more power than the 302. period.

-peace

 

Wow. That is the worst analogy I've read in a while. Your dads CAT motor is MAYBE all of 350 hp. And it is a diesel. This conversation is about an apples to apples, bigger vs smaller comparison. With the bigger motor you get more torque, AND (as a result) MORE HP TOO! RB, five 7, etc. are totally right on this point. With the SAME PARTS a bigger motor will win a race. That's why I plopped a 400 in my car and plugged all the same parts back into it. Guess what? It's faster (than w/ the 350)! But the 350 should be faster 'cause it has a shorter stroke so it can rev higher right?

 

I am procuring time slips for everyone because i knew everyone would be all of "uh-uh" when i posted.

As for :
<b>More fuel = more power. Remember that. Now we all
know it takes air to burn fuel, right? OK, more fuel and air = more power. Now we all know that air takes up space, right? More volume = more air & fuel = more power. How much simpler can it be? </b>

Is everyone forgetting the olde' mustang 302? how about fuel injection? Im not goina throw any mathemetical equations around trying to prove myself right, but, its soo obvious a properly built fuel injection motor can outperforme the SAME thing with a carb, and get 4x better gas mileage. I know several 11 Second mustangs with the ORIGINAL injection system, that get 26 MPG or better. I know several Trans-Am LS-1 owners (check out the F-Body club www.sffba.com) who all run damn high 11's or low 12's while maintaining fuel injection and getting good MPG.

Its obviouselly not about fuel consumption, even my carbed 355 gets 4 MPG and runs like crap at the moment. Mostly fuel-atomization comes into play and increases efficiency, Im told, 1 gallon of perfectly mixed 13:1 air/fuel will produce way more horsepower, and better MPG, than crappy-not-so-mixed (atomized) 13:1 perfect mixture fuel. the engine wants combustion, not detonation or any of the above. look at import 4-cylinders (yuk) respect that super-turbo 33 MPG engine that happens to run 11's. its not 355 Cubic inches by ANY MEANS. more like 10cid lol. or hell, rotory engines, NO pistons, NO heads, NO cam, Nothing. Only 3 moving parts, a Crank, A rotor, and somthing else i forget, can spin 18,000 RPMS if properly set-up because of its simplicity and size, and can out-perform any Streetable 350 in a super-Lightweight car. Those people with 350 Ford Probes got the idea. big engine, small car. riiiiite.

Everyone has their own view on whats good, all engines do is
"combust" gas and air as efficiently as possible, and with as little drag (friction) as possible, and this happens to make more power at higher rpms since its doing it alot more often. there is a border line between high rpms and proper mixture / space available etc...
there alot more to it than this but im just giving a quick example.
things like overlap can seriouselly decrease gas mileage since raw gas and air just fly out the tailpipe on super tight LCA (106) which of course is a bad use of gas, but on the bright side clears the combustion chamber for the next charge, making more horsepower than if it burned old gas and air. now, once more, a borderline. would the power/MPG created by the cleaner combustion chamber meet or pass the uncleaned chamber, causeing the car to make more power and although losing raw gas, it may get better gas mileage since now its burning fresh gas and creating more power which pushes you further thus bringing up your MPG (even though raw gas and air was spit out the tailpipe) or would it hurt MPG because the gains in power were so little that it didnt much affect anything, except wasting gas and air.


its like putting domed pistons in your car to Up the compression Ratio, then realizing that the space taken up by the extra metal of the piston destroys your horsepower because now theres not enough room for gas and air. those dimky CC heads are great for Dished pistons, but you still need some space in there. Then again, on some engines (blower-built) this is a good or bad thing, higher compression means Ka-boom, or possibly lots of horsepower when that air is forced into the bore. like i said before, there is a borderling of big / small and whats better. properly built and fed, any engine does well, and I think I've proved that already about 50 times.

now you wana talk cheap / availability? the 350 is the Emachine of engines, super cheap, super easy to make it fast, and decent size everything makes it somwhat eceonmical. Everyone would agree on that part i Think. but of course, this has nothing to do with anything, just obviouselly we are not rich, and building a proper 350 is about as cheap as it gets.

 

TOM 400CFI
The reference was to low end torque and street power.
I don't see this as a bigger vs smaller comparison...more of a bore vs stroke comparison...
I absolutely disagree that with the SAME parts a bigger motor will always produce more power.
Never mentioned anything that said because a motor has a shorter stroke that it can produce more power. WHat I made mention to was the ability to turn a higher rpm easier, and more importantly in my opinion, quicker...I wanted to know basically if that is true, correct, wrong, or whatever.

No I am not an expert, nor do I build motors regularly, but I am learning, and am open to ideas. I do plan on building a motor that turns high rpms to put into my 5 speed car. I don't think my 305 can do that reasonably with ANY kind of a TPI set up (Miniram, SuperRam, etc.) or boring and stroking. But if a 350 is truly that much better, then I will do that. If I bore the 350 to the max...that should help too, right? What if I stroke the bored out 350...to say a 396...is that better too? Can I still accomplish the same desired objective? Maybe I should just go ahead and get a 400, bore it out too. But isn't that expensive? Durability? Well...where does it end? What is the best balance?
The 350 in my Automatic car runs out of breath at 4500+/-.
If I install some AFR heads, a miniram, proper cam, etc...how high can I expect to make power? Can I reach that 7-8 K power range? What is best to reach that high rpm power level...stroke it to a 396, or get a 400 and destroke it to 377? Wouldn't the 377 help the durability issue, give me some big cubes, and allow for high reving power better than the 396?

From my experience (not much, but some none the less), the high reving cars and low gears do best.

 

A 350 IS the "balance" you're looking for.

If you want a balance of performance, budget, durability and MPG, then a 350 is the way to go.

1. It's just big enough to make smooth streetable power or aggressive racetrack power. It's can be built to have a ton of torque, or a ton of HP. Whichever way you decide to go, the 350 can, and will do it. I mean look......you can find them anywhere from a 1 ton pick-up to a 180 mph Corvette.

2. The parts can be had for cheap because of supply and demand. People demand the parts, so they keep the supply high. Which of course means the companies can sell more parts for a cheaper price.

3. The durability is just a characteristic of the SBC. Especially now that the ring and bearing companies are using great materials. How many people, on this board alone, have 150K+ miles on there cars? A LOT!!!!!!

4. Sure a 350 isn't gonna get as many MPG as a 302, or 305, but it's gonna make more power. And it won't make as much power as a 377, 383, or 400, but it'll get better MPG. A good balance, IMO.

AJ

 

Man... This post has gone to the dogs!!!

There is no argument to the fact the ci equals torque, and that a 350 properly built can out power a 302. (Or did someone make a post I didn't read?)

302 has qualities that I like. 1) Less friction. Quicker revs, less fuel consumption, more hp/litre. 2) The rod versus stroke ratio. More compression, less detonation. The 377 is somewhat interesting, because you can find a 400 block with the crank sucked out of it, and pay much less per hp than buying a stroker kit. Sometimes power isn't the be-all and end-all of an engine!

Thanks to steve and the other guys at the beginning of the post!!! Much appreciated!!!

No thanks, to all of you with the long winded awnsers!!! That gas=hp is pure bull!!! If anything air makes horsepower, you just accompany it by fuel!!!

 

Well, I have some hard numbers. You mentioned an article of a 377 vs 383 in Chevy High Performance? I have it, October 2000 "Is Bigger Better?" pg 44 and "Battle of the Small Block Strokers" pg 54. The engines had IDENTICAL parts installed on them. In fact, in the article they mentioned that the 377 had a "slight advantage" because the same rod length gave the shorter stroke 377 a better rod:crank ratio. And to be totally fair, the 383 should have been allowed to use a longer crank rod. But they wanted the engines as identical as possible so people couldn't claim they cheated in the 383.

Here are the peak TQ and peak HP of the motors.

377: Peak TQ 450@4,900 rpm; Peak HP 454@6,100 rpm
383: Peak TQ 458@4,600 rpm; Peak HP 450@6,000 rpm

The 383 produced more TQ than the 377 everywhere below 4,800 rpm and with over 18 lb/ft below 3,500 rpm. They did not measure below 3,000 rpm, but I'd expect the 383 to be even stronger.

As for the 377, it started making more HP after 5,000 rpm but only had a few (3-4) HP over the 383 until 6,100 rpm. Only after 6,300 rpm was there any noticeable HP difference between the 377 and 383 (13 HP) but both engines had already exceed their peak HP and dropping off; in real life you would be shifting so the HP advantage of the 377 is negligible.

In closing, the article definitely leaned to the 383 as the better street engine due to it's superior TQ and the only minor disadvantage in HP. They said to make the 377 shine, they would have gone to different heads and cam to emphasis high rpms - but then it wouldn't be a straight comparison would it? And, of course, you could still do the same to the 383. But with identical engines parts, the 383 is the preferred street motor.

To quote the article on pg. 57-58 "Looking first at average torque below 5,000 rpm, it's clear the 383 eats the 377's lunch. The 383 scores big-time points here as a powerful street engine since it offers an average of 13 lb/ft more of TQ at every point between 3,000 and 4,900 rpm".

As mentioned above, if you have enough cash you can make a 383 rev to 8,000 rpm and probably at the same cost as a 302. You'd most likely need a solid roller cam with some ridiculous duration/lift and some expensive 18* heads on both engines. Build a 383 and 302 with those parts and both will probably be making power at 8,000 rpm. Except, the 383 will be making more throughout the power band. I wish that CHP would do a similar test of 383 vs 302, but we already know the outcome and their readers would complain "Of course the 383 blows the doors off the 302 when built identically, you didn't have to do a comparison to prove that". And that is why they've never done such a comparision.

If you want different, go buy a Motown 415 shortblock. That's an unusual combination that will be affordable (cheaper than building an 8,000 rpm 302 that will hold together) that is powerful with great "street" temperment.

 

Curious, if considering 5.0 liter maximum requirements...Would a 305 vs 302 comparison yield similar results??

 

Probably, though I'd expect the difference in TQ/HP characteristics to be much more pronouced (greater TQ difference with the 305, but greater HP (and rpm peaks) with the 302. The bore difference between a 305 (3.735") and 302 (4.000) is far greater than a 350 and 400 block (4.125). But it would be a difficult comparison to do, that would be fair to BOTH engines. The narrow bore of the 305 severly limits the heads you can run. The 305s bore heavily shrouds the valves and limits you on the size of valves (Intake 1.94 max) with standard 23* heads. You can run AFR 195s on a 302 but they won't fit a 305. In a "displacement limited" class of racing, you'd want the larger bore for that very reason.

And, if you are going to build a 4.000" bore SBC (because you can run bigger valve heads), may as well go 350 (if you are on a budget) or 383. Then tell all your buddies that it's a 302. They won't be able to tell the difference, except when you beat them.

One other little advantage of bigger displacement motors; you can generally get a cam one step bigger and maintain the same idle characteristics. A cam that is pretty rough on a 302 would sound down right mild with a 415. Or, to put it another way, you can run a much bigger cam and still have a good idle with a big motor. That is why they easier to make power with a bigger motor and still maintain good street manners.

 

You guys have to stop being obtuse.

Colin wants to build a 302. Just accept it.

We all know you can get more hp from a 350. So what? You can get more hp from a 400 than a 350. And more hp from a 427 than a 400. Etc., etc., etc.

So what is the point? Where is there anything intelligent in the statements? Isn't that just stating the obvious?

Why aren't you guys jumping on EVERYONE who wants to build up a 350 and telling them they are stupid and should be going for a 377 or a 383 or a 400? Why is it just the 302 or 305 guys?

Live and let live.

 

Apparently there are a few who don't know. Too many of the youngsters hear from their fathers and uncles about the "fabulous 302 Z/28s in the late 60s" and over the years a lot of fiction has been added to the facts. First, in the late 60s, 302 Z/28s were NOT the terror of the street. A 14.0 second car in the 1/4 mile as I recall. There were MANY cars quicker than the stock 302 Z/28.

Personally, I could care less how anyone spends their money. I just like to make sure they are aware of all the facts and don't end up building a combo "that sounds impressive to their buddies when they are boasting over beers" but wonder why others are kicking their butts all the time.

 

When I read an article in one of the three Chevy mags ( Chevy Hi Perf, Car Craft Or Hot Rod ) I can't remember which one, Chevrolet built a 302 Lt1 fuel injected 96 Z28 and the mag compared it to a 60's something (67-69) 302 Z28. I was intriged at the perfomance Chevy was able to get out of the new 302 and with the off the shelf factory parts they used. Now the 96z wasn't as fast as a mildy modded 350LT1 but it was faster than the classic they were comparing it to. Now this same motor with a stock tpi instead of the LT1 FI would not make as much power or have the same rpm capablities but should have a reasonable rpm limit as high as a good running 305, 5500 to 6000rpm shouldn't be to hard to reach with little or no port work on the manifold or plenum, and would be a nice engine to have in a third gen. If Chevy can put a 48mm tb on a 502 FI engine and make 450 to 500 hp then it should be big enough for a 302 to reach 6000rpm and then some. All I'm getting at is it is possible to build a decent 302 for a reasonable price and have a engine that will run better than the 305 it probably would replace. I will be looking for the parts to do this myself after I get my most inportant projects finished first. 1st- garage, 2nd- get 350, Vortec headed, Lt4 Hot Cam motivated, RPM Air Gap feed, TBI injected engine installed and running smoothly in my 91RS.

Steve

 

I am not totally unreasonable (well maybe I was in the earlier post, kinda angry ) but if the engine is totally unreasonable on the street than I wont build it. The main reason of this forum was not to debate the the big bore vs. strokers or compare it to a 350, but to see if it is a good alternative over the 305.

(Dare I mention) all the 5 litre 'stangs we see at stoplights have a 4 bore x 3 stroke. Are they not streetable?

 

It is my experience that this type of motor is better than a 305, and streetable when using proper gears and a manual. I wouldn't think it would be as streetable with an automatic.

 

One thing the mustang has over the Camaro is less weight to push around but the 302 is still as good as or better than a 305 any day of the week. More potential over all. You have a better choice of heads and pistons ( if used with the 5.95in rods ).

Steve

 

If you want to build a 302, go ahead. I think what everyone here is saying is dont get sucked into the old fables and tales, and think that there is some magical engine combination out there that can make more from less. If that were the case, none of us would still be here.

I just clipped the rest, but from what you said after this about 4mpg just tells me you dont know what you are doing and are putting the blame on something you seem to know little about. I have some major traction problems with my olde' mustang 302, and its still well into the 13's. And I have gotten 32mpg freeway, it gets 28 on a regular basis. With a carb. You can come to witness it for yourself if you want. So much for 4x better mileage.

Im not gonna get into the whole destroke/cubes thing. Those of you who want to do that, be my guest. One less car for me to worry about beating.

Yea those NASCAR and TransAm cars are real slow.

Oh and for those of you that think fuel doesnt make the HP, wheres those cars that run on just air? Too many people missed the entire point of RB's post, here let me quote it "So, the more gasoline you burn, the more power you get." Thats it right there people. Its all about burning the fuel in the cylinder. Too much fuel, go slow. Too little, go slow. Burn it all, all sorts of power. Thats how it works.

 

Where are those cars that run on just fuel?

The more air you can get in the cylinder, the more it can be accopanied by fuel, and burnt. If fuel made power we would all be running rich on carbs.

Uh oh.... Argh... Science teacher alter ego...He's taking control...! Okay class, grade 11 chemistry is in session. Let's take notes, there may be a quiz later. Let's explain limiting agents. In a chemical reaction, like the burning of octane, the limiting agent is the chemical that we have less of, or cannot create or obtain more. The excess agent is the chemical that we can control the amount of, or have more or unlimited supply of. In an engine the limiting agen would be air because we can always add more fuel or octane to it. There! Regainging control...Here...Yes!

You dont put a bigger fuel pump on for more power, you put a supercharger! There is a reason power adders are called frced air induction!!!