I am a newbie to Vettes, but will ad my two cents. Most of the stuff GM designed was the best or a little ahead of its time , IN THE TIME PERIOD. yes , now adays you can drop 1100 for some edelbrock heads and add 50hp, 3-500 and get 40HP on exhuast, and brake and suspension galore options.

But production vehicles, are just that, production. You have to make tons of parts to be cross used in other vehicles, make them appealing and try to make each vehicle unique. I am a Camaro guy, always have been, got the 74 Stingray for my wife, but do admire the way it was designed, from body to independent suspension, even though its a bitch to work on.

My 72 Camaro is original only in the interior and body, the rest I made the way a creative engineer at GM might do today if someone came in and said-I want fun!

The cool thing about GM, particularly Chevy, is their small block is one of the most admired engines and most used. No other engine is so interchangable in parts, supply of aftermarket bolt ons, and ease of working on. Think about it... you can put 305 heads on 350's, a 400 stroke in a 350 block, a 327 stroke in a 4 bolt main , tinker with camel humps, use a 2.5 inch stock exhuast ram horn, etc....

The combos may seem like "crap" in certain cars cause of emission rules, NTSA requirements, etc, but the BASE is there to take those same parts if wanted, rework and get tremendous reward from it. Almost anyone can rework a small block with a SA rebuild book and patience.

As engineers got creative, new talent came in, and times evolved so did options and production vehicles. Look at the Camaro. Up to 73 it was beautiful and mean, then the big bumper era for safety. Added 300 pounds and ugly. Same with Vette, bumper supports for safety, smog systems, etc. But hey you can get flat top pistons, mill a head, use a shim gasket and you are back to 9:1 or higher and add a cam and pocket port some exhuast runners and there you go, close to 70-72 motors.

The Vette was, and always will be a cherished icon. They have gotten much better in the last decade, whereas the Camaro, Mustang, retro Charger, etc, all suck. The new Camaro design is horrible, should be labeled a sedan. Heavy, and heavyily luxury optioned, not sporty.

Up until 3 months ago, I never ran aftermarket heads. i bought some RPM's just cause i could , to try. I always ran 291,186, 461, 441, 487, all great heads for factory mass production. Clean the castings and pick the right combo and there you go.

I realize now how pricey it is to redo Vette components to the Camaro, but still, doing it all myself, I will have a luxury sports car that is fast and envied far below what I would pay today, and have a piece of history as well. The only non gm product in it, is the Vintage Air a/c and I live in houston. My wife CANNOT live without it. Imagine a steam room surrounded by a bubble, thats us.

My car...pure muscle, but i dont work in an office or have to look pretty

But with modern brakes, poly suspension, a reworked 350 and heat and soundproofing, that 74 Ray will run, be comfortable, and turn heads.

 

Woah woah woah! What's wrong with the new Camaro? I like it, it's not retro but still looks Camaro. It also weighs less than any of its competition AND has independent rear suspension.

 

Sorry, just not convinced.

So, you are all saying that in 1981 the engineers at Chevy, having designed heads galore, even L88 stuff, could do nothing better than the heads we are now recommended to trash as first option to get more gee gee's ..............

Are there not heads from previous years that would have done better ??

Were there not aftermarket heads that could have been bought in or copied ??

Lasted the test of time - well, yes, so has the bow and arrow, lump hammer, etc, and they did not take an engineering team to design.

 

One word - emisssions!!!

 

Funny..working up a sweat over a 1981 production car...Vettes were what they were in 1981..and among the very best for the time...
On the racing end,GM engines were in everything kicking butt especially in the Can Am series...oh...and check out this GT vette.. I took this pic in 1981 at R.I.R...



Another...



1978

Corvette wins the SCCA Trans-Am Category II championship as well as the A- and B-Production, B-Stock, B-Prepared and B-Stock Ladies Solo II national championships. Corvette also captures the IMSA AAGT manufacturers’ title.

1979

Corvette wins the SCCA Trans-Am series’ Category I championship and successfully defends its national titles in B-Production, B-Stock, B-Prepared and B-Stock Ladies Solo II.

1980

Corvette wins SCCA B-Production championship and wins last two Trans-Am events of the year to clinch Trans-Am title for Chevrolet.

1981

Corvette wins the SCCA Trans-Am championship.

 

GM builds cars for the street. These cars must comply with emissions standards. All of the car companies had better cylinder head designs but they didn't work on the street. There were very few aftermarket heads back then. When electronic fuel management and more accurate emissions control systems came into the picture the car companies were able to use some of these better head designs. Yes, there were better head designs (for performance) back then but fuel and ignition systems weren't advanced enough to keep the engine running clean while using them.

You can't just focus on one part of the engine when designing a street motor and make no mistake, GM was building street engines not race engines.

Besides, if GM had supplied all the good parts from the start it would have "dumbed down" the hot rod community tremendously.

BigBlockk

Later.....

 

Pull-start cinque-cento's... all over Rome... like ants.

My daughters called them "baby cars" when they saw them for the first time.

Bring some extra rope with you in case the starter breaks.

 

1: By today's aftermarket standards, L-88 heads are very inferior
2: The L-82 heads, used until '80, were on par (albiet with less compression) with all previous SBC high performance heads.
3: Very few aftermarket cylinder head companies existed in the '70's. Even in N.H.R.A. Pro-Stock cars, modified Chevy heads were used. It wasn't until the very late '70's and early '80's the aftermarket head companies came out with their products.

 

"Crap" is, I believe, derived from the old English word "crapper" which means farmer. The word crap is related to the word "crop." Sir Thomas Crapper is regarded as the inventor of the flush toilet. It's somewhat controversal if he was the actual inventor, but he popularized the flush toilet when he received a contract to install the first flush toilets in British castles. His toilets all carried "Crapper" tradename, so the word took on a new meaning. You can still buy a real Crapper today. The company is still in business. But a real crapper will set you back about $2500. Lets hope that at that price, it's not a piece of crap.

 

Yes, but the lump hammer & bow & arrow didn't have a bunch of politicians & the insurance industry slapping regulations on their manufacture & performance like the car industry did. I was 21 in '81 & bought a new T140 Bonnie in the January. This, just like the Vette and most cars our domestic industry was producing for export to the US, met the US emission laws by using the same methods - restrictive cams, low compression ratios, crankcase emission recirculation, appalling exhaust systems & restrictive intake systems. They all did this to get the emissions down & then had to work with the system they ended up with to try to get a good all-round performance. Not meeting requirements precluded it from being sold in the US. The 750 Bonnie I had bought was slower than a '69 650. My wife's '67 MGB was faster than an '81 MGB. They didn't have microprocessor control in '81 at a price that made it economical to fit to cars. It was also not reliable enough, I remember the problems we had with the electonics reliability when we were designing weapon systems for Tanks. Any company that, with hindsight, we could accuse of being slow to use electronic engine management systems probably had the right (conservative) approach. The systems could be a real headache in small production quantities, if some of the issues we found had appeared on a mass produced vehicle then the warrantee claims could easily have sunk the company. I think GM had ***** in equiping the L81 with a computer & the fact that mine is still working 25 years later is proof that it isn't crap (how many of the vastly expensive systems I worked on/used/saw is still in use? The last time I saw one of the systems I used was in the science museum - which mad me feel really old ).
Talk to any "expert" on bikes & he'll tell you that the late T140 was crap. Take a late T140 head & fit it to a gas flow analyser & it'll give results better than the earlier splayed head design (which common wisdom has as the best head made for them). Put the T120 ex cam, CR, exhausts etc in it & it'll blow a stock T120 into the weeds (I know, I tried it). Development was occuring at a frantic pace, but it was aimed primarily at getting good emissions, not performance. Put some earlier engine parts into an L81, along with induction & exhaust bits, & you'll probably be surprised to find that it goes not bad at all. The reason being that vast effort (& expense) was spent on getting weight off of it, following the mantra "Well, we're screwed for making more power & not exceeding the emissions limits, so we'll have to increase performance by losing weight). We can look back now, with modern engine management systems, computer designed engines, standard wind tunnel Jellybean shaped cars, & say "That old 80's stuff is all crap", but that old "crap" is what led the development of what we're using now (& if modern cars are so darn good, then how is it that my sister just arrived at her own wedding on a breakdown truck?!!!!).
Something else people tend to forget is that the fuels & oils available in '81 are completely different to the ones that allow modern engines to produce the power outputs of today & not grind themselves into expensive swarf. It was funny, growing up through the 70's & 80's, watching engine technology advancing in bikes, but stagnating in cars. We were playing with pentroof combustion chambers, multi valves per cylinder, forced induction, gas flowing, etc, etc on bikes while cars seemed to be stuck using the same old designs (even crossflow heads were really "WOW!!!") due to a lack of development resources (possibly because it was being spent on meeting ever tightening emission requirements, or in paying shareholder dividends, or meeting unreasonable demands from Trade Unions). Then the car world, what was left of it, suddenly produced a new generation of engines & within a short space of time people were saying the old ones were crap (the old ones being the ones that helped build the economies of our country, got us to school/work each day, took us on holiday, etc). Give it enough time & people will be looking at todays cars & laughing at them for being crap!

Knowing somebody that worked at a manufacturer during the 70's, crap isn't the word I'd use to describe the results of the emissions & economical requirements they had to conform to (along with manufacturing tolerances far greater that those of today). I'd say "'kin incredible" that they managed to meet the stringent requirements they were given, without completely strangling the output & producing something that nobody would buy.

Fitting some of the T120 parts to my emissions legal T140 completely killed any hope of passing emission regulations (if it had to comply to them). I'd imagine that the performance heads used by GM caused emissions way beyond the limits (high CR = high NO levels, wild cams = high HC levels, or was it the other way round?), hence them having to design a head that gave the best performance possible on a naturally aspirated engine, while meeting ever tightening emissions restrictions. It's easy, all these years later, to criticise the results, but if you've ever had to fiddle with a carb to pass emissions tests during an MOT you'll have some idea of the swings & roundabouts situation that there was. Imagine having to balance out the performance, with emissions over the entire rev range, from cold starts, hot running, hard acceleration, shut down from high revs, what CR to use, the cam used & all the while having to ensure that the engine would stay within the limits after x 000 miles of poor maintainance & being driven by people who wondered what went in the "710" cap! It was difficult then in getting a microprocessor to keep things within spec as mechanical parts wore over time, it must have been a lot more difficult to do it by cam, head, piston, exhaust, intake & filter selection & then relying on some screw settings to keep it all in tune. I think they did incredibly well given the limitations they had to work under. But, from a performance point of view, they are crap! Blame the lawmakers for it though. Just like everything else, once politicians get their sticky fingers in the pie, the whole thing goes horribly wrong.

p.s. I wouldn't criticise what GM were selling in 1981 as I can remember the sort of thing we were producing at the same time

 

I agree. Look at the Corvette's competition back in the 70's. Look at what Ford did to the Mustang in the 70's. How many Mustang II's do you see on the road today? I would say I have seen one or two in the last five years.

I was a Chevy mechanic from '75 to '79. After all those years of tuning hi-perf engines and driving muscle cars (when no rules applied) to explaining to customers why their 180 HP L-48 doesn't drive like their old 375 HP LT-1 was tough. I got out of the business partly due to the emission controls.

 

Some more perspective...

" Corvettes tend to emphasize simplicity over technical complexity when it comes to engine power. Where nearly all competing marques rely on smaller-displacement engines with complex, double overhead cams (DOHC), variable valve timing (VVT), four- and five-valve heads, or turbochargers, the Corvette makes just as much or better power using a simple overhead valve (OHV) head with only two pushrod-actuated valves per cylinder, coupled with a larger-displacement engine. The relatively simple pushrod V8 engine is lighter and physically smaller than the more complex arrangements, as well as cheaper to manufacture. This lack of sophistication is sometimes viewed as a negative by extreme automotive purists, and has fueled the aforementioned "lack of refinement" argument. Regardless of the validity of such criticism, no one can deny the power, efficiency, and affordability of the design."

 

Well, with all this poo pooing on the '79 to '82 heads going on what is a cost saving replacement? I've got an '81 vette and I'd like do something about the poor flowing heads. I'm not sure what to do though. is replacement the only option? If it is then what should I look at to replace them with? Or, can I try getting them ported or trying my hand at porting them myself (if I ruin them, there is my excuse to buy new ones ) Anyway, I'm installing TPI fuel injection from an '85 corvette and I've got the patriot long ceramic headers. I think I've got a handle on the fuel injection, but what are some options with the heads.

Thanks

Jerry

 

The aluminum L98 heads aren't bad. There are better things out there, but you can usually get the L98 heads fairly cheap and they were designed to go with the TPI system.

 

there is no better citycar, also, if you mod it you can build an abarth replica, a master bad *** on sharp bends, imposible to beat.
i just sold a few months ago an abarth replica light baby blue color with an abarth engine (about 80hp at 7.000 rpms!! for a twin cil not bad...).
what a car...the first who will have the idea to import these little babies into usa will make plenty of money...

 

Look at this.

http://www.sa-motorsports.com/diyport.shtm

BigBlockk

Later.....

 

We can't race on sidewalks here...

 

Buick had a heck of a small alm. block engine in the 60s.It was the ticket for MGs ect to go racing.This motor was so good,Range Rover bout the design and still use it today as far as I am aware of.

 

funny though, i believed sidewalks in usa were even bigger then ours in italy....

 

It's kind of funny. In the mid 70s the new hot sports car was the Datsun 240z; 260z, 280z, etc. Why would you want a Vette when you could one of the Z-cars cheaper? Where are they now? Try to find and old Z-car. While everyone thought those were quality rides, they didn't survive very long term.......I guess there are different views on quality.