Into the 90's

Up to this point 35 years of development had gone into the Small Block Chevy. Right from the start the small block proved easy to work on. Anyone could hot rod it or swap parts out without hurting it. At one point in time the engine was tested at wide open throttle with no oil. The first time the small block lasted just over an hour. The second time it lasted two! The small block stayed right up competing with other engines because it was so innovating and simple. And with over 90 million built that's also saying something!

  It's no mystery that technological advancements has brought new life into the small block. Power levels of the little engine rivaled those of the late 60's and performance was alive again.
The 1990 IROC Camaro  had a 2.2 second 0-60 time out of the hole.That put it in a class along with the Corvette and 911 Porsche. To give an example of the the ability of the Tune Port Injected 305's ability in the IROC,it did 0-60 in 6.3. This engine was mated to a 5 sp manual gear box. The Tuned Port 350 mated to a 4 sp automatic in the 1990 IROC did 0-60 in 6.1 seconds. Quarter mile times were both 14.8 seconds,although the 305's speed was 95.4 against the 350's 96 MPH. The 305 did it with better fuel economy. These performance numbers were on par or even better than the performance numbers seen in the 1960's. 1990 would be the last year of the IROC because Chevrolet did not with the International Race Of Champions. and would return to using the Z-28 as their performance platform for the Camaro.

Example of 305 T.P.I. with Automatic Transmission

The 305 T.P.I. powered the Caprice of that year and achieved 17 miles to the gallon in the city and 26 on the highway.This was also partly a result of the Caprice being redesigned with a better drag co-efficiency.

The Gen II LT1
IN 1970 Chevrolet built the strongest small block out of the best parts it had at hand. The result was the LT1. The engine grossed 370 HP give or take. The Gen II LT1 would prove to be the most powerful small block Chevy built to date.A re-disigned low rise intake manifold,a new throttle body and optically triggered ignition that was re-located to the front of the engine. High pressure fuel rails feeding both cylinder banks with dual oxygen sensors in each bank of the dual exhaust leads to the most efficient and powerful small block of the 90's. So much so it improved fuel economy by another mile to the gallon over the L98. This engine produced 300 net HP and 330 net LB/FT of torque. Coupled with the a 6 speed manual gear box the Corvette rocketed to a 0-60 time in 4.92 seconds and flew through the quarter mile doing 103.5 mils an hour in 13.7 seconds.

Gen II 350 LT1

The 1980's

As it turns out there was no shortage of oil,just commons sense. Consumer confidence was effected by alarmists and fear mongers. The line ups caused by the oil embargo did nothing to ease these fears. The big V-8 cars sat on lots allowing smart people to grab some really good deals with the knowledge that oil prices would settle down and the mrket would stabilize.However not before the feeling that the death of the V-8 engine was about to come. The technology that beacame the key to the small block Chevys survival would cost Chevrolet a small fortune but,the advancements in computer controls and induction would create power that would actually surpass the heyday of the late 60' and early 70's.

 The first development came in the form of T.B.I. or throttle body injection. The research on this type of induction started back in thelates 70's as a means of a new low pressure delivery that was to be controlled ellectronically and the requirment was that it was to be less complicated then the earlier fuel injections systems developed up to that time. The reason for this was to eliminate the cost of the high pressure pumps and the in tank booster required for the high pressure systems. They developed 5 main components to the system,1) the injector,2) throttle position sensors or TPS, 3) Idle Air Control Valve or IAC, 4) fuel metering body assembly, & 5) fuel meter cover assembly. Basically in a nutshell with out going into the things that actually are required to make this type of system work, it was simply a powered carburetor. An oxygen sensor was used to gauge the air/fuel mixture by reading exhuast gases and controlled the air/fuel mixture at the injectors. Precise air/fuel mixtures required for every RPM range and engine load were now possible. This is actually a very simple system and can be modified pretty cheaply and a few simple bolt on parts and add up to 30 horsepower at the wheels. This is without modifying any of the computer controlled operating parameters.  Most at Chevrolet didn't think this "force fed carburetor wouldn't make a difference. The system ended up driving fantastic agaisnt the best emission controlled carburetors of the day,creating a more efficient and drivable vehicle. The first systems were available in the 1982 Camaro's and Corvettes and called "Cross Fire Injection"
At this time,Chevy engineers were also putting serious effort in to develping a truly high output 4 barrel 305 to be made available in the Z-28 and Monte Carlo,it would become the top engine option for the Z-28 for the 1984 model year.

Tuned Port Injection
 A completely new type of induction system was on the horizon for the small block in 1982. At the time,engineers were given order to design parts to suit the 305 because the higher up's at GM were telling them that there wasn't going to be engines bigger than the 305. The Tuned Port Injection System was a marvel of engineerning. This system really brought the small blocks power potential back. Coupled with a dual pattern camshaft and electronic spark controls the small block was really starting to show some new signs of life. The runners of the tuned port system allowed the engine to take advantage of the intake pulse created as a result of the dual pattern camshaft. This camshaft utilized a higher lift on the exhaust side,creating negative pressure inside the cylinder so when the intake valve opened there was actually more vacuum to pull the air/fuel mixture into the cylinder giving it a larger charge. With the electronic spark controls giving damn near optimum spark curve through our the RPM and load range of the engine,efficiency levels and power levels were really starting to become impressive compared to just a few years ago.

The Tuned Port Injection system was initially designed to be exclusive to the 305 how ever Chevrolet didn't want to loose the performance image of the Corvette so it was also adapted for the 350. This system allowed for individual tuning of the intake and exhaust ports because each cylinder had it's own computer controlled injector and the intake manifold had a ninth injector for cold starting. The system was introduced to the public on the 1985 Z-28 and Corvette. The 305 Camaro version of the engine,RPO # LB9 was rated at 215 HP and 275 LB/FT or torque,the Corvette got the 350, RPO# L98 and was rated at 230 HP and 330 LB/FT of torque and by 1987 power levels reached 240 HP and 345 LB/FT of torque. Bare in mind that these numbers are also net S.A.E. ratings. These numbers would compete with the net horsepower ratings of the small block of the 66-68 model years.

  Two of the biggest improvements during the 80's for the small block Chevy were re-desigining the way the engine gaskets sealed against the loss of oil and the development of hydraulic roller lifters.

Up to this point the cylinder head heat would dry out and cook the valve cover gasket. Two reasons for this,high cylinder temperatures and the fact that the cooling system ran the coolant through the engine block first. The valve cover rail was raised and machined to allow for a coolant passageway and the water pump was redesigned to run the flow of the coolant in the opposite direction. This accomplished two things. It kept the new valve cover gaskets cooler and better able to keep a good seal and it kept the cylinder head cooler allowing for a cooler denser air/fuel charge to enter the cylinder. This also kept the valve seals from getting to hot and improved their function as well. The rear main seal was re-designed as a One piece seal as opposed to the two piece and the oil pan and timing cover gaskets were designed with compression stops to eliminate over torquing the bolts.

  The second major improvement was the use of the hydraulic roller camshaft. This allowed for more radical lift profiles and reduce overlap and reversion,which is the amount of time both valves are open in the cylinder. It increased flow for low end torque as well that translated into better drivability for the street. The new roller designs were manufactured from steel giving it far greater strength and durability.

High Output 350 

During the last half of the 1980's the idea came along to use a Corvette engine and top it off with and old style Z-28 intake manifold. After some tweeking with exotic roller camshaft grinds and some serious dyno tuning,this compilation of components, 99% of which were already in production for other applications a full blown high output engine was built. This engine dyno'd at 345 net HP. This was also with a carburetor topping it off. This was the first street engine built by the factory that survived the 24 hours of Daytona. It placed 7th overall.

  The 1980's finished with the solid knowledge that the small block Chevy would be a force to recond with for many years to come. With the addition of computor technology,fuel injection developments and roller camshaft designs,without which the small block would be a long lost memory, the engine had established it's adaptability and durability. The hey day of the 1960 horsepower lost through most of the 1970's was back and with it a bigger demand than ever from enthusiasts and hot rodders alike. And there were still further improvements and suprises on the horizon.