my caprice classic wagon has a 5.7l engine in it, probably the same blcok as the vette. i don’t know a whole heck of a lot about cars, but i do know that my engine could not have the same compression as the vette (takes regular octane gas for one, only has 255 lbs of torque for another). the '93 vette has 10.25:1 for coupe and 11:1 for faster model.
what compression does my car have? 1993 caprice classice station wagon. thanks.
also, once an engine comes out of the factory running a certain compression, that compression will never change no matter what you do, correct? (turbo, supercharge, air intake…) i know over time leaks will cause compression to drop, that is not what i am asking here.*
The compression ratio is a mechanical function. You have to change the basic mechanics involved (such as, a crankshaft with different throw or cylinder head volume) in order to change the compression ratio.
A brief snoop of the web says your car has somewhere between a 9.3:1 and a 9.8:1 compression ratio, upon leaving the factory. High performance engines are typically in the 10.XX+:1 range.
please, i need someone to just come on here and tell me that it is absurd to say that my car has the compression ratio of the vette!!! you car guys should know this, right? i can’t find anything on the net about caprice wagons!
Ringo: where did you see those figures? what site?
Your car does not have the same engine as a Corvette. Your engine has a cast iron block and cylinder head, throttle body fuel injection, in block cam and push rods, and is rated at 215 horsepower per my Chiltons manual. Since 1989, the Corvette is an all aluminum engine, electronic port fuel injection, overhead cams and is rated at 380 horsepower. There are other models of the Corvette and factory sponsored tuned versions that go up to 600 horsepower. Although both engines are about 350 cubic inches, there is nothing the same about them. According to my Chiltons, your engine compression ration is 9:1, the 93 Corvette is 11.2:1. The only thing that is probably the same on both cars is the radiator cap.
Since 1989, the Corvette is an all aluminum engine, electronic port fuel injection, overhead cams and is rated at 380 horsepower. There are other models of the Corvette and factory sponsored tuned versions that go up to 600 horsepower. Although both engines are about 350 cubic inches, there is nothing the same about them. According to my Chiltons, your engine compression ration is 9:1, the 93 Corvette is 11.2:1. The only thing that is probably the same on both cars is the radiator cap.
Racer, Where on earth did you get that info? Not all Corvettes are ZR-1s, you know. This special edition car was the only late model Corvette to use an overhead cam design, by Lotus I believe.
If you knew anything at all about small block Chevy engines in general, or specifically LT-1 and LS-1 engines, you’d know that they absolutely do not use overhead cams. They are pushrod engines, with the camshaft in the center of the V. They didn’t produce any way near 380 horses stock in the early/mid nineties, either. Hell, 2002 Corvette is rated at 350, or 405 for Z06
Is Chilton’s a reputable source? that horsepower seems a little high… what does that book say about peak HP and torque, and at what RPM?
i need to compare the ratio to a coupe, not a zr-1.
doesn’t the fact that vette’s take premium gas mean that they have high compression and my car takes regular so it has low? i know there are high compression cars out there that take regular, but for the most part?
Fuel- yes, that is true in this case. Your engine has a lower compression ratio than a Corvette because it does not, as designed, require higher Octane fuel. You have it backwards, but no big deal.
Looking at a less than reputable source, I found 93 Caprice wagons with 5.0l V8 engines at 170 horses and with 5.7l engines at 180 horses. According to the same site, the 93 Buick Roadmaster, which is essentially the same car, was available with a 5.7l rated at 180 horses. I don’t believe both entries would be in error regarding the output of the motor.
In 1993, you are at the end of the line for the unloved “Three-oh five”, and the “small block Chevy”
It’s interesting to note that the LT-1 was available at this time (1993) in the Camaro and Firebird, but it looks like the Caprice and Roadmaster didn’t get versions of the same improvements until the following year, as the 1994 car’s 5.7l V8 engine’s output jumps 80 horsepower (to 260). This engine was standard in all Roadmaster, Caprice wagon, and police versions, but an option on “base” cars.
Fuel- yes, that is true in this case. Your engine has a lower compression ratio than a Corvette because it does not, as designed, require higher Octane fuel. You have it backwards, but no big deal.
Looking at a less than reputable source, I found 93 Caprice wagons with 5.0l V8 engines at 170 horses and with 5.7l engines at 180 horses. According to the same site, the 93 Buick Roadmaster, which is essentially the same car, was available with a 5.7l rated at 180 horses. I don’t believe both entries would be in error regarding the output of the motor.
In 1993, you are at the end of the line for the unloved “Three-oh five”, and the “small block Chevy”
It’s interesting to note that the LT-1 was available at this time (1993) in the Camaro and Firebird, but it looks like the Caprice and Roadmaster didn’t get versions of the same improvements until the following year, as the 1994 car’s 5.7l V8 engine’s output jumps 80 horsepower (to 260). This engine was standard in all Roadmaster, Caprice wagon, and police versions, but an option on “base” cars.
doesn’t the fact that vette’s take premium gas mean that they have high compression and my car takes regular so it has low? i know there are high compression cars out there that take regular, but for the most part?
OK, slow down. You are correct about high compression engines, on the whole, requiring higher octane gasoline.
It is just more proper to state that the compression ratio determines the type of gasoline than vice versa. That’s what you had backwards.
Check the block, post what your casting # is. If the site I visited is correct, you may have a 5.0 (305), not a 5.7.