V tec
#5
RE: V tec
There's lots of terminology that we throw around, 'cause we think everyone understands it. All of this stuff says something about the configuration of some stuff on the engine. It doesn't make a car quicker all by itself. That comes from the whole combination of engine design AND ENGINE SIZE.
The configurations of the camshafts is one thing...
OHV = overhead valves = pushrod engines
OHC = overhead camshaft
SOHC = single overhead camshaft = Accords & Civics (with exceptions)
DOHC = double overhead camshaft = Preludes& Integras
SOHC V-6 has 2 camshafts;1 in each head.
VTEC = Honda's version of variable valve timing & lift
The type of fuel injection is another thing altogether...
EFI = electronic fuel injection = not a very specific term
TBFI = throttlebody fuel injection = 1 injector at the throttlebody
DPFI = dual-point fuel injection = 2 injectors
MPI = multi-point injection = one injector at each cylinder
MPI are often batch-fired; all fire at once.
CIS = continuous injection system = '80s VW, thisis a type ofMPI
SMPI = sequential multi-point injection = each injector fires in sequence
DI = direct injection = injector fires into the cylinder, not into the port
The configurations of the camshafts is one thing...
OHV = overhead valves = pushrod engines
OHC = overhead camshaft
SOHC = single overhead camshaft = Accords & Civics (with exceptions)
DOHC = double overhead camshaft = Preludes& Integras
SOHC V-6 has 2 camshafts;1 in each head.
VTEC = Honda's version of variable valve timing & lift
The type of fuel injection is another thing altogether...
EFI = electronic fuel injection = not a very specific term
TBFI = throttlebody fuel injection = 1 injector at the throttlebody
DPFI = dual-point fuel injection = 2 injectors
MPI = multi-point injection = one injector at each cylinder
MPI are often batch-fired; all fire at once.
CIS = continuous injection system = '80s VW, thisis a type ofMPI
SMPI = sequential multi-point injection = each injector fires in sequence
DI = direct injection = injector fires into the cylinder, not into the port
#8
RE: V tec
Yeah, someearlier MPFI systems are batch-fired. They all fire together, several times during each revolution of the engine. Sequential MPFI each injector fires during the intake stroke of IT'S piston.
So the '99 Accord LX would have SOHC &SMPFI. The EX would have VTEC on top of that.
The carburated 1970 Chevy 350 would have none of that, and it's an OHV pushrod engine,but it's BIG, so its a lot more powerful simply because of size. (To sorta answer one of vtecHef's questions...)
So the '99 Accord LX would have SOHC &SMPFI. The EX would have VTEC on top of that.
The carburated 1970 Chevy 350 would have none of that, and it's an OHV pushrod engine,but it's BIG, so its a lot more powerful simply because of size. (To sorta answer one of vtecHef's questions...)
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