what '82 mods.....
09-22-2003, 03:20 AM
#1
Racer
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what '82 mods.....
'82 owners- what kind of performance mods have you done, and just how far can you take this engine before you lose streetability??? What is the best "bang for your buck" mod for the L-83?
09-22-2003, 04:29 AM
#3
CFOT Attention Whore
Re: what '82 mods..... (Magnum '82)
o.k. my opinion may not be wanted here since i'm not an L83 owner, but i'll throw my two cents in.
the L-83 suffers from one single (and major) flaw when it comes to modifying the engine. i know everyone's heard of the CFI, affectionately known as 'cease-fire injection'. the problem isn't with the injection system at all. it's with the manifold. it is extremely restrictive. and the bad news is due to it's design, there really isn't anything you can do to the manifold to help it.
if you've never seen one off the engine, i'll try to describe it so you have an understanding of how it's restricted.
i'll assume your pretty familiar with the inner workings of the SBC. you know how the intake port on a traditional head is a vertical rectangle? measures approximately 1" wide by 2" tall. pretty close, right? well the intake runners on the L83 manifold measure about 1"x1". no kidding. and the sad part is that there is no meat on them to open them up.
for reasons i have never figured out, when the manifold was designed, they made the bottom really high. so when the manifold is on the engine those 1x1 ports are sitting just about at the top of the head ports. my guestimation is they are a good 30-40% smaller than the intake port and they're not even centered. it really was a disasterous design.
unfortunately, the injection system has taken the brunt of the abuse from the detractors. it's sad though, because some industrious people have taken the factory manifold, cut it off the bottom and welded in a lower floor on it to match the shape of the head port and yeilded some pretty impressive figures.
if you can figure out the intake portion of the engine, your pretty much home free. after that, it will respond to just about anything else you want to do. i've heard that an L83 with a good cam, FIXED manifold and the usual bolt-ons is capable of ~400hp.
the engineer who designed that manifold should be beaten!
the L-83 suffers from one single (and major) flaw when it comes to modifying the engine. i know everyone's heard of the CFI, affectionately known as 'cease-fire injection'. the problem isn't with the injection system at all. it's with the manifold. it is extremely restrictive. and the bad news is due to it's design, there really isn't anything you can do to the manifold to help it.
if you've never seen one off the engine, i'll try to describe it so you have an understanding of how it's restricted.
i'll assume your pretty familiar with the inner workings of the SBC. you know how the intake port on a traditional head is a vertical rectangle? measures approximately 1" wide by 2" tall. pretty close, right? well the intake runners on the L83 manifold measure about 1"x1". no kidding. and the sad part is that there is no meat on them to open them up.
for reasons i have never figured out, when the manifold was designed, they made the bottom really high. so when the manifold is on the engine those 1x1 ports are sitting just about at the top of the head ports. my guestimation is they are a good 30-40% smaller than the intake port and they're not even centered. it really was a disasterous design.
unfortunately, the injection system has taken the brunt of the abuse from the detractors. it's sad though, because some industrious people have taken the factory manifold, cut it off the bottom and welded in a lower floor on it to match the shape of the head port and yeilded some pretty impressive figures.
if you can figure out the intake portion of the engine, your pretty much home free. after that, it will respond to just about anything else you want to do. i've heard that an L83 with a good cam, FIXED manifold and the usual bolt-ons is capable of ~400hp.
the engineer who designed that manifold should be beaten!
09-22-2003, 09:01 AM
#4
Race Director
Re: what '82 mods..... (clutchdust)
Additionally, the computer that runs the EFI, in stock configuration, only allows so much modifications (cam, compression, etc.).
This site: http://www.crossfire.homeip.net/cftest/default.asp deals with all things 'Cross-Fire'.
This site: http://www.crossfire.homeip.net/cftest/default.asp deals with all things 'Cross-Fire'.