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So the roommate is about to leave for deployment and her 84 Corvette needs some TLC. We're a Vette family with her 84 and 00 and my Procharged 08.
Her car was a daily driver for years but after a few issues it's been left to sit outside and hasn't ran in years. I managed to crank it over and get it somewhat running with carb cleaner but I believe the fuel pump is dead or the tank rusted out. The cap is basically welded on shut. First step is obviously to pull the pump and test it but I'm not sure if I want to just restore it somewhat or built it better.
Firstly let's face it the crossfire was an awful engine. I want to get a good used vortec (LQ4) and if I have the means/room I'll slap my old P1 procharger on there with my old stock bracket. The engine now is a mismatch of parts honestly. The serpentine belt is a 4 rib riding on 6 rib parts that aren't aligned. It rides on the front of one pulley and the back of another. Needless to say the engine needs work. However I'm not sure if there's an easy way to interface a 84 PCM with a newer engine or interface a new PCM and still run the 84s gauges and dash. I'd like to keep it stock looking.
I still need to check the engine out but I have a leftover radiator out of my C6 that I can use if it fits... hell I even have a nice set of electric fans to go with it. The paint isnt horrible but the clear is peeling. It needs some love as well. I was thinking (some of you may hate this idea) of having the car sanded down and plasti dipped it's original color with some extra pop to it. There's a few good places around here and it looks amazing if done right.
Only questions I have is can it be done. I've heard of an LQ4 swap but I'm not sure what other parts I can manage to fit into the car. Also what can the old C4s auto transmission/diff hold? I'll be scouring around here for used interior parts as I need them. It's something to keep me busy from blowing a ton of money on my cars and get her classic running around causing trouble again.
FWIW, the Cross Fire can be made to work well. As others will tell you the biggest problem with it is the lower intake is very restrictive. If you port that or replace it with a Renegade that will help a lot... like 20+ HP.
But the first thing I'd do is to get the fuel pump/tank issue straightened out. If it has been sitting that long you need to flush the tank and clean out any of the old dead gas... the stock 1984 fuel pumps are iffy so if you think it is bad and you have the tank out anyway, you might as well replace it with a 1985+ pump. You can usually buy an ACDelco one for under $100 if you shop around.
Provided the internals of the engine are O.K., building from an L83 block isn't that much different than an L48 or similar smallblock (upgrade intake, heads, cam & exhaust). If the compression is bad or something then you may be better off just putting in a new Goodwrench long block.
On the other hand if the block is tired then throwing a supercharger on there is probably going to shell it out quick.
It looks savable to me... but it is going to require a bit of work to make it nice. Door panels, paint and get the engine running right... Probably a few issues caused by it sitting for a while outdoors... belts and hoses, etc...
No joke just telling it as it is. Car was a daily back in 06-07. Small wiring fire under drivers seat and radiator fan issues kept the car out of commission. The 00 ended up being the new daily.
As for the crossfire comment they are simply lackluster. Yes I know all about emissions I had a 1980 but it was still much easier to deal with. An engine that was only used for 82 and 84 Corvettes probably wasn't a crowd favorite.
Yea man! How can you SAY that!? The Crossfire may not be much today, but in it's day, the Crossfire was a world beating,bad ****....
I had a Crossfire, and I loved mine, but...the Crossfire is good for many things...putting out LQ4 + Procharger powerlevels isn't one of them. Looks like you've got a real project on your hands there.
All the dash runs off regular sensors. You won't affect anything but mpg display by changing ECM's. So it won't be hard to make it "look stock".
'84 ECM is not easily or practically tunable, so move on to something way, way newer and better.
Auto trans as when stock won't hold much power at all. Newer/later ones are better w//higher spline counts and other improvements. If it were me, I wouldn't even consider ANY 700R4 with that LQ4 engine; I'd want either a stick, or a more exotic auto. What every you decide on, if it's not a C4 specific 700R4, then you'll have to fab up something to tie into the C-beam.
Rear is going to be a Dana 36 and is not that strong. However, if it's a street driven car on real street tires, it is capable of lasting behind your proposed engine. Anyone can break anything, of course, but a D36 can survive with prudent use. The first obvious upgrade there is the Dana 44 from an '85^ 'Vette w/a stick shift. That rear can handle a lot, when maintained.
Last edited by Tom400CFI; Aug 11, 2015 at 08:07 PM.
FWIW, the Cross Fire can be made to work well. As others will tell you the biggest problem with it is the lower intake is very restrictive. If you port that or replace it with a Renegade that will help a lot... like 20+ HP.
But the first thing I'd do is to get the fuel pump/tank issue straightened out. If it has been sitting that long you need to flush the tank and clean out any of the old dead gas... the stock 1984 fuel pumps are iffy so if you think it is bad and you have the tank out anyway, you might as well replace it with a 1985+ pump. You can usually buy an ACDelco one for under $100 if you shop around.
Provided the internals of the engine are O.K., building from an L83 block isn't that much different than an L48 or similar smallblock (upgrade intake, heads, cam & exhaust). If the compression is bad or something then you may be better off just putting in a new Goodwrench long block.
On the other hand if the block is tired then throwing a supercharger on there is probably going to shell it out quick.
Thats mostly my reasoning behind a new block entirely. I'm fairly certain with the Florida rain and humidity that the piston rings are well rusted and I'd rather throw in a cheap junkyard motor thats been proven to last. The car will simply be a toy at this point but I'm certain if I can make it quicker than her 00 she would love to take it out on weekends. She's not into speed as much as I am but she enjoys her Vettes.
I'm also thinking about trading in the head unit (maybe at the shop that works on my car)- for an engine/trans combo.
Yea man! How can you SAY that!? The Crossfire may not be much today, but in it's day, the Crossfire was a world beating,bad ****....
I had a Crossfire, and I loved mine, but...the Crossfire is good for many things...putting out LQ4 + Procharger powerlevels isn't one of them. Looks like you've got a real project on your hands there.
All the dash runs off regular sensors. You won't affect anything but mpg by changing ECM's. So it won't be hard to make it "look stock".
'84 ECM is not easily or practically tunable, so move on to something way, way newer and better.
Auto trans as when stock won't hold much power at all. Newer/later ones are better w//higher spline counts and other improvements. If it were me, I wouldn't even consider ANY 700R4 with that LQ4 engine; I'd want either a stick, or a more exotic auto.
Rear is going to be a Dana 36 and is not that strong. However, if it's a street driven car on real street tires, it is capable of lasting behind your proposed engine. Anyone can break anything, of course, but a D36 can survive with prudent use. The first obvious upgrade there is the Dana 44 from an '85^ 'Vette w/a stick shift. That rear can handle a lot, when maintained.
Would love to swap in a stick but the roommate doesn't enjoy driving a manual. She can but I'm certain she would avoid that car like the plague if it had a manual. Decent transmission upgrade noted. I'm sure she won't change the wheels/tires so I think the rear end will hold for a while if the tires spin.
- I'm almost thinking this thread is some sort of joke - 
Thinking about restoring/modding an 84
