1 2 3
GCrites80s HalfDork
7/5/21 8:21 p.m.

Opti said:

I think there are some tricky hurdles when LS swapping C4s. I'm pretty sure at least on was completed but i think people where saying it wasn't near as easy as other LS swaps.


Really C5s are so inexpensive and better than C4s it doesn't make sense spending a bunch of money making a C4 into a bad C5. I think if you want a performance C4 you buy a late one with an LT1 or LT4 and 6 speed, because they aren't that much more and are better to modify and drive.


If you want a cool C4 you buy exactly what you got. Crossfire injection, early seats, digital dash, goofy trans, and early body work are the coolest/weirdest/most 80s things out on the C4s. Make it more enjoyable to drive and embrace the weirdness and radness of an early C4.


On an unrelated note if you want the best of both worlds you buy a C4 ZR1


Some C4s have multiple computers which make LS swaps harder. Like not just an ECM and a BCM, but computers for specific tasks. A buddy of mine on FRRAX did manage to get an aftermarket engine management system to work on his '91 but it was very difficult and he wouldn't do it again. And that was with the LT1 that came with the car. With an '84 things might not be so complex.

With that said, I was still able to use an '89 Corvette tune and mask on my '87 IROC. There's just a lot more settings you don't use in the Corvette mask in the F-bodies that do all kinds of Voltron stuff on the C4.

wawazat Dork
7/5/21 9:34 p.m.
11GTCS said:

In reply to wawazat :

This X 10.  Your Dad will actually drive his too, maybe even when it’s wet!  The horror!  So many of those are partial cars / major projects after 50 plus years.  It’s so much better to get them back on the road and seen unlike the perfect garage queens. 

He's been driving it unfinished!  The horrors!   He's been approached by total strangers telling him they can't believe what he's done to the car.  He asks the if they want to buy it and then do what they can do what they want to their car.

MadScientistMatt UltimaDork
7/6/21 7:25 a.m.
FatMongo said:

Yeah, but the early C4s are quintessential peasant cars. The guys that get offended about stuff dont consider them worth preserving any way, so they wouldnt care. On the other end of the spectrum, Corvette enthusiasts would be super excited about an LS C4.

Agreed - I'm not sure it's possible to mod a C4 Corvette in  a way that would annoy Corvette purists, since they generally look down their noses at C4s so hard that their nose would get in the way of seeing any mods up to and including building one with a Honda D16 driving the front wheels. I suppose the might get upset if you cut up a newer or earlier Corvette to add the mods. Which means C4s are pretty well positioned to cut one up and make a great track car if you're so inclined.

ClemSparks UltimaDork
7/6/21 12:21 p.m.

I love it.  This is exactly the kind of Corvette deal I want (and what it would probably take for me to own one).  I'd just follow your plan.  Get it up to date on regular maintenance stuff (Fluids, filters, tires, brakes, de-funk) and drive it to find out what it needs next.  Hopefully you don't have to spend a ton of money to keep it running and you can enjoy it for what it is.  There's something to be said for just enjoying it for what it is (especially when you weren't looking for it when it came along) rather than constantly modifying.   I assume it's going to be a lot of fun to tour around in and enjoy.

Opti Dork
7/6/21 12:41 p.m.

In reply to Cousin_Eddie (Forum Supporter) :

You make a good point, modding the car at all doesn't make sense. I wasn't trying to say someone shouldn't do it, I'm all about spending money on dumb car E36 M3.


I guess I just meant, if you just want cheap performance get a C5, or a later c4. They are just better to start and would be cheaper to get where you are going. 


If you happen to have something already and want to modify it or you want a certain powertrain in a certain wrapper regardless of cost or Performance all the power to you, I'll still read the build thread

Sonic UltraDork
7/8/21 8:50 a.m.

Last night I siphoned about 8 gallons of some varnish smelling, but still clear and liquid, gas from the tank.  I'll work this stuff through the lawnmower and truck a bit at a time.  I tried to jump the fuel pump to drain the tank but it didn't do anything, good thing I have a replacement.  When trying to remove the filler neck/sending unit combo the filler neck snapped off from rust, so order in from Rock Auto which was $60 less than the corvette specialty places.   I did order some trim paint, lower window seals and a few other bits from Ecklers Corvette.  A nice thing about restoring a common enthusiast car is that all the parts are available, and all seem pretty cheap to me.   


we are away again this weekend but work will continue trying to get this running by next weekend, as I'm trying to get it to an HPDE the following weekend.  

Mr_Asa UberDork
7/8/21 11:46 a.m.

Are you going to actually drive it at the HPDE?  If so, that sounds incredibly ambitious.  I'd think you'd want a couple weeks of driving it as much as possible to work out what major hidden issues it might have.


Sonic UltraDork
7/8/21 12:23 p.m.

The plan is to try to drive it there, yes, but we have backups: our Mazda3 race car, friends Veloster N, other friends Miatas and M3, all are generally available as we have fun at HPDEs driving each other's cars and are in different run groups.   

Certainly I'll try to shake it down beforehand and will only take it if all signs point to yes.  

Opti said:

In reply to Cousin_Eddie (Forum Supporter) 

I guess I just meant, if you just want cheap performance get a C5, or a later c4. They are just better to start and would be cheaper to get where you are going. 

I prefer the trip rather than the destination. I'm never happier or more content than when I'm working through a mechanical challenge. Once I reach the end destination, the joy is over for me. Time to move on to another adventure. 

APEowner SuperDork
7/8/21 2:53 p.m.
Mr_Asa said:

Are you going to actually drive it at the HPDE?  If so, that sounds incredibly ambitious.  I'd think you'd want a couple weeks of driving it as much as possible to work out what major hidden issues it might have.


I don't know.  HPDE seems like a pretty good way to shake down a car.  Particularly if you can trailer it to the event.  I mean, if it breaks you get a free tow back to the paddock.  You won't get that on the street. 

On the other hand I thought HPDE in a car that I'd barely looked at was an OK idea.  So, maybe I'm not the best person to give advice on the topic.  Link to thread where I run a car in HPDE just because it was already in the trailer

Tony Sestito
Tony Sestito PowerDork
7/8/21 8:43 p.m.

Man, just seeing this thread now. I love everything about the whole deal: the car, the story, and that awesome garage where it lived! This would be a PERFECT car for my fictional (for the time being) "Cheap Corvette Challenge" my friends and I want to do. We get extra bonus points for a Crossfire car and/or a 4+3. 

This one should clean up nice! I'll be following intently. Good luck with it!

Sonic UltraDork
7/12/21 8:32 p.m.

I spent this weekend with the friend who gave me the car and he was thrilled to hear about the progress so far.  

Tonight I finished the fuel system.  First was removing the original sender to see how bad it was.  Yikes.  

Here's the new one (from Rock Auto)


The bottom of the tank was full of crap



I siphoned as much of the fuel out as I could, got it nearly dry.  Then started taking out handfuls of that crap.   Eventually I was wiping things down with paper towels to suck and wipe up what was left.  I didn't get it perfectly clean but this is solidly in good enough territory and the tank itself seems to be in good condition. 


I installed the new pump and sender and gasket, hooked everything back up, and installed a new top gasket bucket thing around the filler neck.   Now it is ready for fresh fuel.  

Tomorrow I'll pull the plugs and drop a bit of oil in the cylinders and see if it turns over by hand.  

The sock filter was in pieces in the tank and the pump was completely gummed up. 

APEowner SuperDork
7/12/21 9:12 p.m.

Wow!  That fuel pump.assembly was a mess!

Sonic UltraDork
7/13/21 8:42 p.m.

New cap, rotor, wires on.  Plugs out and fogging oil in and it turns over smoothly by hand.  Battery is out and clutch master is 2/3 out. 

GCrites80s HalfDork
7/14/21 10:19 a.m.

This is all typical of what an F- or Y-Body of the time needs to get back on the road after sitting.

Sonic UltraDork
7/15/21 8:34 p.m.

It runs!

Yesterday I replaced the battery and clutch master.  Today I tried to replace the clutch slave to find it ha a different fitting end than the hose.  All other replacements I can find are also the new style and a new hose is $152.  Nope.  I'll rebuild the old housing with the guts from the new one, but I'll save that for the weekend. I also sucked out and cleaned the brake master reservoirs and power steering fluid.  

I disconnected the fuel pump and coil and cranked it and it quickly built up good oil pressure without odd noises, so I put the plugs in, checked firing order, hooked everything back up and fired it up.  It was a bit rough at first and didn't want to idle.  I put part of the intake back on which helped so it would idle on its own so I could check the injectors, only one was firing of the two.   I swapped them left to right to see if it was a wire problem or an injector problem and when I started it again it was running smooth on all 8 at a high idle.   Oil pressure was good, no weird noises or leaks.  

jfryjfry Dork
7/15/21 9:59 p.m.

Woo hoo!   Best news all day

APEowner SuperDork
7/15/21 10:46 p.m.


mickpiston New Reader
1/13/22 1:27 p.m.

Any updates on this? I've been really wanting a cheap C4 and came across this. Hope you're putting some rad miles on it!

1 2 3
Our Preferred Partners