Hello,

I'm currently looking to buy a C3, ideally in the 76-77 range. The reason why I'm writing this is in hope to get some advice. The C3 that I purchase will be my only car. While I look to take great care of this car, it would still be my daily commuting car, so it's not going to be like a garaged and 'collected' car.

With that said, I was talking to my friend who's big on Corvettes and I told him what I was looking to do. My two largest concerns, with this car being a daily driver are reliability and gas mileage. Here are the two options that my friend gave me:

1) Swap in a LS1 engine into the C3. Does anyone know the average gas mileage on an LS1 engine? How much would something like this cost, and how long would it take to actually perform? Would anyone personally be able to do this, and if so, could you PM me with some further info? I'd be looking throw in the C3 engine that came with my car part of this service ideally, since I'd have no need for two engines. If you're looking for a C3 engine, then let me know and I'll keep you in mind if I go this route. Or if you are selling an LS1 engine, then please let me know.

2) Convert the engine in the C3 to fuel injection. Is there a kit to do this kind of thing, and how much would it generally run to install and buy it? Would this change the gas mileage, or make the car run more reliably?

I'm also open to hear any other options that you think may help me. I may sound crazy to some, but I'd take a hit in performance if I could up the reliability and make the gas mileage more manageable. I love the speed of the Corvette, but I'm moreso a fan of the C3's bodystyle. It's been a car I've loved since I was a kid, and it'd be like a dream come true if I could pull this off.

All links, advice, and suggestions are hugely appreciated. Thanks for reading.

EDIT:

I suppose a third option would be to have an engine custom designed with what I have in mind. Does anyone have any good points of contact for a custom engine?

Thanks again.

 

Just rebuild the engine with about 9/1 compression and a camshaft that will provide good low end torque then tune it to run on the idle circuit of the carburetor at cruising speeds should get you into the mid to high 20's as far as mileage goes.

Simple.

BigBlockk

Later.....

 

Thanks for the advice! I'll look into that!

 

Look into an 82. It has duel throttle bodies and the 700R4 tranny. Great gas mileage and is a reliable cruiser. I drive mine almost everyday.

greg

 

I've never gotten better than around 20 mpg with mine. You really need a 4-speed auto & fuel to get good mileage with a C3.......

 

 

Yeah, you need to address gearing to maintain consistantly good fuel economy. Also, a lot depends on how you drive it. Even with an OD tranny and low gears, if you goose it a lot (which Corvette owners are known to do), your fuel economy will obviously suffer.

I think the suggestion of going with an 82 was a good one. You'll spend a lot more making the mods than the cost of an 82 (plus I think 80-82 look the best, but I'm biased anyway). Otherwise, several people on this board have successfully installed 2004R OD Trans in their cars. with great results.

Bueget Fuel Injection: Corvette Fever did an article last year where they did a fuel injection upgrade on their "Shark Attack" project for about $200. They basically transferred over a fuel injection setup off a late 80's/early 90's truck. They reported that it looked nearly stock and fit under the hood. I thought that was one of the more interesting articles/mods I've read. They supposedly are going to (or maybe already have done it) put all the articles of that project on their website. Might be worth checking out.

Last piece of advice: whatever Corvette you end up with. Drive it a while before deciding on the mods. You might find using a C3 as a daily driver isn't for you or doesn't meet your needs. If it does, mod away

Mark G

 

Thanks everyone for all of your advice and suggestions. While the 82's look nice, my favorite has always been the 76-77 range, mainly because of the tunnel back window, if that's what it's called.

I haven't driven a C3 before, but I have been in a couple and I definitely liked the experience. I may find that I like things as they are and just keep it like that.

Does anyone have any suggestions as far as maintaining good reliability?

 

I agree with the guy that said drive one for at least 6 months before making decisions. I don't think C3's make good daily drivers. I spent alot of money and time making my '82 powerful and reliable, and I still have alot of little issues here and there (big issues if I weren't mechanically minded). Honestly, it's not very comfy either. Also, you say you don't care about power, but when you jump in a Civic and you know deep down it can outperform your Vette you might start thinking differently.

About the LS1 swap, it's expensive, but you will gain relaibility and those O-ring seals in the LS1 are light years ahead of the seals in the Gen I engines. I've done an aftermarket EFI swap in my '82 and I'm doing a LS1 swap in my '72, and I would go LS1 over the aftermarket anyday. That being said, you do not need fuel injection to make an engine reliable or fuel efficient, and no matter what way you paint it you're probably looking at quite a bit of money if you want to go to a good EFI system. Buy one with a straight body and rust free cage, and then worry about what your'e going to do with it.

 

you should look into later C3 models for a DD. But if you like the 75 & 77 the best then find one that someone installed a new GM crate motor into. I would stay away from high performance HP motors for a DD the gas milage will kill you. I would also consider a automatic over a 4 sp car. I love my 4 sp but in stop & go traffic my left leg & foot gets a work out. Now if you can't find the perfect C3 buy one in very good condition & install your own 350 crate motor stay away from custom motors and most if not all race or high HP motors break down alot using them on the road as a DD. G/L lets us know what you find. Check out the C3 section. One of the members ESU has a C3 w/a new crate 350 that maybe what your looking for.
Jim

 

Thanks for all of the advice. I'm definitely taking everything into consideration. It's cool to know that there are people who want to help someone they don't even know.

I've done some research on comfortability and things like that, and I know a C3 as a daily driver isn't optimal, or the norm, but for some reason it's just something I want to do. I'll do my best to make it work, though.

Thanks again.

 

I don't use my 75 as a daily driver but I think you may be looking for a setup similar to mine. I rebuilt all moving parts in the suspension and drivetrain and stuck with the stock springs, softer KYB shocks, and rubber bushings. It rides much more comfortably than my 3/4 ton pickup. Of course handling suffers a bit but it's a tradeoff I'm willing to make.
I dropped in a GM 350 H.O. crate motor and put on a 1406 Edelbrock carb. Finally, I installed a 700R4 overdrive tranny. This setup has adequate power, gets in the upper teens for mileage and has been rock solid reliable.
Take your time to do everything right and have an open checkbook and you may be surprised what can be done.

 

I bought my 76 as a dd last year. The main reliability issues have been with aftermarket add ons (fuel pump, carb, etc), but the car has never stranded me. I've been returning the car to stock condition, and find that it runs better and more economically this way. The car was only down 5 days in the last year and this was waiting on a rear bearing assembly to arrive. I've done all of the other work on weekends. The car had 94k on the odometer, and a new crate motor when I bought it.

Only get mid-teens for milage. But when I figure what I have in this car vs. what a late 90s vette coupe would cost, I can buy a lot of 'extra' gas...

 

That's cool, Doe!

Do you have any pictures of your vette?

When I buy one, I'm definitely looking to make sure it either has a relatively new crate engine or I'll be buying one myself to put in. Someone earlier in this thread made suggestions as far as tweaks go to make it run more fuel efficient. What I'd probably do is ride it as it came for a while to see if it's something I can manage before I do any major tweaking. Also, a good friend of mine and his dad are really into Corvettes and they offered to help me out with labor and show me the ropes, so.

I think I just may pull this thing off.

 

Cost for this type of swap will be more than you want to pay and will probably never pay for itself as far as fuel savings go.

Ditto. Cost will be more than you want to pay and will not get you the type of mpg/cost savings you're looking for.

Either of these set ups will devalue your car at resale time.

Not being nosey, but you should consider you age and location. If you are an umarried male under the age of 23 and want to put a sports car on the road as a daily driver, your auto insurance is apt to be your single highest automotive expense.

My 1974 stone stock L-48 with AT was my daily driver for years. She would get 18 mpg when tuned, highway/city combined.

My '80 L82 is about the same. '68 327 AT is a bit lower.

Good advice concerning the '82s.

 

I would recommend you run the numbers before you dump 5-10 grand into a car to improve the gas mileage.

Ex:
Lets say you currently get 13 miles/gallon and drive about 13000 miles/year.
That's a 1000 gallons/yr at about $3/gallon or $3000/yr.

If you swap in an LS1 with a 4 speed auto the mileage goes up to 18.
Your gas consumption has reduced to 13000/18 which is 722 gallons/yr.
That will cost you $2166 per year a saving of $833.

If it it cost you 5 grand, it would take 6 years before you realized any savings.

Now you might drive more, or have access to cheaper parts,
Its worth estimating how much your really going to save.

 

Alright--where to start. I have a '69 as my daily driver.

What would you be willing to spend?

-I had heard about a fuel injection kit for $3K that has step-by-step instructions. The Corvette Fever article sounds intriguing, but it would be a bear to install.

-If you buy the LS1 engine out of a car it should come with everything you need. My friend is going to drop a $12K LS7 in his '98 WS6 Trans Am. These cars have 350 hp at the wheels and the correct transmission set up (remember that C5's have the transmission in the rear while Camaros and Firebirds have it up front like us, otherwise it'll be more work to adapt it). I will probably buy the complete set up right down to the computer from him. Also, the Trans Am gets 20-22 mpg and is a heavier car (it has a trunk and back seats and only some fiberglass).

-I am 23 and we just did a thread on young people. We did discuss insurance, and nobody was paying that much. I pay $60/mo, but I use USAA.

-I would recommend a new engine no matter what. I bought an old 350 for $1600. Anything else that isn't replaced could fail on you later on, but once it is replaced once. You are good to go.

I have looked a lot of what you are talking about, so feel free to PM me.

 

Thanks a lot for the advice, guys. It's really helping me tune my search. If I could get to 18 miles per gallon, I'd be more than okay with that. After all, it's a Corvette.

I guess I propose another question, then. Would a rebuilt/new 350 crate engine hold up as a daily driver? I'd say that I was more interested in reliability than high gas mileage.

Thanks for all of the responses!

Also: I'm 22. I did a quote with my insurance company with a VIN from a '76, and I'd actually be paying less than what I do now.

 

If you havent driven a C3 before and plan on making one a daily driver I would definitely test drive somebodys first. I know guys do it but personally I dont think they lend themselves very well for a DD. You're talking a 25-30 yr old car with who knows what issues. I mean it can be done but why? Gas mileage is suspect, reliability may be suspect, doesnt really make sense to me, again I know guys will differ in opinion. My other love besides old cars is old guns. I belong to several firearms forums besides the corvette forum here. Every now and then a newcomer will ask about the practicality of using his newly aquired Luger or P-38 as a carry weapon for personal defense. Why trust your life to a 50 yr old weapon that may or may not fire when you pull the trigger, is ammunition sensitive and who knows what type of maintenance or abuse it had over the last 50 yrs. Now you may not be exactly trusting your life to a DD vette but the principle is the same. They make great weekend cruisers but I dont believe they would make a great DD. Just my 02.
ESU

 

Safety is another reason to not use an old vette as a daily driver. Newer cars are much safer in an accident.