FRSTR90

With there being 3 '73 Corvettes in the family and the prices of gas shooting through the roof, I've been considering to add an LS engine to one of them... Now you maybe asking what engine I am considering. Well I have considered an LS1, but by the time its over it wont be an LS1 just an LSx engine.... By the time I'd be done, I think I would have an LS built slighty stonger than an LS6. I wouldn't want to go all out because the purpose of the engine is to have a mild street engine with good fuel economy..

What are the pros and cons to an LS engine?

Do any of you have a rough estimate what the gas milage was in the C5 Z06's with the LS6?

Like I said, this is a consideration I might put one in and I might not, but I think this brings up an interesting topic...

dgruenke

If you are doing to save money, it would take A LOT of gallons of gas to save enough money to reach the amount of money spent on the conversion.

If you are going to do the project, make sure you are doing it for reasons other than to save money.

palamesa

I just got back from buying an LS6 with auto tranny out of a wrecked (on the side) 02' Camaro SS 35th Ani car. It's kind of dirty and has 95 k on it. Paid 2900 and comes with everything I asked for. I also picked up the dual fans for an extra 100. Not keeping track of costs....don't care....gp

FRSTR90

Well, here's my situation, in the car that I want to do it in, it has an L48 that gets roughly 12 mpg on the highway if lucky. It is pretty much a plain jane. The car is slow, not fuel effecient, and I was planning to do a rebuild on it. I am not sure what it is equipped with as far as lowerend goes, but I imagine the L48's were 2 bolts. However, some low perf cars that you would never expect to get a 4 bolt got one back in the early to mid 70's.

If I were to do a rebuild, I'd go with a forged 4340 crank, rods, and forged aluminum pistons... Right there puts me at around $2,000. I imagine that the L48's were not the 2.02/1.6 valves... So to keep the original heads, I'd have to take it to the machine shop and prolly end up spending more than a grand. Then for a cam, I was planning on going with a Hyd. roller Performer RPM with the intake to match and a holley 750 (set-up is very similar to my dad's 355 and it's got tons of power)... That will probably bring me up another grand. Now to increase my torque to the real wheels and at the same time save money of gas mileage, I was planning on going with a 700R4. That puts me at another atleast another 2 grand.

With that kind of setup, I am looking at atleast $6,000 and probably getting around 10-14 MPG.

FRSTR90

I have seen engine tranny combos go for about that much... Thats why I am leaning towards the price being about neutral to get running how I like it....

I was thinking about buying a set up the way it is (maybe slight cam it up and put an intake on it), dropping it in, see what the mileage and power was like... Then when it came time to rebuild, I'd decided if I want more power or keep it the way it is?

P.S. Are you planning on rebuilding it soon?

I am still unsure about my plans, in ways, I cant see putting a new engine in an old car, if ya catch my drift...

7T1vette

Or, you can keep the car as it is...you don't have enough power to "show off", so you'll save a lot of gas there...and you'll have an extra $6K to buy gas with! [Not as much fun...but a lot more practical.]

Little Mouse

Friend of mines C5 Z06 gets 28/29 on hwy 17 around town, I
would say it would be worth it if you use the car mostly on the
hwy, but most cars are used about 75 percent of the time in town
driving. Aerodynamics are not as good on C3s as a C5 hwy milage
would be slightly lower.

palamesa

Before this comes back to bite, I'm pretty sure the engine in the Camaro I bought today is an LS1 but came from the factory with a LS6 intake and probably an LS6 block. I think it was still labeled an LS1, not sure. I hear it's still an upgrade from the regular LS1. Still learning. That's what makes this stuff fun....gp

PatsLs1vette

Go Ls1 youll never go back,lol

The best part of having a ls1 was last weekend i went to a local show,everyone that walked up was like,Hey that doesnt belong in there,and it starts a conversation and when they walk away they get a new understanding of new into old and how it can be done and have a old car but modern technology and creature conforts.

Palamesa i see you took the plunge good job.

frstr90 go over to ls1tech.com in conversions,alot of good info over there.

MYBAD79

I have the LS1 with auto trans in my DD, 24mpg on the highway, 16-19mpg in the city.
My LS1 is stock except catback and air filter, can't complain about performance and reliability, 100K miles without any problems

Aftermarket performance parts are very expensive for these engines, a lot more expensive than for the older LT1 engines.

If you're looking for a reliable and fuel efficient engine/trans combo I'd suggest a LT1/5spd combo out of a 94-97 Fbody, these are almost dirt cheap.

Jims79

its sounds likes a fun project but to do so to save on gas MPG's it would take 10 years to recoup the $$ spent for the swap.

72LS1Vette

The '02 LS1 would have the LS6 block and intake. 2001 was a transition year. I think all of the LS1s had the LS6 intake but only later production engines had the LS6 block. You have to check the casting number to be certain.



Rick B.

79 Camaro

I have a 79 Camaro with 2002 LS1/4L60E combo.

3:73 gears and 17 mpg in town and 22 mpg on the highway.

I also did a 98 Wrangler swap using a 2001 4.8 and it gets 17 mpg around town. Its a great everyday hot rod.

Best swap there is.

FRSTR90

Sound like some interesting info! I like to see the difference of opinions!

It sounds like the gas mileage would be great, but then again you all do have a point.. It will be awhile until the money is recovered...

I guess my main reasons for the swap were:
-good performance
-better fuel economy
-something different and unique (not something that everyone has)
-lighten the car up on front

What is usually the first to come to mind when you see an old car with modern technology?

Budman68

My LS6 averages about 23 - 24 mpg with burnouts, highway, and darting around town.

FRSTR90

Thats twice than what my L48 gets on the HIGHWAY!!! thats pretty cool!

Just Wondering, how often do you drive your vette? and what tranny and gears are you running?

Little Mouse

Sell the C3 buy a C5.

2000FRCZ19

i have 3.90 gears in my z06 ls6, mn12 trans and get an avarage of 23 mpg in it. i let it rev a little between each shift. it really likes the 3500 to 4000 rpm range to rev into between each shift around town for smoothness. i am guessing the milage could be closer to 25mpg avarage if i drove more conservatively ( 1st to 3rd shifting ) but i hit the upper rpms quite often when i get the oppertunity ( no traffic and no cops ). if you want to do it right i would go with an mn6 trans and a 3.90 gear out back. you will get great milage and a much better ratio than the mn12 trans. i have had both mn6 and mn12. my vote goes to the mn6 with 3.90's. with that gearing you will be testing the limits of your tires with the ls6 engine.

mrvette

My '72 vert had the L48/muncie 336 rear in it when I got it, engine was fresh with mild cam, Qjet/intake/exhaust stock as a stove....
car ran fine, but like you got crappy economy....so, in went a TPI setup with 1227730 speed density computer, which instantly doubles the fuel economy, and I not kidding 24 on highway, 18+ around town....course in there also I ditched the heavy gear oilin the tranny, and used straight 30 weight synthetic engine oil....right there the muncie shifted like a new tranny...

anyway, for the money, just putting a TPI on your car will vastly improve the mileage, and performance....sounds like a stock system would work fine for you....

it's a easy conversion...really, not involving much keep all your accessories the way they are....I did my own wiring harness, built to '91 firebird wiring diagram....watch the grounds, they are critical...

as for overdrive, the cheepest easiest way is to go 200 4r tranny, i'ts a drop in for any automatic/stick shark....use a trans go shift kit...don't leave home without it....

Budman68

I drove it for the last two summers, once up to Bowling Green for the CI and to a few out of town drag racing events. Currently the car is stripped for paint and a few upgrades. Got to stay the fastest, with all these supercharged C-3 in the works. Once Monty get his going I'm out.

Last year I ran a T-56 with 3:55's. The problem with 3:55's is you are lugging around on the highway at 1700 rpms and only doing 78 mph. I didn't care for that to much. Thanks to a trade on the forum and Traccdog2, I got the back changed to 4:11. My cruise rpms should be around 2200 now.

Your going to like the LS1.