3.8L or 5.0L
Thread Starter
Registered User
Joined: Feb 2008
Posts: 11
From: Ohio
3.8L or 5.0L
I have a 1980 cutlass stripped down to the frame and I am building it for a sixteen year old boy. This veichle is going to be a dalily driver. What is everyone suggestion on the motor. I have a 5.0L-305 and a 3.8L-v6. I want gas mileage but dont want a dog. Dose any one out there have either set up and can tell me what kind of mpg the get.
Thanks
Thanks
Moderator
Joined: Jul 2007
Posts: 18,133
From: Edmond, OK
Hmm... I don't know much about Chevy engines. I didn't even know the 305 was offered in Oldsmobiles in the early 80s. I knew the Chevy in-line 6 was offered in the late 70s.
I had a 3.8L V6 in my 93 Buick LeSaber. It was an excellent car.
I had a 3.8L V6 in my 93 Buick LeSaber. It was an excellent car.
Moderator
Joined: Jul 2007
Posts: 18,133
From: Edmond, OK
Yeah, I was thinking that a 3.8 V6 available in the early 80s would be different than the one in my 93 Buick. I wonder if it is the same block? 
If you are building an engine for gas mileage then I would suggest purchasing a crate engine. Just replace the engine that orignially came in the car. If you want to build a street engine, then ditch those engines and at least find yourself an Olds 350.
Truthfully, every Olds engine is going to get CRAPPY gas mileage unless you have a late model Olds like Redog. 30mpg is DECENT. Anything less is atrocious! Especially with gas at $3.00+ / gallon.
If you are building an engine for gas mileage then I would suggest purchasing a crate engine. Just replace the engine that orignially came in the car. If you want to build a street engine, then ditch those engines and at least find yourself an Olds 350. Truthfully, every Olds engine is going to get CRAPPY gas mileage unless you have a late model Olds like Redog. 30mpg is DECENT. Anything less is atrocious! Especially with gas at $3.00+ / gallon.
Past Administrator
Joined: May 2004
Posts: 10,349
From: Rural Waxahachie Texas
For what it is worth, I just saw the window sheet on a new Crown Vic equipped with police package (at my work) and 3.27:1 rear gear ratio. Advertised at 14 mpg city and 21 highway. Yuck!
Thread Starter
Registered User
Joined: Feb 2008
Posts: 11
From: Ohio
The 3.8 is out of a 1983 the 305 was put in by the previous onwner, the car came with a 4.3 v8 and I dont have it. I wonder if I can turn that 3.8 in for a core on a v8. According to Haynes oldsmobile used a chevy 305 between 1977 and 1982.
Decisions,Decisions,Decisions!!!!!
Decisions,Decisions,Decisions!!!!!
Registered User
Joined: Apr 2008
Posts: 15
From: southeast TX
not a boat anchor
If the car has already been converted to a small block chevy. get you a decient 350 crate motor and go with it. The 260 cu 4.3 V8 was a bigger dog than the 305 or the 3.8 could ever think about being. I have a chevy 305 in my 80 cutlass that replaced the 260 V8 that came in the car originally.
