3.8L or 5.0L

riverrat · 04-21-2008, 12:43 AM

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

Olds64 · 04-21-2008, 05:14 AM

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.

Oldsguy · 04-21-2008, 05:47 AM

That 5L V8 might be an Olds 307, maybe?

Redog · 04-21-2008, 06:04 AM

I'm sure the 3.8 he's talking about is the old 3.8 which was carbed.

Both engines are dogs

Olds64 · 04-21-2008, 07:48 AM

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.

Oldsguy · 04-21-2008, 01:03 PM

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!

riverrat · 04-21-2008, 09:58 PM

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!!!!!

Olds64 · 04-22-2008, 10:08 AM

Quote:

oldsmobile used a chevy 305 between 1977 and 1982

Disgusting. Get an Oldsmobile engine and use that Chevy engine as a boat anchor.

80 cutlass man · 04-29-2008, 12:06 PM

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.

04-21-2008, 12:43 AM	#1 (permalink)
riverrat Junior Member Join Date: Feb 2008 Location: Ohio Posts: 7	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

04-21-2008, 05:14 AM	#2 (permalink)
Olds64 Landyacht Club President Join Date: Jul 2007 Location: Lawton, OK Posts: 1,242	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. __________________ "Some men are Baptists, others Catholics. My father was an OLDSMOBILE man." Ralphie Billingsley A Christmas Story 1983 "We rei-eign, supreme, ooooh god! Burrito supreme, and a chicken supreme, and a CUTLASS SUPREME!" Tenacious D 2007

04-21-2008, 05:47 AM	#3 (permalink)
Oldsguy Administrator Join Date: May 2004 Location: Lees Summit MO Posts: 2,779	That 5L V8 might be an Olds 307, maybe? __________________ Dan '46 2 door

04-21-2008, 06:04 AM	#4 (permalink)
Redog Alero Chapter Secretary Join Date: Aug 2006 Location: Newtown, PA Posts: 679	I'm sure the 3.8 he's talking about is the old 3.8 which was carbed. Both engines are dogs __________________ Me 2000 Alero running 14's 1985 Delta 88 w/1968 350 rocket 2005 Nissan Altima (her's)

04-21-2008, 07:48 AM	#5 (permalink)
Olds64 Landyacht Club President Join Date: Jul 2007 Location: Lawton, OK Posts: 1,242	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. __________________ "Some men are Baptists, others Catholics. My father was an OLDSMOBILE man." Ralphie Billingsley A Christmas Story 1983 "We rei-eign, supreme, ooooh god! Burrito supreme, and a chicken supreme, and a CUTLASS SUPREME!" Tenacious D 2007

04-21-2008, 01:03 PM	#6 (permalink)
Oldsguy Administrator Join Date: May 2004 Location: Lees Summit MO Posts: 2,779	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! __________________ Dan '46 2 door

04-21-2008, 09:58 PM	#7 (permalink)
riverrat Junior Member Join Date: Feb 2008 Location: Ohio Posts: 7	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!!!!!

04-29-2008, 12:06 PM	#9 (permalink)
80 cutlass man Junior Member Join Date: Apr 2008 Location: southeast TX Posts: 6	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.

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