CK5
Register an account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members.

Best Engine For Economy vs. Grunt

Which Engine for best Power vs. Best Economy

  • Built 305

    Votes: 1 0.4%
  • Built 350

    Votes: 100 43.3%
  • Turbo'd 6.2 Diesel

    Votes: 97 42.0%
  • I'm Nekkid! Here me roar!!

    Votes: 33 14.3%

  • Total voters
    231
but is your 4200 in a K5? probably not. swapping it in is going to be a PITA just bolting it in, much less actually wiring the stupid thing.
 
How bout a mildly built 250??? My stocker in a 70 K5 used 11 gallons of fuel ona 100 mile hiway trip with bout 3 hours of wheeling thrown in.
 
DieselDan said:
Oh, that right. No one makes stroker kits for 305's :rolleyes:

http://www.speedomotive.com/sbc_305_to_340_cid_stroker_crank.htm

http://www.rpmmachine.com/305-chevrolet-stroker-sb.shtml

http://www.beckracing.com/page24.htm

Shrouding of the valves could be an issue, if you're talking about large valves in a "performance type" head. I think I said Vortec.

I no, I don't do Japenese. Ever. :haha:

PS. Just because my truck's diesel, doesn't mean my Vette is ('86 coupe, 377 Eagle crank/rods, Haltech ECM).

so i mistyped. hardly noone makes a stroker kit for a 305. 383 kits are everywhere. shrouding the valves in a 305 is an issue no matter what head you use. the valve spacing is the same on all production small block heads. 350 heads commonly have 1.94" valves, and 305s commonly have 1.84", that's .05" difference, not really that much. when you consider the 3.735" bore of the 305, and the 4.00" bore of the 350, you'll notice an extra .1325" between the valve and the cylinder wall. this helps performance dramatically, wether you're running a smogger 305 head, a Vortec, or even a 230cc AFR head.

at any rate, for the money invested, the power gains from a 335 arent worth the investment.
 
My vote is an unturbo'd 6.2. Turbos are expensive and you said you wanted cheap. For simplicity and ultimate cheapness, an sm465 is the best route for tranny, or a th400. Turbos reduce your mileage too. A 700 built to last will cost a bit.
 
I'm gonna throw in another vote for the big block. I didn't vote cause the big block option wasn't in there.

A stock bb will get compareable milage to a stock sb and it'll be consistant no matter what. Waaay back in the day, I had an '85 K30 with a 454 and used to have a 407bb (402 bb .030 over) in my K5. Both got 10-12mpg no matter what I was doing. Haulin a load, towin a trailer, doin a burnout, cruisin down the freeway, puttin around town, blowin through a mud bog...it was always the same. I had an old tired 350 in the K5 before the 407, and have a new Goodwrench 350 in the truggy now. MPG on both small blocks have been up and down depending on what I'm doing. Puttin around town and cruisin down the freeway, I got 13-14. Wheelin or goin fast with my foot on the floor and it sinks down to 6-8mpg.

If your priority is more towards milage, then I would vote for the Turbo'd 6.2. If you're priority is leaning more towards power, I'd go with a stock bb.
 
afroman, I like your idea the most now. My vehicle will probably be weak as crap, but that'll likely keep me from getting speeding tickets, so I'll probably be able to drive with a lead foot without getting pulled over. Go with a N/A 6.2, convert it to run off veggie, and put a 435 and twin-stick 205 behind it.
 
I would go with a mildly biult TBI 350/Turbo 700 R4 combonation. If you do your own EPROM tuning, this should get you about 285 Ft. Lbs of tourque and about 14 to 15 MPG.
 
17-20 out of a gasser motor aint gonna happen. 6.2 is your only hope of any respectable mileage.
I get 17 to 20 MPG highway no problem out of my gasser TBI 350. Average city+ highway is 15-16 MPG Its has plenty of low end too.
Rember Gas is also around 50 cents cheaper a gallon than diesel.
There are plenty of members on here that get just about as good milage out of 350 TBI as 6.2 rattler.
A well built TBI 350/ 700R4 is a great engine trans combo for offroad grunt because of the low first gear, and on road MPG
I would not even concider a 305 in a truck in any form.
 
The problem of the rising cost of diesel fuel would be taken care of by putting a veggie conversion on the 6.2. I've just about decided that yes this will be a trail toy only because right now I actually don't have a vehicle of my own to drive, and I'm looking at getting some kind of econo-box to serve as my DD when I finally go back to work at IOI next summer. Dad's also been trying to get my former high-school vehicle, a 5-speed '92 F*rd 2WD Ranger, fixed up enough to where I can safely start driving it again (brakes and clutch currently need some work).

Anyway, back to my future K5. Since it's going to be a mostly-trail and spare temp DD vehicle if the need arises, I can sacrifice having an overdrive. I've about made up my mind I'm going with a 465 tranny too 'cause I kinda like the challenge of learning to finesse the clutch even better than I already know how for navigating on rocks and the like.

Assuming I go with a 465/203 doubler/205 drivetrain with 4.10 gears in the pumpkins, what's my crawl ratio going to come out to?
 
Thunder said:
Rember Gas is also around 50 cents cheaper a gallon than diesel.

From 1997 (when I bought my K2500 6.5L TD) to earlier this year, diesel was cheaper on the average of $0.20-0.30/gallon. I think it will be back there soon.
 
Here's what you do: Hit the junkyards and grab both a Camaro 3.8L engine and a Pontiac/Buick/Olds Supercharged 3800 engine with the PCM and wiring. Swap all of the supercharged internals (it's all roller) into the Camaro block. Use the whole SC top end and controls. Now you have a S/C 3.8L V6 that bolts to your Chevy transmission and gives you like 300HP and 350TQ (with pulley, headers and PCM flash). It will take premium gas, but should give the kind of fuel economy you're looking for.

I've always wanted to try this.
 
Blue85 said:
Here's what you do: Hit the junkyards and grab both a Camaro 3.8L engine and a Pontiac/Buick/Olds Supercharged 3800 engine with the PCM and wiring. Swap all of the supercharged internals (it's all roller) into the Camaro block. Use the whole SC top end and controls. Now you have a S/C 3.8L V6 that bolts to your Chevy transmission and gives you like 300HP and 350TQ (with pulley, headers and PCM flash). It will take premium gas, but should give the kind of fuel economy you're looking for.

I've always wanted to try this.

or why not just put a crate motor in it that has about the same hp/tq? fuel economy wont be that much different, and it likely wouldnt require premium, and would be much cheaper and easier.
 
as a trail only vehicle, why do you care about fuel economy? Maybe i misread.

they did put the 700R4 behind the 6.2. I have one in my half ton burb.
Works just darn peachy. Does it like to putter around town? Surely. Does it cruse at highways speeds? Yep, no problemo.

Is it a new powerstroke or cummins? No freakin way. But as i can constantly get 20mpg on it, and my buddy's excursion gets 14-15, it is more the mileage master, and it is also a simple design.

Dont bother with veggie unless you plan on driving quite a bit. is it worth it? In my opinion, yes, but thats for you to decide as well. Do not try and run it without a conversion, the IP isnt deisigned to handle such thick fuel in the winter.

You really start feeling the weakness of the 6.2 NA when you start towing some loads. You'd be surprised though- becuase the 6.2 is such a miser, it will continue to run, even with a heavily clogged fuel filter. You'll feel it in the performance though, and it is what sometimes gives the 6.2 a bad name.

Have you considered doing a TPI setup on a 350? A swap to TPI from TBI offers some hp and economy gains.
 
cummins 12 valve....
if a direct bolt in is required then i would say a 6.5L TD with a port polish job and a upgraded turbo and injectors.
Grant
 
go with a caddy, mine is bone stock, got it for 500 bucks and gets great power and mileage compared to my slighty built 350 (maybe even in the 17-20mpg range). You don't even need to modify it to get what you want.

But if you need to stay away from BB's I would say the only way to achieve your goal would be to use a diesel.
 
How much can I expect to pay for 12-valve Cummins alone? Not mentioning the hassles in trying to get it to make up to 465 tranny.
 
Inu-Hanyou1776 said:
How much can I expect to pay for 12-valve Cummins alone? Not mentioning the hassles in trying to get it to make up to 465 tranny.

bend over, grab your ankles... they're not cheap, or light i still vote for the TBI SBC
 
skip the 465 and go with the nv4500 that would be behind it. 2 to 5k. easiest thing to do is find a donar truck. then you will have a transfer case that can take the torque. some years are 205's other years i dont know.

then the cost of the engine mounts being made as well....
Grant
 

Latest Posts

Top Bottom