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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
THe 12v 5.9 Cummins would be your best econo engine as far as mileage goes with so much power you wouldn't know what to do. The problem is the initial cost to acheive that. That in it self rules the 6BT out.

The next choice would be a turbo'd 6.2 That will not be cheap either, probably not to far off from the cost of the 6BT cummins by the time you buy the 2K turbo kit from Banks.

If economy is your number one priority than there is only one choice. Like to know what it is?

When you are K5 shopping find one with a half decent SBC in it that is probably stock and drive the thing, wheel it, what ever with it. You will spend 10 fold more money on another engine trying to get a couple MPG's more out of the truck than you will ever get back from savings in increased in mpgs.

A person has to put a LOT of miles on his vehicle with a mileage performance part that costs $750-1,500 to ever get that money back out of increased mileage.
 
effiency is the word of the day

daleearnhardt01 said:
Are you seriously expecting 17-20 mpg out of a 305 in a K5? That motor doesnt get much better mileage than a 350 and you have a weak ass motor..
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a 305 won't ever get better gas mpg's than a 350...its has to work harder to pull the same load ..therefore its less effiecient and will burn more fuel than a 350 because the 350 doesn't have to work as hard...simple physics...and has been proven!
 
Okay, another question. Here's another scenario:

I find a late 70's-early to mid 80's K5 with a carb'd 350 in it. Now some of you guys are saying when it comes EFI I should go with a TPI setup out of a Camaro/Firebird/Corvette instead of a TBI system, and I agree that a TPI setup would be better (and look cooler too), but how much more difficult to hook up would a TPI-setup be compared to TBI. I Know TPI will work on pre-86 two-piece main blocks because TPI was introduced on the '85 Corvette.

What I'd do is get a TPI motor, and either swap the heads, and TPI onto the K5's original motor, or more likely, just swap the the whole TPI engine into the K5.
 
blazin_blazer said:
a 305 won't ever get better gas mpg's than a 350...its has to work harder to pull the same load ..therefore its less effiecient and will burn more fuel than a 350 because the 350 doesn't have to work as hard...simple physics...and has been proven!
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Not exactly. In theory that could be correct, but not in most cases. With that theory having a 4.3L V6 must just do horribly on mileage since it would have to work even harder than a 305, but just like someone said in this thread, the V6 gets around 20mpg. Just like the Mopar 360 and 318, both engines were an option in many of the same pickups, but the 318 always managed better mileage.

If you are talking about a moderate amount of weight, say a basically stock K5, it doesn't take a lot of power to put around really. THe bigger the engine you have, theoritically it is going to consume more fuel. THe only scenerio I could see where the smaller engine would do worse is when too much is being asked of it, like pulling a larger trailer around behind that same K5 in some hilly terrain. Then the 305 would be overworked and would have to get the fuel poured to it, where a 350's torque would probably allow the driver to get up to speed, and maintain speed on hills more quickly getting out of the throttle sooner.
 
in stock form, the 305 would do better for economy. however, since he plans on lifting it, upgrading the drivetrain, and installing larger tires, the 350 would be the better option.
 
So which EFI system would be harder to implement if I wind up with a pre-TBI K5? The TBI system or the TPI F-body/Vette engine?
 
TBI is the easiest install. You can get an aftermarket GM TBI system that is a 4 wire hook up + you need a TBI dist, fuel pump and return line.
 
And would it be a system that replaces the carburetor-type intake manifold with one specially meant for TBI, or would it retrofit onto the carburetor manifold?
 
i see you say built!

now you spending money....why not buy a $1300 gm crate engine that comes with a 3 year/36,000 mile waranty and swap the cam ,put and aluminum intake on it and some headers.....you'll spend just as much "building"1 and it won't have any waranty..when you buy your intake just buy the 1 for a tbi unit!
 
Quote:
Originally Posted by Inu-Hanyou1776
I Know TPI will work on pre-86 two-piece main blocks because TPI was introduced on the '85 Corvette.


'84 Corvette... :rolleyes:
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WRONG again. Inu was correct. '84 Vette still had the CrossFire (twin TBI) injection. '85 was the first year of TPI. Late '86 (starting with the roadsters) was the first year for the aluminum heads. :rolleyes: :haha:
 
I dont mean to be a dick but how much mechanical skill do you actually have? I'm talking real world tearing **** apart and sometimes puting it back together work, not web wheeling. Even a gas to diesel swap is not "easy", and most of the people throwing the "C" word around dont realize how much work it is to put one in a chevy. My basic point is, no motor swap is going to be a cinch, so think long and hard before you commit yourself and your money to something you may not be able to finish.
 
Inu-Hanyou1776 said:
And would it be a system that replaces the carburetor-type intake manifold with one specially meant for TBI, or would it retrofit onto the carburetor manifold?
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All you'd have to do is buy an efi manifold... tbi won't retrofit a carb manifold unless its a 4bbl tbi (1000 bucks) or you buy a carb manifold to tbi adapter which is a waste of power and they usually don't fit right.

The tbi swap is very simple as far as efi goes and would be the easiest to do. But why don't you just buy a efi k5?
 
beater_k20 said:
'84 Corvette... :rolleyes:
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Pretty sure he was right on this one ;)

TPI isn't tough to install, but unless you buy an entire running car for less than a grand, expect to be putting at least a grand into it to get it running.

TBI isn't as high of performance, but it does well for a truck, and is boat loads cheaper. (300 - 400 for a complete setup)

I put TPI into my K25, I'm sitting at approx 1000 USD into it, and looking at least 150 - 200 bucks more till it runs.
 
Well, here's what I would do. Look at a few different trucks before you buy. If you plan on large tires, you'll need lower gears. Not going too be a high MPG vehicle anyway you look at it. When you have the $$$, see what's avalible. I'm not a fan of the 305 due too it's lack of low end torque. I love the bodystyle of the first gens, had a 72 that I am still kicking myself for ever selling. The 89 to 91's are good looking K5's also. Mid 70's can be had pretty cheap though.
 
Inu-Hanyou1776 said:
And would it be a system that replaces the carburetor-type intake manifold with one specially meant for TBI, or would it retrofit onto the carburetor manifold?
Click to expand...

Yes. all you need to retrofit TBI to carb manifold is an adapter. turbocity, CFM-Tech, affordable fuelinjection, all sell them. They will adapt TBI to any square or spread (quadrajet) bore SBC manifold. Open squarebore aftermarket mild performance manifold is the best to use. They work just fine. Apparently GM thought so. On all TBI 454s GM used a heated adapter plate to mate TBI to a stock carb q-jet manifold.

http://www.affordable-fuel-injection.com/ These guys can fix you up with anything you need.
 
afroman006 said:
I'm prety sure they didnt use them on ALL 80s and R/V series 454s and am CERTAIN they didnt use them on C/K series 454s.
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my uncle's '91 C3500 has one, as does my sister's boyfriend's '93 K3500. not sure why they'd cast a TBI specific intake, and then go back to a carb intake.
 
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