Am I crazy? Engine decisions...

[Snoozer]

FOR THOSE OF YOU WHO NEED A GOOD, LONG READ...

Its going to be a tough call when the time comes. In any case, I would like to see myself building the engine I decide to transplant under my hood.

I've been mulling around E.F.I. versus carbed. small blocks, strokers, and big blocks....Ram Jet manifolds.... other EFI manifolds..... aluminum and Vortec heads....... dyno graphs....... comparing power numbers.....
...all this data compared against the scale of power v.s. fuel economy. All important things to consider.

If the engine can't pull my 5000 (soon to be 6000) pound truck up and over mountain passes without being in the slow lane with the hazard lights blinking... I don't want it in my truck. Been there... done that... (with a 305 sbc) Gotta have adequate power!!!
On the flip side, if I can't afford to drive it because it gets 3 miles per gallon no matter how I drive it, I don't want it either.

Gas is predicted to go back up to $4 per gallon this summer.

Being that we drive 4x4 trucks with heavy modifications (or at least plans for mods), its imperative to consider these criteria in our decision making process. No one wants to make an $8000 mistake because of ignorance. . Be it not enough power, or unaffordable fuel economy. My joint income isn't that expendable. Options must be weighed and compromises must be made. If I could bolt-in an aluminum-headed GMPP 572 big block and STILL get 20 mpg, I would do it. We all would. MAYBE I'M JUST SCARED OF BIG BLOCKS...

Hey... I like driving my truck. Maybe I just need to resolve myself to only driving it to work on Fridays and weekend wheeling.

I just want more power. But where is the fine line? Which engine will accomplish the magic combination. Any engine can be built to suck fuel down from a garden hose and burn some of it. I want a star athlete that outperforms all others... efficiently.

My engine considerations:
Ram Jet 350 (with aftermarket ECM)
Ram Jet 383 stroker (aftermarket ECM)
454 HO with aftermarket EFI
zz454 with aftermarket EFI
Ram Jet 502

Plans for the truck:
8"-10" suspension lift
38"-42" tires (14.50-15.50 wide)
Overdrive transmission (either 4L60E or NV4500)

My driving habits:
Easy on the skinny pedal around town. No rabbit starts.
Below 70 mph on the highway.
I'm a conservative driver 90% of the time. The other 10% I like to see if I can put the pedal through the floor, just for fun!

AM I CRAZY to hope that I can have the power I want and still get "fair" fuel economy? I don't have the experience to know. I've never run a big block or a Ram Jet. I'm not naive either. I have a mechanical knowledge and background to know what decides these outcomes. I just don't know if GM took it into consideration when designing their crate motors.

Do you?

 

[dyeager535]

As much as I like small blocks, with that much lift and tires, WITH overdrive, I don't think you can get away with anything smaller than a 383, and even then I don't think you will.

The low end torque of a big block is simply going to make more low end power, no matter how you figure it, than any small block equally built.

The larger the tire the harder they are to get to turn, which means a decrease in economy when you change gears to get the motor turning faster. A lower RPM torque monster (diesel?) would probably suit you better than a small block that you have to wrap the heck out of every time you try and start.

 

[jt512]

If it were me and the bank account (and wife) could handle it, I would drop in the 502 ramjet. I have had alot of different sbc combos, but once I went with a bb I will never go back. The only other motor I would even consider in a truck your size (mine is in the same ballpark- 40's and 10" lift) would be a cummins swap.

 

[dfl701]

so GM is coming out with the smaller 4.5 diesel if i remember right. that would be exactly what you need!

 

[blazin_blazer]

if you got the cash def a 502 ramjet....i've been buying low mileage 97-99 vortecs for 800-1200...a 99 denali vortec w/ gmpp $250 carb intake, good ignition supposed to net somewhere 350-400hp & 400 ft. lbs tq....you can't build anybetter cheaper!

 

[ZukiJohn]

The "RIGHT" engine....

For what you want....or desire to have " the perfect engine" go diesel...
5.9 cummins nv4500 some small mods = 500hp 600 ft lbs torque 18-19 miles to the gallon... just my .02 cent see below....

Cummins 4BT & Diesel Conversions Forums - Powered by vBulletin

 

[Thunder]

38-44" tires? BBC? and good gas mileage??
Thats all I have to say about that.

If you want good... well ... er ..Fair ( with big tires) gas mileage and lots of usable torque. I would build a mild/ torque cammed TBI 383 with ported 193 TBI heads.
It wont build high HP but torque will be in the BBC range.

 

[Hogback Fabrication]

The cummins will do it the easiest with the best mileage, but its more involved. You should be able to pick up a used Cummins for $2K or less.

My 383 could hold the speed limit in 4th all the way up I70 (K5 on 37's, 4.56 gears, 5200 lbs), I averaged 13-14 mpg on the highway.

 

[1979jimmy350]

Look into newer LS based engines like a 6.0. I have a Blazer that is around 5500 pounds no overdrive, 35's 4.10's. I have the 5.3 and with some tuning i managed to get 20 MPG on the highway

 

[Blue85]

 

[tRustyK5]

Injected is nice, but I'd rather be blown...

Rene

 

[Snoozer]

WOW!
GREAT replies! Thanks everyone!

As much as I like small blocks, with that much lift and tires, WITH overdrive, I don't think you can get away with anything smaller than a 383,...
...The low end torque of a big block is simply going to make more low end power, no matter how you figure it, than any small block equally built.

I too am a small block fan (they are all I know though)... Just by looking at dyno graphs, by the time a SB is competing with BB power output, the SB is sucking down some fuel. Kinda defeats the purpose of staying with a small block, IMO.

If it were me and the bank account (and wife) could handle it, I would drop in the 502 ramjet. I have had alot of different sbc combos, but once I went with a bb I will never go back. The only other motor I would even consider in a truck your size (mine is in the same ballpark- 40's and 10" lift) would be a cummins swap.

My wife wants me to build my truck the way I want to. That doesn't mean there is no budget. But she is just supportive of my habit and wants to see me happy with it's outcome.

so GM is coming out with the smaller 4.5 diesel if i remember right. that would be exactly what you need!

Diesel huh?

38-44" tires? BBC? and good gas mileage??
Thats all I have to say about that

I know... I know... Trust me, I was expecting MORE of these types of comments! I don't think TBI is going to cut it. TBI is very performance-LIMITED in its stock form. And to get nitty-gritty with the fuel tables requires a new chip to be burned every time. And I'm the type of guy that would get nitty-gritty with it. I want to squeeze every bit of efficient perfomance I can out of it!

My 383 could hold the speed limit in 4th all the way up I70 (K5 on 37's, 4.56 gears, 5200 lbs), I averaged 13-14 mpg on the highway.

REALLY?! Now THOSE are some numbers I can deal with. ESPECIALLY pushing up the steep grades of I-70. Now... what is your mpg like around town?

Look into newer LS based engines like a 6.0. I have a Blazer that is around 5500 pounds no overdrive, 35's 4.10's. I have the 5.3 and with some tuning i managed to get 20 MPG on the highway

I actually did email some folks who deal with LS series crate engines (can't remember who it was off the top of my head). But they replied back to me recommending the 5.3 just like you.

How is the performance with the 5.3?

Injected is nice, but I'd rather be blown...

I can't see the picture you posted... Why blown versus injected?



Blue85...
A Corvette motor would look SWEET under the hood. But isn't it built for more high-end power?

 

[yellowK20]

if its geared properly a stock tbi 350 will push 44" tires and will get better mileage then any of your above options (except maybe the ramjet 350)

But Ideally I would want a Newer LS series engine or a 4bt or 6bt cummins or even a turbo 6.5 . I like to drive my rigs so BBC just suck down way to much fuel I've had big hairy engines in my trucks and there fun for smoking tires and throwing mud but there not thayt great for cruiseing down the highway

 

[1979jimmy350]

I actually did email some folks who deal with LS series crate engines (can't remember who it was off the top of my head). But they replied back to me recommending the 5.3 just like you.

How is the performance with the 5.3?



I can't see the picture you posted... Why blown versus injected?



Blue85...
A Corvette motor would look SWEET under the hood. But isn't it built for more high-end power?

The power is great, the torque is amazing, when i am trail riding's i will leave it in low range 3rd gear and let it idle and it moves if i come up to an obstacle i just tap the gas and it goes over it. I noticed i can hold gears at a lot lower speeds than i used to, when i had a 350 i needed to be going about 35 to hold 4th with the new motor 25 is no problem to hold.

 

[rufusbooth]

I have to agree with a lot of these guys that a cummins would do you well. If you want to really stay with gas look into the gen IV LS based motors. They have displacement on demand. When your foot is light you are running a v4 or v6. When the foot is heavy you get 400+ HP of screaming furry (and the consumption to go with it). It is the best of both worlds.

Cheers,

Rufus

 

[Snoozer]

Your comments have all been great. Very helpful. Thanks everyone.

I like to drive my rigs so BBC just suck down way to much fuel I've had big hairy engines in my trucks and there fun for smoking tires and throwing mud but there not thayt great for cruiseing down the highway

That's what I've heard about BBC's; that they get horrible gas mileage no matter the driving conditions or habits. But what is horrible to some, is reasonable to others. Some people drive like a bat out of hell everywhere they go! Horrible economy is to be expected in such cases.

I think 15, 17, 20 mpg is TERRIFIC for a big, heavy, barn door of a vehicle to get.

10, 12, 14 mpg... I can live with.

...4, 6, 8 mpg.... especially at $4 per gallon. Makes my head hurt.

I know better than to concern myself with "fuel economy" when talking about a tall vehicle that weighs 3 tons and is about as aerodynamic as the broad side of a barn, turning big tires. But people are making some claims that they've acheived a compromise of the best of both worlds. And I want in on it


Not so sure about a Cummins diesel conversion though... A little out of my league I think. The 5.3 LS has my ears perked at the moment.

 

[Snoozer]

1979Jimmy350,
What's that 5.3 LS get around town (mpg wise)?

 

[Blue85]

Blue85...
A Corvette motor would look SWEET under the hood. But isn't it built for more high-end power?

Well you get big block power and displacement from a small block (427 cu). Yes, it makes big power, but it also makes more torque than a 383. I understand that the Vette gets like 25MPG, but no idea what you would see in a truck.

LS7 is a dream......until you look at the price tag.

 

[Snoozer]

Its probably safe to say a truck would see half of that number. Which is still around 13 mpg. Not so bad when you consider what you're getting.

Still... the price tag would hault my truck building project in a hurry.

 

[dfl701]

i havent seen the price, im almost scared to ask but im goin to...
whats the price tag