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.

It's time for opinionated replies. It's open to all responses. Gas or diesel?

For mileage, even if my dads 454 makes more power than a 6.2, it does so at a pretty large penalty of 11-12MPG on the freeway, (I think most on here will agree with that 454 milage being close to standard in an older rig) unloaded, cruising at 60MPH with carb, 4.10's, SM465, GV Overdrive, and 33" tires, which is at 1937 RPM. Down around 8-9MPG in the city, but thats not much worse than when he had the 350.

According to the online calculations and Rene's vehicle specs, he's turning 2327 RPM in the same situation, and he's pulling down MUCH better economy.

Trucks are pretty similar in weight, Dads is a 6000# K20, Rene at 6300# K5 last I saw him post.

With diesel now at LEAST $.50/gallon more than unleaded, I'm not sure what the savings work out to though. Don't feel like doing the math. I'm sure still better economy.
 
dirtwarrior17 said:
if you want power get the gas.

I think your response should read: "If you want HP get the gas." Diesels make better "pulling" power.

dirtwarrior17 said:
stock ratings
'96
454: 290 hp @4000 rpm , 410 ft lbs at 3200 rpm.

I thought i read somewhere that the 6.5 made close to 485tq in the Hummers? But the HP was low.
 
With an overdrive I would see 20 mpg even on the 40's...the 6.2's fuel economy is very related to rpm, more so than a gas engine. Even so, for what it is and what it weighs, to be getting 16.5 on the freeway is great!

Diesel prices have gone stupid though. I just paid 99.9 cents a litre this morning :yikes: :yikes:

That is $3.02 per gallon (USD and US gallons...)

I'd feel worse, but regular gas (87 octane) at the same station was 98.5 cents a litre.

Rene
 
Rene, do you think I will be fine with the 465 behind the 6.2 with my current setup? I don't really think the budget will allow for a new engine AND a 4500. This truck will largely be used to get me back and forth from college and to respond to fire calls. I won't be towing anything absurdly heavy except the beater truck. How would a turbo setup affect mileage and life on the 6.2?
 
As long as you arent pushing the EGT's to high or boosting it past 15psi, it really shouldnt effect longetivity much, if at all.
 
You'll be just fine with a SM 465. Your cruise rpm at 65 will be a bit lower than mine. Mine turns ~2500 at 65, yours would turn ~2360 at the same speed. I'd say for power it'd be OK to good, and for economy it'd be a little better than mine. Might see 17-17.5 mpg.

The manual tranny does get a little more power to the ground, so that'll help IMO.

Rene
 
BigOrange90Jimmy said:
Rene, do you think I will be fine with the 465 behind the 6.2 with my current setup? I don't really think the budget will allow for a new engine AND a 4500. This truck will largely be used to get me back and forth from college and to respond to fire calls. I won't be towing anything absurdly heavy except the beater truck. How would a turbo setup affect mileage and life on the 6.2?

Ash, you get rid of the big orange??? Im going to assume your just building another truck. :)

As far as the 6.2 and the NV4500, yes, it is avaliable, and yes, it will bolt up. My pickup came stock that way. These came in a lot of GM pickups from 88-> 2000 I think. I happen to have one of the early NV4500's with the 6.31 first gear. Its completely useless unless I have over 5000lbs of trailer. But its highly desired by a lot of people. (its 6.31 in reverse too!) There are some bell housing differences that you might have to deal with, as the clutch on the IFS setups are on the passenger side, not the drivers.

I've netted 21MPG on the highway before in spring. thats crusing at approximately 1900-2000 RPM. It was an easy cruse, the only problem was with 4.10 gears and OD, I was only turning like 62-64mph. Where the speed limit was 70-75! :blush: (I have 245 tires on).

The current upgrades im working on- (But have had 0 progress)

1. 255/85 or 285/75 tires, should let me increase my cruise speed to like 70, at the same RPM.
2. Turbo Upgrade for the 6.2- I've got a GM8 turbo and exhaust manifold. I've been trying to find a 6.5TD intake manifold, but they are kinda hard to find cheap. Might be cheaper to get the banks intake manifold. Your installation may vary, your AC may have interference, requiring you to use a banks Exhaust manifold as well. They also sell a flow master cross over pipe/down pipe kit for about 100 bucks, so that is what i will be doing.
3. Full Waste Vegetable Oil conversion. I no long have rights to post (probably cause I didnt pay, duh) on the diesel forum. This summer I did my own testing and stuff with it, did about 8000 miles in a 83 mercedes Turbo diesel, and about 10000 with my 6.2 pickup. Both ate it up like it was nothing. In fact, the only reason I stopped running it was that I bent my clutch fork, so... yeah. :)

It seems most research indicates that Vegetable oil acutally has superior lubricating properties- So much so, that some folks have been using a quart every fill up, for nothing else other than for lubricating properties. The Stanadyne DB2 injector did not complain at all about a 50/50 mix of WVO and diesel, and on several occassions, I just carried a few race jugs full of WVO and filled it up along the way. I've probably had concentrations up to 80% without problems. The only issue you will run into is that when the engine is cold, the WVO isnt as loved. hard startups and what not will happen if ambient temps are below 60 (for 60/40 blend) and below 75 for 80/20 blends. This is why i am installing dual tank systems. Hence project number 4.

4. Tri tank setup- 34 gallon diesel primary, 34 Gallon WVO secondary, 24 gallon WVO primary. It may seem a little excessive in terms of "capacity" but when you think about fuel prices, you'll understand my thinking. Lets say I want to go to uwharrie, and tow my k5 and bring my truck camper. Assuming tihs combo, I get 13mpg. I would need 61 gallons of fuel each way. My under belly capacity will be approximately 60 gallons of WVO. That means my drive down will be essentially free. And free.. is good! Oh yeah, and instead of the diesel stench, you get deep fryer stench. You know, that smell you get when you heat up oil right before frying a turkey? Yep.. that smell. It also depends on where you get your oil from. The oil picks up ... shall we say, the "essence" of whatever was cooked. So if you go to a burger place, you will get burger and fries smell, so on and so forth. My current batch smells like General Tso's chicken and Tempora.

If your interested in this kinda setup, there are several boards that are quite good- For your k5 however, the 6.2 I think is an excellent choice in terms of simplicity, avaliability, and overall acceptance of a variety of fuel. Though I've heard that all the older IDI diesels are quite reliably running WVO. I'd also check neighborhood avaliability of good WVO. the first few times asking is worse than a 13 year old asking a girl out. After a while, your skin just gets tough, and you can ask anyone!

If you can, I'd suggest fabricating a tank- Even maybe using one of the side saddle tanks from the C/K trucks up to 1987. That should fit easier on the outside of the frame rail, and fit 20 gallons of fuel.

Now all I need is some time to finish up some projects!!!
 
How is WVO for emissions? Does the truck smoke more or less or???

Rene
 
Emmettology 101 said:
I think your response should read: "If you want HP get the gas." Diesels make better "pulling" power.



I thought i read somewhere that the 6.5 made close to 485tq in the Hummers? But the HP was low.
I've learned to just ignore him.;)

I'd vote for a 6BT with a 4500 but I love my ISB so I'm biased. The swap that makes most sence in my book would be a 6.2 or a 4BT if you feel ambitious.
 
I would go 6.2, if you want more power later, Turbo it, turn up the injector pump, exhaust modifications, maybe even propane. But a 6.2 with the correct gears isnt really that bad of a motor.
 
The studies acutally show that the exhaust gasses are BETTER for the environment than regular diesel fuel.

"Throughout 2003,....... conducted SVO tests in Japan, which showed that the fuel released almost no nitrous oxide or carbon dioxide emissions. This preliminary research is positive news in terms of stalling the greenhouse effect and reversing ozone-depletion. Also noteworthy: According to the EPA, running a car on vegetable oil cuts sulfur dioxide emissions, a primary cause of acid rain, by at least 50 percent. "

However, the results I have seen was that I think Caron dioxide was acutally increased, but almost no NOx. So it depends on circumstances. Other than that, why does it really matter? if your doing a two tank setup, and you have to go get your emissions check, just flip back to diesel, and your all set. :)

I love the NV4500- the only thing that could be better is a 6 speed. With a load, you really notice the steep jump from 3-4th gear. You have to rev 3 higher so that 4 doesnt fall flat on its face.
 
Drey said:
I would go 6.2, if you want more power later, Turbo it, turn up the injector pump, exhaust modifications, maybe even propane. But a 6.2 with the correct gears isnt really that bad of a motor.

Shoot, if I could find a good 6.2 , I'd toss that into my k5. My k5 has sat for the past year due to gas prices.
 
I still have the tub and frame of Big Orange. The rest was parted out and/or going towards a different project. Don't worry though, it will be resurrected later.

That's some interesting and informative things about WVO. That's something to consider while I'm building my K5. Now if only I could source out a good 6.2......
 
I can guarantee you that there is no way NOx was reduced to nothing, in fact it probably was not reduced much at all unless engine timing or injection pressure or a number of other parameters were changed. I work with diesel emissions everyday at work and can tell you that if biodiesel or WVO was that good, they wouldn't need me or a couple hundred other test cell operators and engineers to get emissions reduced on diesel engines.
 
It seems you could learn a few things by opening a chevy 88-98 manual

top is hp bottom is torque

6.2 6.5 6.5 TD 454 tbi 454 mpfi
'88
123 at 3600 230 at 3600
240 at 2000 N/A N/A 385 at 1600
'89
155 at 3300 230 at 3600
257 at 2000 N/A N/A 385 at 1600
'90
155 at 3300 230 at 3600
257 at 2000 N/A N/A 385 at 1600
'91
155 at 3300 230 at 3600
257 at 2000 N/A N/A 385 at 1600
'92
150 at 3500 190 at 3400 230 at 3600
280 at 2000 N/A 380 at 1700 385 at 1600
'93
150 at 3500 190 at 3400 230 at 3600
280 at 2000 N/A 380 at 1700 385 at 1600
'94
190 at 3600 230 at 3600
N/A 280 at 2000 385 at 1600
'95
190 at 3400 230 at 3600
N/A 380 at 1700 385 at 1600
'96
180 at 3400 290 at 4000
N/A 380 at 1700 N/A 410 at 3200
'97
180 at 3400 290 at 4000
N/A 360 at 1800 N/A 410 at 3200
'98
180 at 3400 290 at 4000
N/A 360 at 1800 N/A 410 at 3200



After looking at these numbers I can't figure out why people choose the diesels over the bbc for towing... sure they have more off idle torque but in 10 years they never made more peak tq or hp than the 454. The 454 made its peak at a lower rpm than the diesels peak with another 50 or 100 hp.

EDIT: WTF!!!!!!! why did it come up like that? thats a half hour out of my life i'll never get back. dammit.

the whole point was that from 1988 to 1998 the 454 made its peak torque at a lower rpm than all the diesels and had 5 to 30 more ft lbs more then the diesels all ten years. It also had another 50 to 100 hp.
 
Because the real world is a lot different that what your "manual" states. Luggability, low end torque, the ability to be run hard at those #'s for long periods of time, peak HP and torque being closer together, and easily getting twice the fuel economy under the same conditions are just a few reasons people run diesels. One day, you may realize this.
 
you missed the "for towing" part of that statement. I said yes they have better off idle torque... you can run a 454 at 1600 for days....

if what i typed out came up right you would have seen that the 454 makes 385 ft lbs at 1600 rpm.... actually less rpm than the diesels peak. Even the turbo diesel 6.5 only made 380 at 1700. Really the only thing that those years of diesels have over the bbc is getting the load moving from a complete stop, longer life, and gas mileage. Even so the sm465 has somethiing like a 6.00 ratio in 1st gear. with that tranny you would have no problems getting it going.

best year for the diesels was 95... 96 for the 454.

6.5: 190 hp at 3400 rpm
380 ft lbs at 1700 rpm

mpfi 454: 290 hp at 4000 rpm
410 ft lbs at 3200

TBI 454: 230 hp at 3600
385 ft lbs at 1600



if you look at the numbers the diesels is not even close as far as hp and torque peak being close as you said.
 
Look at 96,97,and 98

454's not making peak torque until 3200 rpm, and the 6.5 still making it at 1700 rpm. The difference in peak was about 50 lbs, but 1500 rpm lower.

Funny how the 454's tq peak moved up 1600 rpm farther with nothing more than better FI.

I'd take those numbers with a grain of salt. Stick a TBI or Vortech truck on a chassis dyno and then a comparably equipped 6.5 TD truck and you'll have some data worth analysing. Numbers from the manual I don't trust, but maybe that's just me.

Look at the 6.2 in 91 and then 92. Virtually identical, in fact I don't think there were any changes to the 6.2 from 91 to 92.

In 91 it makes 155 hp at 3300 rpm and 257 lbs of tq at 2000 rpm.
In 92 it makes 150 hp at 3500 rpm and 280 lbs of tq at 2000 rpm.

Those numbers make no sense. They're in the range for a NA 6.2 but I wouldn't take either set as gospel. You're certainly not going to gain 23 lbs of tq (at the exact same peak rpm) and then make less hp at 200 rpm more...

my two cents.

Rene
 

Latest Posts

Top Bottom