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

BigOrange90Jimmy

BigOrange90Jimmy

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I have, currently, no engine in my K5. It is stripped down to the point where I need to make a choice.

Do I want a gas or diesel engine?

If I go gas, it'll be a 350 with a 465.

If I go 6.2 diesel, it'll be with a 465.

If I go 6.5 diesel, it'll be most likely with a 465 or a 4500. (not sure if the 465 will bolt up)

If I go 4bt route, it'll be the 4500.

If I go 5.9 Cummins, it'll also be the 4500 most definitely.

FYI, I am basing my options on current petro price trends, and not having anything in it at all allows me to have whatever budget I need to get it done.

Gearing is set at 3.73 with a 35" all terrain.

Give your opinions please!
 
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IMO, if you want a bolt in deal, 6.2 and 465 is your best bet. If you don't mind a little extra work, a 4BT and 465 would be best. Slight changes to motor mounts is all that is needed from what I have heard and seen. A 5.9 would be way overkill.
 
Id go with the 6.2/465 combo. I myself run 3.73 gears and a 36" tall tire and find myself pulling drive in my 700r4 comfortably quite often, if there are any hills or headwind it hunts in and out of OD so i just leave it in 3rd. Gearing is good enough to still give you pretty good economy on the highway with enough power to lay it on the floor and pass people, slowly. Not to mention it would be a relatively cheap combo to put together, maintain, and get parts for. Plus you could run it on WVO with very little work and make your own fuel.

Or, if you are willing to spend a bit more, a 4bt/NV4500 combo would work nice, and be a pretty easy swap if you get one out of a P-30 stepvan with a SM465. A 4bt/465 would hurt on the interstate unless you got a spring kit for the pump to allow it to turn more than 2200 RPM's, but it wont make much power above that and economy wouldnt be the best. The P-30 4bt's have the correct motor mounts for a SBC/6.2 as I understand it, and the adapter plate to run either a TH400, or a 465/NV4500. The 5.9 would be severe overkill and would most likely push past the weight rating of anything less than a Dana 60.
 
Dumb question time....a P-30 is a chevy right? Can it be sourced on car-part.com? What the heck does a step van look like? I'd really like to do the 4bt swap if it's as good as everyone says it is. What kind of power could I expect from the 4bt? Would I get the good and relaxing sound of the turbo spool and the great cummins exhaust note?
 
BigOrange90Jimmy said:
Dumb question time....a P-30 is a chevy right? Can it be sourced on car-part.com? What the heck does a step van look like? I'd really like to do the 4bt swap if it's as good as everyone says it is. What kind of power could I expect from the 4bt? Would I get the good and relaxing sound of the turbo spool and the great cummins exhaust note?
Click to expand...

This is a p-30 step van....http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&category=80764&item=4535546867&rd=1

This example has a 6.2 but this is what you are after.

Also, have a look in the diesel forum...one of the stickys at the top is about swaping a cummins into a second gen..
 
Im sure it could be, but i was just informed that motor mount modifications are required. If you already have it down to the frame this may not be an issue though. And yes, the P-30 is a GM chassis.

Stock power out of a breadvan ranges from 105hp/265 torque to ~120/300. They have a LOT of potential, though. Stock in marine form they came all the way to 250/500, and they have plenty of room to grow from there. Good little motors, most internal parts are the same as the 6bt's, pretty much all they are is a 6bt with the last two cylinders lopped off. Not many differences between the two, aside from one having two less pistons. This is the motor i plan on replacing my tired 6.2 with one day, hopefully soon.

And yes, they sound almost exactly like a 6bt.
 
Step-van, Walk-in van, Value-van, breadvan..... all the same thing

http://brochures.slosh.com/1991/comm34.jpg

car-part.com doesn't list the 3.9L cummins. Although I did notice a 5.9L cummins repower for sale in Ohio when I searched for a 6.2L diesel.

There were aftermarket re-power kits. Although at some point ('91 if you go by Dremu's brochures) it became an option. Many of the used ones are from Frito-Lay vans, with an SM465.
 
If mileage isn't a concern and you aren't towing with it, I'd vote 454 all the way, but knowing what i know now having already swapped in a big block, I kinda wish i would have gone with a 5.9BT. In my opinion the only draw back the 5.9Cummins has is the initial cost of the install and the complexity of making it fit in our trucks. I personally believe it is one of the most bullet proof motors avaliable and capable of excellent millage with awsome power on tap.

So I vote: BBC or 5.9Cummins
 
Is this gonna be a daily driver? Wheeling rig? Tow rig?

We all know the 6BT is one hell of a motor, with huge power potential. The prob's I see are that the initial cost isn't going to be cheap, and I'd seriously not want anything less than a D60 underneath it. The 6.2 comes in around the BBC as far as weight and the 6BT is a lot heavier than the 6.2.

If you're after economy it's pretty hard to beat the 6.2. With 3.73's and 35's it should move out all right and return 17-18 mpg on the freeway (assuming a 65 mph cruise speed)

I love the 6.2/465 off road, on the road I would be happier with an overdrive...in town it's just fine though. Having the diesel makes it affordable enough to drive regularly.

a 6.5 TD would give you more power, and a little less mileage. Probably a fair bit more money to buy one, and might be a little more work than a 6.2 install wise.

It really just depends on how you plan to use the truck, how big the money tree in the yard is, and a million other things. I weighed my options for a few weeks and surprised myself when the 6.2 started making more and more sense. I could not keep feeding the 350 at 8-9 mpg and I HATED the carb off road...

Rene
 
I dont own one(would love too though), but I will throw in my vote for a diesel... As far as which one, depends on what you can afford. If you have deep pockets, go with the 6BT.... Lots of aftermarket support, great power out of the box, etc...

Good example..... My friend has an '01 Dodge 3/4 ton, 4x4 ext cab, shortbed with a 6bt and an auto. I drove it back from Butler, PA about 2 months ago. I averaged 18.5 MPG!!!! And the trip is mostly up hill.... Only changes he has done to it is a 4 inch exhaust from the down pipe back with a high flow muffler.

When the time comes to redo my 82 Jimmy, it will definately get a diesel.. But probably a 6.2 just because you can find them cheap! :D
 
I would do diesel also. I miss mine now. It was just neat having something a little different. I'm thinking 6.2 or 6.5TD. As joez said, you can build some power into the 6.2 With 33s, 3.08s, and TH400 I would get around 18-19mpg.
 
I was going to say pretty much what Rene did: your usage is going to determine what is going to work best for you.

For a vehicle you take on long trips, or drive a lot, I'd think the 6.2/4500 would be the best combo. Easy to install, and I would *think* the 4500 in OD cruising the freeway would net some impressive MPG with the 6.2, which would probably be very happy in OD at freeway speeds.

That'd be one of the things I'd figure out...where is your gearing/transmission/tire selection going to put you in the engines powerband in the conditions you are most likely to drive it in.

You lose nothing (strength? Not sure, seems the 4500 has SOME problems) with the 4500 over the 465, and gain OD. I don't see how you can go wrong with that transmission no matter what you choose, except the 350, which if you lug it, won't be impressive in power OR economy. Besides, the 4500 always gives you the option of lower gears without as much cruise RPM penalty for future mods.
 
You think the prices for fuel are bad now. Wait for the Federal diesel regulations to take effect in 2007. Low/no sulfur fuels are one of the big hits. That alone will make diesel fuel cost much more than gasoline due to the increased refining needed to make the cleaner fuel.

A side effect of the low sulfur/ no sulfur fuels is going to be injection pump failures. I deal with a guy in detroit that rebuilds diesel injection pumps for many types of engines (the standadyne on the 6.5 is what I deal with) and from what he has seen already sounds problematic for diesel owners in the next couple of years. He has seen areas where local refineries had already made the change to low sulfur fuels and injection pump failure rates doubled or tripled other areas. New engines built for the low/no sulfur fuels should be ok as they will be designed for it, but the older diesels will be most succeptible to problems on the new fuel. He did say that there already are fuel addtives out there to add lubricating qualities back into the fuel, Standadyne is one that makes a good one he says. The stuff is not cheap and you would have to add a bottle to every tank (best case) or at minimum every other tank of fuel.

Don't get me wrong, I think diesels are an excellent alternative to keep power and get good fuel economy, but the Feds are cracking down in the name of emissions. Ask any fleet manager with diesels in his fleet, its been all over the industry newsletters. Bottom line is in the real near future, the mileage/cost advantage the deisel engine has had will be lost. Diesels will still get good fuel economy, but fuel costs and additives needed to keep the older ones alive will cost more per mile than a gas engine. Sucks.....
 
We are getting off topic here, but I do believe that the fuel companies are going to be replacing the lubracative properties with additives before it even gets into your tank. Also, I think as the use of biodiesel goes up, and the cost of making it goes down, we will see diesel prices go down and the biodiesel should add lubrication to the fuel as well, so I think things will pan out in the near future for the good in the diesel market.
 
Didn't mean to hijack.....:grin: Anything added back to the fuel is going to drive the cost up...

Unless you are running biodiesel or reclaimed vegtable oil from Micky D's the days of really cheap diesel costs are coming to a close. (just look at european diesel cost for low sulfur fuel)

[Hijack off]

I'd go for a turbo'd 6.5 in my K5 after seeing my buddy and his 6.2 banks equipped suburban never break a sweat on the highway or off road. That thing could run under water as long as it had a snorkle to breath through.
 
tRustyK5 said:
Is this gonna be a daily driver? Wheeling rig? Tow rig?

We all know the 6BT is one hell of a motor, with huge power potential. The prob's I see are that the initial cost isn't going to be cheap, and I'd seriously not want anything less than a D60 underneath it. The 6.2 comes in around the BBC as far as weight and the 6BT is a lot heavier than the 6.2.

If you're after economy it's pretty hard to beat the 6.2. With 3.73's and 35's it should move out all right and return 17-18 mpg on the freeway (assuming a 65 mph cruise speed)

I love the 6.2/465 off road, on the road I would be happier with an overdrive...in town it's just fine though. Having the diesel makes it affordable enough to drive regularly.

a 6.5 TD would give you more power, and a little less mileage. Probably a fair bit more money to buy one, and might be a little more work than a 6.2 install wise.

It really just depends on how you plan to use the truck, how big the money tree in the yard is, and a million other things. I weighed my options for a few weeks and surprised myself when the 6.2 started making more and more sense. I could not keep feeding the 350 at 8-9 mpg and I HATED the carb off road...

Rene
Click to expand...

I'll be using the K5 for mostly highway travel, but it will occasionally be used to tow the beater truck to Uhwarrie and such. The more people post up, the better the 6.2 sounds. I would love to have it turbo charged, but I doubt that will happen when it goes in.

I wasn't aware that an NV4500 would bolt up behind the 6.2 though. That would be the hot ticket for me.

Would it work ok for the gearing I have currently though? (3.73's and 35's)

Also, where could I source a good used or freshly rebuilt 6.2? Possibly one with the turbo already installed?
 
The 35's, 3.73 and NV4500 combo would net you low to mid 20's for mileage. 1700 rpm at 65 is ideal for mileage. in 4th at the same speed you'd be turning 2350 rpm so if you're towing something it should have enough grunt to stay in 4th...

4.10's might be slighty better, or 33's...but the combo you have wouldn't be too bad.

84CUCV is giving a 6.2 away right now. If he wasn't on the opposite side of the continent I'd prolly have jumped on it already. Might want to have a look in the diesel forum...

I found my 6.2 in the local paper...

Rene
 
ZooMad75 said:
Unless you are running biodiesel or reclaimed vegtable oil from Micky D's the days of really cheap diesel costs are coming to a close. (just look at european diesel cost for low sulfur fuel)
Click to expand...

A few gallons of pre-filtered WVO dumped in the tank (K5-sized tank, that is) before a fill of low-sulfur diesel will likely add more lubricity than regular diesel ever had.
The cost difference between regular diesel and ULSD when I was in Italy last year was about 20-25 eurocents per liter. Regular diesel was around 90 cents or so per liter, and the ULSD (sold under the brand-name "BluDiesel") was about 1.15 or so per liter. Not as big a difference as you seem to be making it out to be.

Now getting back on topic...
I'm going with a 6.2 in my K5 for economy, low-speed power (yeah, I said "power" and "6.2" in the same sentence... :p: :p: ), and simplicity. Plus, I can make or acquire my own fuel to supplement the refinery's product and save even more $$$, while thumbing my nose at Big Oil.
 
if you want gas mileage get the diesel

if you want power get the gas.

sure the newer diesels will out pull gas but the old 6.2's are dogs.

As soon as you hit a hill with or without a load you'll see what i mean about the 6.2's.

IMO a 454 would be the best of both worlds tho...

the bbc had more power than all of the chevy diesels all the way from 88-98 and made more torque at a lower rpm than the 6.5td,6.5na, and 6.2.

there are benefits either way.... diesels last a LONG time.

But don't get caught up in the diesels are better than gas for towing because it all depends on what year.

the 96 mfi 454 puts the diesels of 88-98 to shame

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

every year before that to 88 it made at least 5 more ft lbs at 100 less rpm than all the diesels and a lot more hp. same goes for up to 98.

I'm not knocking the 6.2 or the 6.5 TD but if you get your hands on a manual you'll see the 454 was far supeiror than both diesels in those 10 years.
 
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