Chevy & GMC Vans

Dead Cell wrote:also do not use platinum spark plugs with a standard ignition system (distributor) Platinum plugs are actually designed for high energy and distributorless ignition systems. The standard ignition does not produce nearly enough voltage to fire the platinum plug properly and you will take a hit in performance and mileage. A/C Delco makes a fine standard copper-core plug which should make for a nice replacement, Delco plugs are actually pretty good by my comparisons with other plugs over the years.

Actually, these vans come standard with platinums since at least 96. My truck is distributorless and won't run very well on platinums...standard coppers for it!

LiftedAWDAstro wrote: Actually, these vans come standard with platinums since at least 96. My truck is distributorless and won't run very well on platinums...standard coppers for it!

I guess it is a vehicle specific? I would almost bet the 4.3 with a distributor would benefit from the lower resistance copper... the platinum coming factory is most likely just a consumer reports/buyers guide fudge over to lower the total ownership maintenance costs.

I have been looking at astro cargo vans and I did not realize they still had a distributor system so late in the model years, anyone know what year they did away with the distributor on the Astro?

Detectorist wrote:Holy CAMOLI!!! I just got a quote from my local chevy dealer for plugs, wires, dist cap, rotor with labor.


$650.00

I'll do it my self. Insane. I almost asked her if she was on crack.

thats how they earn the rep "Stealership" and yet we bail them out over and over...

Oh crap, I must be doing something wrong I've been using platinum plugs for over a decade in my vans while getting better mileage than most. #-o

Astros or anything else with the GM 4.3L SixBC never made the switch from distributors.

ihatemybike wrote:Oh crap, I must be doing something wrong I've been using platinum plugs for over a decade in my vans while getting better mileage than most. #-o

Astros or anything else with the GM 4.3L SixBC never made the switch from distributors.

out of curiosity... have you ever tried standard copper Delco plugs and then did some comparisons?

the manufacturer was surely thinking about the 100k mile advantage when deciding to use the platinum in alot of cars that actually still have ignition cables and a distributor system. When it comes to copper, (in theory) it is about less resistance, more spark energy and less duty on the ignition system in general.

ihatemybike wrote: Astros or anything else with the GM 4.3L SixBC never made the switch from distributors.

that's a bummer for me! I am in the market and am kind of tired of the dated distributor ignition system, wires, ect. So the V8's got the coil packs but the 4.3 didn't? The only other determining issue right now with a purchase is the AWD system, the pre/post electronic transfer case dilemma is holding me up.

I need the AWD for work...

The standard replacement has been the Delco cap,rotor,wires,plugs and the service life isn't a issue as long as the user stuck to that brand.As far as the AWD part of your decision,Lifted and many others here have answers to that part.Guys on a regular bases run their vans 200,000 miles or more making a purchase of one a very wise choice.The site does support it's membership during that ownership with advise.

I haven't tried copper. To me it's not broke and the later Astros were designed with platinums going in them. Seeing how many complain about spark plug changes or don't change them at all, having 100k mile plugs sounds like the way to go.

Aside from when they are terribly worn, the distributor system works well enough. The newer V8s with coil packs are based on a different architecture than the SixBC, which was based on the traditional 350 SBC.

If you get creative it appears that the Supercharged, coil packed, GM 3800 can be adapted if you get the modified bell housing off a V6 Camaro's transmission.

As far as which transfer case to go with, having had a van with each. It doesn't matter much. They respond about the same and get the same gas mileage. Since it's for work, I'd just get the nicest running van I can find.

won't hurt to try something different... just because it's platinum does not automatically make them superior plugs. I know how enthusiast are too and I bet most of them change the plugs atleast 5 times before the 100.000 magical mile expiration date is achieved. I see you are always trying to improve your mileage numbers so that might be something new to try

I am most likely going with the 03-05 range and finding info on this site about being able to slap a NP231 in there still. I have already been debating a simple way to get individual valve cover mounted coils on there and the best system I have seen still using a dummy distributor as a base and only housing the CPS which sends the info to fire the coils would be something like 2000's model Grand Cherokee 4.0 litre. I have a 01 that I drive right now and it has a good system on it.

I also wonder why the gas mileage figures did not change with the addition of the electronic transfer cases? being it is in 2wd until needed... Guess there is always a sure fire way to improve mileage and start drilling holes and shedding weight, but actually the mileage is not looking so bad compared to alot of vans I have been looking at (full size) and I really only need the cargo capacity of the Astro... I found a 02 Sprinter here in Tysons Corner for a pretty good price, just traded in and needs some repairs, I have an opportunity to jump on that for a decent price (in their price range anyway) before repairs are done to it. I save quite a bit going with an Astro and the Sprinter mileage figures are not all they are cracked up to be (people claiming 30mpg) more like 20-22 mpg real world.

Dead Cell wrote:I also wonder why the gas mileage figures did not change with the addition of the electronic transfer cases? being it is in 2wd until needed...

In both cases (mechanical & electronic), the front driveshafts and axles are being rotated while you're on the road. When you really think about it, an electronic AWD van will probably lose traction BEFORE a 2WD (before power is transferred of course) just because it needs extra torque to overcome the inertial mass (both static and angular) of the front drivetrain components. This is not so much the case with the older style AWD because the front is receiving constant torque through the transfer case, rather than being a reactive system, although the 136 clutch preload would help with that.

Sorry for veering away from spark plugs like that but the thought just occurred to me.

timelessbeing wrote:

Dead Cell wrote:I also wonder why the gas mileage figures did not change with the addition of the electronic transfer cases? being it is in 2wd until needed...

In both cases (mechanical & electronic), the front driveshafts and axles are being rotated while you're on the road. When you really think about it, an electronic AWD van will probably lose traction BEFORE a 2WD (before power is transferred of course) just because it needs extra torque to overcome the inertial mass (both static and angular) of the front drivetrain components. This is not so much the case with the older style AWD because the front is receiving constant torque through the transfer case, rather than being a reactive system, although the 136 clutch preload would help with that.

Oh no! now I am back to thinking 97-98 #-o ...only which one performs best in the snow?

sorry for going all off topic, I have been lurking about a week and a half, not long as some others but I just wanted to chime in... I wanted to have a van by this weekend but I may be jumping the gun.

Sorry for veering away from spark plugs like that but the thought just occurred to me.

here is a little more accurate short write up about plug material, imo an enthusiast would never go platinum, on the other hand someone trying to sell you a car and using it as a plug /pun intended) -- "this here vehicular has platluminum spark plugs in it... it won't even need a tune up for a hundred thousand miles" -- :^o yeah right buddy!

Copper Spark Plugs vs. Iridium and Platinum: Understand for Top Performance

Many people come to the point where they are forced to change the spark plugs on their vehicle and face a difficult decision; copper spark plugs or those of another type? You can find spark plugs in a variety of different metal combinations, including aluminum spark plugs, iridium plugs, platinum and more. Copper core spark plugs are still the most commonly seen, however, and many people agree that they are the best. However, the advertising that accompanies the different types of spark plugs is potentially misleading, so it's important to recognize the real difference between the spark plugs in question. In order to do that, it's necessary to first learn about what the metal in the spark plug is used for.

Purpose of the Metal:
The metal in a spark plug serves a single basic purpose: to channel the electric energy from the plug wire through the spark plug so that it can be forced to the engine block in the form of a spark. Therefore, any metal that conducts electricity at all could potentially be used for a spark plug. The metal should also not get too hot; one of the main problems with some metals is that they overheat quickly, causing the electric charge itself to be compromised and the spark plug to not operate as smoothly.

Copper Spark Plugs:
Copper spark plugs are generally considered to have the best performance of any spark plug type. This is potentially different from what advertising companies suggest, but the other metals are, unfortunately, not as conductive in general as copper is. Platinum and iridium plugs are more likely to overheat, which causes damage to the plug components and can compromise the delivery of the spark to the engine block.

Platinum and Iridium Plugs:
Platinum and Iridium plugs perform at a lower level than copper spark plugs, because they are less conductive and they tend to overheat. However, the overall longevity of these two types of metal is better than copper plugs. In reality, copper has the best performance of all three and the worst longevity. Platinum has good longevity and the worst performance. Iridium has good longevity and a performance that is decent, which is why iridium plugs tend to be more expensive than any other type. Still, the difference between these plugs in terms of overall quality is minimal, as there is a trade off for each.

Most copper plugs need to be changed every 20,000 miles or so. Platinum and iridium plugs can often go for twice that before they require changing, but the overall performance will not be as good and you may have to deal with overheating of the plugs. This is potentially not worth the added cost of both platinum and iridium spark plugs, although the decision will depend upon your preference.link

platinum may be good for harry homeowner, just not the guy that usually details the engine with a toothbrush

Hmmm, well maybe I'll give coppers a chance next time. Makes me wish I could remember what I stuck in Grumpy when it had it's first full tune up at 300k. That was over 32k miles ago.

ihatemybike wrote: wish I could remember what I stuck in Grumpy when it had it's first full tune up at 300k. That was over 32k miles ago.

looks like you went with the +4's which are generally the most problematic spark plug when it is installed in a vehicle it was not designed for like alot of conventional ignition types or in recessed plug applications.

Screw all those electrodes... enthusiast index

I haven't had any trouble at all with the +4 plugs.

That was Green's last tune up, I don't spend that kind of money on Grumpy if I can help it.

I understand the indexing thing, but the +4s put the spark out in the middle which appears to eliminate the need for indexing.

ihatemybike wrote:I understand the indexing thing, but the +4s put the spark out in the middle which appears to eliminate the need for indexing.

looking at the way this cylinder head design has really not changed much over the years with the positioning of the valves, it is more likely that the extra electrodes are only reducing flame propagation... you do realize the spark is going to follow the shortest path using only one electrode to jump the gap, that is of course until that electrode wears down and the path is changed to the next closest one. It does not mean that the spark fires directly in the center.

Ignition Mechanism

The explosion of the air-fuel mixture by a spark from the spark plug is generally called combustion. Combustion, however, does not occur in an instant, but proceeds as described below. The spark travels through the air-fuel mixture from the center electrode to the ground electrode. As a result, the air-fuel mixture is activated along the path of the spark, reacts chemically (through oxidation), and generates heat to form a so-called flame nucleus. The flame nucleus activates the surrounding air-fuel mixture, which further activates the surrounding air-fuel mixture. Thus, the heat of the flame nucleus expands outward in a process known as flame propagation, to burn the air-fuel mixture. If the temperature of the electrodes is too low or the spark plug gap is too small, the electrodes will absorb the heat that was generated by the spark. As a result, the flame nucleus is extinguished, causing a misfire. This phenomenon is called electrode quenching. If the quenching effect of the electrodes is great due to the heat generated by the flame nucleus, the flame nucleus will be extinguished. The smaller the electrode is, the lesser the quenching function will be. And the squarer the electrode is, the easier the discharge will be. Some spark plugs have a U-shaped groove in the ground electrode or a V-shaped groove in the center electrode in order to improve ignitability. Those spark plugs provide a smaller quenching effect than the spark plugs without grooved electrodes, which allows the flame to form a large nucleus. Also, there are some spark plugs that reduce the quenching effect by providing thinner electrodes.
link

/Quenching