Here's your chance to spend someone else's money.

[guy99]

My 1984 310 Limited has 105,000 miles on it. In the two and a half years we have had it we have put 30,000 miles on it. We plan to keep it indefinitely. I just put $5,000 in the suspension. I don't mind spending money to improve the performance/ reliability if it seems to be good value. I know someday soon, the engine will require major repairs or fail entirely and I'll have to decide what to do.

The performance of the 454 with the Banks Power Pack is adequate but I wouldn't want to downgrade. I get 7.5 - 8 mpg while towing our Scion.

So my questions is what would you recommend as the most cost effective solution to providing the motive force for the Silver Slug for the next 100, 000 miles?

I have thought of three broad options:
1. Retain 454 power plant - rebuilt, or re- manufactured, or a new crate engine, or ...
Perhaps add gear vendors overdrive unit, Electronic Ignition, TBI, built up transmission...
2. Stuff a newer generation gas engine/transmission ems, etc. in
3. Some sort of diesel option
I dislike the noise and smell of diesels but if I can get 40% lower fuel costs and 100,000 miles of service, it might be worth it.

Some assumptions:
The days when I was willing to do an engine swap myself have long past so I will be paying someone to do this work
Reliability is my greatest concern, next would be economy although I wouldn't want to see fuel economy go down.


So please respond with ideas (including sources and approximate costs if you happen to know)

[2airishuman]

guy99

what did you do with the suspension...me likey upgrades....

if the engine was about to crap out and the tranny was going at the same time......it would be easier to suggest a couple of drivetrain options and just do the whole thing....

more likely the tranny will need work before the engine, since you have a toad...

how many miles per year of travel....getting to the next 100k?

the newer diesels are smell less and are quieter...but not with that dogcage....

that's still the p-30 chassis right..... for easy of fitting, go for the gm crate/new tranny/rear end and do the banks upgrade again....and do a brake upgrade as well.

i don't think you will recoup the cost of a custom diesel setup with better mpg...and current fuel prices...

cheers
2air'

[Tinsel Loaf]

With a new diesel engine and drive train with a gear vendors overdrive unit
you would save on fuel and with proper maintenance you would achieve 300,000 to 500,000 miles. Would cost about $ 15 to 18 thousand installed.

[guy99]

I'll have to break out my recipe to give a detailed list but I took out the airbags in front and went with super steer springs, new steering gear, steering coupler, Koni shocks in back (I have bilsteins in front), I already have super steer bellcranks, there were a few other suspension components that needed to be replaced.

Yes it is a P30. I'm figuring 10-12,000 miles per year. A back of the envelope calculation says that if a diesel cut fuel costs by 40%, that would $12,500 saving in fuel cost. Would a diesel setup really cost as much as $12,500 plus a gas engine or two with installation?

[guy99]

Tinsel,
What engine/transmission combination are you suggesting?

[Chaplain Kent]

[quote=guy99]3. Some sort of diesel option
I dislike the noise and smell of diesels but if I can get 40% lower fuel costs and 100,000 miles of service, it might be worth it."

I stand on my soap box again as a loud supporter of the "new" diesel engines. First my old diesel was loud and smelly, the exhaust was black and nauseous. I agree with you that it is not a pretty thing. BUT there have been major improvements and my new diesel is a dream. You would not know I had a diesel engine unless I told you. It is as quiet or even more quiet than the standard 345. There is little to no odor from the exhaust and rarely do I get a shot of black smoke. I can sneak out of campgrounds in the early AM with no one knowing I am leaving. I can warm up my engine with out waking even my closest neighbor. Inside the coach we can carry on a conversation at normal volumes and even have people from the back seats join in. I play classical music on my stereo and hear all the parts. Shall I go on? Truthfully, I get more road noise than engine noise now that I made the engine swap. This spring I will be working on how to lower some of that road noise.
The draw backs to the diesel is power and the present cost of diesel fuel. However my engine is set to run on Bio- Diesel, it has all synthetic fuel lines and i use it when I can get it. The power issue is not a problem for me since I drive slowly regardless of what i am driving. My son on the other hand was a nervous wreck not being able to maintain a 65 to 70 MPH speed. I am happy at 55! I also think our coaches are safer at that speed. I have plenty of torque and can maintain that speed on any incline so I always drive a steady speed. In fact once I set the cruise control I rarely touch a pedal for miles.
You might guess that my vote is for the diesel. It will be expensive, mine cost $20,000 but it will last forever. Service is better than a gasser in that there is no tune ups and recommended oil changes are 10,000 miles and they mean it. A trucker told me he would be a fool to change his oil every 3000 miles and he had 500,000 on his engine!
Good luck with your decision, anyway you choose I am happy to hear you are keeping your classic. I could not imagine life with out mine.

[2airishuman]

chaplain kent

i agree the newer sludge burners are much nicer/quieter/cleaner and so on..

and all that torque would sure help.

very much enjoying the superduty psd....

can you describe your upgrade and how hard was the fitting.

pricey?

sure but if it's what you wanted and done right......worth every penny.

i'd sure like to see/read about your upgrades...

cheers
2air'

[Tinsel Loaf]

Diesel engines are different because of the many choices you have for your application. In doing your homework you need to look at the amount of power and torque you want compared to the compatibility of the engine compartment and drive train mounting and room. Anything can be done, but keeping it simple is best. When looking for an engine select a turbo charged model. Find a manufacturer that has a well time tested engine on the road. Go to a motorhome diesel engine rebuild shop and talk to a ‘certified mechanic’ that specializes in rebuilding motorhome diesel engines. Don’t talk to the service writer they usually have been out of the (hands on) aspect of repair and rebuild to long. Talk to a older seasoned mechanic, one that has worked on the newer style electronic diesels. There is a huge difference between the old crackle of everything mechanical and today’s electronic timing of cams, injectors and sensors that keep diesels quiet and clean burning. Check the history of recent diesel reliability in motor homes journals and by surfing the web in motorhome forums. You can find a lot of third party dealers that sell after market products and some (just a few) really know what they’re talking about. But you must whittle down your possibilities to about two. Remember a bigger engine is not necessarily a better engine. Sounds like Chaplain Kent has already been through the search, what and where did he get his. You have a lot of reading in your future, not to mention fingernail biting. Wish I could help more but I must be there and see what limitations, if any there are. Ask questions. Good luck. This reminds me that I must go change my fuel filter.

[guy99]

Chaplain Kent,
When are you going to head out my way so you can take me on a test ride?

Or, we were in Wisconsin summer of 05, maybe we'll get that way again.

Guy

[Steve Heywood]

Originally Posted by guy99

The performance of the 454 with the Banks Power Pack is adequate but I wouldn't want to downgrade. I get 7.5 - 8 mpg while towing our Scion.

So my questions is what would you recommend as the most cost effective solution to providing the motive force for the Silver Slug for the next 100, 000 miles?

I have thought of three broad options:
1. Retain 454 power plant - rebuilt, or re- manufactured, or a new crate engine, or ...
Perhaps add gear vendors overdrive unit, Electronic Ignition, TBI, built up transmission...
2. Stuff a newer generation gas engine/transmission ems, etc. in

If I were you I'd go with a GM Performance Products 502 crate motor sold as a replacement for the 454 used in trucks (320 HP-515 lb ft Torque). I'd resue the Banks headers, stock ignition, & carb but replace your stock cast iron intake manifold with an Edelbrock Performer aluminum intake. I think you'd net nearly 350 HP and end up with an engine that wouldn't work near as hard as a 454.

As for the transmission you have to decide where to most effectively spend your money. A gear Vendors OD will net you increased mileage and power in the mountains but will never come close to paying for itself. A wide ratio gearset (2.75:1 1st gear) would increase low-end punch.

[Chaplain Kent]

As some of you are aware my engine swap was not planned but the cause of a mechanic using the wrong oil filter on my old engine. I am a chaplain trained and educated in things not mechanical and can only say God was with me when Chummy was towed into Standard Truck on the south side of Chicago. This is one of the largest truck dealers in the country. My mechanic was a young man who grandparents owned an Airstream! he fully understood what this motor home meant to me. He began to rattle off numbers and statistics, turbo ratings and injector sizes. He mentioned several manufacturers, including Cummings and recommended I stay with Isuzu for the most advanced engine on the market today. Once again I was towed in here and had little time to prepare and my knowledge was scant to say the least. But I looked around at hundreds of trucks to be repaired and a mechanic who was certified in everything except making ham sandwiches and decided faith is my best guide and put my trust in Charley. I am not sorry. As for the cost the insurance company paid all but $2000.00. My original engine had 60,000 miles on it and was depreciated 20% and if that does not speak for an Isuzu I do not know what would. I can not say how hard it was to swap out other than Charley patted me on the back and told me he would take care of everything and I was not to worry. The job took 8 weeks and that included sending to Japan for an engine. If you take off the dog house in my coach everything is new right down to the hoses and wires. Charley even put on a block heater as a special present for me since we like to winter camp.
Now for you Cummings lovers out there when I picked Chummy up I had my choice of hats and did choose a Cummings hat. They are really cool but for our application I would stick with an Isuzu engine..

[swebster]

Guy,
I'm facing the same decision in the coming years. I "suspect" there are about 40,000 miles on my engine (454). I baby it and love it and fanatically monitor it because I want to extract as many miles as possible from it. Like I do compression checks at every oil change – I know – it’s a problem.

However the time will come when it's given me all it had and I'll have to replace it.

My coach however recently turned 195,000 miles and is now 20 years old. We've invested a small amount (< $4500) on repairing/improving the drive train, chassis, suspension, exhaust and engine accessories to date. I bought the coach right and we're investing more each season by updating the interior and systems to make this coach ready to serve our family for another 20 years.

We also use it a lot; we're young (late thirties) and we and plan to keep it as long as we can. (A recent trip to the RV Show confirmed for me I don't really need four slide outs). I can also see a day when my children might use it for their families – after all it is an Airstream right?

Chaplain Kent hit on another attraction for us; alternative fuels. I don’t like the volume of refined gasoline that goes into my tank. Bio Diesel, SVO, future fuels – all seem more realistic and cost competitive every year. Will there be a time when I can fill up with SVO? Well….there already is here in Louisville. Should I be planning for future fuels? Not sure, but it’s in the back of my mind when I think about this decision. Honestly, for me I think it’s about having choices in fuels. That seems like a smart idea to me.

So, I believe the diesel powered coach is the way to go.

You do need to consider that you have very limited options given the weight constraints on the P30. Cummins/Allison is a proven performer but it's heavy. (Of course there was a factory 345 with this setup for sale recently). There are also other GM options that came in the P30 (delivery van) like a turbo'd 6.2 rebuild from a donor - more of a shade tree project but kind of appealing (http://www.airforums.com/forums/f159/6-2-turbo-diesel-conversion-anyone-19271.html).

And then there is the ISUZU power plant, which Chaplain Kent and Cooperhawk have had terrific personal experience with and Airstream used on their MoHo's from the factory. It’s proven, they have service centers everywhere, parts or readily available, there are a lot of mechanics who know these engines and there is a large public knowledgebase available through books and websites about them.

I think something that's often overlooked when considering a diesel conversion is that an Airstream Moho, if properly maintained, baring any collisions should outlast three or four gas power plants. I say that because I can easily see my coach (on it’s second or possibly third engine) going another 200K miles. So if you figure $10K for a gasser R&R per pop X 4, then an ISUZU replacement should be roughly 60% - 70% of the cost for replacement over the life of the vehicle.

Of course, you will have to deal with transmissions, fuel systems conversions, cooling, generator conversion (LP?), engine mounts and about a million other things.

But I figure, if you're going to keep the coach forever and pass it down to your family then gasser replacements over the years may cost you less per replacement, but more in the long run - gas mileage aside.

OK...my flame suit is on. Fire away!

[ralley]

Taking my cue from SWebster (we haven't met, but thanks very much!!) I have begun to pull together a matrix on a spreadsheet about diesel and other engine replacements, to be posted on the Forum occasionally or sent directly to interested parties.

I am limiting it to Airstream and Argosy Class A's, simply because my time and knowledge is limited, and I haven't pulled a trailer in many years. I will be home for the next month recouperating from back surgery, and this seems a reasonable way to effectively use some of that time away from work.

My search of the forums appears to be a bit hit--or--miss, and I do not always catch useful information buried in obscure threads. I don't know why. In order to be as thorough as possible, I need forum members and moderators to direct me to forum information about repowering AS or Argosy Class A MH's which have ACTUALLY BEEN ACCOMPLISHED with diesel or other engines and transmissions (new or used) over the last, say, 10 years. Information about aftermarket ancillary stuff (cruise control, over/underdrives, etc.) will be included if provided.

My goal is to be able to provide the forum with a matrix of what has been done and by whom, boiling down the options ( and speculation) to what is actually accomplished, possible, cost effective (more or less), efficient, and dare I say--fun?

I would prefer folks contact me either privately by email or publically through the forum. Phone calls invariably catch me without paper, pencil, or brain.

Rob Alley
1991 AS 350

[guy99]

Rob,
Sounds like a very useful project, I look forward to what you find.

Steven,

Like you I am concerned about the amount of fuel which my gasser drinks and the attendant pollutants. We still use less gas per year than we did when we were working and commuting but still... I guess one question which I would love to have the answer to is whether diesels are really better environmentally I know that the particulates they spew are very bad. But perhaps the new motors are better?

On the cost side, it seems clear that if you are going to put enough miles on the rig the greater fuel economy will eventually compensate for the higher initial cost. But what about repair costs, it seems that diesels are not trouble free and parts and repairs seem to be quite a bit more expensive. Then you also need to consider the costs if you have a early demise of a diesel such as Chaplain Kent and at least one other contributor to the forum has experienced. There is no guarantee that a failure will be someone else's fault or that repair costs would be paid by a third party as was the case for Chaplain Kent.

If a mistake or bad luck causes the replacement of a gas engine, its a $4,000 bummer, if its a diesel its a $14,000-20,000 bummer.

We all hear about diesels going 300,000 miles. But I wonder if we really hear about all the times they don't go that far.

I read a couple of diesel RV forums or lists and there seem to be a lot of very expensive repairs even in the cases where you are not looking at an engine replacement.

What we need is some good TCO data.

Another consideration for me is that I'm not willing to take this on myself so I will need to hire someone to do the job. I have no idea how to find someone who can give me a good up front idea of total costs including instruments, and converting the generator, etc.

Having said all of this, I'd still like to find a practical way to achieve good reliability, durability, and economy.

Ideas?

[ralley]

guy 99 has some good points. Diesels are not perfect. Nothing is (Except my old Laborador. She, even at age 13, can tell the difference between my Mercedes diesel running half a mile away and my wife's Mercedes diesel running half a mile away. It may have something to do with the fact that my wife feeds her. I don't.)

I will leave it to the more environmentally clued in to explain why diesels, which pollute, do so differently than gasoline engines. Everything pollutes.

I should point out that I am a diesel fanatic, and I try to see the big picture. What has not been addressed here is the fact that more diesel passenger vehicles are sold in Europe than gasoline powered vehicles. In Europe, environmental standards are significantly higher than they are on this side of the pond. In some Western European countries, the authorities can force owners to replace their vehicles ( or overhaul their engines) because they cannot meet ever-increasing environmental requirements. Western Europeans are not happy about the influx of old, beat-up barely rolling gasoline junkers from Eastern Europe.

Regardless of what you may think of all of this, my point is that new diesels (even overhauled diesels) are by definition more efficent than old ones. The prospect of more environmentally friendly fuels is a definate plus, even though there are a few unique problems.

Engines Break down. I can see no benefit to replacing a gasoline thunker twice or three times instead of buying and properly maintaining 1 diesel. If it breaks, it breaks, but the average purchase and operating cost of a good new or rebuilt diesel over an average engine lifetime is significantly less than the cost of a series of gas thunkers over their respective lifetimes. All those 18 wheelers on the road are trying awfully hard to keep their costs per mile down, and they are not driving gas thunkers.

I, too will be looking for someone else to put a diesel in my vehicle. If anyone else out there finds a shop with known competence, let us all know. I will put the owner's name and phone number on the matrix for all to use.

Best
Rob Alley
1991 AS 350
Presently snowed in

[roderickm3]

Hi to all. I now have an Isuzu sitting outside . It's also sold as the Chevy and GMC I think 3500 and 4500. Mine is a 14 ft box truck. Diesels are indeed not perfect. They NEED maintanance to reach the higher mileages. I had a diesel Volvo a BEAUTIFUL car and I checked it out MYSELF MISTAKE I missed a belt out back and it's junk now... but I get the same milage on a 14 ft. box truck that some of my friends get in a large work van...... and I can haul there van IN my box...I worked on boat tankers and swore off anything diesel the smell made me sick... My truck smell a bit at start up and not at all after .So I'm surprised at the availability of isuzu diesels in the airstreams and will be looking for one when I'm replacing my Argosy.Besl o luck in th future Rod

[cooperhawk]

I drove diesel truck for a number of years and thoroughly enjoyed the response and power as well as their low cost per mile. My Father owned the trucking company and it was a hard sell to get him to buy his first diesel. I drove the old gassers for years before he capitulated and bought his first diesel just for me. Within 2 years he had no more gassers and had a fleet of diesels. The reasons are the benefits I listed above.

We now own a 345 turbo-diesel and love it. It gets up to 16 mpg and has very good power. It does smoke a little starting up on a cold morning, but that is just for a few minutes. The particulates in diesel smoke are larger than gasoline smoke and settle out quickly so they don't pollute as much. It just looks like they do.

A lot of the arguements are nonsense. When you get better mileage, go 10,000 miles between oil changes, get 4 to 500,000 miles on an engine before major overhaul, these all add up to less cost per mile. Yes, they do smell, but if you use the new bio-diesel, the exhaust smells like French Fries!

I listen to all the rhetoric about the so-called "green cars", like the Prius that brag about 30 some mpg. My Wife drives a VW Jetta diesel and it never gives us less than 40 mpg and often close to 50 mpg. We will never have to replace several thousand dollars worth of batteries either. You never hear much about that do you.

[guy99]

Suppose I wanted to have my 310 converted. What sort of vendor should I look for to undertake this change?

[cooperhawk]

That's a very good question. Here in Minnesota I would go to the kid up the road. He is a farmer and has a diesel shop and road graders on the side. He can fabricate whatever he needs in his shop and he is familier with Isuzu diesel engines.

In California I wouldn't have a clue where to go. Probably have to beat the bushes a bit.

[ralley]

My matrix now contains just (2) TWO known repower jobs. Hardly a track record to be sanguine about.

Cooperhawk: Can you please call your guy up the road and see if he is interested in doing more repower jobs, and, if so, send me his name, business address, and phone number? That might provide at least one source in the mid U.S.

Others--how about calling the shop where you get your work major done, if you don't do it yourself. Ask the same questions. Send to me. I will take on the responsibility of calling the shops to try and determine what tack record, if any, these people have. Anywhere in the US or Canada is OK.

I cannot recommend the last place to do any work on mine, although they do a lot of diesel truck maintenance--see recent posts.

PS I love the smell of diesel in the morning--it is the smell of $ staying in my pocket......

Rob Alley
1991 AS 350
Thawing out!!