Isuzu Turbo Diesel

[Fred]

What are the pros and com with the Isuzu diesel? Iam looking at a 30 ft 1981 . I think I would like to try a motorhome and sell the A/S trailer. Let me knowwhat yall think.

[zduke4x]

Only know that the Isuzu has a pretty good rep.....have only heard positives but am no expert, just a motorhome follower...cost of purchase and condition were my issues in buying..diesel is more durable and better mileage....lol..jem

[alfalsetto]

I like my Diesel. I get about 14 mpg. A little short on power up hell. It a good diesel.

[ALANSD]

argreed with the above, also factor in a higher cost of maintenace than a gas engine, but less maintenance may be required if its a good one. Isusu has been long time owned by GM so parts are usually easier to find, and the duramax dielsel is made by them, so knowledge of working on those engines is almost as common as Chevy.
I would be careful to check out the motorho and trans, or have someone do it if you are not that knowledgeable. The other spots to check are suspension, air bags and all....and you already know how to spot problems with the coach part, just like a trailer in that respect.

[mike lis]

I am looking at purchaseing a 1964 Allegro 24 ft airstream motor home but unable to find any information, the engine is a GM v8 diesel these have a bad name for diesel engines here in Europe. The camper look the same as the early argosy with the curved glass sky lites help please are part available are the allegro and argosy basicly the same coach.

Mike

[swebster]

Mike,
Can you clarify for us, Allegro and Airstream are two different motorhome manufacturers here in the States and Airstream didn't start making the Argosy motorhomes until the mid seventies.

The GM V8 6.5 diesels have a reputation as dogs, non-turbo, underpowered, etc. They are however cheap, can be upgrade and came in many P30 chassis from GM.

Seems like the year, model and powerplant don't quite add up. Are you looking at a custom unit, or something retrofitted with a diesel at some point during it's history?

[Mobile1]

The main problem with the Isuzu Diesel is that the Isuzu engine service groups like International truck aren't very good or cheap. The parts are hard to get and the horsepower is on the low side. If you can find an Airstream with a Cummins you will be much better off. You can also put a Cummins into an Isuzu rig. It will give you much more power, cheaper parts, more reliable service and service centers to pick from. Joe Popsil wrote about the conversion on this forum and I personally have done it to my 280 Turbo Diesel. It works great and I can cruise around 70 at idle. Struggling up hills is a thing of the past. The only thing you have to worry about is finding a reliable mechanic to do the install. You might expect Airstream to be some help since they made this a factory option but they only support the cabin structure and not the chassy. The diesel will give you more power, great gas mileage(14 - 17), longer life, and better reliability.

[cooperhawk]

Originally Posted by Mobile1

The main problem with the Isuzu Diesel is that the Isuzu engine service groups like International truck aren't very good or cheap. The parts are hard to get and the horsepower is on the low side.

Where I live I can get parts all over the place. Different companies have whole fleets with the 6bd1 or newer engines and Allison transmissions can be purchased rebuilt right up the road from me.

I have driven Cummins, Detroit, Isuzu and Cat and haven't found any of them to deficient.

Now, for the money, I would take Cummins or Cat anytime. They cost a lot more though.

My izusu has one hundred twenty thousand miles and never had a wrench on it yet. I reckon it will go at least five hundred thousand before needing work. Spect I will some time, but right now I won't spend thosands to replace a perfectly good engine.

[Mike Leary]

Cooperhawk & other Izuzu folk: Not the case of "my moho has ZZZZK" miles
turbo is always suspect, look for white to grey smoke. Injectors should be
pulled before bragging rights expire. Filters should be checked too often.
Airstreams have a fuel metering device mounted on the passenger frame
behind the manual bleed, which can also go south. Easy fix..except in B.F.
name your state.

[ACETONE]

Hello All,
Is there anyone with an AS diesel that is/has considered converting to WVO ?
I call myself ACETONE 'cuz I use it in our '92 MB 300 TD with great success !
The MB was getting 27 MPG when we got it. Started using ACETONE plus a basic tune-up - the MPG went to 35/36 MPG - - more over the road.
i don't want you to believe me. Go google it and find out what I did.
I'm seriously thinking of converting the diesel to WVO or at least a 'blend'.
Is there anyone out there with any knowledge - experience in this area ?
Also:
The engine in our 310 '83 AS is an Isuzu 351 6 cyl. TD.
All comments are invited.

Richard

[vasellers]

To change to WVO it seems that you have to have a dedicated fuel tank for both the diesel and WVO, coolant line to heat up the WVO, a solenoid valve to turn on the WVO and turn it off, and remember to start the engine on pure diesel and make sure to turn off the WVO prior to stopping the engine.
Have to filter the WVO very very well, but that's just about it, other than making sure your supplier doesn't through too much junk in it, water, etc.
LOTS of information on the web, was thinking of doing this very thing to my wife's Jetta diesel.

[Silvertwinkie]

I too have only heard great things about the diesels placed into Airstreams.

[cooperhawk]

My brother used Bio Diesel in his over the road White Freightliner for a time. I don't remember all the specifics, but he quit using it. I believe he said the mileage wasn't as good or the power either. There was also a problem running in cold weather.

Here in Minnesota we burn a blend of Bio and regular diesel in our Jedda Diesel with no problem. I find that the Izusu runs best on good old number two diesel. Best mileage and power.

[thecatsandi]

are all the seals in your fuel system and engine of a type that can withstand acetone?

[Dansboatwork]

I have a isuzu 6bd1 and am looking for what trans and parts needed to change from 4 speed to a alison 4 speed auto my email is dansboatworks @aol.com

[Smartstream]

Welcome to the asylum. We could use a little more info. The Isuzu has a SAE #1 bell housing mount so bolting up the Allison should be easy. The Airstream supplied Isuzu used a shop made adaptor ring to mount the GM TH400/475 trans. The Isuzu retained it's flywheel, ring gear and starter. The flywheel is setup for a clutch. Airstream mounted a "spud" to the flywheel and attached a GM flexplate to connect the torque converter. I'm not sure if Allison has a means to connect a torque converter to the flywheel or if you would need to change to an Allison flexplate or fabricate a shop made adapter like Airstream did for the GM trans. If you source an older Allison the installation will be mechanical, if you use a newer Allison you will need some electronic/computer controls to make the transmission work. You will also need to fabricate a trans mount and modify the driveshaft. I believe Airstream/Isuzu all had 4 wheel disc brakes and a trans mounted parking brake so you will need a parking brake on your Allison.

The above assumes you have an Airstream with a TH400/475 trans. You mention a 4 speed so you may have a totally different set up. If so ignore the above. Good luck.

[JohnTF]

I would 2nd / 3rd or whatever for the Cummins as #1 .
Isuzu is far better than the GM diesel in that timeline .

WVO is just wrong in the long run , too many issues and will not let a fuel system live long .
WVO is some combination of heating , filtering , additives etc. and a lack of PH balancing , not addressing water as much and the list goes on .

Bio-diesel on the other hand is the correct use - transesterification of any plant based oil , including use vegetable oil - as a base .

I've been a mechanic for a living for decades , and studied bio-diesel with universities & farmer coops , and made it & used it .

[2smoker]

My 85 6bd1T loves B20 diesel
(74 24’ argosy w/6bd1/t hx35 intercooled
Allison 545
With wide cam torque conv. 3.21 gears)

[2smoker]

Originally Posted by 2smoker

My 85 6bd1T loves B20 diesel
(74 24’ argosy w/6bd1/t hx35 intercooled
Allison 545
With wide cam torque conv. 3.21 gears)

Earlier post wanted to know about putting Allison 545 behind Isuzu 6bd1
As AS motorhome’s with 6bd1’s came with TH400/475 putting an Allison in couldn’t be easier , as torque converters 400/475 to Allison are interchangeable,NOT recommended, so all that is really needed is to remove the adapter for Th400/475.
My 6bd1t w/Allison 542 has a 1” spacer between engine and trans.
As stated by another you will have to come up with some kind of trans mount.
I had to rebuild drive shaft as Allison universal’s are way bigger, 3 different sizes that I’ve run into so far.
kick downs are also a bit tricky. There are 3 of those also.
There are also 4 different torque converters, I started with a 270 wide cam, worked good enough, but grenaded it!
(wrong oil, kick down not hooked up right not sure why it happened?)
Now have 290hd works way better for climbing with turned up 6bd1t (35psi boost)
Can climb grades at 60, not as fast as some 454’s, but not too many people are going to complain about only holding 60 on a climb, (little black smoke but not obnoxious)!