The trend today is to go for more power and speed, but I have never been one to always follow trends, but rather do what suits my need, whether or not people think it's "cool". 5 years with my Sonoma diesel had convinced me that the Isuzu is bulletproof, if not too powerful. The old truck is getting kinda worn, and I had this lower mileage engine laying around, so....

I bought another truck to make the almost exact same conversion to - from 4.3 auto to Isuzu diesel and 5 spd. This truck is a lot better looking and a lot better shape. In some ways it was easier, such as being able to re-configure the module for the speedo so it reads correctly for tire size and rear end ratio, to more difficult where I had to completely remove the dash and make brackets to hold the clutch pedal assy in place. Overall it wasn't too bad. Compared to some of the projects some other guys in here do, it was a cake-walk. I didn't have to modify frames or body work...even the same cross-member and driveshaft worked (yea, I was surprised too).

Anyways, to keep the post short, here is a couple of pics as it looks today.



It starts better than the old truck. I hope it lasts like the old truck. <img src="/forums/images/graemlins/kewl.gif" alt="" />

Man, I love the way you present the entire completed conversion so nonchalantly in one post - I know it was a lot of work. Now if I could just finish mine (I've only had 3 years so far!). Looks good.

Let us know what MPG you get with the newer engine. Have you ever done a compression test just to see what you're workin with?
Nice ride Congrats! <img src="/forums/images/graemlins/cheers.gif" alt="" />

Thanks for the nice comments guys.

It was quite a bit of work, and I'm pleased with the results. It's much quieter than the old one - less exhaust noise and much less road noise - so instead of putting a stack on it like I thought I might at first, keeping it quiet is the plan. Stack might look tacky on this one anyway.
Gonna yank the alternator out tomorrow and dis-assemble it to tap one of the wires to the rectifier, so I can run my tach off of it. I miss having a tach. Comes in handy when pulling the trailer.

I only checked once so far, and my checks are from week to week, not tank to tank. It normally never gets below 3/4 tank before I refill. I reprogrammed a speedo control module late this week for the rear ratio and tire size, so I can't say how accurate my mileage #'s are, until I verify with a GPS, but it worked out to 42.9mpg. Remember these are Imperial gallons, bigger than US gallons. Still, if anywhere accurate, I'm pleased. Especially with fuel at $6.95 a gallon. ($152.9c/l when I filled up).
I'll keep you posted when I can verify my speedo accuracy.

ZackaryMac I have a 1982 S10 body in good shape, and 1981 Isuzu rust bucket good motor and trans, was looking to do the same swap you did, but not sure about motor mounts, the s10 had a 2.8 v6 with auto trans. what motor mounts did you use? Also what throttle cable? Was your clutch hyd or cable?
your write up was great took about 2 hours to read all the orginal.
thanks for any info and help you can give to old wore out redneck
freddie

freddie

I started out with an engine from an S10, so it fit in rather well. The S10 donor truck and the 2 I converted used hydraulic clutch (with an external slave cylinder), and I used the throttle cable from the donor truck, which actually fit in both the 1991 and 1994 with no mods. The mounts came with the engine from the S10, and also bolted right in both trucks. The holes were there and everything. I wasn't expecting that, believe me.
The S10 also used a separate vacuum pump that mounts above the alternator (you can just see the top of it in the engine picture, between the air filter housing and the upper rad hose), and they are self-lubricated. Someone said they are the same as a 6.2 used. I don't know. This means you can use whatever alternator you want. I just use a cheapie Delco alt. Kind of nice, compared to some of the expensive alternator fixes I've read about with the Isuzu set-up. I'm not knocking them, but less $$$ to do the same job isn't always a bad thing.

The only thing I can think of that MAY be a major headache is the oil pan. The GM version fits close to the cross member - so close, to remove the engine you have to take out the transmission first. It's less than an inch from the cross-member. I have never looked at the Isuzu version to know, but I thought the GM version may have had it's own oil pan to fit the chassis, which may mean different pump pick-up, etc. You'll have to have a good look and some measurements to know. The bulk of my oil pan (it's a 2 piece thing...bottom "bowl" bolted to the upper half - are they all like this?) is at the back of the engine, near the flywheel.
On the other hand, it may not be a problem at all and fit right in.


People around here still question me why I did the conversion, running such a low-powered engine, especially with diesel over $7 a gallon. It's the 40mpg, the cheap to run factor, it's certainly different, it has character that the gasser doesn't have (good, bad, or otherwise), and I built it, so it means something to me. It still gets me anywhere I want to go, just not as fast. The emphasis today is power, at the expense of economy...I like to make my own path. <img src="/forums/images/graemlins/smile.gif" alt="" /> Besides, if I need to haul something the truck can't, I can just borrow my father's 1997 Dodge ext cab diesel.

Hope this helps some. <img src="/forums/images/graemlins/kewl.gif" alt="" />

ZackaryMac
Thanks for the info, I found some motor mounts O'Riley Auto parts for a 1983 S10 the Picture looks like they will be just what I need, should be here tomorrow. The old Isuzu I have has a cable clutch and I think I can use the bracket in the S10, hope that works. the S10 had a Auto trans. so no clutch.
From what I see in the Isuzu the oil pan is the same as you described, but you said you had to put the engine and trans in separate? was hoping I could put it in together but not a real problem just more laying under truck.
the throttle cable on the S10 is too short and wrong fitting to match Ip linkage, will try to use the one from the Isuzu and make it work on the gas pedal in the S10, maybe that wont be to hard to do.
The alternator and vacuum pump are good on the old truck, but when it goes out I plan to do what you did with separate pump and GM alt.
My old truck has A/C but not Power Steering, and the S10 has Power Steering, got to make a bracket for that, does yours have Power Steering? How does it mount? Not sure I need Power Steering.
I am like you there is no where I have to be real fast so it does not matter if I drive fast or slow, and 35 to 40 MPG makes more sense with gas out the roof, I have another reason for doing this, my son makes bio-diesel from wvo, so its a lot cheaper than petro diesel, and being retired on fix income have to do all you can to save.
Again thanks for the reply, and for your write up of your swap, I read it all and got a lot of help from it.
thanks
freddie

freddie

Glad to help in any way.

Both GM/Chev trucks came with power steering, as did the diesel S10, so I used the power steering pumps that came with them. It is bolted on just above the alternator, below the vacuum pump. Both trucks came with AC, but I never hooked them up, as neither one worked anyway, and I didn't want to rob more HP for just a few weeks in the year it would be nice to have it. Wear little and open all the windows <img src="/forums/images/graemlins/lol.gif" alt="" />. No doubt down south it's more a requirement than a luxury.
Fitting in the clutch pedal assy is a bit of fun, though not too tough. Your clutch is cable, so you will need the pedal to pull the cable. You will also need a S10 assembly to fit, and since it's hydraulic, it will push (on the master cylinder rod). Might take some thinking here. Looks like somehow adapting the Isuzu clutch pedal into the Chev.

I think you'll enjoy the truck when you are done. Great too that you have a good source of biodiesel.
Feel free to ask if you think I can help.


Good luck with your project. <img src="/forums/images/graemlins/cheers.gif" alt="" />

ZackaryMac
I tried to put the engine in but will not work, the oil pan will not let the engine go froward enough, and the motor mounts that are in the chassis are wrong, I think I need the chassis pads from a 2.5 truck as the motor mounts I got from O'Reily's are listed to fit this motor too. I also wonder if this being a 82 and the first year for the S10 if GM change the frame in 84 for the diesel, don't know enough to ask right questions. Have a Picture of oil pan but don't know how to put in thread.
Thanks
freddie

freedie
As far as I know, the S10 (NOT the Luv) frames were pretty much the same from the beginning to the end (the engine compartment area). It is hard to find any of this info, as each frame would have a different part number if it had any differences from another. One web site I was at (can't remember where) figured at least to '99 had the same frames.
You likely need both halves of the motor mount: the half on the engine and the half on the frame.
The oil pan was where I was more concerned, and unfortunately it looks like my concerns were justified. This could be a major hurtle to overcome...though, if you found a junked S10 diesel engine, it may be really no issue, as you could swap the required parts.
Let me know what you come up with.

<img src="/forums/images/graemlins/cheers.gif" alt="" />