: Reliability: Isuzu vs. Cummins



mooktank
06-22-2007, 05:08 PM
discuss...

xtrm4xjp
06-22-2007, 10:41 PM
My 4bd1 has been very reliable so far. Since I didn't have a vehicle to use as a referance at the parts store it was kind of a pain getting parts for it at first but no problems once I know what vehicle to tell them. In the dead cold of winter it would always fire up.

As for the cummins, I can't speak for a 4bt, but the 6 in my dodge has ben running like a clock since I got it. Only real issue I've had with the engine is the KDP and that was my own fault for not taking care of it sooner.

Anders

Dougal
06-23-2007, 01:17 AM
My 4BD1T has had a bad run due solely to aftermarket parts.

Aftermarket valve seals which came loose, got hammered apart and went through the oil pump.
Aftermarket rings which weren't compatible with the chrome liners (27,000km and needed a full rebuild).
Aftermarket gasket set with seals that fall apart in the presence of oil.
An air cleaner that wasn't dust tight.

Rebuild with the genuine parts and you'll have no problems.

The problems in mine started when the previous owner (my father) got it balanced and rebuilt with cast iron liners.
The engine didn't need new liners, but the local engine recondition suggested it while we had it apart for balancing.

Cue the valve seals coming apart.
Rebuild #2, courtesy of the parts maker.

This is when I got it.

I find that blowby is excessive, pull apart the aircleaner and find nothing fits properly.
Make a new aircleaner which is less restrictive, the engine can now get a cylinders full of air and produces enough blowby to lose all it's engine oil in 800km.
A fantastic example of fixing one problem and finding another.

New rings were tried (one weekend insitu rebuild). But the results weren't good enough.

3 months later rebuild #3.
Buy a piston/ring/liner set and gasket set from a well respected engine parts supplier.
Pull engine, full rebuild back to chromard liners.
Engine takes a long time to bed in, the resulting blowby pushes oil out the seals. I find the seals have gone soft, being eaten by the oil they're supposed to keep in.
Engine is pulled several times over the next year, and both crank seals are replaced with genuine items.

1 year old from rebuild #3 and the engine finally frees up, feels like it's broken back in. Blowby hasn't improved, engine smokes a little at idle.

2 years on from rebuild #3, the blowby is getting worse, the engine is starting to use oil and blows blue smoke when cold.
I made the call to rebuild it, on the last trip before rebuild it used 2L of oil in a 200km drive.
Total 27.000km from rebuild #3.

Rebuild #4.
Genuine gasket set actually costs less than the problematic aftermarket one.
I pick up an unused set of liners from a bus company, buy genuine rings but cannot buy genuine pistons seperately (only come as a matched piston/ring/liner set). Settled for aftermarket pistons.
Rebuild engine insitu, notice genuine ring set has about 1/3 of the friction of the aftermarket ones I just pulled.
Head valve guides and seals were also done (but not by me).

Start up the engine after the rebuild, within 1 minute the exhaust is clear enough to see right up. Despite the oil that was poured onto the pistons and down the bore during assembly.
Blowby is minimal, fuel economy improves by approx 20%.

Truck has done about 8,000km since rebuild #4, I've currently got the engine back out for a gearbox swap.


Often you can get away with using aftermarket parts in an engine. But for these I'd never stray from the genuine rings and gasket set.
I used aftermarket pistons solely due to getting a deal on liners and not being able to buy the genuine pistons. Aftermarkets are visually identical but I don't think I'd do it again.

JimmieD
06-23-2007, 06:54 AM
Dougal, that is simply incredible! Next time I need some lessons on patience I'll e-mail you first! Amazing indeed.

Where can I get some specs on this engine? The reason I ask is somewhat complicated: I have a 70's Iusuzu pickup, called a Chevy LUV. I'm no Chevy guy but this is a good little truck. Just doesn't have enough poop to pull the mountains around here. But, a whole bunch of guys have taken Chevy LUV's and stuffed in a GM small block [direct bolt-in, bellhousing and all], and quite a few have used a GM big block! AWESOME power of course, and with torsion bar front suspension it's no problem to add some twist for increased engine weight.

So, that makes me think about a diesel engine for this truck, more power, and still good mileage, with better reliability. Anybody have some specs or description, plus approximate engine weight?

66gaza
06-23-2007, 10:20 AM
Dougal your middle name must be perseverance, I would have weighed it in after 2nd rebuild failed.

Gaza

Wyle E. Coyote
06-23-2007, 12:58 PM
Jimmy, your answer isn't far away. The later LUV's came with a good little Diesel. I had an 82 with one and it was really good. No turbo and it made something like 58HP. Not zippy by any means, but no matter how much you hauled with it, it drove the same. Though doggy on hills, it got a constant 45MPG. Add a turbo and I think it was 85HP, IIRC. In other words, Izuzu made a little Diesel for those trucks specifically. Might be an option to consider for ya.

Dougal
06-23-2007, 04:57 PM
Dougal, that is simply incredible! Next time I need some lessons on patience I'll e-mail you first! Amazing indeed.

Where can I get some specs on this engine? The reason I ask is somewhat complicated: I have a 70's Iusuzu pickup, called a Chevy LUV. I'm no Chevy guy but this is a good little truck. Just doesn't have enough poop to pull the mountains around here. But, a whole bunch of guys have taken Chevy LUV's and stuffed in a GM small block [direct bolt-in, bellhousing and all], and quite a few have used a GM big block! AWESOME power of course, and with torsion bar front suspension it's no problem to add some twist for increased engine weight.

So, that makes me think about a diesel engine for this truck, more power, and still good mileage, with better reliability. Anybody have some specs or description, plus approximate engine weight?


Yeah my wife doesn't understand why I persevered either. But I know it's all worthwhile and refuse to be outsmarted by an engine.

That's over a 7 year period, so it's nowhere near as bad is it sounds. It also always made it home under it's own steam.
Only two occasions has it been towed, one an electrical fire, another was an oil hose that split on the alternator. Both were about 1km from home and neither was the engines fault.

The same day of that electrical fire, we had recently bought a toyota corolla as a "reliable" second car.
The corolla alternator crapped out, leaving us stranded on the side of the road for a couple of hours.


But as for reliability of the engines with factory parts, the local newspaper used a couple as their delivery trucks. They reached 500,000km before needing a piston/ring/liner set. After that they'll do it again.


The best engine for one of those LUV pickups is an Isuzu 4JB1T. 2.8L turbo four cylinder. Should bolt straight up to the old C223 bellhousing.

JimmieD
06-23-2007, 11:06 PM
Thanks for the info, Wyle. I was aware of that LUV diesel but they're rare as hen's teeth from what I can see. That's why I was wondering about this other Isuzu. The one Dougal just mentioned might be just the thing. Also I live in the mountains so this larger diesel would be much better. If I sell my Ram I might buy one, then if the LUV falls apart around it I can swap the diesel into another truck!

Elbonk
06-23-2007, 11:29 PM
Thanks for the info, Wyle. I was aware of that LUV diesel but they're rare as hen's teeth from what I can see. That's why I was wondering about this other Isuzu. The one Dougal just mentioned might be just the thing. Also I live in the mountains so this larger diesel would be much better. If I sell my Ram I might buy one, then if the LUV falls apart around it I can swap the diesel into another truck!

Yeah, There was a 4x4 with a 2wd parts rig-both diesel for sale locally. I have too much now. I'm sure its gone.. hen's teeth.

Dougal
06-24-2007, 01:49 AM
This forum:
http://www.4x4wire.com/forums/postlist.php?Cat=&Board=UBB74&page=&view=&sb=5&o=

Has plenty of info on the C223 powered troopers and pickups.

JimmieD
06-24-2007, 11:05 AM
Sorry, Mooktank, my fault, I blew it! Should have asked my question in another thread. I was asking about the same engine but didn't know how it was going to end up. I'll back out of this piracy. Sorry!

I must say though, Isuzu has been in the diesel business since at least 1920, so they don't have a whole lot left to learn. Their reputation, from what I've heard elsewhere, is excellent for reliability.

1103.9TD
07-24-2007, 05:16 AM
Hey Dougal,
Heard exactly the same recommendation from a good mate of mine, who is a respected diesel fitter from these parts, he also is an admirer of the 4BD1 & 4BD1T, owns a few himself. He also reckons, don't stuff 'round with non-genuine parts, it'll end in tears.......:) :) I'm going to stock up on some genuine kits for later, and keep the proverbials open for the odd dust-covered bargain:D :D .....

Dougal
07-25-2007, 12:51 AM
Hey Dougal,
Heard exactly the same recommendation from a good mate of mine, who is a respected diesel fitter from these parts, he also is an admirer of the 4BD1 & 4BD1T, owns a few himself. He also reckons, don't stuff 'round with non-genuine parts, it'll end in tears.......I'm going to stock up on some genuine kits for later, and keep the proverbials open for the odd dust-covered bargain:D .....

Yeah I learnt the hard way. Hopefully others can learn the easy way (from my mistakes).:)

Isuzu are still doing B series industrial engines, so spares will be around for some time yet.bounce

nhdiesel
09-24-2007, 11:19 AM
In my opinion the Isuzu engines are great, with good power and awesome reliability. I would put them very close to the 4bt in those regards. On the other hand, I don't think there is anywhere near the aftermarket/swap resources for the Isuzu motors.

I have a bit of experience with an Isuzu 4 cyl. that was in my old rollback ramp truck, a 1987 Chevy Tiltmaster (Isuzu NPR) that hauled anything I put on it, including my father's 1-ton dump truck. I even had 2 vehicles behind it, one on the body and one on a trailer behind it. We have lots of hills and mountains and it handled them fine, although I did have to slow a little when VERY loaded. Oh, and it had over 300k miles on it when it was doing this.

Jim

dieselcruiserhead
09-24-2007, 02:21 PM
I consider the 4BD a more of a lighter duty build than the Cummins. I consider them about 250K engines (should go 250K with regular maintenance) whereas I consider the Cummins a 400K engine. That said who knows and a lot varies but my engines with 150, 175K or higher from Cummins have been flawless while the Isuzus are a little more ligth duty and I have not seen them last as long, as far as pistons and internals. The good news is the Isuzus are sleeved, so easy to rebuild with little work, but at least in the US, expensive OEM parts. That said in a lot of ways I consider the Isuzu to be possibly an overall superior engine mostly because of noise, power, etc. I am on my second 4BT swap and my first 4BD swap as we speak. I obviously like both a lot.. :)

coog
09-24-2007, 04:03 PM
I think it depends on the variant.I have a 4bd1 N/A that has over 300k that runs as new.I also have several 4bd1t's that have 100 to 250k and run well.I think it is rare, however, for a 4bd2t to go even 150k.I know this because I have bought several NPR with blown up 4bd2's and replaced them with 4bd1t's.I think that anyone who is considering a swap should study this.

Dougal
09-24-2007, 07:04 PM
I consider the 4BD a more of a lighter duty build than the Cummins. I consider them about 250K engines (should go 250K with regular maintenance) whereas I consider the Cummins a 400K engine.

I know of several Isuzus in delivery trucks that were rebuilt at 500,000km (300,000miles), but I don't know what state they were in then.
One factor to consider is the Isuzus are factory rated lower than the cummins (less torque, spin faster to generate the same power). At the same torque levels I'm afraid my money would be on the cummins too.

That said, hopefully enough of us can tweak the 4BD1's to see how they handle it. With cummins it's pretty well known already. These have a big question mark.