engine swap opinion

[Ronbo]

Hey guys , I could use an opinion ,
I really hate the 6.2 in my 1028.. Its been a constant problem, every week its something breaking. Whats your opinion on putting a Small Block 350 in it ? Easy swap? worth the switch? Better gas than a diesel...? any majors issues when swapping? Electrical issues etc ? Just some good general info would be appreciated . Thanks

 

[jdemaris]

Hey guys , I could use an opinion ,
I really hate the 6.2 in my 1028.. Its been a constant problem, every week its something breaking. Whats your opinion on putting a Small Block 350 in it ? Easy swap? worth the switch? Better gas than a diesel...? any majors issues when swapping? Electrical issues etc ? Just some good general info would be appreciated . Thanks

A 6.2 can be made reliable, but it might not ever have the power you want. No matter what you do to it, it will always be a light-duty, short-stroke diesel.

A SB gas engine is almost a direct-fit swap. In a civilian vehicle, even the y-pipe for the gas engine exhaust fits the 6.2 diesel and the 305 and 350 gas engines. Same with the trans-mounting bolt pattern and engine mounts.
A 305 will have the same power and torque as the 6.2 and the 350 will have more power. A 400 small-block even more. But the 400 will get 10 MPG instead of 20 MPG.

If you pulled the 6.2 and wanted to put in a gas engine - you'd need the gas engine flywheel, for manual or auto trans. If a carbed engine - you'd have to adapt throttle linkage and wire in the igntion system. If a later engine with electric fuel injection, then you've got to get a computer wired in along with a electric speed sensor in the transfercase, etc. You could keep the hydroboost brake system or just stick in a vacuum booster.

With any of my 6.2 trucks, if I had the money - I'd swap to a Cummins 3.9 turbo diesel. It is MUCH more rugged then the 6.2, gets better fuel mileage, and makes the same power. They were made in "repower" kits to replace 6.2s in big vans. Not cheap though. I've never found one yet for less then $2500.

I'm wondering what all these problems are you've been having. Maybe one big and thorough checkover is all you need and fix potential problems before they happen.

I got 520,000 miles out of one of my 6.2s - a J-code in a 3/4 ton 4WD Suburban. It was very reliable, but I was careful about preventative maintenace. I'll add that I've gone to many auctions selling military 6.2 rigs. All I ever saw were in terrible shape and needed a lot of work to made reliable.

 

[southdave]

I have consider swaping in a Merc. 300 TD with a 700r4 adapter in a m1009 I have as parts truck.. 1009 boby is about 600lb than the W123 it cam out of..

 

[spicergear]

SBC swap will be fairly easy. You may need to junkyard a PS pump brackets but all in all a pretty straight forward swap. Oh, and go with an HEI distributor. All you need with them is one switched hot wire and you're ready fire. May even be able to use the solenoid switch wire on at the 6.2's IP for that.

 

[Freedive4life]

Just slap in a Two-stroke Detroit Diesel. I've done this swap many times over and it just drops in, same motor mounts and everything

 

[jdemaris]

Just slap in a Two-stroke Detroit Diesel. I've done this swap many times over and it just drops in, same motor mounts

Which Detroit are you suggesting?

I had a 3-53 in a 1/2 ton pickup and it was awful. Too heavy for the front-end, noisy,and gutless.

You'd need a 4-53 or 4-71 ot make the same power as a 6.2, and those engines weigh twice what the 6.2 does. They also don't match any GM automotive transmissions - so adapters would have to be used.

6.2 weighs around 650 lbs. Detroit 4-53 weighs 1100 lbs. and a 4-53 weighs 1800 lbs.

 

[Wolf.Dose]

The 6.2 l Diesel is better than its reputation.
The weak points are:
the injection pump,
the electrics,
the starter.
The engine itself only fails with misstreatment.
You also will fail when mistreated.
Every engine needs an understanding of its function and therefor the propper treatment.
If you only understand gas engines, forget about a Diesel.
If you only can live with a Diesel, never go to Gas.
That is the choise.
Wolf
My M715 with a 6.2 l DD is like powered with a steam engine, torque at any rpm above 1000. However, it is NOT a race truck.
Wolf

 

[Westech]

I never have had a Engine problem. I have replaced pumps, lines, water pumps.. but for 25+ years old it does not matter your going to be doing that in any engine.

 

[mrcucv]

Should be easy I havent done one myself, but the 6.2 were considered the 350 diesel. Any problems I am sure that there are many people on here that will help you out.

 

[Westech]

Should be easy I havent done one myself, but the 6.2 were considered the 350 diesel. Any problems I am sure that there are many people on here that will help you out.

The 6.2 and the Olds 350 diesel are NOT the same engine. 100% different.

 

[Ronbo]

Thanks for the replys Guys ! I am a fairly decent mechanic, But I havent got much experience with diesels.. Can I get TM 's on Ebay? I havent a clue about the motor or electrical on the truck. Gas engines chevy V8s no problem , automatic trnas overhaul no problem , But diesel thats another story. I guess I'm spoiled . I build a 1979 chevy 1/2 ton in the late 80's and with 500k miles the valve covers havent even been off, . I bought this 1028 and it seems every week is something else, , dash lites wont work , starter went out , Oil cooler lines leaking, fuel leak on the box thingy on the firewall , now that its leaking it wont start.. I wish I understood the electrical sytstem on it .. will the TM's tell how to work on the engines etc?
anyway Thanks guys for any info.. You are Greatly respected !!!

 

[Cucvnut]

they are down loadable in the wiki there is a link to where you can get them

 

[original]

500K My Arse!

 

[jdemaris]

The 6.2 l Diesel is better than its reputation.
The weak points are:
the injection pump,
the electrics,
the starter.
The engine itself only fails with misstreatment.
.

Not true. Many 6.2s develop cracks at the main-bearing webs, regardless of how well treated. Some fail by 100K and some last much longer. 200K seems to be an average fail-point. 1983-1991 #660 blocks seem to be the worse.
1982 blocks -also marked #660, seem to have less of a problem. The theory is that the first-year blocks had higher nickel content for extra strength.

Many engine rebuilders will not even accept 660 blocks for cores. The 2nd 6.2 blocks with the one-piece rear-main-seals are the ones that are preferred by many.

I don't believe anybody knows 100% for sure, why some last and some do not. In the mid 90s. GM tried to fix the problem by making the outside bolts in the main bearing caps smaller. That to leave more metal in the block to prevent cracking.

For anybody with a 6.2 that they want to keep for a long time - I suggest you pull the pan and inspect for cracks. If you see none, you can assume you're good for at least another 100K miles.

As to injection pumps and starter problems?

Most injection pump problems were fixed by late 1985 as long as you use good fuel with proper lube.

GM stopped using direct-drive Delco starters in 1988 (for civilian rigs) and that change to gear-reduction Japanese and Chinese Delcos made them much more reliable

 

[jdemaris]

500K My Arse![/QUOTE]

I would not want to use your "ARSE" as an information source for anything.

In reference to my 87 that lasted to 520K? Believe whatever you want.

I find that most 6.2s and 6.5s fail beyond repair by 220K. Not all, though.

My 87 was bought new by a friend of mine. 3/4 ton 4WD Suburban. J-code engine, 3.73 gears and T400 trans. He towed a small livestock trailer all over the USA, transporting goats. At 190K, after many repairs - it got a loud engine knock and was skipping and smoking. Thel local Chevy dealer condemend it and said the crankshaft was broken. He also told the owner it wasn't worth swapping a new engine into since all the dash-board controls were bad and would cost a fortune to fix.

So, I bought it for $150. Got it in my shop. Pulled the oil pan and it was like new inside. Ended up the engine-knock and smoking was caused by . . . broken rubber in the crankshaft pulley and bad injectors. I had it running two days later. And the "bad" dash controls? All were fine, just the vacuum pump pod on the engine was bad.

After that, I used it for many years. Everything fell apart - except the engine. I had to rebuilt the T400 trans twice. Even the splines on the rear axle stripped off (14 bolt SF rear). As rountine winter maintenance, I did two more injector nozzle changes and freshened up the pump twice.

By 500K miles, the engine sounded and drove like new. Only sign of wear was it burned near 2 qts of oil every tank of fuel (42 gallon tank).

One day, I was bringing a friend to the Albany NY airport, going down the NY Thruway at 75 MPH and . . . with no warning - no vibration - no overheating - the engine siezed. Later when I got it home on a flatbed and tore it apart, I found the crankshaft in three pieces and two main-bearing saddles in the engine torn out of the block.

By the way, that Suburban still lives. My son came here to NY from Colorado. I gave him a good running 200K engine from an 88. He stuck it in, and drove it back to Colorado. Then found out he could not pass the smoke-inspection until he installed a turbo. As of now, he has 240K on the second engine and it runs fine.

 

[91W350]

Should be easy I havent done one myself, but the 6.2 were considered the 350 diesel. Any problems I am sure that there are many people on here that will help you out.

You are not even close to correct. The 350 was a converted gasoline engine. The 6.2 was designed to be a diesel.

 

[ehuppert]

BTDT with the SBC conversion. 350 4 bolt main, mild cam, aftermarket intake and HEI. Best carb so far has been a Q-Jet, no surprise there. Some finagling is needed with the radiator hoses, but fairly simple. I bought a "towing" convertor and fine tuned the trans governor. Removed a lot of the extraneous wiring to neaten things up. Exhaust bolted right up to the manifolds. Eventually will put headers on when i have to replace the rest of the exhaust.... Power steering bracket needs replaced to fit the SBC

Bought this 1008, someone else was in the midst of converting to gas and gave up. Turned out they put a 305 in which i yanked. Also turned out that when they had run it prior (years before) they started without tranny fluid and seized the convertor to the input shaft...

The SBC makes this vehicle much simpler to maintain and eliminates a lot of electrical issues inherent to these models. After 26 yrs of service (and subsequent retirement) i have no desire to ride around or parade in MV's, (Well, unless i could drive my old 900 series for just a bit!) For all the purists, please realize i need a work/plow truck for my own use. This truck is a plow and haul monster......

The engine i would really love to put in is the 400 SBC I've got in storage. I've had that motor in numerous vehicles spanning the last 25 years. (one of which was a C30 diesel to gas convert) Alas, it really needs a complete rebuild besides the short stroke 400 probably wouldnt really care for the 4.56's

Downside to the conversion, slightly less mpgs..... Then again, diesel is quite a bit more here, so may even out dollar wise.

Eric

 

[jdemaris]

You are not even close to correct. The 350 was a converted gasoline engine. The 6.2 was designed to be a diesel.

Many have made that mistake since the 6.2 first came out. I'm glad. It's one reason why so many good 6.2s got junked with minor problems. I've gotten many for free, or close because of the undeserved bad-rap.

350 diesel has an Oldsmobile bolt pattern and won't fit any transmissions used on Chevy gas V8s or 6.2/6.5 diesels.

6.2 was made with the Chevy bolt-pattern since it was designed to be a 305 gas engine power equivalent [- with 30% better fuel mileage.

 

[jdemaris]

.
Downside to the conversion, slightly less mpgs..... Then again, diesel is quite a bit more here, so may even out dollar wise.

Eric

I think the fuel mileage difference is more then "slight."

I've got a 79 Blazer with a 400 SB gasser, T400 trans and a Chalet camper body. Best fuel mileage ever was 10.2 MPG, but 9 MPG is more common.

I've also got an 86 Blazer diesel with a 79 Chalet camper body. Weighs the same as the other. 6.2 diesel with Banks turbo and 4l60 trans. Gets 16 MPG consistently.

Right now here in central NY - pump diesel is $4.10 per gallon. Farm/off-road diesel is $3.40 per gallon and reg gas is $3.70 per gallon.

 

[Ronbo]

Correction 487K miles... I rebuilt the engine , steel crank, Forged pistons , cross drilled crank, balanced, molly plasma rings, etc ,1003 head gaskets, etc etc. 487k still runs strong. OH and Mobil 1 and dura lube !! I actually sold it to a friend who just passed away and I'm try'iin to buyt it back. Its rusted down but still hauls ARSE