gm 350 diesel

[JR]

I aquired the engine on pallet heared run years ago in totaled olds. It sat inside five years. i bought it on a slurg because the owner needed storage space. and it sat all summer in the elements. I have a test stand so i plan to get running and tuned in.
i was wondering what oil to use. i understand sae30wt was recommends. by gm.

ken

 

[spasm3]

That sounds like a converted olds 350 or 403. I'm guessing 77-79 model. I don't think they ran that great to begin with.Interesting project, just don't put much money in it.

 

[jrustles]

Have heard legend of those engines....
hey, if it runs I'd go with nothing less than 15w40, even a C-rated 10w30 if you wanted to stick with 30, or run it in the cold. Be easy on it

 

[eljefino]

Head bolts were weak on them. ARP came out with studs that worked better.

 

[Zaedock]

Originally Posted By: spasm3
That sounds like a converted olds 350 or 403. I'm guessing 77-79 model. I don't think they ran that great to begin with.Interesting project, just don't put much money in it.


It's a wives tale that the Olds 350 gas was converted to diesel. They are two different engines. You can use a diesel block to make a kick-bum gas motor though!

Originally Posted By: eljefino
Head bolts were weak on them. ARP came out with studs that worked better.


GM used a TTY head bolt that was prone to stretching (not unlike the later Ford Powerstroke 6.0L).

 

[JR]

I have plans to it in a zr2 blazer. i have a few clean rollers with bad engines in my area for cheap.
I think a th400turbo will transmit the torque to the four corners. i would love a five speed but not sure if any bolt to the olds diesel. i am a ford guy.

the engine will get all new gaskets including head gasket s. i will replace the head bolts with strongest studs and nuts available in needed size to revolve the olds gasket problems.
remote oil filter (dual- 2qt ford filter), oil cooler with fan.
aftermarket fuel filtration, dual filter plus water separator.
new glowplugs, rebuilt or new starter.
Fleetcharge coolant. block and oil pan heaters.

ken

We used sae 30 or 40 at my cousins trucking company. he had screanin jimmys and cummins powered ford lth series tractors and dumpers. bought used I H heavy dumper double lift tags. warrenty mandated 15w40. Switched. back a few years ago, right at the end of warrenty.
he get a couple barrels at a time. i can't afford. that at the time. so i may have a hard time getting name brand sae 30 diesel.

thanks in advance

 

[DemoFly]

The only issue with these engines is that they used essentially the same headbolts and headbolt pattern as the gas variant.

ARP headbolts/headstuds make the engine more reliable, but there still isn't enough fastening locations around the head as there should be.

 

[Zaedock]

Originally Posted By: DemoFly
The only issue with these engines is that they used essentially the same headbolts and headbolt pattern as the gas variant.

ARP headbolts/headstuds make the engine more reliable, but there still isn't enough fastening locations around the head as there should be.


The diesel did not use the same head bolts as the gas.

 

[Zaedock]

Originally Posted By: JR
I have plans to it in a zr2 blazer. i have a few clean rollers with bad engines in my area for cheap.
I think a th400turbo will transmit the torque to the four corners. i would love a five speed but not sure if any bolt to the olds diesel. i am a ford guy.

the engine will get all new gaskets including head gasket s. i will replace the head bolts with strongest studs and nuts available in needed size to revolve the olds gasket problems.
remote oil filter (dual- 2qt ford filter), oil cooler with fan.
aftermarket fuel filtration, dual filter plus water separator.
new glowplugs, rebuilt or new starter.
Fleetcharge coolant. block and oil pan heaters.

ken

We used sae 30 or 40 at my cousins trucking company. he had screanin jimmys and cummins powered ford lth series tractors and dumpers. bought used I H heavy dumper double lift tags. warrenty mandated 15w40. Switched. back a few years ago, right at the end of warrenty.
he get a couple barrels at a time. i can't afford. that at the time. so i may have a hard time getting name brand sae 30 diesel.

thanks in advance



Sounds like fun, but a LOT of work and money for 125HP. You would be better off swapping in a GM CUCV drivetrain with the 6.2L diesel/SM465/NP208.

 

[Chris142]

One of the problems was no water trap for the fuel. So the pump and injectors got damaged from water. Then people would use either to get them started and that broke pistons, rings,knocked the precups out and smashed the rod bearings.
Make sure to get a filter/water trap on it somewhere.

 

[OVERKILL]

Originally Posted By: Zaedock
(not unlike the later International VT365).


Fixed that for you

 

[Garak]

I'd avoid an SAE 30 in that and stick to a 10w-30 HDEO or 15w-40 HDEO if you do intend to use that motor. That was the practice up here when they were used, and oiling was never the weak point of that motor.

An SAE 30 is more obsolete than that engine is.

 

[Zaedock]

Originally Posted By: Garak
An SAE 30 is more obsolete than that engine is.


Although I prefer a lighter viscosity for less parasitic drag, SAE30 (the $.99/gallon Delo) has performed most excellently in my applications.

 

[Garak]

I'm sure it would perform well. But, I bet it was $0.99 a gallon for a reason, and that price reinforces my view of it being obsolete.

Nonetheless, given the small sump sizes of these engines (relative to modern diesels) and the container size that one usually finds a straight grade HDEO in, that just adds to the reason not to use such a viscosity.

When you have winters like this, you realize that straight grades were obsolete before they were introduced!

 

[m37charlie]

The Delo 400 30 is not exactly "obsolete":. It has a pour point of -24F, TBN 10.2, ash 1.35%, P = 0.116%, Zn = 0.127%
In other words as good as a typical "modern" HDEO in many respects except viscosity curve.

Charlie

 

[Zaedock]

Originally Posted By: m37charlie
The Delo 400 30 is not exactly "obsolete":. It has a pour point of -24F, TBN 10.2, ash 1.35%, P = 0.116%, Zn = 0.127%
In other words as good as a typical "modern" HDEO in many respects except viscosity curve.

Charlie


Very well said!

 

[bullwinkle]

Down here in the (relatively) warm southern Midwest, the Delo 400 SAE 30 has worked well for me-but in Saskatchewan or Alaska I would use something thinner. Biggest problems with the Olds 350 diesel were weak head bolts, no water separator nor heated fuel filter (a Racor separator would solve that), and lack of power. I've heard that GM did put a 4 speed manual behind them in the 1/2 ton pickups, but they are pretty rare-and apparently there was a 4.3 liter GM diesel that was even rarer!

 

[Zaedock]

Here's some info on the Olds 350 diesel. Enjoy!


LF9 Diesel

The LF9 was a 350-cubic-inch (5.7 L) Diesel V8 produced from 1978 to 1985.
Applications;

350N 1978-1985 Chevrolet, Buick, Oldsmobile, Pontiac, and Cadillac cars
Early 120 hp (89 kW) 220 ft·lbf (300 N·m) torque
Later 105 hp (78 kW) and 205 ft·lbf (278 N·m) torque
350N 1978-1980 GMC and Chevrolet light trucks "pickups"
125 hp (93 kW) and 225 ft·lbf (305 N·m) torque
Variations;

1978-1980 Early block Identified by "D" cast into both sides of block
Up to 125 bhp (93 kW)
external EGR from 1978-1981(single stud air cleaner)
internal EGR from 1982-1985(2 stud air cleaner)
Rumored that some early main and head bolt holes were not tapped to bottom
Used a conventional flat tappet hydraulic camshaft/flat tappet hydraulic lifters which required 3000 mile oil change intervals.
1981-1985 Improved block Identified by "DX" cast into both sides of block
Up to 105 bhp (78 kW)
Internal EGR
Fully tapped head bolt holes
Longer main bolts with fully tapped holes in block
Newly introduced roller lifters/rollerized camshaft extended oil change intervals.
Diesel differences;
The Oldsmobile diesel is believed by some to be a converted gasoline engine. While they share the same bore and stroke and some external bolt patterns (transmission and exhaust manifolds) they are quite different.
GM began with a substantially different bottom end when compared with its gasoline cousin.

Diesel blocks
3" diameter injection pump mounts are cast into the top of the lifter valley
Camshaft nose modified to incorporate injection pump drive gear
Block castings are much thicker and heavier. It's possible to overbore the cylinders by 0.125in without sonic testing.
Solid heavy cast main webs were used.
Reputedly GM used a higher nickel cast iron alloy for the block and heads.
Diesel crankshafts
Nodular Iron used in all Diesel cranks
Main bearing journals increased to 3.000"
Vibration damper modified to allow eccentric for crank-driven fuel lift pump
Diesel pistons and rods
Diesel rods are shorter at 5.886" long.
Diesel pistons have large valve reliefs and steel inserts behind the first compression ring.
Fuel systems;

No OEM fuel/water separator was factory installed on any Olds Diesel.
Crank eccentric driven fuel lift pump mounted in same location as gasoline fuel pump.
Fuel line heater between lift pump and filter.
Intake mounted 10 micrometre fuel filter.
Stanadyne Roosamaster DB2 mechanical diesel injection pump.
1978-79 Pencil Injectors held in by clamp.
1980-85 Poppet injectors screw into head.
Heads;

The same 10 head bolt pattern as their smallblock gasoline cousins.
The same exhaust manifold bolt pattern as their smallblock gasoline cousins.
Have injector pre-chambers and glowplug bosses.
Valve springs contained a vibration dampener with rotators.
Head variations;
Very early castings were stamped D3 and used 5/16" injector hold down retaining bolts and clamps.
D3A castings were created a little later and used 3/8" injector hold down bolts and clamps.
Both D3 and D3A heads accepted external EGR and pencil injectors.
Some D3A heads accepted poppet injectors as well.
D3B Later heads
All had internal EGR
Pencil or poppet injectors
1 or 2 locating dowels

 

[Garak]

Originally Posted By: m37charlie
In other words as good as a typical "modern" HDEO in many respects except viscosity curve.

That's what I meant. I have nothing against its additive package or any of its other specifications.

 

[JR]

I have heard the exhust manifolds are same as gasser sbc. if it is i have a sweet set of hedman headers.
i believe it is a dx roller cam block.
i i got engine on engine stand. i have to get it set up to test run. . i have a barrel of off road at the barn so fuel tank taken care of.. i have to hook up radiator on stand to motor and fuel lines and filter/separator, and hook up wiring .

as to the ARP headbolt kit. i am shopping tommorrow for that and reseal kit just to be safe from future headaches.

Ken