The FAQs

The 350 Diesel is a Converted 350 Oldsmobile Gas engine Right?
Wrong! The 350 Diesel Is not a converted Gas is a completly different block..It isn't a gas engine with different heads or a gas engine sleeved, etc etc..There was no gas Oldsmobile engine sharing the same block. The Diesel block is specific to the diesel, it is a heftier, more solid block with stronger mains and a port in the valley for the injection pump adapter. The block is cast with a high nickle content. The 350 Diesel is not a converted gas block but can however be converted into a gas engine.

Did you know advancing the timing (statically) 5 degrees makes the engine perform alot better? Yes, but this is a quick way to blow a headgasket or bust a headbolt..back it down to 2 degrees (2 marks) and your in the safe zone. Performance can be gained through the fuel system with out over advancing the timing.

I cant find the specified oil as shown in the manual..what should I use?
I use Shell Rotella 15w40 myself..good for all year round applications

Wheren't there two other Diesels Oldsmobile made?
Yes, there was a 4.3 260 V8 (90 H.P) and a 4.3 262 V6 (85 H.P) in which where also not converted gas engines.

Is the 350 Diesel really a TRUE Diesel?
Do you see spark plugs? It runs on Diesel Fuel doesn't it?...Sure it looks similar to a 350 Gas engine, But why not? It had to run down the same assembly line and fit in under the same hood and bolt up the same. If I do recall correctly, the International 6.9L V8 Diesel, which Ford used in their light duty trucks was an engine that was infact based on a gas engine also made by International, (Click here to see my list of Diesels based on gas engines) was quite a good engine. YES it is a True Diesel.

Does the 350 Diesel share any of the same parts that the 350 Gas engine does?
While the valve covers, oil pan, water pump and oil pump, and exhaust manifolds are the same, the 350 Diesel has a different crank, pistons, rods, heads, rockers, cam, pushrods, valves, valve springs, and intake..not to mention vaccume pump, and the injection system.

Whats the average MPG with a 350 Diesel Engine?
For Me and my daily driver (1981 Pontiac Bonneville brougham 4 Door Th200 metric 3spd w/ OD) about 20 city and 40 highway (ran 200 miles through highway and city on $5 with Diesel fuel @ $1.09/ do the math!. Usually, the 4.3 V6 and V8 Diesels will get 4+ MPG over the 5.7. The 4.3 V6 definatly performs better then the 4.3 V8 when it comes to the 0-60....

Why Did they always Blow head gaskets and break head bolts?
The Factory head bolts where not strong enough to with stand operating conditions, stretching and eventually breaking naturally blowing the head gasket.

Why Did they blow the head gaskets shortly after they have been replaced?

Reusing old factory head bolts would cause them to stretch more, naturally blowing the head gasket..also, an irregular surface in the head or block that has been over looked would also assist future gasket problems.

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The 350 Diesel Page