Bought 2 Olds 350 engines..

[GMNorway]

Picked up two Olds 350 engines on thursday.
One of them is a 75 model with 3A heads , but the other one i was not shure what it was, couse the casting number diden't match up with anything.. But then i noticed the letters on the block saying 350D!!? Som early owner had conwerted it into a gas engine. It has J heads wich i assume is '73 - '76 455 Smog Big Block heads..
The guy i bought them from dident know what it was and thought it was a regular 350 engine. He said it ran pretty good when it was pulled from a car about 10 years ago.

So i'm a bit curious about the rest, what crank, rods and pistons that have been used. Or did they use the stock crank, pistons etc..

Anybody who knows anything about those converts!??

 

[bbcolds]

Found this on what it takes to convert a diesel to gas. Know they make a pretty stout basis for building a race engine.Believe Warren Johnson used one when small blocks were the norm in Pro Stock in the 70's.You can also put in a modified 425 crank to up the cubes to over 400(434 i think) Hope this sheds some light on what you got.

Engine has same stroke as all other small block Oldsmobile, same bore as 350 gas. Flexplate is smaller for humongo diesel starters, gas unit bolts on. If you obtain a good gear reduction diesel starter, consider using that over gas unit. Otherwise, use gas flexplate and starter together.

You will need to remove the injector drive, and plug the oil hole to the injector drive (we pulled the bearing from the block, and re-installed it where the oil hole was blocked). You have to pull the timing chain to do this. We used 350 gasoline engine timing chain, eccentric, fuel pump, front cover, and harmonic balancer. Not sure if you can use the factory diesel parts, due to different fuel pump.


#8 heads/ 4A (403) work well for this. C heads can work. EITHER set, you will HAVE to make sure the head bolt holes are drilled to 17/32nds, and you move the left- head alignment dowels in the block to a gasoline location. This involves drilling the locator in the block deck surface using the gasoline head gasket for location. You will need to plug the manifold drain at the back of the block, get a distributor (It fits right where the vacuum pump went) , use a SBO intake manifold-C heads requires the Edelbrock Performer RPM.

All of these blocks are iron, this one has more where needed, and a better grade of it.
I wish 455's were cast as well as this block was cast.

 

[snotrocket71]

yeah, you scored yourself a diesel block. not bad, wish i could find some cool olds engines around me.... not that i need anymore crap laying around...

 

[GMNorway]

Consider myselfe as lucky to get that diesel block 🙂 Great fun to dive into the odd Olds world 🙂
That engine wil be my next project after i'm finished with my ongoing engine owerhaul.

Just baught the Mondello books some other Olds engine books. Time to get serious at learn all about the Olds engine secrets.

Thanx bbcolds for adding great info. That wil help alot. 🙂

 

[79loserbluebu]

The gas 350 you have should have a nodular crank in it. That's favored over the other SBO cranks when sticking with an original SBO crank minus the 330. Not sure about the diesel, I'd imagine it'd have one too though.

 

[GMNorway]

The Nodular cranks have N stamped on them don't they?

 

[bill]

The Nodular cranks have N stamped on them don't they?

Yes...thats correct. And the D-blocks have a higher nickle content similar to the olds blocks of the 60s and early 70s

 

[GMNorway]

So will my 72 350 block have higher nickle content to? Are there any stamps/casts to tell that?

 

[79loserbluebu]

I thought higher nickle content was a bad thing? It really won't matter for a street engine. For a race engine I thought lower nickle content was preferred, that's why people building race engines shied away from the Target Goodwrench engines.

 

[bill]

From what I have been told and read, higher nickle is more brittle, but also less likely to need boring, in other words, its a harder cast. Im not sure it would make a better race engine, but it does make for a longer lasting and more durable street motor. IIRC, the army used engines with chromium/nickle blocks that would literally last forever in the 2.25 trucks back in the day.