Diesels and turbocharging them. If you read my recent thread I recently drug home a Cutlass with a Olds 350 diesel motor under the hood. I have thought it might be fun to add turbos to this old diesel to boost the performance a bit intead of installing the 403. Problem is I know zip about diesel engines let alone getting more performance out of them.
Anyone have some ideas?
Just heresay but I've -heard- that the Olds 350 diesel is a terrible diesel engine.
You may cause it to give birth to metal bits and oily shrapnel if you turbo it.
But, that could be fun too!
I would do this http://www.isuzudieselswapper.com/
That engine has a compression ratio of 22.5:1 and blows head gaskets on a regular basis. Whatever you are thinking, stop right now.
The Olds diesel was based on the Olds gas engine. It ate head gaskets and warped heads like they were going out of style. A turbo would just accelerate the destruction.
Toyman01 wrote: The Olds diesel was based on the Olds gas engine.
Not really...
Turbo charge an Olds diesel ?
So...Duramax then?
Why not pull the diesel heads put gas ones on and turbo that?
rebelgtp wrote: Diesels and turbocharging them. If you read my recent thread I recently drug home a Cutlass with a Olds 350 diesel motor under the hood. I have thought it might be fun to add turbos to this old diesel to boost the performance a bit intead of installing the 403. Problem is I know zip about diesel engines let alone getting more performance out of them. Anyone have some ideas?
Save yourself the pain and suffering now. I had one. My in-laws gave it to us right before we got married when my Dakota was hit and totaled. It was a '81 Delta 88 2-door with the 350 diesel. I would have been better off walking.
93EXCivic wrote: Why not pull the diesel heads put gas ones on and turbo that?
I have thought about that as well
You can use that block with a turbocharged gas motor and make ridiculous power. Or you could sell it to an Olds guy that wants to make ridiculous power!
Those are sought after blocks in the Olds world. Here's some more info:
Just yank that diesel. It's poorly designed, the swirl chambers in the head became loose over time and fell into the pistons, the blocks had problems coping with the 22:1 comp ratio, they were a horror show to start when cold, and no, you can't just swap the heads. Your best bet is to either really baby it for the novelty/collectability (condition of the rest of the car?) or put in that 403. You will have to change the gas tank, lines, filters, anything associated with diesel fuel when you swap. Don't know about the trans--others will--but, that original 350 diesel from GM was rushed to market, and in the rushing, engineering got thrown out the window. I worked for a company that was turboing the GM 6.2 liter diesels at the time, and we looked at the 350, and after 6 months of dyno and engineering time for turbocharging, we decided against it.
One day they will become more rare, and there will be a niche market of collectors for them. If you've got an 8 car on a scale of 1-10, keep it, otherwise, get rid of it before you are stuck on the side of the road with a blown motor. Or, go crazy, bolt on a turbo and run it till it breaks....it'll be a short time.
Wow, I can't believe one still exists. Not sure I'd want to spend the money to do anything to one, but if you want to spend enough, anything is possible.
I do remember my uncle having one as a company car. They updated their entire fleet with them around 1980 or so, and 6 months later they were all gone. GM had to buy them all back or face a lawsuit from the company they were that unreliable, if I remember correctly. They were being fixed under warranty, but then they started getting billed for downtime as more than half were always in the shop at the same time.
It was a poor design rushed to market. Many were coverted to gas back when they were new, so like I say, it's amazing any exist outside of the GM museum.
Well I already have another 80 that was originally diesel but then converted to gas so I do have those parts available to me. So I seriously doubt putting in the 403 would be a huge ordeal especially compared to what some of you guys do.
It is sounding like the turbo charging of the motor as a diesel is a bad idea though maybe as a gas it would be good for a future project or sell it to put more into the car.
I have actually had a couple Olds guys be mad at me because of the whole wanting to convert the car to a gas motor because the car is now "rare". This car had the original motor swapped when new for one of the fixed diesel motors from gm.
Keep that block!!! No windowed mains like the 403 block (or the 75ish-up 350) has. And on that topic... don't try and turbo that 403 or add any other power adders either. The cranks like to leave when that happens.
tuna55 wrote:Toyman01 wrote: The Olds diesel was based on the Olds gas engine.Not really...
Yes really.
Oh yeah I would not turbo the 403 maybe add a cradle and a small shot of nitrous which I have been piecing together.
I do like the idea of building a twin turbo olds motor from the block though I would also want to go fuel injected which there was only one injection manifold built for the Olds small block motors without modifying a carb intake to do it.
rebelgtp wrote: Oh yeah I would not turbo the 403 maybe add a cradle and a small shot of nitrous which I have been piecing together. I do like the idea of building a twin turbo olds motor from the block though I would also want to go fuel injected which there was there was only one injection manifold built for the Olds small block motors without modifying a carb intake to do it.
...And I have one of those, and it's a rare aluminum one. 
Check Late 70's Caddy Sevilles at the junkyard. Multi-port fuel injection Olds 350's in those!!! Perfect for a Megasquirt conversion.
In reply to SilverFleet:
Trust me I have been looking and have not found one. In fact I got all excited to find an old Seville in the scrap yard and it was one year after they changed the motor...you wouldn't want to part with yours would you?
I'll have to think about it. 
It's a cool and rare piece, but I have been getting rid of all my Olds stuff. I can also keep an eye out for one for you, as I know a few junkyards around that might have one. What would you pay for one? It looks like this:
I also have a 1970 Olds 455 long block for sale, but I'm not sure that it would factor well into a Challenge budget, but who knows! And the fact that I'm on the other end of the country doesn't help either.
Definitely let me know if you want to sell or find another because I really want one. If I get one you can be assured an injected twin turbo SBO would be built to go in a G Body.
No clue what I would pay considering I have never found one for sale so I wouldn't know their worth to be honest with you. I have found articles on updating them for more modern setups.
PM sent your way.
bravenrace wrote:tuna55 wrote:Yes really.Toyman01 wrote: The Olds diesel was based on the Olds gas engine.Not really...
You're both right and both wrong...
The Olds 350 diesel shared the same architecture as the gas, but it was an entirely different casting. MUCH beefier. It doesn't take too much to convert the diesel to gas and then you have a pretty bulletproof gas engine. Lots of guys take the old "big block" forged cranks, turn down the mains, and make a nice forged stroker out of the 350 diesel blocks.
The 350 diesel is NOT a gas engine with different heads, it is its own casting and it was designed from the ground up as a diesel. The head gasket problems started with poor gasket design, then made worse because the warranty repair stated to re-use the old 3/8" head studs. The "easy" fix is to drill and tap for 1/2" studs, use a good quality gasket, and it will never blow again.
On the old Gmail Olds 350 diesel listserv there was a guy running 40 psi of boost from twins on a 350 diesel in an S10. He mentioned that he kept breaking things at 40 psi, but 30 psi was dead-nuts reliable. The crank is fine, the pistons are fine, the rods should be upgraded and the head gasket failure fixed.
It is a crap engine but not as bad as everyone thinks it is.
rebelgtp wrote: Diesels and turbocharging them. If you read my recent thread I recently drug home a Cutlass with a Olds 350 diesel motor under the hood. I have thought it might be fun to add turbos to this old diesel to boost the performance a bit intead of installing the 403. Problem is I know zip about diesel engines let alone getting more performance out of them. Anyone have some ideas?
Selecting diesel turbos is very similar to selecting gas turbos - find maps for them and pick the right one(s)
Diesels are throttled by fuel, so more fuel = more boost since there is more mass exiting the exhaust. Just adding a turbo alone won't really do anything for you unless you increase the fuel. Diesel output is limited by how much fuel you can fit in there up to it the point where there isn't enough air to burn it all. At that point you can add nitrous for a similar effect - it increases how much oxygen is available so you can inject more fuel.
Since diesel injection is relatively simple, there is less to change. Unlike gas where everything has to be changed to match (cam, head flow, intake type, compression, timing) a diesel is simply more air and more fuel.
One thing you can do is advance your timing a bit. OEMs kept injection timing a bit sluggish to avoid NOx emissions. Adding more advance will greatly improve cold starts, MPG, and slightly improve power.
As far as adding more fuel... I'm not good enough with the Olds diesel pumps to tell you how to do it, but it can be done.
You will have to find a way to bring down that 22:1 compression if you plan on any usable boost.
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