Turbo 350 Oldsmobile build.

[theoldsone]

So I wanted to start a build thread on building an Oldsmobile 350 Turbo. I have an Olds 350 pulled from a 76 Olds cutlass brougham. So there not windowed mains. With obvious specs like 8a heads cast everything...etc. I thought I wanted a future N/A engine but I think if its worth any thing id be more into a turbo'd gbody.

So all the parts I had in mind to build a W30 350 out the door.

I am definitly not going to go all in at once. As everyone knows not every thing goes as expected when building engines.

So specific parts im going to need help locating are
1. Decent exhaust mnifolds for a T/C Olds350
2. A turbo specific cam designed for T/C Olds350
3. Heads? 8a heads are good because they have lower comp ratio. But I loose some +points due to poor flow.

I dont plan on using tons of boost to make power (8psi) so other areas would have to be the power adders.

 

[L92 OLDS]

This is not a new subject. A few thoughts here that may help you. Boosting a carbureted engine is a difficult task. GM couldn't seem to get it right either. Computer management is key for your success and is one of the reasons why everyone wants to slap a turbo on junk yard LS truck engines.. I wouldn't do it any other way with an Olds motor. Putting fuel injection and computer management on an old school SBO is a cool idea but will be very expensive and time consuming not to mention the fact that it will require some serious skill to do it right. FYI,...the W30 designation was for a big block Oldsmobile. The W31 was a small block.

 

[olds307 and 403]

You could get BBO W/Z manifolds and flip them upside down. Sanderson and Hedman make shorty headers that would also work. A cheap TBI off a sbc 350 has a knock sensor. The knock self has a specific torque that needs to be followed. You can use an Olds 307 CCC distributor for timing control. Just get a bored 350 TBI or a 454 TBI with adjustable regulator. You need to use the 350 injectors. The factory regulator just needs a spot weld ground out to expose the hex screw. The 454 also uses different sensor connections than the later 350 TBI. The 454 flows about 250+ cfm more, 490 vs 670 cfm. The 94-95 computer is the best TBI computer. You also need either a Monte 4.3 TBI or Buick Turbo fuel tank or a good inline electric pump putting out at least 15 psi. Much less than the aftermarket kits but still expect close to $1000 with a used turbo.

 

[theoldsone]

You could get BBO W/Z manifolds and flip them upside down. Sanderson and Hedman make shorty headers that would also work. A cheap TBI off a sbc 350 has a knock sensors, just use an Olds 307 CCC distributor. Just get a bored 350 TBI or a 454 TBI with adjustable regulator. You need to use the 350 injectors. The factory regulator just needs a spot weld ground out to expose the hex screw. The 454 also uses different sensor connections than the later 350 TBI. The 454 flows about 250+ cfm more, 490 vs 670 cfm. The 94-95 computer is the best TBI computer. You also need either a Monte 4.3 TBI or Buick Turbo fuel tank or a good inline electric pump putting out at least 15 psi. Much less than the aftermarket kits but still expect close to $1000 with a used turbo.

I thought about a blow through carburetor. A nice blow through carb is at least $1000. And for the hassle of rigging up a efi sytem im not too crazy about that. Carbs can do great if you do it right. Oh and yes I did see some hedman shortys. They would work if I flipp them around. I would like to have a top mount turbo much like a buick's. Good thing about turboing through a carb does not require a intercooler like a efi system would. Thats $ and weight saved. A good and easy set up I think would be using two shorty headers flipped. One side runs down and around to meet up right between the header and turbo between the header and turbo fab up a pipe to merge the two manifolds and at the end of it a flange to connect the turbo.

 

[theoldsone]

This is not a new subject. A few thoughts here that may help you. Boosting a carbureted engine is a difficult task. GM couldn't seem to get it right either. Computer management is key for your success and is one of the reasons why everyone wants to slap a turbo on junk yard LS truck engines.. I wouldn't do it any other way with an Olds motor. Putting fuel injection and computer management on an old school SBO is a cool idea but will be very expensive and time consuming not to mention the fact that it will require some serious skill to do it right. FYI,...the W30 designation was for a big block Oldsmobile. The W31 was a small block.

Thanks I get w31 and w30 mixed
Hear me out im not building a backyard hackjob. And Ls engines are too too common and in fact maybe boring? I mean you could walk into a car show with 1000 cars and see 100 lsx swaps 25 being turboed id say. But how many olds 350 turbo? Supercharged maybe 1 lol turboed...no. Im not playing "I want to be different" card here 8) I just want to know what it felt like when the wright bros. took that first flight over 852 feet. You know what im trying to say.

 

[theoldsone]

If I by all costs the carb I know will be a tackle. EFI systems $$$ twice as much than a carb. What I am thinking is since I do not intend this engine to run 8s all over the place, I am only looking for a durable turbo setup. 8psi in my opinion doesent sound like its out of this world to run on a carb. But at the same time I would like to treat this engine as if it where in your daily driver. Turn key and go. And thats where my considerations come in for efi. I dont mean taking a heap of 4-5 gm cars and making a Macgyver efi system. It just doesent float my boat. Now I know holley make TBI units. Run boost/NOS it doesnt matter now thats a real nice kit. 2k yea :| 2,000 american dollars. But it gives me what I ask for and thats a price I can pay. If I do go down that route its going to take me MAJOR time making the $$ for the build.
There she is

 

[pencero]

This all sounds ridiculous to me. A turbo just doesn't belong on an Oldsmobile. It would be much cheaper to just buy a complete 3.8 turbo from a wrecked GN and cut to the chase with it's proven reliability than to waste several thousand more dollars only to arrive at a fractional amount more horse power while most likely having very bad reliability / safety (stalling out all the time during test runs at first) ...

 

[pencero]

Before you proceed trying to build this you should watch some of the documentaries on youtube of the countless thousands of hours of research and development that actually went into making the 3.8 turbo work. It took thousands of hours of crunching numbers. Obviously today it wouldn't take nearly as much time with what we know now but consider the fact you are just 1 guy not a team of geeks with endless hours to devote to this project. Even a professional racing team with years of experience would have a hard time conquering some of the obstacles you may encounter on this pursuit. It would definitely make a better track car than a daily driver if you do get it together. For a daily driver it would be horrible. Only a wide open track or dragstrip even has enough tarmac to take advantage of a properly turbo'd 350 anyway. Look at what 4 and 6 cylinder turbo's can do so imagine getting everything lined up right on the 350. Definitely a beast that should only be unleashed at the track. It would have so much unpredictable loopy boost that you would not even be able to drive it in rush hour traffic without rear ending someone by mistake...

 

[pencero]

save at least $2,500 and years of anguish. If you just get that EFI system to work that alone would wake the 350 olds up enough that it would feel like a turbo in comparison to a stock qjet... it would probably run thousands of miles - without breaking down or overheating all the time like a turbo does if you try to drive it daily!

 

[pencero]

Yeah I just re-read this thread again. I would be quick to point out the wright brothers crashed at least 12 times before their success; you only have 1 car to play with and 1 w-30 block to experiment on. I highly doubt anyone who has gone through the time and effort of setting that EFI system up properly would advise you to taint it's reliability with the additional outside variable of a turbo. Then again, we only live once and it would be cool to see something new on here for once. Who am I and who is anyone; but I'd be quick to say that the olds 350 is a fantastic engine close to stock. Why take a chance on messing something good up when there are so many cheaper engines to experiment with a turbo system on. People 'slap' turbos on ls and 305's because if that breaks you can just go buy another one who cares. Try finding a nice w-30 block for cheap again. They are not for sale at LKQ for a few hundred bucks anytime like a 305 or an LS might be...