How far away is a stock motor

K

keithnh

Member
Joined
Mar 8, 2016
Using a nice running 3.8 with low miles in a 77 Astre/Sunbird wagon and wondered before I bolt it in if a functional turbo setup could be installed without changing engine internals such as cam and heads. May not do turbo right away but if something is easier now to change to make this possible in the future I might. Wish I could see pictures of the whole system and possibly a functional block diagram.

Major additional component list .. my guess

Modified computer
Turbo unit
Wastegate valve
Intercooler
Exhaust system to accommodate including modified exhaust manifolds
Additional sensors needed to control turbo operation

I may install a Ken Bell #1 intake and a Holley 390cfm 4bbl and would hope it might be usable with turbo and or fuel injection, was thinking I might modify it eventually to use port injection and a dry carb.
 
GNTIM said:
You don't want to put a turbo on that motor. It will explode
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Id heard the little v6 was pretty stout. Are you saying the cylinder pressure would become such that the motor would be prone to detonation or blow the head gaskets? If so what is the difference in factory engines with turbo? Isnt there a gate thats adjustable so that boost could be limited to a sustainable level? Looking for a daily driver with some goose not a strip toy.

If you Google Kenne Bell you will find his manifolds with good reviews. Supposedly very good if not best hi-rise 4bbl for Buick v6
 
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OOOOOHHHHHHHH! .....Kenne Bell.

Stupid auto correct, right? ;)

I've been told that if you merely have a K.B. catalogue inside the car it shaves 3 tenths off your 1/4 mile time.........:D

The 3.8 Turbo Buick engine, particularly the intercooled variation is not anywhere near the same engine as a standard 3.8 GM V6 or 3800 motor. Period.
 
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That year engine won't take boost, but can be modded with the same stuff as any other motor; like cam, intake and headers.
 
The engine is an 84 3.8 out of my rwd Cutlass supreme ... I am trying to matchup with a flywheel right now. Have actually ordered one with my first Rock Auto order along with motor mounts and an intake gasket set for the Kenne Bell. Machine shop may have to match balance the flywheel. Is there a particular engine aspect that wont take boost? I have an older 350 olds v8 block that had windowed main webs, supposed to make it unsuitable for a performance build. Not sure my usage would cause that to factor in. Found in my Buick book Stage 2 blocks have numerous strengthening modifications including 2 extra head bolts per cylinder, I think if I try to boost I would at least pop heads and see if the additional bolt holes could be added. Will talk to my turbo buddy about it. If I go that far I could redo heads and change cam.
 
Just found a lower cost stainless exhaust manifold setup for GNX with 231. Was thinking this may not be a super system for a real GNX but might improve exhaust flow over a factory standard manifold setup as well as allow me to plumb in my own turbo if I choose to later. I wanted to improve the power output of the standard 231 and believe throwing a 4 bbl at it alone might just be mismatching that part unless I change the cam heads and exhaust. I can effectively change the cam alittle with 1.65 rockers and feel this exhaust might complement the 4bbl. The heads should flow more with the higher valve lift. Just a guess but the exhaust might be a sensible improvement as well as new factory shaft rockers at 1.65 if I can find them.
 
I used to own a 1968 Jeep CJ-5 with the 225 Dauntless V-6. Jeep had purchased the rights to use the odd-fire Buick V-6 for several years. With an after-market performance camshaft (unknown specs), Offenhauser manifold, Holley 390CFM 4-barrel & headers, it was a little screamer. That Jeep could scoot right over the sand dunes & roost through the mud!

Forget about a turbo & just build a nice street performance naturally aspirated engine. It will move that car just fine.

If you have to have a turbocharged Buick V-6, start looking for a complete turbo engine, or parts car.
 
~JM~ said:
I used to own a 1968 Jeep CJ-5 with the 225 Dauntless V-6. Jeep had purchased the rights to use the odd-fire Buick V-6 for several years. With an after-market performance camshaft (unknown specs), Offenhauser manifold, Holley 390CFM 4-barrel & headers, it was a little screamer. That Jeep could scoot right over the sand dunes & roost through the mud!

Forget about a turbo & just build a nice street performance naturally aspirated engine. It will move that car just fine.

If you have to have a turbocharged Buick V-6, start looking for a complete turbo engine, or parts car.
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Well the little H-body seems to have a roomy engine compartment, I think the only negative to installing the turbo ready exhaust manifold/headers would be having to install a block off plate and whatever room I would lose to accommodate the setup. It supposedly improves exhaust flow and since I was going to have someone bend a custom duals setup whichever way I go it seems to make sense to me to go forward with it unless there is something else that makes it not feasible. I do intend to follow a similar path as you did to start ... just wanted a little more performance and figured upgrade the carb, intake and cam/(with rockers) and exhaust and see what happens. Be set to add a turbo to the car if I want to or find a turbo engine ... the exhaust would serve either most likely. Am having some trouble locating 1.65 rockers for factory oem or HD shafts that I would like to stay with to control costs. Thought GNX were a different ratio ... cant find them listed in my old Sealed Power engine catalog ... just find r-870 and r-869 rockers .. performance cam cs-1112r or cs-1016r identical listings for the #38 (GM Car standard 231) and #39 (GM Car turbo 231). Wondering if anyone makes heavy duty shafts and rockers original style that are still available with the higher 1.65 ratio. Cant afford Harland Sharp although if Comp Cams had magnum roller tips I would jump on them.
 
You need to do MUCH more homework.

http://www.gnttype.org/general/v6hist.html

I have no clue what type of "GNX exhaust" you are talking about, but anything that is marketed under those terms, is most likely crap. An exhaust header system that is suited for a turbocharged application, won't work worth a damn in a naturally aspirated application.

Keep it simple. Perform your swap with the NA engine & leave it that way. An NA Buick V-6 engine & a turbocharged Buick V-6 engine are entirely different.
 
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Kiethnh, It appears that at this moment you may be biting off way more than you can chew. I believe there is much, much, much, more you need to understand about Turbo Regal motors, and what makes them work like they do, before you could consider this as an option. Please don't get discouraged. Just give it a few years of socializing in the Buick community before you waste a lot of time, energy and maybe a little money.

PS. Talking to other "motorheads" won't count for anything. Only people like the ones on this forum.
 
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Thank you for your reference material, printed it out for my build notebook. I am not claiming to be building a GNX motor. What I am doing is a project car with a stock Buick V6 that I will modify as I choose. Saying something is crap without even knowing what you are you referring to doesn't demonstrate much objectivity that I can use. It may be crap, I see Summit selling a "real" GNX exhaust manifold setup for 900+$ which is out of my price range. The stainless header type setup I see on Ebay is 209$. Looks like it will flow possibly better than the factory na manifolds which is something I needed for my na mods, at a cost not much more than replacing both of them. Probably wont work as well as factory turbo setup manifolds but again Im not doing up a GNX motor ... Im a Pontiac boy diddling with this because it happened to fall on my plate. And Im curious. Noone here has convinced me a standard 3.8 will not support a mild amount of boost in a limited rpm street application, a stage 1 block has the same amount of head bolts as a standard block .. granted the block material is stronger, an intercooler is a radiator basically between the turbo and the intake, I see no reason a standard block would not accommodate it, there are differences between standard, stage 1 and stage 2 blocks and heads but Im willing to gamble they wont affect my application in a terminal way. Have a recipe for a production turbo build using a stock block from a well known (HP Books) publisher. If it does get destroyed I will salvage what I can and build stronger next time if I choose to. I have a lifelong mechanic/weekend racer friend who specializes in turbo mods. This may eventually be my first one. If I find the 1.65's Im looking for I will post where I did as others here might be interested in that info. Apparently they are hard to find.
 
keithnh said:
Thank you for your reference material, printed it out for my build notebook. I am not claiming to be building a GNX motor. What I am doing is a project car with a stock Buick V6 that I will modify as I choose. Saying something is crap without even knowing what you are you referring to doesn't demonstrate much objectivity that I can use. It may be crap, I see Summit selling a "real" GNX exhaust manifold setup for 900+$ which is out of my price range. The stainless header type setup I see on Ebay is 209$. Looks like it will flow possibly better than the factory na manifolds which is something I needed for my na mods, at a cost not much more than replacing both of them. Probably wont work as well as factory turbo setup manifolds but again Im not doing up a GNX motor ... Im a Pontiac boy diddling with this because it happened to fall on my plate. And Im curious. Noone here has convinced me a standard 3.8 will not support a mild amount of boost in a limited rpm street application, a stage 1 block has the same amount of head bolts as a standard block .. granted the block material is stronger, an intercooler is a radiator basically between the turbo and the intake, I see no reason a standard block would not accommodate it, there are differences between standard, stage 1 and stage 2 blocks and heads but Im willing to gamble they wont affect my application in a terminal way. Have a recipe for a production turbo build using a stock block from a well known (HP Books) publisher. If it does get destroyed I will salvage what I can and build stronger next time if I choose to. I have a lifelong mechanic/weekend racer friend who specializes in turbo mods. This may eventually be my first one. If I find the 1.65's Im looking for I will post where I did as others here might be interested in that info. Apparently they are hard to find.
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I wish you success. Take it slow learn as you go.:)
 
Well thanks for the links and the constructive ideas, sorry you feel your time was wasted. While I am no professional engine builder I do have 3 customs on my plate right now I have been working for sometime and so am not completely unfamiliar with what goes on inside them. I joined this site because I have to move on this one fairly quickly and hopefully without a trip to the machine shop. It did intrigue me and I will be doing several mods on it externally I hope will be successful. Possibly they will help me with similar modifications to the others. My little hobby to keep my brain ticking. Have trouble understanding when people say the turbo block and standard block are completely different and then don't explain why. I see the differences between standard stage 1 and 2 and guess these are what they are referring to. Differences such as those between a stock Pontiac 400 or 455 2 bolt block and a SD455,RA4 or Trans Am 366 with stronger main webs, lifter valley reinforcement, forged rods provision for dry sump oiling etc. Heads were improved for high-end motors as well. The blocks are stronger and more desirable but out of reach of most people $ wise. A stock 400 block is capable of maintaining 650HP and most people's choice for a block if using a factory one. Makes a fine street/strip motor with a few mods. Stock Poncho cylinder heads can be modified to best any the factory offered and most aluminum aftermarket. Right now Im trying to stuff this Buick motor in a cute little H-body tho. Maybe use similar Buick info to make a sweet combo out of it. Like to entertain as many possibilities and use the resources at hand to do it. Not trying to ruffle anybodys feathers.
 
keithnh said:
Well thanks for the links and the constructive ideas, sorry you feel your time was wasted. While I am no professional engine builder I do have 3 customs on my plate right now I have been working for sometime and so am not completely unfamiliar with what goes on inside them. I joined this site because I have to move on this one fairly quickly and hopefully without a trip to the machine shop. It did intrigue me and I will be doing several mods on it externally I hope will be successful. Possibly they will help me with similar modifications to the others. My little hobby to keep my brain ticking. Have trouble understanding when people say the turbo block and standard block are completely different and then don't explain why. I see the differences between standard stage 1 and 2 and guess these are what they are referring to. Differences such as those between a stock Pontiac 400 or 455 2 bolt block and a SD455,RA4 or Trans Am 366 with stronger main webs, lifter valley reinforcement, forged rods provision for dry sump oiling etc. Heads were improved for high-end motors as well. The blocks are stronger and more desirable but out of reach of most people $ wise. A stock 400 block is capable of maintaining 650HP and most people's choice for a block if using a factory one. Makes a fine street/strip motor with a few mods. Stock Poncho cylinder heads can be modified to best any the factory offered and most aluminum aftermarket. Right now Im trying to stuff this Buick motor in a cute little H-body tho. Maybe use similar Buick info to make a sweet combo out of it. Like to entertain as many possibilities and use the resources at hand to do it. Not trying to ruffle anybodys feathers.
Click to expand...

Turbo Buick engines are generally interchangeable from 84-87. The cranks in these engines is the same. The NA motors are not built with these cranks. There are other differences as well. But lets stick with that for now. You cant just drop a 3.8 from some NA application from some pre-84 plain jane car, turbocharge it with a carb using mixed matched parts, and expect us to have faith in you getting it right. You are setting yourself up for heartache.

It takes a long post to explain it all. And I have no desire to live up to my reputation of writing long boring posts right now. But take my word for it. Just buy a used 86-87 Turbo Regal engine from a trashed car, get the entire set-up, turbo, headers, intercooler, computer, wire harness, everything!!!!! Then get back to us. We will guide you through every step. But you can't start this way. PLEASE TRUST US!!!!! We are not here to hurt you!
 
Why would someone ignorant about buick turbo engines ask for advice from the most knowledgeable forum on the web and then when you are given good solid proven advice that you don't want to hear argue that proof hasn't been given that an early 3.8 block is unsuitable for a turbo build? Do yourself a favor and do your homework before wasting time and money on a setup doomed for failure. Most of the guys on this site know more about the 3.8 than buick ever did. Listen to them!
 
Because In addition to accomplishing something Im trying to learn, not just blindly follow what someone else I've never met says. That way I can become less ignorant of buick turbo engines as well as learn abit about turbocharging. All 3 of my other engine endeavors have custom crankshaft modifications I am spec'ing. Not sure what the crank has to do with implementation of a low-mid rpm turbo setup. Both the chev and poncho factory engines Im doing are routinely turbocharged when they were not from the factory. The Harley not so much but it might be possible. Did you read the title of this thread I started before attempting to insult me?? Just trying to find the actual weak points that would limit the stock block. Maybe there are some issues I could address now. I don't have a stage 1 or 2, the stocker is going in.
 
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