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gyrhead

Supporting Vendor
Joined
Feb 4, 2005
Messages
353
Good Morning Folks:

I'm a relative newcomer to this forum, and the Turbo Buick as well. Some of you may have done business with my company, where as a local AC-Delco jobber we do offer some GN specific parts.

We are the proud owners of a stock 1987 GN. Owning one of these cars has been a dream of mine since 1987 - and my excitement over finally owning such a legendary car is incredible. In my opinion, this car will soon become the Hemi Cuda of our time.

GN has 160k family owned miles (brother in law bought it new) It's a rock solid, well maintained Southern New Jersey car. Underhood it's grimy/greasy beyond belief. It also is a bit tired with some blowby, loose TH2004R etc.

I recently got started on the path of making it roadworthy for the season: Complete front end rebuild, 1LE rear coil springs with custom adapters, rebuilt stock turbo, new water pump, new oil pump, timing chain and a spring cleaning.

However, I'd like to make this a company project car, using the best parts (not necessarily the most expensive) and most importantly tapping into the incredible collective knowledge here.

We want to decide on our performance objectives, concoct a workable recipe, do the work and then fully document the results on our website. In our position as a parts jobber, we can obtain most any OEM and aftermarket part at low cost, and we'll be candid about exactly what works and what doesn't.

It's our hope that this project will involve the community here, and provide a complete how-to for building a GN from the ground up. Does this sound like a worthy project? I realize there are some serious experts here that will find this project a "been there, done that" sort of thing, but perhaps those with mechanical expertise but limited Turbo Buick experience will find it useful...best part is, you get to help spend OUR money - and hear the results BEFORE you lay out the money!

The first step will be defining objectives - and to get started here's what I'm thinking:

1. Keep it looking relatively stock
2. Build a stable and reliable platform that'll run low 12's with the foundation for more (ie stout, ablse to tolerate the inevitable detonation from time to time)
3. Keep it docile, with a smooth idle, and low noise.
3. Be street and emissions legal (we're in New Hampshire)

Anyone game for this?
 
I think you are goin to get a lot of different "opinion's" .. most will want to throw $10k into it an then "maybe" run 12's :rolleyes: ok Ill start

low 12's
inj ...50 or the new 60's
stock engine that is up to snuff
chip ..turbotweek :biggrin:
Alky
Air Cleaner K&N
good rear tires ... we run drag radials
good exhaust
a good driver :p

11s
44 Turbo old tech that has been proven and proven (or maybe you can try one of the GT series)
 
Thanks Grumpy

You're in our backyard, as my shop's in Lawrence...

Let's start with stock motor getting up to snuff. Once the current projects are complete, we'll get a cranking PSI and perhaps a leakdown test. Based on earlier posts, it seems logical to expect weak valve springs. I'm hesitant to just swap springs - as this could wipe the cam.

Rather than chasing one problem after another, I'm inclined to pull the motor and rebuild it in the late summer. Given the tendency of turbo cars to detonate from time to time, am leaning towards:

1. Forged pistons - recommendations?
2. premium ring package - recommendations? gapless?
3. Strong rods, bolts - keep the stockers with ARP bolts or upgrade?
4. Premium bearings - Clevite?

Am also considering an Eagle steel crank, especially since the cost of machining the stocker makes it nearly a wash dollar wise. Thoughts? I realize lots of folks have no problems with the stock unit...

Anything to consider with the main caps? Are the stockers sufficient?
 
the oldest question ??? How fast do ya want to go :confused: :eek: :biggrin: to me put it in the low 12's high 11s and leave it alone .. drive it and enjoy the car .. wayy to easy to turn this into a $$$ pit like you would not believe :eek:
 
If the car wasn't run hard before/no noises: chances are the crank's still fine. If you're planning on going faster than 11/12's in the future: you might want to use billet main caps. TRW forged pistons/Speed Pro Plasma Moly rings don't cost much and will do fine with your current objectives. The TE44(as suggested) or a TA49/stretch intercooler(or Alky)/3" downpipe/good 2 1/2" duals(much quieter than a 3" single-shot) and a test pipe(no cat)/a good chip burned for whatever injectors you pick(42.5lbs and up)/a new fuel pump/Scanmaster(or some data logger)/3200 stall torque converter/drag radials(like Sticky Mickys)/maybe an airbag or big rear swaybar(if needed)/adjustable wastegate actuator and fuel pressure regulator. You should be in the mid 12's easily. Just get rid of that blow-by and do an overall check-up/spring update before you start beating on it! Oh- Federal Mogul 6-3755APA rod bearings are 10% wider than stock(better load carrying capacity), and don't forget to use a two piece neoprene rear main seal(Fel-Pro BS-40613).
 
my opinion

I agree, way to easy to turn into a money pit, but low 12's high 11's and a stock look don't have to be that costly. I can't remember what they all cost but here is what you will need to have.



Fuel Pump - I have Red Armstrong
Intercooler - A must
injectors - at least 42 lbs
Turbo - TE44 is proven
(older motor) Valve springs
Volt booster - Red A.
down pipe - Terry Houston
computer - To Keep from Tearing it up
Cold Air Induction

I've heard of people doing great numbers with less, but I'm in south MS where it is real humid and I think that this is a great settup and safe build for those numbers
 
Many, many guys run just fine on a fairly stock rebuild. I'ld consider some light porting on the heads. Lots of debate on the cam. Some guys are running the stock cam beyond 11s. Aftermarket ones, brands, roller, etc is way open to choices and costs. I would stick to something stockish for a mid eleven-what brand is ?. I'ld stick with the stock crank if it's not mucked up. I'ld do a dutt neck intercooler, alky and 44 with a good exhaust. I skipped the converter (I will talk to you about that ;) ) and have the Hooker cat back. Oh ya a nice chip from TT.
 
Look at the "recipes" at GnTTYpe.org, or at the RJC racing web site. RJC has a recipe for 11s, car ran 11.74 with a stock long block. Rods, pistons, rings, etc, all stock. 43 lb injectors, an upgraded stock location intercooler. K&N air filter, an RJC "power plate", upgraded fuel system. You don't have to do a whole lot to get into the low 12s. But whatever your goal, you NEED to upgrade the fuel system. Stock pump and wiring is just too marginal for "safe" use.
 
E-85

Since this car may become a co. flagship, I would consider at least having the short-block near bullet-proofed would be a good idea. especially if you need a rolling test-bed once in a while. learn all you can before makeing your decissions, and insure whoever does the block work, is familier w/the buick engines. Close tolerances are a must for longevity. As you go thru some of the posts, I'm sure you will read of some horror stories of guys putting their hard earned dough and trust in mach. shops that build chevy's and ford's, :eek: etc.
now may I make a suggestion, you know w/ the rise of fuel costs and the governments tendency to make things worse, alternate fuels are on the horizon. There was a post out recently about the E-85 fuel being experimented w/ by a group of mustang guys that were having great success. managed to produce nearly 1100hp w/ a 331cu.in. engine. might want to look into this. basic requirements were larger injectors, (I believe) teflon coated gas tank, fuel lines, and pump(hi-output). :biggrin:
 
Thanks Guys!

great stuff - all makes sense to me. I've always built my street engines with the stoutest short-blocks possible (within the limits of the finances of course)

I think short block prep is all the more vital on the Buick due to the higher than normal risk of detonation - particularly when sorting out the combination.

While streetable and reliable 12s are our immediate goal, it's funny how such performance quickly becomes old hat, then the quest for 10s begins...I think we should build the short-block with that male motorhead inevitabilty (is it in the genes?) in mind.

Since we're getting started with short block ideas, here's what I've gleaned so far.

1. TRW Forged slugs
2. Speed-pro plasma moly rings
3. Federal Mogul 3-7555APA rod bearings
4. Billet caps (for cars headed for the 10s)
5. Eagle Crank (overkill for a 12s car, a nice to have if financially justified)

How about the rods? I assume ARP rod bolts are a must?

I really do love the idea of a roller cam, for durability and reduced friction. This is an entire new can of worms, but is there a mild roller that folks have used sucessfully? Brand?

With respect to short block build, what are the things to be aware of? Are there any tips regarding clearances, oiling system mods etc?

Keep it coming guys!
 
By the way...

I'm an information junkie, so are there are any good books specific to Buick Turbo engine builds?

I've read the Kirban guide, but it's very high level - not much on internal engine build...

Tom
 
gyrhead said:
....Let's start with stock motor getting up to snuff....
You'll find three links to GM Tech articles covering the LC2 rebuilding process on the TTA FAQ List. Look at the bottom of the General Information heading for the links. :)
 
gyrhead said:
great stuff - all makes sense to me. I've always built my street engines with the stoutest short-blocks possible (within the limits of the finances of course)

I think short block prep is all the more vital on the Buick due to the higher than normal risk of detonation - particularly when sorting out the combination.

While streetable and reliable 12s are our immediate goal, it's funny how such performance quickly becomes old hat, then the quest for 10s begins...I think we should build the short-block with that male motorhead inevitabilty (is it in the genes?) in mind.

Since we're getting started with short block ideas, here's what I've gleaned so far.

1. TRW Forged slugs
2. Speed-pro plasma moly rings
3. Federal Mogul 3-7555APA rod bearings
4. Billet caps (for cars headed for the 10s)
5. Eagle Crank (overkill for a 12s car, a nice to have if financially justified)

How about the rods? I assume ARP rod bolts are a must?

I really do love the idea of a roller cam, for durability and reduced friction. This is an entire new can of worms, but is there a mild roller that folks have used sucessfully? Brand?

With respect to short block build, what are the things to be aware of? Are there any tips regarding clearances, oiling system mods etc?

Keep it coming guys!

#6 should be a Race Jace Girdle to hold that crank in
 
Today's Progress..

A lot of work today - spent some quality time in the parts washer with the front cover, valve covers, balancer, oil pan and a bunch of smaller parts. Absolutely disgusting, caked in about 1/2" of gritty, grimy goo. All nice and clean now.

The Cloyes double roller (without tensioner) goes on this week, followed by an NOS stock oil pump, new cam button, new cam sensor, AC Delco water pump and new serp. belt. Lastly, we'll install the rebuilt turbo, cleaned out intercooler and all related goodies.

Coil pack is stock, and we did have a high boost pop that consensus shows is probably ignition related. Will install a new Delco coil, Accel 300+ wires and AC plugs. Clean the TB, adjust IAC and TPS.

Then, we're gonna drive - get some vital stats and enjoy the summer. Engine project will begin later this summer.

Tom
 
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