New GN Owner with 87 in need of rebuild

R

RenleyRenfield

New Member
Joined
Dec 20, 2015
Hey there all!

I just acquired a 87 GN in great shape. The one stickler is that its engine is fully disassembled from a previous spun bearing.

My understanding is that the engine has been machined and all the parts are ready for re-assembly.

SO - with that said, can you guys help a newbie along with what I need to do.

I am looking to restore the car to 100% original condition.... with a few exceptions.

Normally I work on DSMs, so in that community its common to install forged internals, oil pressure upgrades and maybe cams.

Is that worth the cost for a GN? Are the OEM parts decent enough to get the car up to 100%

What are some good ideas I should take into mind for this engine rebuild?

Thanks!
 
RenleyRenfield said:
Hey there all!

I just acquired a 87 GN in great shape. The one stickler is that its engine is fully disassembled from a previous spun bearing.

My understanding is that the engine has been machined and all the parts are ready for re-assembly.

SO - with that said, can you guys help a newbie along with what I need to do.

I am looking to restore the car to 100% original condition.... with a few exceptions.

Normally I work on DSMs, so in that community its common to install forged internals, oil pressure upgrades and maybe cams.

Is that worth the cost for a GN? Are the OEM parts decent enough to get the car up to 100%

What are some good ideas I should take into mind for this engine rebuild?

Thanks!
Click to expand...


How much power you want make .. if that answer is less than 450 hp .. then the stock stuff is fine !
 
turbo89 said:
How much power you want make .. if that answer is less than 450 hp .. then the stock stuff is fine !
Click to expand...
This car is a numbers matching, original paint, mint interior, 78,000 original miles, no dents/dings/scrapes on body, etc etc... great condition.

Been sitting in a garage for 15 years waiting for the engine to be rebuilt from a spun bearing.

I am ok to add power and modify some of the parts that wont devalue such a great condition car. Since I am new to this make/model (as an owner, always have coveted them at car shows) - I have been wondering what parts those might be that I can squeeze a little more performance but not compromise the value of the car.

With that said, I am happy to go as high hp as that can get me (I am guessing that means lower than 450hp.)

( note - i do live in Colorado, a E85 producing state. So all my DSMs run E85 since its super easy to get all over, and its often easy power with less physical mods... fuel pump, injectors, updated fuel map, larger MAF flow, intake, exhaust. Does E85 play nice with Grand Nationals?)
 
RenleyRenfield said:
This car is a numbers matching, original paint, mint interior, 78,000 original miles, no dents/dings/scrapes on body, etc etc... great condition.

Been sitting in a garage for 15 years waiting for the engine to be rebuilt from a spun bearing.

I am ok to add power and modify some of the parts that wont devalue such a great condition car. Since I am new to this make/model (as an owner, always have coveted them at car shows) - I have been wondering what parts those might be that I can squeeze a little more performance but not compromise the value of the car.

With that said, I am happy to go as high hp as that can get me (I am guessing that means lower than 450hp.)

( note - i do live in Colorado, a E85 producing state. So all my DSMs run E85 since its super easy to get all over, and its often easy power with less physical mods... fuel pump, injectors, updated fuel map, larger MAF flow, intake, exhaust. Does E85 play nice with Grand Nationals?)
Click to expand...


E85 plays awesome with GN's .. visit the E85 section .... I wouldn't hesitate to run 500 hp on E85 all day long with a stocker .. total blast !

you don't need an intake .. leave the long block stock and just do bolt ons .. that way it wont devalue the car .. no reason you cant run lower 11's on a totally stock looking setup
 
RenleyRenfield said:
On pump gas, what kind of power can I safely make with stock turbo and stock throttlebody/intake/MAF?
Click to expand...


not even worth talking about ... a GN running around on pump fuel, stock turbo, stock everything else is boring ...

pump gas just neuters the car ...
If you have E85 near you don't even think twice about it .. do the conversion and turn the wick up .. totally different car on E85
 
RenleyRenfield said:
What is safe max psi on stock internals?
Click to expand...


need to be more specific with your question ..

on pump fuel ? on E85 ? on Race fuel ? on 93 and alky ?

on a stock turbo ?

Safe with a good tune or just throw on some parts and hope for the best ?

450 is safe on stock internals with a good tune and Zero knock .. I wouldn't turn it up much past that as at the 500 hp mark the tune becomes everything.. with a good tune
they can push 500 for a long time.. on a crap tune they can let go at 300 or lower
 
I have a great tuner here, so...

The idea is... on pump fuel with stock turbo, stock internals, stock trans - but with a pro dyno tune.
 
How hard is it to figure out the vacuum lines for a GN? Is there much in the way of emissions crap in the car to work through and see if its good or rotted? (car has been sitting for 15 years)
 
What you you consider devalued ?

My car just turned 45,000 miles , numbers matching engine and transmission were removed and stored. Most of the stock parts I kept in case I ever decide to go to stock again.
My car just went 6.22 @ 112 in the eighth mile on Pump gas and Alky, and there is still some left in it ...

Bryan
 
@Phoneguy - while I think it's totally amazing you hit those numbers, and that you took the time to store all the original parts...I am not looking to make this into a drag monster. I already have a 10sec quarter at 1123mph trap DSM I have sunk wayyyyyy too much into... the GN, I was just gonna sit on as a classic, yet simple rocket car.

So while I am sure I could do more, I am just looking to rebuild the engine I have, and get the car on the road. Mostly I am looking to just take take the stock car and make it quick and fun.

Thanks though!
 
I have been quoted $4000 to rebuild the engine.... then i can install it.

Sound excessive?

Then I would have to install the engine and get the car going...
 
Sorry , I don't know any in your area. If you don't mind shipping it out , Richard Clark is the most anal person I have ever met when it comes to measurements. There is a link to my build in my signature. He is in Burlington NC ...he is quite well known in our community

Bryan
 
RenleyRenfield said:
I have been quoted $4000 to rebuild the engine.... then i can install it.

Sound excessive?

Then I would have to install the engine and get the car going...
Click to expand...

To answer your question yes... You dont need any high dollar parts at all as with your stock everything build on pump fuel your not getting much over 300 hp... Easy peezy !!
 
Not a bad price but what exactly are you getting for 4k? Thats the question.

You can buy a built shortblock for around 5k. Thats with a steel crank, steel rods, forged pistons and 2 center mains. Then add shipping for both the new motor and the core back to builder. 4k not sounding so bad. As long as you are getting the same parts.

Rick
 
For $4000 I am getting a like-new running motor. I drop off the pile of 15 year old parts, and one week alter i pick up a fully running long block - all I need to do is drop it into the car and hook it up.

As for internals, the $4000 only includes the parts I have, stockers, the price could go up if I decide to buy any upgrades

Decent upgrades sound like =

- Oil squirters
- little more aggressive cams
- stiffer valve springs

The oil squirters sound really expensive, but this car did have a spun bearing that caused all this in the first place...

I have no idea how much boost the stock turbo can hold...

I also don't know how much air the stock intake manifold/throttle body/intercooler can flow...
 
You must log in or register to reply here.

Similar threads

J
Detune Engine
Replies
3
Views
690
SCOOBY DOO
SCOOBY DOO
T
Engine rebuild
Replies
16
Views
1K
Jonasterg
Jonasterg
WE2Regal
PEVR Rebuild
Replies
4
Views
611
sowle
S
D
DFW new owner (again)
Replies
3
Views
328
HotAirWH1
HotAirWH1
J
Found an 87 GN that has been sitting for 10+ years in storage..
Replies
10
Views
561
granitestategn
G
Top