Bought '86 GN last year, learning but somebody been in it already

hensleyt

Well-Known Member
Joined
Feb 20, 2008
Was the rear main a rope seal ? Was the bearings GM? Looks like a unopened 109 on the bottom. The heads look not ported but just a cleanup, not your normal exhaust port work you usually see. I would use studs.
Keep up the good work
 

scgnx2

Active Member
Joined
Jan 24, 2009
Using studs around the cylinder bores provides a better clamping force and more accurate torque readings compared to bolts.
 

Daniel454SS

Member
Joined
Jun 6, 2020
below are three links to threads about clearances. keep in mind the open ended answers that it depends upon the application for the engine. sometimes the conversation veers off course and gets heated and off topic when one person can be referencing a street build engine while another if referring to a purpose-built race engine.

Main bearing clearance...

Bearing Clearance

Bearing Clerance
Thanks, I have read a couple of those and other made for good reading as well, think I still have similar idea for the clearances as a guideline for MAX before tearing more into anything, hope to plastigage them tomorrow evening if I get the time

Was the rear main a rope seal ? Was the bearings GM? Looks like a unopened 109 on the bottom. The heads look not ported but just a cleanup, not your normal exhaust port work you usually see. I would use studs.
Keep up the good work
Thats what I am thinking since the car itself is just in 66-67k miles (cant recall have to check), but someone definitely did some mild work.
Not too sure if the bearings are GM, will take some pics if I get some time to work on it tomorrow.
doing my nest to keep plugging away at it ;)

Using studs around the cylinder bores provides a better clamping force and more accurate torque readings compared to bolts.
@hensleyt @scgnx2
Is there any down side other then cost when going with studs?
I think I remember reading something about hitting headers or having to grind areas?????

I plan for this to be capable of being my daily driver for short periods if needed so do not want to take anything away from drivability.
Most likely 90mile total round trip once a day for 5 days but only every month or 2 is the commute it would make while I get my work truck serviced.
 

scgnx2

Active Member
Joined
Jan 24, 2009
Thanks, I have read a couple of those and other made for good reading as well, think I still have similar idea for the clearances as a guideline for MAX before tearing more into anything, hope to plastigage them tomorrow evening if I get the time


Thats what I am thinking since the car itself is just in 66-67k miles (cant recall have to check), but someone definitely did some mild work.
Not too sure if the bearings are GM, will take some pics if I get some time to work on it tomorrow.
doing my nest to keep plugging away at it ;)


@hensleyt @scgnx2
Is there any down side other then cost when going with studs?
I think I remember reading something

I plan for this to be capable of being my daily driver for short periods if needed so do not want to take anything away from drivability.
Most likely 90mile total round trip once a day for 5 days but only every month or 2 is the commute it would make while I get my work truck serviced.
Thanks, I have read a couple of those and other made for good reading as well, think I still have similar idea for the clearances as a guideline for MAX before tearing more into anything, hope to plastigage them tomorrow evening if I get the @hensleyt @scgnx2
Is there any down side other then cost when going with studs?
I think I remember reading something about hitting headers or having to grind areas?????

I plan for this to be capable of being my daily driver for short periods if needed so do not want to take anything away from drivability.
Most likely 90mile total round trip once a day for 5 days but only every month or 2 is the commute it would make while I get my work truck serviced.

Well, if your motor was using the stock factory head bolts they need to be replaced. The OEM bolts were torque to yield and should not be reused. ARP has or had headbolt/stud kits specifically for Turbo Buick’s. Not aware of any issues with them other than early headbolt kits that required an extra washer on a certain bolt. Certainly one of the vendors on this forum or ARP themselves should be able advise you.
 

Daniel454SS

Member
Joined
Jun 6, 2020
Dang didn't realize its been since the 4th that I had been in here, been crazy with work again, worked on some house projects before going out of town for cousins wedding. Just got back Monday and finally getting back into the groove of things here at work.

I still haven't gotten around to plasti-gaging my bearings, yeah I know I am slacking....

So I got in the correct timing set from TA performance while I was out of town.

Figured I would go back over some of the parts I ordered this last year since I found some old invoices

Installed:
ScanmasterG, Powerlogger, Turbosmart Vac/boost gauge and silicone lines, RJC boost Control and PCV valve, Tinman CAI, 2 good working OE MAFs, Taylor sparkplug wires, Denso O2 sensor, Caspers Cam tool, fuel psi gauge

NOT Installed YET....
Turbotweak 6.1 chip with 60# injector combo, innovate wideband o2

Precision 6262e turbo(standard actuator), Precision SLIC, PTC converter spec'd to match turbo

TAperformance: stainless headers and crossover, 9-key silent timing et (just got in right one), oil pump assembly, timing gaskets

RJC: Powerplate, Cam sensor repair kit, 3" down pipe, CAT delet pipe, 3" crossflow exhaust, rocker shaft supports, HD motor brace
rear main seal kit, oil pan gasket kit, turbo gasket set, front cover gasket set, valve cover gaskets

comp 980-12, comp-4753 valve spring shims, BTR spring height tool, OTC 4573 spring compressor, Bluegrass Performance valvespring tool, melling CB100 cam button

So plan was originally get things running right, then add my chip/injectors and up the boost a little... then decided to snow-ball things to going 6262 and after getting it good on low boost add and alky kit and start upping boost from there....

well stuff changed and here we are, and the plan is still changing....
NEXT POST COMING UP.....
 

Daniel454SS

Member
Joined
Jun 6, 2020
I am sure I am forgetting stuff on last post but will add them as I remember or go through boxes... literally.

So I have built a ton of small and big block chevys but keep seeing that the turbo Buick should not be taken to machine shops or builders who will treat it like a sbc.... AKA people like me :D , but I have been doing learning, alot of reading and seems like other then oil setup that the clearances are the main difference which I don't mind taking time to setup.

As for tuning I have done plenty of race tuning from suspensions, carbs, as well as efi on sbc/bbc into 9's (not really impressive times but live well and great daily drivability). My truck drives over 100 miles round-trip to track, runs 10's on motor and is tame enough my wife drives it around town.

Just to be clear I want something reliable and reasonably quick (subjective, I know), but my budget from where I was last year and literally all of my project have been on hold since the end of last year and just getting rolling
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my belair was supposed to have frame off and back under it and be going to paint in April with GN to follow, I still haven't touched it... so yes I am behind. Truck has new trans just waiting for me to install (truck and belair both run but I don't want to take apart with my other 2 cars apart, camaro just needs engine bay and hood painted before installing engine).

So I would like to take advantage of the parts I have and get "OPTIMUM" power out of them and as much as I would like to eventually work my way to a low 11 sec time slip; I am in no rush to get to it and I am told trans should be built to hold it.

I hope this would be able to make it, but if not I would rather keep this shortblock stock and slowly build a stroker down the road as funds allow.

Now If this is close to meeting my needs with turbo and all parts I currently have would it be a good idea to just save up for a few months (guessing close to $1800-$2000) and...
get +.010 forged pistons then either do
206/206 (or larger???) roller cam along with getting heads set up and possibly more porting
>>>>>OR<<<<<
Go with a RJC girdle, line bore and ARP main studs (stock crank/rods)

Ideally I know build it all would be the best idea but not in the cards at this time, and I don't mind pulling it in 3-4 years or so to swap it out once I have a beast or a short or long block built.

hey and thanks for all the help and taking the time to read my chapters I am posting here
 

Daniel454SS

Member
Joined
Jun 6, 2020
Looked into heads a little... sadly they are not ported, just port matched. :rolleyes:
So leaves room for improvement, I messaged champion and am looking into them redone and ported by them hopefully.
we will see.
pulled the cyl3 intake valve to see what was issue and seems like it may just be due to carbon deposits, nothing major, lapping probably would solve but plan it getting ported now.
valve sizes are Intake:1.71 Exhaust:1.49
Valvesprings look identical to comp980 I have and were installed at 1.680
If I remove valvespring I only get .488 before my retainer hits seal so definitely need some work there if I plan to ever go with a cam.
interestingly the spring pocket is pretty wide if I put my large spring height tool in there upside down (knurled side down) it still has room and that thing is 1.495 diameter :oops:

Will see what champion says and at this point looking into getting heads done with porting and setup for roller cam(leaning toward roller 206/206 or 206/210).

Need to also keep looking into into about a good forged piston, hoping with some good airflow, lighter piston that is balanced to stock rotating assembly with ARP studded mains it should hold well for some low 11's and not break the bank.... but still planning and reading ;)

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Daniel454SS

Member
Joined
Jun 6, 2020
ok so last night got home and ended up pulling off my rear main to check out the rear main seal and also the rear main clearance.

The rear bearing is GM , but the rear seal had already been swapped out and does not seem to have been leaking, so probably could have just swapped out the pan gasket and called it good.

I need to pull cam but the lifters (flat tappet) seem just a bit past broke in, forgot to get pics but will take some tonight and try to pull cam also.

honestly reconsidering doing pistons now at this point and leaving the stock short-block alone. Then just buying a block to build as soon as I can find one and start buying parts for that once this engine is running.

That way I can spend on Champion doing my heads right (maybe port stock intake also) and getting a proper roller cam setup and whatever else may arise afterward. Plus once I build a beast of a shortblock everything I add on to this stock shortblock should be able to swap over.
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The short block feels smooth as can be and everything feels really tight so I now feel pretty confident in it, depending on what champion quotes me I will either send off my heads or wait to get a set of their complete heads.
If i save enough by sending in my heads I will most likely also send my intake to get ported as well.

I would like a reliable stoplight to stoplight cruiser that can make around 500-550 torque to the wheels and make a low 11 pass once a year (after dot radials, tuning and suspension work of course) and I usually drive my cars once a month unless my daily is getting worked on in which case I may drive or rotate 2 of my cars for my commute (90mile round trip/day).
 

~JM~

Wrinkled Member
Joined
Oct 31, 2007
Might look into TA Performance heads also. Probably can't go wrong with either, more a matter of who can supply the parts in a timely fashion.
 

Daniel454SS

Member
Joined
Jun 6, 2020
Was the rear main a rope seal ? Was the bearings GM? Looks like a unopened 109 on the bottom. The heads look not ported but just a cleanup, not your normal exhaust port work you usually see. I would use studs.
Keep up the good work
you were exactly right
rear seal redone, yes GM bearings, unopened bottom end. and not a full port just cleaned up port

planning to go studs now, plan still unsure on gaskets since I may just leave short block alone.

If leaving shortblock alone would like to leave the "fuse" of a softer headgasket like victor reinz or felpro.
 

hensleyt

Well-Known Member
Joined
Feb 20, 2008
If you can find the Victors that’s my choice but Fel-pro is a good choice too. I like my champion irons and they will clearance the rocker stands to clear roller rockers if you go that way down the road
 

Daniel454SS

Member
Joined
Jun 6, 2020
Might look into TA Performance heads also. Probably can't go wrong with either, more a matter of who can supply the parts in a timely fashion.
Ok, so I didnt quite understand the weight of this til now.
Seems a new set of heads will be either 3-6 weeks or 3 months depending on which heads I go with.

I was thinking that if I sent my heads that it would be quicker and cheaper and that is not really the case (I understand why), but for the roughly $150 credit for pair before shipping I feel I am better off just keeping my heads.

So think I am going to go ahead an lap my valve and see IF I can get 3 to seal up and clean up heads, IF not they will be going to local machine shop for just basic freshening up.

From there I will go with some studs on the heads with a VR or FP head gasket.

I will also keep the same stock flat tappet cam that is engine now as it all looks really good condition.

pretty much all stock long block other then the port matched heads.

I may get a precision plenum with matching power plate as that seems to have the least difference in of air distribution between cylinders, but otherwise mainly use what I have.

Plan will be in the works to start sourcing parts to build a beast of a long block slowly as I can afford and get parts while also allowing me to do further research
 

1986 Buick GX1

GX1 #001 [The One and Only]
Joined
Apr 24, 2015
Ok, so I didnt quite understand the weight of this til now.
Seems a new set of heads will be either 3-6 weeks or 3 months depending on which heads I go with.

I was thinking that if I sent my heads that it would be quicker and cheaper and that is not really the case (I understand why), but for the roughly $150 credit for pair before shipping I feel I am better off just keeping my heads.

So think I am going to go ahead an lap my valve and see IF I can get 3 to seal up and clean up heads, IF not they will be going to local machine shop for just basic freshening up.

From there I will go with some studs on the heads with a VR or FP head gasket.

I will also keep the same stock flat tappet cam that is engine now as it all looks really good condition.

pretty much all stock long block other then the port matched heads.

I may get a precision plenum with matching power plate as that seems to have the least difference in of air distribution between cylinders, but otherwise mainly use what I have.

Plan will be in the works to start sourcing parts to build a beast of a long block slowly as I can afford and get parts while also allowing me to do further research

dank GN here on the forum ports and polishes heads and intakes that may have a more favorable turn around time.
He’s in California.

 

Daniel454SS

Member
Joined
Jun 6, 2020
OK, so been a little bit since I have updated and was saving up a bit for parts so here is where I am at right now...

As for the heads seems like most places are taking a while, spoke with DankGN, but would still be a short while so am taking them to my local machinist/head porter.
The ports are already matched so just going to go with Manley or Ferrea big valves and some mild bowl/throat porting.

Going roller Cam from full throttle, was originally thinking 206/210 but Michael Licht convinced me that going with a 210/215 would be the way to go and not hurt drivability (-7.5 overlap which is close to -12 to -8 overlap I have seen bison recommend with 6262), kit comes with beehives and morel lifters.
only issue now is that comp is behind on cores so will not get the actual cam til Aug-Sept best case, but will will get my heads and short-block set up slowly by then anyhow.

also ordered new melling oil pump pickup (20-IS2) and ARP headstuds (039-1234003) from full throttle and some Victor Reinz headgaskets from Scoggin dickey so slowly getting to point of making a healthy stock shortblock beast.

will update as I get parts in or start assembling :)
 

Daniel454SS

Member
Joined
Jun 6, 2020
So tiny update..

heads at machine shop, it's a machine shop that has been doing performance work forever and has done all my BBC/SBC stuff as well as know the owner from local dragstrip.
He said its been a while but used to do a ton of GN stuff back in the day

Since the ports already very well matched just going Big valves (ferrea F6237 1.500 / F6238 1.775) bowl and throat work and also closing up the EGR.
also trueing all surfaces.

Cam cores are on backorder (end of Aug-Sept) so that will take a while, but FTS said they would send me the rest of valvetrain parts so I can get heads set up.

I also would like to get my intake restored because it is powder coated black and I prefer stock look.

SO... my machine shop guy can blast it (guessing bead or walnut) and cut out EGR port and port intake or should I just send it as a core for a Champion ported intake?

Ported is a benefit but really would like to just get it looking semi original under hood.
 

HotRod231

New Member
Joined
Jul 16, 2021
more pics
View attachment 365834

oil pump
View attachment 365830

found what looks like shredded cotton rope in oil pump pickup screen
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View attachment 365831

and then the oil looked good when changing it but I found this oil "booger" in oil pan (engine had been on stand for 5-6 months
View attachment 365833

SO should I don't mind buying parts if it will make a difference but also don't want to try and replace what isn't broke, SO should I replace oil pump gears?
what about timing set?
what about valves springs?
Just noticed you have a stock cam chain tensioner on a double row timing chain...trouble waiting to happen...should only use that style tensioner on stock style chain...I learned the hard way....Enjoy
 

HotRod231

New Member
Joined
Jul 16, 2021
well I ordered the cam back in august and spoke with both hartline and also verified with TA and then ordered the right timing set as well as right part number (ta_v1522a) but just opened box and guess got the wrong part in, hoping to get it sorted out...


Not trying to come off as a complainer and not trying to cheap out, just not where I was financially when I bought these parts.

I bought this timing chain and most of these parts in August-sept, shortly after I got covid, I recovered after a few weeks but not before sharing it with my wife who already had(still has) health issues and long story short I am barely getting to work on my car and I am now behind schedule on just about everything.

I am willing to do compression and leakdown tests to see if there is any sign of problem, but at this point even though the engine is out I do not see a reason on pulling the head since engine was running well, no leaks, and no indicator that there is any issue.

will update and may change response after those tests though, we will see.
Just ck with some people who Really KNOW what they are talking about....when I first started with these cars back in 95....the So Called specialists were far and In between ...take your time...learn the platform..
It's very finicky but a very good PowerPlant if you have the right machinist and support parts that work together(bigger is not always best...ie...stroker motor...sounds good but not necessary for the average power goals)...Be careful who you listen to
 

HotRod231

New Member
Joined
Jul 16, 2021
So tiny update..

heads at machine shop, it's a machine shop that has been doing performance work forever and has done all my BBC/SBC stuff as well as know the owner from local dragstrip.
He said its been a while but used to do a ton of GN stuff back in the day

Since the ports already very well matched just going Big valves (ferrea F6237 1.500 / F6238 1.775) bowl and throat work and also closing up the EGR.
also trueing all surfaces.

Cam cores are on backorder (end of Aug-Sept) so that will take a while, but FTS said they would send me the rest of valvetrain parts so I can get heads set up.

I also would like to get my intake restored because it is powder coated black and I prefer stock look.

SO... my machine shop guy can blast it (guessing bead or walnut) and cut out EGR port and port intake or should I just send it as a core for a Champion ported intake?

Ported is a benefit but really would like to just get it looking semi original under hood.
I had my first 109 block prepared by a Great Machinist on Fords, Chevys, and other brands....tolerance is totally different on these motors...mine blew up(knocking) before I really broke it in....just my .02...deal with a machinist knowledgeable in your Buick turbo motor
 

HotRod231

New Member
Joined
Jul 16, 2021
Was the rear main a rope seal ? Was the bearings GM? Looks like a unopened 109 on the bottom. The heads look not ported but just a cleanup, not your normal exhaust port work you usually see. I would use studs.
Keep up the good work
You can do away with the rope and use a washer to place over the rope seal openings and use Black High temp RTV until you see it start coming out the seams slightly and put your gasket and pan and won't get any more leaks...I have done it multiple times on engines I built for myself and others with stellar results
 

scgnx2

Active Member
Joined
Jan 24, 2009
I also would like to get my intake restored because it is powder coated black and I prefer stock look.

SO... my machine shop guy can blast it (guessing bead or walnut) and cut out EGR port and port intake or should I just send it as a core for a Champion ported intake?

Ported is a benefit but really would like to just get it looking semi original under hood.

If your machine shop can port and clean up your intake I would go ahead and have them do it. While Champion has been a great source for the Turbo Buick’s, they are not a quick turnaround company. The stock intake has well known flow issue due to the plenum design not the manifold. Many guys resolve this by using RJC’s power plate or using a different plenum like a Hemco.
 
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