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

Daniel454SS

Member
Joined
Jun 6, 2020
the engine itself was running very good and no smoking or noise from engine, the reason it would not build boost quickly was due to pre-turbo exhaust leaks and poor setup it had.

oh also forgot to mention on disassembly I found that it only had 1 nut holding turbo on!!!

Only reason I pulled engine itself was to make it easier to seal up oil leaks (pan and front and rear main seals) and replace valve springs.

Since you've got the engine on a stand and it appears to be an unknown quantity, I'd suggest you take a look at the rod and main bearings at the very least. Personally I'd blow it all apart and give it a good look over. If the major stuff looks to be in good order I'd clean it up and put it back together. At least you will have answered your own questions in regard to condition and know what you're dealing with.

Neal
I wouldn't say unknown quality as mileage is low and the quality of engine seems to be good from how it ran and also from inspection so far.

I was planning to change the rear main seal and would be be accessing that one and re-torquing that one.
I will inspect bearing, if it looks bad then I will be sending crank to get polished or turned and replacing all bearings, but I do hope not to have to go that far.

I'm not trying take any short cuts but I'm also not trying to get into a full build since it was running good.

I agree. Your heads are ported. I would have them cleaned and looked at. If you go roller rockers the pedestals will need to modded so that's the time to do that. Looks like a stock bottom end, rods and pistons. They should be cleaned and inspected since you have the engine out. It all depends on your goals and how much you plan to spend. Don't forget the Buick factor, take the money you plan to spend and double it.
I never had any intention of taking any of it apart other then fixing oil leaks, so I guess it is definitely good news I decided to inspect further to find that they were ported and since the engine was running good itself and now knowing how good it looks inside I think I may go am little just clean up more and start putting back together.

my budget was originally just the gaskets now I think I am going to get the complete TA performance timing cover with pump and once I do rear main seal I may inspect bearing and see if that doesn't lead me deeper into my budget lol
 

750H.P.V6

Brutal 6 Racing
Joined
Sep 4, 2001
I don't want you thinking I'm trying to spend your money for you but you have access to everything in the engine right now. If you don't pull it apart I understand but inspect the cam lobes closely and it wouldn't hurt to put a fresh set of head gaskets in. You don't know what they've been subjected to and it's much easier at this point.

Neal
 

Pronto

You can't knock them up with spit.
Joined
Dec 9, 2002
Yes! Now's the time to check everything. Better to spend a little money now and confident in the engine that have any doubts in the back of your mind especially since you don't have the whole picture with this build.
 

Daniel454SS

Member
Joined
Jun 6, 2020
Hey guys sorry I went missing, got busy with work and ended up having to stay on jobsite for these last 2 days straight.:sleep:

So finally opened up box from new ta timing set (v1522A) and think Hartline sent me the wrong one, this one doesn't have the 2 bolts, instead it just has a keyway (?????). messaged them will see what they say.
IMG_2485.JPEG


I don't want you thinking I'm trying to spend your money for you but you have access to everything in the engine right now. If you don't pull it apart I understand but inspect the cam lobes closely and it wouldn't hurt to put a fresh set of head gaskets in. You don't know what they've been subjected to and it's much easier at this point.

Neal
I know, I am trying to do what is best but on a shoestring budget right now, and I know everything is going to add up anyways.

I've inspected cam and it looks good, as for head gaskets I really don't want to try to pull the heads as that leads to might as well pull pistons and inspect rings lol

Yes! Now's the time to check everything. Better to spend a little money now and confident in the engine that have any doubts in the back of your mind especially since you don't have the whole picture with this build.
well right now I don't have the budget to put into changing too much so I am going to try and leave the heads on and inspect what I can without having to replace parts.

good thing is it looks as though whoever did the heads and previous work did quality work.



If anything I am mainly trying to get car running reliably then plan is going to see if I can find a 109 block this winter to build up a forged stroker over that next year ('22).
 

Pronto

You can't knock them up with spit.
Joined
Dec 9, 2002
You're complaining you don't have money for checking the engine but drop more than a C note on a timing chain. At Rock Auto you can get a replacement chain/sprockets for 50 bucks.
 

Daniel454SS

Member
Joined
Jun 6, 2020
That's an odd fire timing set. That would be what you need if you were running a billet cam.

Neal
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...

You're complaining you don't have money for checking the engine but drop more than a C note on a timing chain. At Rock Auto you can get a replacement chain/sprockets for 50 bucks.
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.
 

750H.P.V6

Brutal 6 Racing
Joined
Sep 4, 2001
The oil pump pickup screen looks like it could have head gasket material on it to me. The stock gasket is a composite graphite material. A common failure is to blow them out into the lifter valley on the middle cylinder. Prior to doing this they will shed material into the oil as they degrade.

Neal
 

Chuck Leeper

Toxic old bastard
Staff member
Joined
May 28, 2001
Just my $.02..
From what I see in the pics, that show the intake ports and EGR ports, there are some issues.
1. Ring seal could be shot. A leak down would help with that diagnosis.
2. EGR and, or PVC is not working.
Engine has been using oil. A lot of "nasties" in those ports.....
Other items, such as valve seals, etc, could be in the picture.
Neal is right.. Blow it apart and see what's there.

Back under my rock.;)
 

Rick the pool guy

Active Member
Joined
Feb 7, 2017
more pics
View attachment 365834

oil pump
View attachment 365830

found what looks like shredded cotton rope in oil pump pickup screen
View attachment 365832
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?
That cotton rope on your pickup screen could be from the rear main seal buick used rope on these 3.8's
 

Daniel454SS

Member
Joined
Jun 6, 2020
The oil pump pickup screen looks like it could have head gasket material on it to me. The stock gasket is a composite graphite material. A common failure is to blow them out into the lifter valley on the middle cylinder. Prior to doing this they will shed material into the oil as they degrade.

Neal
what was in the screen doesnt seem like graphite and seems exactly like the cotton rope like material from front seal.
will do a leakdown and compression test and see what they look like, then go from there for sure.

Just my $.02..
From what I see in the pics, that show the intake ports and EGR ports, there are some issues.
1. Ring seal could be shot. A leak down would help with that diagnosis.
2. EGR and, or PVC is not working.
Engine has been using oil. A lot of "nasties" in those ports.....
Other items, such as valve seals, etc, could be in the picture.
Neal is right.. Blow it apart and see what's there.

Back under my rock.;)
definitely going forth with the compression and leakdown tests just for peace of mind

as for the EGR and PCV; when I bought the car pretty much all vacuum lines were garbage.
I went to a turbotweak chip but did not remove the EGR valve
PCV valve was bad and I replaced it with an RJC PCV and new lines.

getting more in depth but still not all the way to point of wanting to take it all apart... yet.

That cotton rope on your pickup screen could be from the rear main seal buick used rope on these 3.8's
I haven't gotten the time to pull and replace the rear main seal yet because work has been busy, Although the front cover did have similar seal and it was pretty torn up.

I should be able to get to it by Wednesday and also will have compression/leakdown results as well as have an idea of bearing condition
 

750H.P.V6

Brutal 6 Racing
Joined
Sep 4, 2001
One thing I was going to mention is that the timing chain that is on the engine looks fine. If it helps you stay in your budget you could reuse it. Just remove the tensioner and it go with it. At that point the largest cost would be gaskets and maybe bearings depending on what you find.

Neal
 

Anthony P

sharing knowledge with those who care to listen
Joined
Jan 24, 2007
Hi Daniel, congrats on the purchase, gaining your heath back and welcome to the group. You're getting some great input from the regulars here. I will echo what Neal noted in post #17. I always suggest verifying what you are starting with. after 3 decades, it's worth a peek to visualize what's been tinkered with or not.

on the rotating assembly, if the bearings are going to show wear, it's going to be mains #2 and #3 and rods #5 and #6 - just how the Buick V6 oiling system works. not a bad idea to just remove main caps 2 and 3 for a peek at the bearing. rods are fed from the mains so just confirming the mains is a start without taking it all down.

you noted you have experience with SBC/BBC engine builds. Please recognize the clearances/tolerances on the Buick V6 are a lot tighter. it will be a mess if a Buick V6 is built with SBC clearances.
 

Daniel454SS

Member
Joined
Jun 6, 2020
One thing I was going to mention is that the timing chain that is on the engine looks fine. If it helps you stay in your budget you could reuse it. Just remove the tensioner and it go with it. At that point the largest cost would be gaskets and maybe bearings depending on what you find.

Neal
Thanks, although I had already purchased the timing set, alot of these parts I purchased back in August just I am barely getting to work on car.

Hi Daniel, congrats on the purchase, gaining your heath back and welcome to the group. You're getting some great input from the regulars here. I will echo what Neal noted in post #17. I always suggest verifying what you are starting with. after 3 decades, it's worth a peek to visualize what's been tinkered with or not.

on the rotating assembly, if the bearings are going to show wear, it's going to be mains #2 and #3 and rods #5 and #6 - just how the Buick V6 oiling system works. not a bad idea to just remove main caps 2 and 3 for a peek at the bearing. rods are fed from the mains so just confirming the mains is a start without taking it all down.

you noted you have experience with SBC/BBC engine builds. Please recognize the clearances/tolerances on the Buick V6 are a lot tighter. it will be a mess if a Buick V6 is built with SBC clearances.
thank you much appreciated :)
the bearings look fine although I need to actually check clearances, what is a good recommendation to read up on for clearances and also torque specs?
is there recommended book to buy by any chance???
 

Daniel454SS

Member
Joined
Jun 6, 2020
So... got good news and slightly not so good news.

Did the leakdown test yesterday and all were near 10%
Cyl (all tested to 100psi)
1 95
3 88
5 90
2 96
4 90
6 98
bad news is someone jinxed me :eek::ROFLMAO:
cylinder 3 was leaking slightly through the intake valve, used a rubber mallet to try and re-seat valve a little and same result.
removed all the rocker arms and tried cyl 3 again, same results.
pulled head and sprayed some carb cleaner in port for cyl 3 and can tell it barely seeps into chamber when I push air into intake port,

head gaskets looked good, sprayed pistons with some carb cleaner and they looked good as well
even side
IMG_2500.JPG

odd side
IMG_2499.JPG


So now I am going to take heads to machine shop and have them gone through.

when it comes time to put heads back on what is the recommended head gasket since I am not resurfacing the deck?
I have been using alot of RJC projects and they seem to be of great quality, should I go with their kit?

also I would usually go with ARP head bolts but keep seeing ARP head studs offered, is there are reason head bolts aren't a good option?
 

Daniel454SS

Member
Joined
Jun 6, 2020
ok so bearings do look good as in not beat up...
So on to bearing clearances... I am going to plastigauge my bearings for now to make sure they come out under my MAX goal *fingers crossed*
from what I read so far it seems as though I would want
rods .0015-.0025 FAIL if over .003
mains .002-.003 FAIL if over .035 (would figure ok on chevy :ROFLMAO:)

I don't currently have a bore gauge set so if they are not where they need to be I may have to pick up a set
oh well will be a good tool to keep anyhow.

so if I end up getting into bearings... and I didn't really plan to go this far at all...
should I upgrade piston rings and give it a fresh hone even though can still see crosshatch?
if I end up going that far.
 

TexasT

Texas, Where are you from
Joined
Sep 10, 2002
You have quite a little project going on there. Nothing wrong with that. I am in the dfw area. My brother is out in Midland and we spent the mid 2ks out there. I worked wireline for Schlumberger. Good money while it lasted and when it wasn't we left.

As far in as you are I'd have the block vatted and checked and the crank too while it is out, but I can tell you I would have pulled that leaking valve spring and hit that valve with a hand lap and a gasoline leak check and put it back together, but I'm cheap.

Nothing wrong with what you have going. Oil pump is pretty important. A cloyes timing set is budget friendly but you already have that double roller setup and that is even cheaper.

Keep the pix and updates coming. You're doing great.
 

Anthony P

sharing knowledge with those who care to listen
Joined
Jan 24, 2007
for clearances on a factory block with the stock style oiling system you're shooting for...

mains and rods at 0.002"

mains at 0.0025" and greater is a bit loose since you're not pushing 7000+rpm and 800hp.

some builders are ok with 0.0025" mains - depends what they are building.

a few years back, Chris (dank GN) posted an electronic version of the Buick PowerSource Manual published in the mid-80s. when this site's servers failed and all the pics and attachments were lost due to lack of backup archives, I re-posted the pdf of the PowerSource book. You can read the clearances they were using for the Stage engines. below is the link to that thread - last post is the PowerSource book pdf attachment.

How to hotrod your Buick V6 PDF
 

Daniel454SS

Member
Joined
Jun 6, 2020
You have quite a little project going on there. Nothing wrong with that. I am in the dfw area. My brother is out in Midland and we spent the mid 2ks out there. I worked wireline for Schlumberger. Good money while it lasted and when it wasn't we left.

As far in as you are I'd have the block vatted and checked and the crank too while it is out, but I can tell you I would have pulled that leaking valve spring and hit that valve with a hand lap and a gasoline leak check and put it back together, but I'm cheap.

Nothing wrong with what you have going. Oil pump is pretty important. A cloyes timing set is budget friendly but you already have that double roller setup and that is even cheaper.

Keep the pix and updates coming. You're doing great.
That's awesome, Im third generation generation west texan lol, left a couple times but came back home.

I havent quite gotten it all the way apart yet, but yes I am getting close.

I would've just lapped the valve but since I'm already way more in than I planned I figure might as well give them a good once over.

I have considered it but being as my budget is low it just means it would take alot more time, and think it would be better to just save up a couple years and build a proper stroker if I going all in.

I had a TA set I ordered back in august that was wrong part but they are going to swap me out so going to their silent single timing set; as well as their oil pump assembly now.

will keep updates coming as I go, but pricier it gets the more time between updates :D

for clearances on a factory block with the stock style oiling system you're shooting for...

mains and rods at 0.002"

mains at 0.0025" and greater is a bit loose since you're not pushing 7000+rpm and 800hp.

some builders are ok with 0.0025" mains - depends what they are building.

a few years back, Chris (dank GN) posted an electronic version of the Buick PowerSource Manual published in the mid-80s. when this site's servers failed and all the pics and attachments were lost due to lack of backup archives, I re-posted the pdf of the PowerSource book. You can read the clearances they were using for the Stage engines. below is the link to that thread - last post is the PowerSource book pdf attachment.

How to hotrod your Buick V6 PDF
man I looked through alot of threads with dead links, that is exactly what I was looking for THANKS!!!! now to do some reading.

I will see how close the clearances come out, but also have to consider accuracy of plastigauge.
 

Anthony P

sharing knowledge with those who care to listen
Joined
Jan 24, 2007
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
 
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