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

Daniel454SS

Member
Joined
Jun 6, 2020
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
yes, good thing I opened it up
I actually have a TA performance 9-key silent single roller and will be using a new tensioner
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
My local machinist seems to be very knowledgeable and I also spoke with a couple GN owner from track that he has done work for and they all have had good results.
Plus I am also here to learn as much as possible to to double check things myself :)
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
verified clearances myself and yes very different then my Chevy engines, bearings just under .015"
plus still keeping my fingers crossed lol
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
It didnt have the rope seal in the rear main, it had already been swapped.
I am replacing it with the Rear main seal RJC sells and they highly recommend it, I have spoke to them quite a bit and is a big reason I have gone with so many parts from them.
 

Daniel454SS

Member
Joined
Jun 6, 2020
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.
I spoke with Champion a couple weeks ago and they said they have stock ported intakes on the shelf ready to ship out, my only concern is if there would be any issue with my core or it being powder coated.

I have a powerplate for the stock intake although I thin k I will more than likely end up going with the precision plenum with matching powerplate as RJC shows that as being the most balanced flow by far.
we will see if its in budget when I finally get all my other parts in, plus the polished one looks pretty good
 

HotRod231

New Member
Joined
Jul 16, 2021
I spoke with Champion a couple weeks ago and they said they have stock ported intakes on the shelf ready to ship out, my only concern is if there would be any issue with my core or it being powder coated.

I have a powerplate for the stock intake although I thin k I will more than likely end up going with the precision plenum with matching powerplate as RJC shows that as being the most balanced flow by far.
we will see if its in budget when I finally get all my other parts in, plus the polished one looks pretty good
Jason and his father are definitely good people to work with for your power goals
They have done ground breaking advancements for our old tried but true platforms...I have a procharged C5 manual that I built with GM parts(Heads) stock bottom end that does 703rwhp and 600rwt at only 8psi...but the feeling of GN is my favorite and has a special place in my heart...Enjoy...wouldn't part with it to just any Joe Blow but wanted an automatic C5 so my wife could have one also...This is what landed me on this site at this time...I have Many Friends in the Buick community...but your BEST friend is YOURSELF if you are going to advance far in these cars..They are unlike anything else you have ever dealt with...Good luck and enjoy...I have
 
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Daniel454SS

Member
Joined
Jun 6, 2020
hey guys been a while but not trying to rush this...
especially since it seems the whole aftermarket parts world seems to be going slower than ever :LOL::sick:

myself as well as everyone I know is waiting on parts.

Waiting on cam and lifters but I knew that when I ordered parts, expected date is end of this month or some time next month.

Good side is Full throttle got me my valvetrain parts so that I could get my heads assembled.
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valvesprings didnt come in any packaging just wrapped up but my machine shop checked them out and said they should be good.

heads came out nice, went with the larger Ferrea valves and got them resurfaced just for flatness and they did a good bowl and short turn port job (didnt get pics while they were apart)
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Daniel454SS

Member
Joined
Jun 6, 2020
Also had my intake ported to match the factory gasket which is the same one the heads are matched to, as well as cutting out the EGR tower and welding it closed.
The machine shop still has it because they are going to try and bake the intake and blast it to try and remove all the black powder coat for a more original look.

I had them do the process to my valvecovers because I did not like the blacked out look and I have to say that I really like the fresh aluminum look
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I like the Raw aluminum but I also like the idea of having them and intake polished and then going with precision polished plenum but not too sure I want that much "bling" lol


Oh and I had ordered my head gaskets on June 30 from Scoggin-dickey because they showed as being in stock... well I am still waiting on them and they now say that the manufacturer showed them in stock but currently show no shipment ETA, I am going to keep waiting as I need to wait on cam anyhow.... will see....
 

RmvBfrFlght

Well-Known Member
Joined
Sep 28, 2007
You may want to relieve the sides of the rocker shaft pedestals. This way roller rockers will drop right on. It is much easier to do it now then once the engine is assembled. Or worse when the engine is in the car.

RemoveBeforeFlight

P.S. silver or aluminum powder coat on the valve covers and intake/plenum will keep that aluminum nice and clean.
 

Daniel454SS

Member
Joined
Jun 6, 2020
You may want to relieve the sides of the rocker shaft pedestals. This way roller rockers will drop right on. It is much easier to do it now then once the engine is assembled. Or worse when the engine is in the car.

RemoveBeforeFlight

P.S. silver or aluminum powder coat on the valve covers and intake/plenum will keep that aluminum nice and clean.
I was considering that also as I do love the look of harland sharp rockers :love:

I will look at some of the powder coat options, I just removed the black powder coat because I didnt like how it made the whole engine bay too dark, but the clean up would be easier compared to a raw or even polished aluminum.

thanks for suggestion (y)
 

scgnx2

Active Member
Joined
Jan 24, 2009
Here’s another option for your valve covers that you might want to consider.
I used it on my intake and valve covers and it holds up well.
 

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