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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