Refreshing motor, been sitting since 2012 accident


86 GN T-Top
Hi Everyone, So my GN was totalled March 2012... the motor survived and has been on the stand in a garage... untouched ever since. Now, I need it... as some douche blew up my current motor. So.... I need some advise on what to do before putting it in the GN please.

I have a full set of gaskets. I planned to open it all up give it a good cleaning, and check out some stuff. My heads and valves were just redone on the motor thats blown up.... I thought it was a head issue... turns out its the lower end.. hence the engine swap goin on. So... can I put these heads on the 2012 engine stand motor? When the heads were done I had them scoped... no cracks, and I have stock valves put in... nothing fancy.

Aside from cleaning, gaskets and swapping heads... any recommendations? I would be so upset if I missed something and car didnt run after all this upcoming work. I cant do another Power Tour without my GN... last year was miserable. =(

I figured Id redo motor mounts while im at it... anyone have new HR poly mms they want to sell ?

Also, I love u guys.. but please spare me the "dont let anyone drive your car" speeches..... I know.. I know... lesson learned.... thats for dam sure ! ! =)

turbo nasty

Turbo Dojo / MNTR
Set up front cover/oil pump and replace timing set. Not sure if dip shit hit the rev limiter and that caused it to blow if so get it remove from the chip as it is a fuel cut with the factory ecm...aka bad.
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runs with scissors
If there's nothing fancy with the blown engine's heads, why put them on the stand engine? If it was running fine when the car was totalled, I'd replace the mounts and stick it in.



Well-Known Member
If there's nothing fancy with the blown engine's heads, why put them on the stand engine? If it was running fine when the car was totalled, I'd replace the mounts and stick it in.


X 2 .. if its a factory sealed motor that ran good before ( to your expectations) .... Don't mess with it .. drop it in and go ... you can mess with the blown motor all you want at whatever pace you choose .. while you get to drive and enjoy your car .


86 GN T-Top
If there's nothing fancy with the blown engine's heads, why put them on the stand engine? If it was running fine when the car was totalled, I'd replace the mounts and stick it in.(giggity)

Thanks everyone. I agree with just sticking it in ;)... but, my heart would be crushed if I do that and have issues afterwards. So a few days of work to ensure the best result is my plan.

So, its been on the stand untouched and uncovered in a non-climate controlled garage. Im just going to do all the gaskets and clean it up. Swapping heads, cause newer is better.. and Im doing head gasket anyways... might as well put redone ones on.

Also hope'n to put a decent radiator in while im at it. Some douche put in a china aftermarket POS and its horrible... has to go. =)

GN is all unburryed and Im starting tomorrow. Wish me luck.. lol


runs with scissors
A Harbor Freight leak down tester is cheaper than head bolts..... If those head gaskets are factory, I'd rather get punched in the nose than break a working factory seal.

I think GM used (now discontinued) tears of orphans mixed with unicorn blood as a sealing agent.


Active Member
Just pull the pan and check the oil. If nothing wrong in the oil. Put in fresh oil after putting the pan on and prime the motor and drop her in.


86 GN T-Top
Ughhh... first GO day... Im beat ! 9am - 6pm... non stop.

So... engine on the stand (sitting since accident) Is completely stripped down. All looks good... EXCEPT... wear on cylinder walls... and main bearings are wore down to copper in places... so... we'll see. Heading to machine shop in am with block, pistons, and crank. Crank looks like it was polished imporperly and not squared. Its already 30 over... may need to go 40 over. Might be lookin for good quality 40 over pistons. Ughh. ughh. ughhh.

Engine in the car has everything taken off the top and ready to pull out of car tomorrow afternoon. Will take that down to the block tomorrow afternoon and see why I lost oil pressure.... I feel really really about that lower end.

So, why not just throw 2012 accident motor in the car and roll? ... Because if im going to do it... im going to do it right... and Im excited to learn about the lower end work... something ive never done and been intimidated about.

Will post pics tomorrow. Thanks for all your help and support guys. ^huge hug^


86 GN T-Top
If i would've thrown it in as is... who knows how long id have before I would have issues again... And I NEVER want to do all this work again. Well... its inevitable. . but this should buy me years vs days. :)


86 GN T-Top
Also hope'n to put a decent radiator in while im at it. Some douche put in a china aftermarket POS and its horrible... has to go. =)

Well, no new radiator. .. looks like someone already bought TB3s Alradco one :( I really really wanted it. I sold his GN for him.. was hope'n for the radiator as a finders fee... oh well


Staff member
Here's what i would do in this order:
-Tear down 100% and remove plugs from galleys front and rear and casting plugs, remove dowels, and wash the block
-magnaflux the block
-magnaflux the crank
-if all good with the block id have the block honed to the worst cylinder as determined by a dial bore gauge at the top tapered part of the bore of if a bore was really bad on the visual plate hone that hole till its clean
-deck the block to clean it and straighten it and measure the deck height.
-order the appropriate size pistons and compression ratio using the deck height, head gasket info, and head chamber volume. You may be able to get away with 3.833", 3.835", 3.836, etc
-cut the caps and line hone the main bore. Almost nothing should come off the block during this process. If you want to spend a few $ you can replace the center two caps with steel. It will need a line bore if so
-replace the old rods with new stock rods which are cheap and plenty good
-gauge all the new rods and re-size if needed. Yes some new stuff is wrong
-if the crank is not cracked measure all journals and polish or grind crank on mains and rods separately. It will likely need to be ground if you saw copper on the bearing inserts. Its ok to have std rods and -.010 mains if you can hit the clearances you want. The machinist should be able to determine this right away when measuring the journals.
-gauge the new pistons and torque plate hone all the cylinders to final size
-wash the block
-file fit the rings and install on pistons
-install inserts on mains and gauge the dimensions. Using the crank journal measurements determine clearances. If you want to be really accurate install the inserts and gauge the bores before grinding the crank and grind to clearance. You may need several sets of bearings if you want it to within a couple ten thousandths if you dont grind to clearance. Additionally the rod journals could be ground for stroke if you want them all exactly the same. Some variance is common unless this is done. Common practice on high dollar race engines
-install new cam bearings
-check cam for run out and straighten if needed.
-Once all the bearings are set and the clearances are determined you can put them away carefully and paint the block.
-install casting plugs
-install the bottom end assembly

this is just a basic run down and will have a very high success rate if assembled in a very clean area. There is work in between that i didnt mention. If you were looking for a little better rod you could go to a Chinese forged rod for a few hundred more. You could go right to a .040" piston and skip the double hone as i mentioned above but removing the least amount of metal is good practice and if youre ordering custom pistons for specific compression ratio or other reasons its not much more work and leaves you more room to freshen in the future.

Also the timing cover and oil pump will need to be addressed as well as the valvetrain and heads. Do not use the factory oil cooler if you are re-using the old radiator.


86 GN T-Top
Thanks Guys ! Bison, I will follow the list above.... thx sooo much for taking the time to do that ! Charlie... Hopefully i wont need pistons... but will keep u posted. thx :)

Heres a pic of the spun bearing. The machine shop was closed Saturday. .. so Im bringing the block from the car up there on Monday. Hes going to clean and magnaflux everything he needs to.... and let me know which parts are best. The block from the engine stand has a 1/4" ring on the top of the cylinders, and is 30 over. Im not sure if that means the block is bad, worst case I can go to 40 over.
Rather get an engine in the car with as little machine work cost as possible.. then build up the extra one.
So... break time today... church and time for mini me. Will post again when I hear back fm machine shop. They were swamped over there.


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Well-Known Member
That bearing looks like it didn't get oil

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As in EVER ! holy smokes .. there is no way in the world someone would have not noticed that

I just cant believe some of the stuff that we get to see .. unreal