: 4.0 rebuild



aurora guy
06-03-11, 11:17 PM
so ive decided to just rebuild mine, the whole thing that started the rebuild was some metal and plastic in the pan. i tore in to it and found no real bad bearing damage, just some signs of overheating. crank and rods in great condition, just gunna have the crank machenied,new bearings and of course gaskets. it all torn apart now, heres a few pics
pile of parts
http://i816.photobucket.com/albums/zz85/oldsmobile99/rebuild023.jpg

carbon !
http://i816.photobucket.com/albums/zz85/oldsmobile99/2011-05-26134120.jpg
http://i816.photobucket.com/albums/zz85/oldsmobile99/2011-05-26134107.jpg
http://i816.photobucket.com/albums/zz85/oldsmobile99/2011-05-26132308.jpg

timing chains
http://i816.photobucket.com/albums/zz85/oldsmobile99/2011-05-26122021.jpg

something i found odd, no cam bearings
http://i816.photobucket.com/albums/zz85/oldsmobile99/2011-05-25144824.jpg

also a few questions for you gurus
1. rod bolts, does anybody make good after market ones ? like arp
2. you guys know of anywhere to buy bearings cheap, but good quality ?

thanks

JoeTahoe
06-03-11, 11:26 PM
I used gm rod bolts. And Clevite Bearings from Rock Auto

89falcon
06-04-11, 01:02 AM
Have you though about putting a 4.6 block in it?

Be sure to get the rods journals checked for roundness before you put it back together....I here the deform....and if they aren't round, you'll be doing it all again soon!

johnny kannapo
06-04-11, 01:39 AM
What year model is your northstar?
How many miles?
It looks pretty good.

Many here will be interested in following this thread.
I kind of like how the 4.0L cylinders are so much heftier looking than a 4.6L.

johnny kannapo
06-04-11, 01:47 AM
Any professional crank/cam grinder will provide you with the proper spec. bearings.

Submariner409
06-04-11, 08:11 AM
Remember: the GM Factory Service manual says "Do not machine the crankshaft bearing journals".

JoeTahoe
06-04-11, 08:31 AM
mine had 130000 miles and the crank was still in spec. also if you do rering I have read horror stories on non GM rings, smoking and useing tons of oil. I have rebuilt two Northstars a Eldo and my Sts and used GM rings with great success.

97EldoCoupe
06-04-11, 10:51 AM
You have to be careful with the clevite bearings. Great quality- but the thrust bearing sometimes need filing from the backside because of raised edges during the crimping process. I've found a couple that I would not use without a bit of very careful filing otherwise the bearing wouldn't have seated properly.

From what I can see in the photos that is a 1995-1997.5 Aurora. I think you may be a customer of mine with the initials of T.C.? If so- that timing kit is definitely needed, that lower tensioner looks a bit worn. When you get the timing kit use the bolts that I sent along as the guides are the newer style (1997.5+).

Looks like a great job so far, should be an awesome car again. The studs finally came in last night so orders are being filled and shipped. Again if I'm correct about who you are, the drilling and tapping kit has already shipped and is on the way so that you can get the block prepared.

Great job and wish you the best with the build-up! :thumbsup:

postman2000
06-05-11, 11:56 AM
Is there anything one can do as far as normal maintainence do minimize the carbon on top of the pistons like the pic's above? I am aware of the W.O.T. procedure, but will one particular kind of gas or oil help to minimize this?

Submariner409
06-05-11, 03:26 PM
Carbon deposits are, unfortunately, a normal byproduct of petroleum combustion.

Oil burners and city driven engines (cold combustion chambers) tend to develop excessive carbon deposits. Highway engines and those subjected to occasional "spirited driving" tend to stay much cleaner.

If you're a tad paranoid, do some Google work on Chevron TECHRON. Used according to the directions it MIGHT help a bit. GM likes the Top Tier gasolines - Google that, too.

postman2000
06-06-11, 12:33 AM
Thanks for the tips Sub, I usually throw in a chevron techron every month or so.. Hopefully it helps some..

stoveguyy
06-06-11, 10:34 AM
can you include a closeup pic of the piston ring grooves if you can? before cleaning. would like to see if the story of carboned up ring grooves is true. oh, the cam does not have bearings. thats why oil changes are important.

johnny kannapo
06-06-11, 03:12 PM
The oil control ring assembly is the the ring that is the most problem. The top & second ring can only build up on the inside vertical groove wall and ring movement would keep these self clean for the most part but the combustion heat & oil presents causes it to bake on hard.

The 3 piece oil control ring has many areas for carbon to collect. The ring gets stuck and the 2nd ring becomes overwhelmed with oil then up to the top ring.

auroradude
06-07-11, 02:17 AM
Why rebuild it? I just bought a brand new leftover Aurora V8 from the Shelby plant, in a crate that says shelby, inc on it. Everything is new top to bottom - can't wait to put it in my car. There is one left, I paid $2000 + shipping for mine, but the last one for sale is bid up to $2700 now plus $400 shipping.

Submariner409
06-07-11, 06:04 PM
=stoveguyy;2616318 oh,the cam does not have bearings.

????? All four cams have line bored bearings - lots of them.

Pictures ???? Go look at the slew of shots taken by JoeTahoe in his engine rebuild thread. Same engine, only 0.6 litre larger. Plenty piston pics............

stoveguyy
06-07-11, 11:20 PM
sub, i meant to say there are no cam bearings that can be separated from the cam bearing caps. like a rod bearing.

aurora guy
06-08-11, 08:30 PM
sorry for the delaied response, been at work alot.
the engine has 142,000 miles. the whole engine is tore down now pretty much, im leaving the pistons and rods in block due to cylender looking perfect to cut down on cost. got the crank polished and cleaned. are there any other bearings you guys recomened ?

all the crank jorunals are round and look new.
@97eldocoupe, no im not a customer...yet lol i will be buying the stud kit and timing components and oil mainifold plate from you tho.
the reason im rebuilding it is that when all said and done ill only be in alittle over $1000 and ill be able to say i rebuilt it, and never worry about headgaskets again.

i have a bunch of pics ill post tomorrow

aurora guy
06-08-11, 08:33 PM
also just wanting to triple check, the crank was only polished and cleaned. so just standerd size bearings right ?

thanks

97EldoCoupe
06-08-11, 11:25 PM
Correct. If the crank is perfect- no wear, nice finish, still round; standard size bearings.

I had another 4.0 customer recently so I confused you and him :) Best of luck with that build and I will be happy to help you when you're ready! :)

stoveguyy
06-09-11, 01:18 PM
never took off the lower stud girdle before. you can leave pistons in block and somehow align all rods and not nick crank during the reinstall step? do you need to change oil control plate if stud girdle comes off? thought the gasket material is usually messed up if lower block is taken apart.

Submariner409
06-09-11, 01:59 PM
It ALL comes apart to get to the rods and mains..........("bolt girdle" = lower crankcase half - no studs down there).............and the oil distribution manifold plate is bolted to the lower (oil pan) side of the lower crankcase half.

EVERYTHING gets new silicone seals/RTV work in accordance with GM TSB's on the subject.

aurora guy
06-09-11, 02:45 PM
never took off the lower stud girdle before. you can leave pistons in block and somehow align all rods and not nick crank during the reinstall step?

yea this is how i did it in my 3800, just got to be very carfull when setting crank in place

stoveguyy
06-10-11, 12:00 PM
upload a pic of your block with rods exposed. or i guess its like the illustration but with crank removed.

Submariner409
06-10-11, 12:41 PM
It's already in here - go to the thread "97 Eldorado ETC HG repair..........." right near this thread - 6 pages. Lots of block pictures......... many more in this Forum and in Cadillac Tech Tips.

stoveguyy
06-11-11, 10:19 AM
i have seen pics of blocks before. never seen a pic of block with crank gone and pistons/rods still installed.

Submariner409
06-11-11, 12:30 PM
i have seen pics of blocks before. never seen a pic of block with crank gone and pistons/rods still installed.

I'll buy that - you would probably need 10 hands and a lot of rubber tubing over the rod cap bolts if it could be done...........

OK, from the horse's mouth: GM Service manual - with the engine on a stand and upside down, remove the lower crankcase half, remove the connecting rod cap bolts, push the rods and pistons out the top of the cylinders. Install the lower crankcase half, measure crank endplay. Remove the lower crankcase half, carefully lift out the crank.

The pistons, rings, and rods are serviced and installed with the crank set into the new bearing halves in the block (block is still upside down), the rod bearings and caps are installed and torqued, then the lower crankcase half and main bearing halves are installed and torqued. Crank is checked for end play.

aurora guy
06-16-11, 02:08 PM
it's really not that hard to do, just gotta be carfull. heres an update, got all the bottem end parts ordered, fixing to order the stud kit and head gaskets.

the block with the rods and pistons in place.
http://i816.photobucket.com/albums/zz85/oldsmobile99/2011-06-16102620.jpg

parts
http://i816.photobucket.com/albums/zz85/oldsmobile99/2011-06-15091654.jpg
http://i816.photobucket.com/albums/zz85/oldsmobile99/2011-06-15091946.jpg
http://i816.photobucket.com/albums/zz85/oldsmobile99/2011-06-15092332.jpg
http://i816.photobucket.com/albums/zz85/oldsmobile99/2011-06-15112638.jpg

okay i got a question, how do ya'll remove the left over head gasket material from the heads and block ?

thanks
-josh

vincentm
06-16-11, 02:29 PM
Plastic scraper of some sort, dont get near it with a brillo pad or any such material.

89falcon
06-16-11, 03:20 PM
Plastic scraper of some sort, dont get near it with a brillo pad or any such material.

is it ok to use a chemical to? something like "gasket remover"?

89falcon
06-16-11, 03:23 PM
Did you get the rods checked? If so, were any "out of round"?

stoveguyy
06-16-11, 06:09 PM
i used spray gasket remover. seemed to soften up the crud on the surfaces ok. did you check cam lobe/lifter contact area? hard to inspect area without removing cams but maybe there is an easy way to check. might have got lost in thread. someone here had worn lifter faces.

aurora guy
06-16-11, 09:44 PM
i have not cheacked the rods yet, but i will.
the cams and lifters look brand new,this engine had the oil changed every 3000. i have the records on it to prove. but also my old negleted one out the car has almost perfect lifters and cams too, and it had been ran without oil pressure before.

aurora guy
06-22-11, 05:56 PM
well ive been cleaning up the engine while waiting for parts, ive claened the head gaskets surfaces with peratex gasket remover and a plastic scraper, but i cant seem to get it all off. heres a pic of what im talking about
http://i816.photobucket.com/albums/zz85/oldsmobile99/IMG_2180.jpg is it normal ?

also a friend said i needed to have the heads decked, ive heard of having the block decked but not the heads. and what would you guys use to clean the carbon off the pistions and heads ? brake cleaner ?

thanks

ternstes
06-22-11, 08:10 PM
I think it looks okay. That is what my 97 STS looked like when I put it back together. You want to look for any areas that catch your fingernail. Brake cleaner can work with a lot of scrubbing. No pads with aluminum oxide abrasives! Check the heads and deck for flatness with a good straight edge, or take them to a shop.

I used some gm top engine cleaner on the pistons and valves. The exhaust valves had a lot of baked on carbon that came easy with a brass wire wheel, but I removed all the valves and changed the stem seals anyway.

Submariner409
06-23-11, 12:37 PM
Because of the extremely thin piston top/head quench area, GM does not allow milling the head beyond that required to remove OVER .003" of departure from dead flat. And you can't deck these blocks. Any problems and its new block time.

89falcon
06-23-11, 10:58 PM
Because of the extremely thin piston top/head quench area, GM does not allow milling the head beyond that required to remove OVER .003" of departure from dead flat. And you can't deck these blocks. Any problems and its new block time.

Sub,
if you were "cheap" and needed a little milling, could you make up the diff with a nice cometic custom?
http://www.cometic.com/custom.aspx

of course, by the time you got the custom gasket, you could prob get a cheap set of heads.....

Submariner409
06-23-11, 11:13 PM
You'd have to compare the Cometic thickness with the compressed thickness of, say, a FelPro gasket. Cometic might let you get away with .003" or so. I've stacked head gaskets in other engines to lower compression ratios - don't try it in a Northstar.

But, to mill off .010" to .015" in a Northstar is way outside the envelope. The compression ratio change in 2000 was done with chamber design, not piston clearance.

marsala4
07-09-11, 05:01 PM
Hi, looking through your pics, I have a couple of questions. I recently changed my oil pump, I need to know if the crankshaft balancer fits flush with the end of the shaft, and ,then, tighten to torque spec, or what. Also, when I was checking the timing chains, I noticed the the chain on the right had a slight bit of play in it, the others did not, and the plastic guide , while tight, had a little play in it as well, is this ok?

I am a 97 Aurora owner chasing the low oil pressure warning alarm. So far I have changed the pump, oil pressure sender, and several different oil viscosities, along with the extra 10 qt flush. All to stop this anomolly. And I am still getting it occasionally. Temp here in Atlanta has been very hot. I have read post after post and tried all fixes with only temp results.

Any suggestions.

Thanks for any help.

89falcon
07-09-11, 11:21 PM
Hi, looking through your pics, I have a couple of questions. I recently changed my oil pump, I need to know if the crankshaft balancer fits flush with the end of the shaft, and ,then, tighten to torque spec, or what. Also, when I was checking the timing chains, I noticed the the chain on the right had a slight bit of play in it, the others did not, and the plastic guide , while tight, had a little play in it as well, is this ok?

I am a 97 Aurora owner chasing the low oil pressure warning alarm. So far I have changed the pump, oil pressure sender, and several different oil viscosities, along with the extra 10 qt flush. All to stop this anomolly. And I am still getting it occasionally. Temp here in Atlanta has been very hot. I have read post after post and tried all fixes with only temp results.

Any suggestions.

Thanks for any help.

A bad main bearing (too much clearance between bearing and crank) could cause it. Also, don't be so sure that the pressure coming from the sender is correct....could be a short in the wiring.......

aurora guy
07-28-11, 12:20 AM
sorry havent been around in awhile mostly been at work or helping friends with their cars. i almost have enough to buy the oil manifold and studs. but ofcourse ive had some ideas on howto sceaze more power out,but not sure if it will work. so after research and talking to several people ive determened that the cams used in the shelby aurora v8 and the 300hp northstar are the same and should work on my engine. but also while the heads are off,what about a mildport job ? and throw on some 4.6 exhaust manifolds. so with the cams and port and exhaust manifolds would i need a tune ? also would have just a warm air intake with a cone filter. id really like to do this stuff but ive heard that the pcm is locked so cant tune it.

thanks

89falcon
07-28-11, 11:19 AM
sorry havent been around in awhile mostly been at work or helping friends with their cars. i almost have enough to buy the oil manifold and studs. but ofcourse ive had some ideas on howto sceaze more power out,but not sure if it will work. so after research and talking to several people ive determened that the cams used in the shelby aurora v8 and the 300hp northstar are the same and should work on my engine. but also while the heads are off,what about a mildport job ? and throw on some 4.6 exhaust manifolds. so with the cams and port and exhaust manifolds would i need a tune ? also would have just a warm air intake with a cone filter. id really like to do this stuff but ive heard that the pcm is locked so cant tune it.

thanks

I've heard that switching to a cone filter is a BAD idea........the PCM is cooled by the airflow into the filter

aurora guy
07-28-11, 01:43 PM
ive heard that too but on the aurora the pcm isnt near the air intake , so i should be good on that.

aurora guy
08-03-11, 11:12 PM
so i finally saved enough for the stud kit, i will hopefully get that ordered tomorrow. just wondering how long has it taken you guys to receive your stud kits ?

thanks

Speedygman
08-04-11, 05:21 AM
Ask Jake, he is the one that will know?

aurora guy
08-10-11, 11:55 AM
so i was wondering how many of you guys that have replaced the head gaskets, replaced the timing chains as well ?

because im pretty much a broke college kid lol i was wondering this because timimng chains seem to last a long time and i didnt want to spend the money unless nessicery. the engine has 146,000 miles. i also have a 100,000 mile nothstar i can take the chains from. what do you guys think ?

thanks

johnny kannapo
08-13-11, 10:33 PM
The chains are a minimal wear item and to replace the nylon wear shoes will restore proper tension. I believe there is a kit availiable with all the wear parts associated with the chain.

You will find this very helpful.
Reference down to message #131 here
http://www.fiero.nl/cgi-bin/fiero/showThread.cgi?forum=3&thread=000116&style=printable

aurora guy
08-23-11, 12:42 AM
okay thanks, i also looked over them all very closly ,they looked new with very minimal slack.

well somemore progress...assembly !
all the parts are in and picked up the block frombeing cleaned
http://i816.photobucket.com/albums/zz85/oldsmobile99/northstarbuild015.jpg

all taped up ready to be drilled and taped for studs
http://i816.photobucket.com/albums/zz85/oldsmobile99/northstarbuild019.jpg
alittle overcarfull lol

aurora guy
08-23-11, 12:49 AM
also what are the tourqe specs for the bottom end ? rods ?

thanks