to find the size of the main bearings...


for the crankshaft...


there are 5 numbers engraved on the corner of the block (top and bottom)....


that correspond to 5 numbers engraved on the crankshaft itself...



you add the number on the crank to the corresponding number on the block.
no number means 0. so the 01 on the crank pictured combines with the 2 printed on the block to come up with a #3 bearing.

that's looks amazing, makes we wonder why i didn't pick up to being a mechanic, regretting it now, but that's looks awesome

I cleaned and painted the block yesterday...


and we honed the cylinders. I don't have a picture of the tool we used but it looks like a bunch of wire bristles with balls on the end attached to a drill. you have to break the glaze on the cylinder walls in a crosshatch kind of pattern so the oil sticks better...


and today we just re-ringed the pistons..


there are two thin rings that go above and below the oil control rings in the bottom groove and the top two are the compression rings. you want to place the openings in the rings on alternating sides and always right above the wrist pin since that takes the least stress. so in the picture the opening in the ring under the oil control ring is facing back, the one on top is facing forward, the first compression ring facing back (there is a "2R" written on it that should be facing up), and the top ring facing front. they fit very loose like that so as to make a tighter seal with the cylinder wall when installed.



we can't do much else until the main bearings come in (probably Monday) since we need them to put the bottom end back together. we want to finish the bottom completely before starting on the head, just to keep things organized.

This post has been edited by hurley97: Sep 13, 2007 - 6:10 PM

if your not gonna get the pauters and want a little extra strength id shotpeen the rods while they are out. its cheap and it gives a little bit of strength to them

reminds me of rebuilding a cummins engine, same process but cummins is like 10x bigger!

this has to be the most interesting thread ever!
keep up the good work!

I personally would check all parts with a micrometer and
make sure crank, rods, oil pump meet all specs.
Thats kinda my thing though. The thrust bearing journal
looks a little scuffed at least in the one pic.

Steff this thread is awesome! keep it up

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from what I hear the pistons and rods will more than stand up to the abuse of a turbo (I'll save that for when I rebuild the engine thats in my car since it'll be much worse and probably need a re-bore anyway), the head gasket is already metal, I will be replacing any and all seals/ bearings I possbily can, this is going to be like a brand new engine when it goes in, I do want to smooth out the head some to make it flow better, right now I'm thinking about the bigger cams.

WebCams has done a grind for the 7A before and it would cost about $575 and about 3 weeks. Reasons I'm not sure about them right now is 1, they cost more than the rebuild parts 2, I'm not sure if I want this engine to sit at work for another couple weeks and 3, I really don't know how they will affect the car since they tell me it has only been done twice before. Also, what I kind of want to do is dyno the stock re-built 7A, then with just the cams, then the turbo. still thinking about it...

Steff i love this i feel like im in class Your pictures and descriptions are amazing!

I wish i had someone around to learn off of, this is a GREAT opportunity.

4ag(z)e head gaskets will work also (i do believE)

yes you probably could but the 7A headgasket is metal so I can just use that

Stef, good to see that you're on your way with the project.

I think a pretty modest increase in the I/E duration of the camshafts wouldn't be a bad idea, as long as its not so agressive that it affects the off-boost performance alot. Maybe keep the same proportion as the stock camshafts, just increase their duration slightly to allow more compressed air in, more exhaust gasses out per cycle but with good drivability?

Between a rebuilt and ported top-end, camshafts, and perhaps using some uprated 4AGE/4AGZE valve springs with the proper shims to prevent any float from the reworked head when it sees boost, you would have an awesome setup.


Looks great so far Stef, I don't think you're going to need alot of our advice with the build. It looks like you have the best help you can get with the rebuild and you already have a solid start on the bottom end.


Best of luck, I'll see you on the dark side...of boost.

>
that would also allow you to rev a bit higher as well, as long as the stock rod bolts can take it.
whoops manny posting as brennton on moms puter...lol

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Haha. Lets put it to the test!

Nice pics!

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I always thought the stock rods on a 7A were weaker but has a bigger stroke.

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oh you know I will Corey


Finally! the main bearings came in and we got back to work...

There are two sides to each main bearing, one is smooth and the other has a groove and a hole in it.
remember these bearings corresponded to the number ont he crankshaft + the number on the block, I had four #3 bearings and one number 2, so here you have to make sure you put the bearings where they belong.

the smooth half goes on the caps that hold the crankshaft in, there are little notches in the bearing that match up with a notch on the cap, you can see them on the two caps all the way to the right in the pic...


the other side of the bearing goes on the block itself and lines up with the journal hole and the same kind of notch as on the cap...



the middle bearing seat also contains the thrust washers. there are four of them in the set, two with little tabs and two without. there are also two side to each of them, one side is smooth and the other has some sort of material on it (sort of like a brake pad).

the two without the tabs go on the block, we put some vasaline on the smooth side and stuck it to the indentations provided with the material side facing outward...


the two with the tabs go on the cap in the same orientation, vasaline on it and smooth side in...


then we oiled up all the bearings and placed the crankshaft back in place.


then oiled up the bearings on the caps and put some oil on the bolt threads as well before putting the caps on and torquing them down to 44 ft/lbs


next was the rear main seal and the crankshaft seal. hammered the seals flush with the housing, put some FIPG (Form In Place Gasket) on each side of the regular gasket, lubed up the inner part of each seal, then put them in place and bolted them in.



And that was it for today. Pistons and top part of the oil pan are going in tomorrow morning and that will pretty much be all for the bottom end.

made sure it all turned good and smooth after the caps were on?

wow are you keeping all the receipts and costs tallied? i want to know how much it is as i have a 7a in my garage that needs some tlc

nice job so far btw

Looking good.

Looks great. I love threads like this.

>
X infiniti

wow this truely is the most interesting thing right now!

sorry for the delay on the progress report... that CSP meet was kind of crazy...


now for putting the pistons in...
the rod bearings come in sets of 2 and both sides are the same


on the pistn rod itself there is a hole that matches up with the hole in the bearing, and just like the main bearings there is the little notch that matched up as well...


on the cap end there is not holes so you just use the little notch to place it in the right orientation...


then oil up both sides of the bearings


now if you remember from before the compression and oil control rings stick out a lot


so you need to use a ring compressor to push them in, the pistons need to be dunked in oil before this step...


now at this point you want to put in two pistons at a time (either 1 & 4 or 2 & 3) and you are going to want to push them all the way down so make sure the part of the crank the rod sits on is all the way down and straight. then we cleaned off the cylinder walls a little in case anything had gotten in there from it sitting for a while.

double check to make sure the right piston is going into the right cylinder using the stamped numbers on them...


so with the ring comrpessor still on the piston you place the rod end into the cylinder and use the end of a hammer or something to gently tap the piston down into place. once its out of the ring compressor you put that aside and finish tapping it down while you kind of guide the rod end onto the crankshaft


the caps are held on by stretch bolts that need to be torqued to 44 ft/lbs then tightened another 90 degrees. so once they are torqued you mark them so you know where to stop after doing the 90 degree turn...



the cast part of the oil pan is easy, put a crap load of FIPG on and tap it a little with a hammer so it sits properly.
there are a bunch of allen head bolts and some normal ones that go on the inside


put the little gear and the crank postion sensor back on...


and thats how it sits right now..

Looking good, nice work.....you impress me

wow. this thread amazes me.
rebuilding doesn't seem too hard now..

very nice progess.

HOT!

not trying to be an internet mechanic here, but why aren't you using assembly lube? motor oil is ok for most stuff, but i would worry that most of it will just drip down into the pan, an you'll have little protection the first time you crank it up.

This post has been edited by lagos: Sep 23, 2007 - 9:40 PM

for deisels we use gear oil to lube the bearings

motor oil works fine for putting pistons in, its what myself and most other people i know normally use.