My Build Thread

[maximk2]

Hi guys, this is where I am going to document this rebuild. I guess I can't really call it a build because funds are limited, and can't afford to go all-out right away. Basically, the goal for now is to end up with a reliable forged bottom end, and pile back in the stock turboes.





Second day of owning my 1990 GTR back in the fall, got a little carried away with the boost controller for too long, broke piston #4 like this:



The machine shop (Cetus Calgary) says the block only needs to go 86.5mm

Taking it all apart was happy to find out that the engine has probably spun a bearing before, and has a newer crank. I was pretty happy about that. I am hoping to assume that the oil pump itself is newer as well.


Does it have to come apart to find out what kind it is?

Being under pressure to have this car back on the road by May, I ordered Wiseco pistons and K1 rods. Kind of scared of the rods selection because I never heard of those before. They should be here middle of this week.

Next decision to make is what rod/main bearings to use (if change them at all). Reading the shortblock build thread, seems that everybody is using ACL, and I guess something like that is a bad thing to cheap out on. I suppose machine shop should order the bearings because they have to measure the crank first.

PS- I haven't had a chance to look into piston clearance yet, but I know it is probably the most important thing to consider, and I have a story about that:

A buddy of mine has a turbo KA24de in his white altima. If you guys are in Calgary, when you see him at Race City, note the INSANE piston slap this thing has.

This is a result of his first build, where he brought machine shop X the parts and told them to put it together properly, and they did not leave much for clearance, and one night on a long highway bull his piston rigs got stuck inside the pistons (On two middle cylinders).

So the second time around he got it bored out some more, and installed the pistons himself, with the pistons just jumping into the holes. The piston slap is very loud, but I guess piston expansion is not going to be a problem.

If somebody could please comment on what kind of clearance would work best with the wisecos, that would be awesome.

[NismoS-tune]

A new crank (how can you tell? part number) is good if it has a longer oil pump drive collar. Oil pump is probably stock unless you can tell otherwise. Nothing wrong with a stock pump if you stay under 8000rpm. As for bearings, most people use ACL but they're race bearings and aren't always the best for every day street use. If you can afford more expensive bearings, check out cosworth, tomei or nismo (around $400) and they are much better on the daily drivers supposedly, maybe something about clearances, I'm not sure.

About clearance for pistons, you're machinist should have that figured out for you when he is boring unless you are sure you know what you're doing. I simply paid the machinist to make the decisions so I don't F up.

[BenC]

I went with the Nismo bearings simply because of the different grade selections. Makes it nice and easy to fine tune your clearances to what you want

Your Wisecos should have came with spec sheet. Just use the piston clearances that are on there

[maximk2]

About clearance for pistons, you're machinist should have that figured out for you when he is boring unless you are sure you know what you're doing. I simply paid the machinist to make the decisions so I don't F up.

I guess you are right about that, but if I won't mind a bit of piston slap, do you think there can be a real downside to it? Rings not lasting so long?

I went with the Nismo bearings simply because of the different grade selections. Makes it nice and easy to fine tune your clearances to what you want

Your Wisecos should have came with spec sheet. Just use the piston clearances that are on there

Is there a known problem with stock bearings, or are all the spun bearings stories I hear of caused by the oiling issue?

[NismoS-tune]

The break in is the biggest thing about rings. If they're cleared right, the break in tells all.

[disrupt]

Oil pump looks stock. the cover has 7 screws. N1 has 8 screws. As stated earlier the biggest thing with the crank is the size of the faces that engage the oil pump drive. if it is an early r32 crank the faces will be about 3/8" measured in the direction of the length of the crankshaft. The newer cranks or oil pump collar upgraded cranks will be about 5/8". it doesn't seem like a big difference but it is if you are going to run higher output than factory over time.

If you are rebuilding make sure your rods, crank, head, and block have no cracks.

I had my r32 crank oil pump drive upgraded, rod journals polished, mains ground down .025 because the cranks wasn't straight and then balanced totaling about $700 cdn. I think a new r33 crank can be had for around $600 usd but there are no guarantees it will be straight after it gets shipped across the world and it will take around six weeks to get it from japan.

When you buy pistons they will come with clearance recommendations based on intended use of the motor from the piston manufacturer. the rule of thumb is .001" clearance per inch of bore. So. 86mm = 3.38" therefore .0038" clearance is ballpark. That being said, I am rebuilding right now with mahle low expansion aluminum forged pistons and the manufacturer recommends .0025" for factory applications and .0035" for nitrous and/or high forced induction. There is a guy in Edmonton selling a mint condition 86mm r32 block with girdle for like $450 cdn. search the classifieds.

Also I would try to stick will 86.5mm bores. taking off as little as possible allows for more future rebuilds and say for example tomei 87mm head gasket once crushed is less than 87mm. so if you go to 87mm you would need the next size up 88mm gasket.

I have heard that you can use a factory gasket for bores up to 87mm but again this is what i heard. I crudely measured a new factory gasket with a ruler and i got slightly bigger that 87mm.

I am certified by the canadian government in magnetic particle inspection, ultrasonic inspection, and liquid penetrant inspection. I would gladly mag your block, crank and rods for case of beer per hour.

Hope this helps you out.

[maximk2]

Hey disrupt, you just answered all the questions I was just about to ask! Since I already got my 86.5mm fancy wisecos with the Armour glide, and just started shopping for a head gasket realized that nobody makes mls 86.5mm gaskets.....

My machine shop has a huge catalog for ACL bearings, and they can actually get them in several sizes, not just the STD size that is in the online catalog.

At first I was going to do the bottom end myself, but now I guess I might as well get them to do it for me....then I will be able to sleep better at night.

And they are line-honing the block, polishing the crank, balancing the entire rotating assembly, also resurfacing the head and the block.

The block was in amazing shape, with no cracks. Turns out it's an n1 block. I was wondering what that 24U stamped on the side means.



And yeah, the crank has the later oil pump drive. The engine must have spun a bearing before, and they had to replace the block and crank.....to bad they didn't also put in some forged pistons. You can kind of see it in this picture.


Weird how the oil pump is not an n1. I guess they just wanted to put a new one in and stock was more available.

Thanks to Ryan from VEX for getting the rods and pistons here so fast, and thanks to the guy who brought them to Calgary!

Here are the pictures, ended up doing quite the photo shoot:

[tryingtobebest]

A buddy of mine has a turbo KA24de in his white altima. If you guys are in Calgary, when you see him at Race City, note the INSANE piston slap this thing has.

This is a result of his first build, where he brought machine shop X the parts and told them to put it together properly, and they did not leave much for clearance, and one night on a long highway bull his piston rigs got stuck inside the pistons (On two middle cylinders).

So the second time around he got it bored out some more, and installed the pistons himself, with the pistons just jumping into the holes. The piston slap is very loud, but I guess piston expansion is not going to be a problem.

If somebody could please comment on what kind of clearance would work best with the wisecos, that would be awesome.

I used different kind of pistons the second time around (Arias) instead of Wiseco and i just hone my block but i guess Arias 20 over is different than Wiseco 20 over!

Here is a video of car idling, ya i know sounds like a diesel!))) But up to now been running with 20+ psi with no problems (of course its winter and i didn't drive it much)

http://www.youtube.com/watch?v=cE5LwsYQ2T0

This is how my Wiseco's end up expanding!!
( 4 picture from the top )

http://www.nissanclub.com/forums/forced-induction-forum-turbo-sc-tuning-technical-only/295660-need-specs-you-build-guys-brent-jose-brian-etc.html

[maximk2]

But, you just told me on the phone that you used the recommended clearance that you got with the wisecos. Yes, your turbo compressor side was too big for the exhaust side and it probably ran too hot, but I heard from someone (not going to say any names, but this someone took the engine apart with you) that machine shop X was mostly to blame.