Rods worn?

[wild_maxx]

This is a set of turbo240/ams sportsman series rods with 1500 miles on them. I ran Arias pistons on these rods along with clevite bearings.

While inspecting them I noticed some wear in the wristpin area bushing. Is this normal wear for this amount of mileage? Can I replace that brass bushing? Or have my machinist re-hone the bushing? CLICK FOR LARGER PICS!

The crank end of the rods is very smooth but has a a coating of what I think is the backside of the clevite bearing... should I have that end hone out as well?

[WDRacing]

How come you have the rods out after 1500?

[wild_maxx]

I found some metal shavings in the oil and compression went down to 120 so I pulled the motor apart to find out what went wrong. From what I found... the crank was being pushed foward by the clutch and caused the crank to eat up the main bearings back side.

That was just about the only thing I found with any wear on it. Info on the bearing stuff found here

zerothread?id=239995

[WDRacing]

A machine shop can hone thos rods for you and provide oversized bushings/bearings if needed.

[Poor_S13_Driver]

But should they look like that after 1500 miles? or could that be from the crank being pushed forward?

[WDRacing]

Its from the crank moving around.

[wild_maxx]

sounds good. My machinist replaced the rod bushings on my stock set of rods ( then I decided to run these) so he should be able to replace these ones.

The crank had about .004" play back and forth. I'm not sure what caused it but my machinist thinks its something to do with the clutch/PP being to heavy duty... but i'm only running an RPS SS clutch...

[rotorimp]

How did you lose compression? were there score marks on the cyl. walls? What cylinder was 120? What is the bore geometry like-still square? What tolerances did you use for assembly?

[wild_maxx]

Score marks were on the cylinder walls mainly on the intake side of the piston/cyl. all cylinders were at 120 psi but this was with DE 10.6:1 pistons in an E motor along with an aftermarket cam.

i'm not sure on what you mean by "bore geometry like-still square" so if you can give me more info I might be able to answer that.

I don't remember the exact tolerances off the top of my head.. but I used stock clearence's for the main and rod bearings. I think it was around .002"

[rotorimp]

Bore geometry---cylinder is round and straight--not barrel or hour glass shaped. the diameter will be the same at all points in the cyl.

I have seen extreme wear caused by a clutch but only if the thrust bearing was way off.

how clean was everything when the motor went together? how did you do the break in? when did you first change the oil?

[wild_maxx]

I don't think the thrust bearings were way off... I set them in there with the tabs lined up with the journals so they wouldn't slide or anything.

Breakin was done NA for 500 miles of easy driving just accel up to 4k them decel... went up and down alot of hills and varied rpm's alot. Changed the oil after first warm-up cycle (15 minutes) then at 50 miles, then at 500 miles.

The engine was very clean... had everything hot tanked and used a parts washer for all the small misc stuff.

[nissanfanatic]

The main girdle probably wasn't aligned correctly in relation to the main journals of the block.

[wild_maxx]

You said this before but I have no idea what your talking about. How can the gurdle not aligne up with the block? I used ARP studs and there's only one way the gurdle can go on.... I torqued it down correctly.

Can you please give more info on what your saying.

[nissanfanatic]

The Girdle can sit out of line with the journals machined into the block. Set it on without putting the nuts on the studs, and you can move it from front to back right..?? Can you see how the lip could overhang just a little bit from the machined journals in the block?

You should sit the crank in the journals, set the girdle on the crank, and put the nuts on the stud. Without tightening the nuts down, strike the front of the crank with a rubber mallet. Then strike the back of the crank once. Then strike the front again, once. That will ensure the girdle is sitting in alignment with the block journals. This way, there is no lip to cause any damage..

[wild_maxx]

alright I understand what you are saying. When you give it the final blows with the rubber hammer is that after I check bearing cleanences? Then after a few blows torque the nuts down to spec?

[turbokas13]

How big were the metal shavings that you found in the oil? i have a magnetic drain plug and there is very fine metal particles on the drain plug every time i change my oil. i changed it 3 times already. will breaking in cams and bearings cause this?

[nissanfanatic]

You should be checking clearances after all bolts are torqued down.