ARP rod bolts?

[ST240]

So im of the understanding that a guy absolutely should not reuse RB rod bolts ever ever ever?

But is it worse to install ARP rod bolts without getting the big end resized? Have any of you installed them without resizing?

[Carl H]

install ARP rod bolts and skip resizing if you like seeing the rod outside of the block...
RESIZE IS A MUST!
I would reuse stock nissan bolts over using arp rod bolts on rods that have not been resized.

[ST240]

Thanks for the reply.

Have you reused stock nissan rod bolts before? I think I'm just gonna have to bite the bullet and get the damn things resized...

[Carl H]

yes, but its a ticking time bomb...we did it on a ka-t i did up ages ago and its still running around but we've kept the rev limiter low on it.
a good friend of mine had a ka-t let go and we determined it was due to the rod bolt, again stock gear.
resizing is cheap, local shop does it for me for 12$ per rod.

[ST240]

I'm just gonna do it proper. What does it all involve? Do they need your crank and bearings too? Or just the rods and bolts.

[Carl H]

a good machine shop should just need the rods and bolt as well as the service manual for dimensions...bearings should be sized approprately.

[FinkenS14]

OK im kinda a newb at rebuilding engines so whats this "resizing" you guys are talking about?

reason being is im building a full forged bottom end RB30 for my car.

[Darius]

I didn't have the big ends done on my rods, but I mic'd them after I got them back from the machine shop to make sure they were within factory spec. Haven't had problems. <knocks on wood>

[RustspecS13]

OK im kinda a newb at rebuilding engines so whats this "resizing" you guys are talking about?

reason being is im building a full forged bottom end RB30 for my car.

Basically they are checking for roundness, as you don't want the bearing surface distorting when you put in the new rod bolts.

~Alex

[SullivanRacing06]

arp rod bolts are something you need, factory bolts will stretch, the large end on the rods need to be tqd down to new spec and be resized to true the roundness

[ST240]

Right.

Ok so then riddle me this:

Lucky for me every f*** machine shop in this redneck city has barely worked on import engines, let alone RB30s. So i gave the guy the tunnel dimension out of the ACL catalog.

So he resized them, everything looked fine. He hands the bearings back to me in a pile. I said "wtf mate" to which he promptly tells me, "they were all the same size anyway". I don't trust that statement at all. There was one piston that had a grade 0 and the rest were grade 1. Which is a huge b**** because now i dont know which ones are which, can i identify them by other means? the stamped numbers on them are all the same, and ill be damned if im measuring the difference in thickness, a tenth of a thou, accurately. But isn't that moot anyway? By rights shouldn't a guy have to to mic the f*** things up and get new bearings when the rods are resized, regardless?

Edit: So i just thought about it. And seems to be pretty obvious that yes, i gotta check them/get new bearings. We use telescopic gauges or "snap gauges" which are then measured with mics for measuring bores on our downhole tools at work. Is this acceptable for measuring bearing clearances?

Man i should goto bed. I hope that post made sense.

[Bluefire]

I generally prefer an actual bore gauge to measure bearing clearances, but the telescoping gauges with a micrometer is fine. It just takes a lot of practice feeling confident in your measurements. But with stock style rebuilds i don't even bother with measurement, i just use plastigage...

If you were going to reuse OEM bearings then you'd have to keep them in order, but if the motors apart you might as well get new bearings. Are you also reusing pistons? New rings? balanced rotating asssemby?

[ST240]

Everything is being reused except for rod bolts and headstuds. It's just a slapper to drive around for the remainder of this season. I'm building the block over the winter.

[ST240]

Bump. Again... And thanks guys for the replies.

So thanks to rod resize and the bearings being who-knows-what in a f*** pile on my floor, I figure I need to buy all new OEM as per the grade stamping on the rod/crank, or go with a new set of ACL.

Have any of you bought ACL race bearings and installed them, and ended up with the proper clearances without grinding? I was under the impression that anytime you go for ACL or other after-market that journal grinding is manditory, as bearing grades aren't available.

[l0nestar]

I didn't use ACL, but King main and rod bearings. no complaints. All I had done was when the collar was being installed, I had the journals all micro-polished. no real 'machining' done.

[ST240]

Ok... I'm gonna polish the journals for a second time and a set of std ACL race bearings are on the way. Wish me luck with the measuring.

[neo240sx]

I got a set of ACL race bearings in my setup. Didn't resurface anything. Re-used stock rod bolts. Its been fine for like 10k miles. I take it up to 7000 rpm occationally but dont really make any more power up there because of stock cams. never had a problem.

[Bluefire]

I've used acl bearings on quite a few motors, and they were almost all within the fsm bearing clearance limit. its a pain in the butt dealing with oem bearings

[Carl H]

the variance in tollerance for the oem bearings is silly, it can drive you insane picking the 'right' oem bearing grade and even then it may be a hair tight or loose!
acl bearings by and large are the same thru and thru with some deviation (unavoidable) but like bluefire said, they are always within nissan's tollerance range for bearings.
however, once you have installed a bearing set with a rod and its respective cylinder journal you MUST keep it with that rod, position, and journal as it will seat to that particular setup.

[ST240]

Excellent replies guys. You're restoring the faith. And yeah i did gather the tolerances were a little ridiculous.

It looks like ACL makes all their bearings to the STD 0 (ie thinnest) size. So everything should have proper clearance. I'm going to check to make sure though.

[ST240]

Looks like they're 2.3 to 3.5 thou clearance measured using a snap gauge and mic. I'm calling that good enough for this summer although she is creeping up to the limit value. "f*** it, lets go bowling"