static low 92

iTrader: (2)

I'm on my 3rd engine in my C-10, I've relied on machine shop in past with huge disappointment is longevity because of shoddy and not detailed work, and got bent over and no warranty or help in rectifying the problems.

So. This go around im assembling my own engine with utmost detail I can achieve as well as attempting to "blueprint" the build with critical measurements etc.


With that said. I'm at stage of needing to order main/rod bearings to start assembling the short block. History of parts. I have my old rod/piston assembly from last failed engine (06 LH6) that had been honed "resized" to correct from having ARP bolts, the last engine had a crank turn. So need to figure out what rod bearing size/part number to use with fresh unturned crank.

Rod Journal: 2.226
Crank Journal: 2.099





Block is now an Iron 5.3 with ARP main studs and line hone. Crank is stock un-turned and polished.
Block Bore Specs:
For simplicity Well call them all 2.7515

Crank Journals- 2.5586



Question #1

Use aluminum bearings or Tri-metal? Was originally looking at Clevite Calico coated stuff.


Question #2

What size- over/under to be suitable for my turbo application given goal of .0023-25 clearance

I believe ACL 5M7298HX will get me in my range I want for mains, but that is the only option except std size.

http://www.aclperformance.com.au/Che...7LBearings.htm

static low 92

iTrader: (2)

Well, after a bunch of my own research. A call to BTR and to Mahle. Looks like they don't offer a rod bearing in the configuration that I want to achieve the clearance goal I have.

Only option I have now is to have my crank rod journals turned .001. Fantastic (insert sarcasm)

KCS

iTrader: (20)

That's not so bad. Get the 1776p-10 and turn the journals .010" (usually what the crank grinders prefer over only .001"). Measure the bearing bores before hand and give them the journal OD measurement that will give you the exact clearance you want. No screwing with sets to get your clearance or getting close enough.

static low 92

iTrader: (2)

Well after some more talking with a engine builder/machine teacher at local tech school that does a ton of LS stuff. My path to correct this issue is a new set of rods.

Apparently if they egg a rod using ARP hardware (1 in 50) they toss it, they don't resize. Which is why im having a difficult time. Clevite/King is only one offering a bearing for overbored rod, which limits me to essentially 3 bearing options. And none of them are a high performance bearing.

Seems my removing the alignment sleeves on bolt installation is probably what screwed me. So on the hunt for an unmolested set of GEN IV rods to install my ARP bolts in, and I will have all the bearing option I could ask for.

Most likely looks like I will use ACL rod/main bearings.

KCS

iTrader: (20)

Check out Competition Products. They have an ACL Race bearing for the oversized stock rods. I'm pretty sure they're availabke in STD or X sizes.

static low 92

iTrader: (2)

Problem I've been told is if I end up with a bearing that thin, I loose some crush/squish. Considering its a turbo application, that probably is bad for longevity.

After all my previous issues, I want this thing to be as well assembled as possible.

KCS

iTrader: (20)

That doesn't even make sense. Each bearing shell is .001" thicker for the .002" oversize. An X bearing shell would only be .0005" thinner, so you still have a thicker bearing shell than a standard bearing you're considering going to.

Regardless, we're talking very very minuscule differences. A sheet of paper is like .003" thick. It's not really going to matter if you have an X or 1 under or .002" oversizdd bearing. Get the bearing clearance right, that's the most important part.

static low 92

iTrader: (2)

That's true.

At this point, I would rather buy new rods. So I have broader range of quality bearings. VS taking material off crank and being stuck with essentially 1 bearing.

Cost is actually cheaper as well. $100ish is what used stock rods are going for. Crank turn I think was $170+

KCS

iTrader: (20)

The ACL bearings I mentioned are not for turned down cranks. They are for standard journal sizes.

B663HOS2-STD is your standard sized bearing. B663HXOS2-STD is for .001" more clearance. To my knowledge, Competition Products is the only company that can get this bearing.

rpturbo

iTrader: (47)

I don't see how buying a different set of used rods, is going to solve your issues. Anytime you use ARP rod bolts in stock rods, they need to be resized because they simply have more clamping force and will at least, close up your tolerances. It has been discussed numerous times.

Why did they say they don't resize the rods? I only heard that in the past before they started making oversized bearings, but now they do. The way they resize these because they are cracked rods, is they open them up, and you simply run a oversized bearing. Since you want to coat your bearings, start with the rods and work backwards. I know that sucks and it's MORE money.

IDK, my junk goes together Tuesday.

machinistone

I'm not a huge fan of reusing the stock rods in any performance application unless it's they're truly virgin and I can size them perfectly. That being said, if your 2.226" measurement for the rod housing bore is correct, thats .0007" under the low end of the spec and will cause too tight oil clearance and distorted bearings leading to odd wear patterns as the bearing is over-crushed.

Either get a virgin set of good late model bushed rods and have a competent machinist size them to the proper spec for the .002" oversize bearings, or get a set of aftermarket rods and have your choice of any bearing out there.

I have a low mile take-out set of the good LS rods here if that's the way you want to go...but considering you're going turbo I honestly think aftermarket is the smart choice.

ACL Race(tri-metal) is my bearing of choice for the LS engines.

static low 92

iTrader: (2)

I had a conversation with Jim Grey of Ranken, he's the machinist/high performance engine teacher. They do TONS of LS stuff. He told me they use ARP in stock rods on a regular basis. 1 in 50 with have an issue, they DON'T resize them, he said they toss it and snag another one.

I removed my sleeves when I originally built that motor which caused my egg issues. I will grab a set of clean rods and leave them sleeved and see what happens.


ACL bearings have already been ordered.