GhostXR

I'm "somewhat budget" refreshing a 2008 LC9 (aluminum 5.3) and ran into an "interesting" issue. I had the crank polished and it still measures out within factory specs. I bought King SI bearings for both rod and mains in standard size (king main part# MB5293SI). All rods measured out to between 0.0019"-0.0021" clearance, so I'm good there, but the mains are a little too loose for my taste considering the aluminum block. Here are the measurements (journal diameter and clearance, this is using factory bolts):

1: 2.5588" ; 0.0031“
2: 2.5587" ; 0.0030"
3: 2.5586" ; 0.0035"
4: 2.5586" ; 0.0034"
5: 2.5589" ; 0.0034"

All measurements were done with a micrometer and a bore gauge (4 times with the same results). I might plastigage them just for grins as a sanity check. I wasn't expecting std size bearings to be so loose. Do I just bite the bullet and spend the $100+ on a different bearing brand either in std or 0.001 under? My fear is that I'll drop the cash and they'll still be loose, unless this is a common phenomenon to King si series. I've built several engines, latest being a 400+ HP Ford 2.3T and a 700 HP Audi 2.7T so it's not my first rodeo, but never used King bearings before.

Any thoughts or advice?

KCS

iTrader: (20)

I just rebuilt a 5.3L with Kings and they weren’t that loose for me. Check the housing bores without the bearings. It should be 2.7509” to 2.7515”

GhostXR

Thanks, that's going to be the next step tonight. Didn't see any abnormal wear on the cap/block bores but it won't hurt to check.

GhostXR

Just measured the block. All main bearing bores came in at 2.7518". Should I worry about losing 0.0003" of bearing crush? Or just get "high crush" mains in 0.0001 tighter clearance and send it? This is going in a 3200lb xr4ti with prc 2.5 heads, 600/600 220/224 Texas Speed cam, TPIS 90mm ls6 intake, honed for new rings and will stay NA. Don't plan to rev it past 6500. Block came out of a 2008 suburban with 120k, it's been cleaned, new cam bearings put in, crank polished. Car will be a 6 speed.
EDIT: as soon as I move the bore gauge about 10-15 degrees off vertical all bores fall into 2.7510". I'd expect that at 45+ degrees... Weird.

KCS

iTrader: (20)

When I line hone an aluminum block, I try to put it on the low at about 2.7509” since I know it will grow a lot as it gets hot. If I were you, I would look into having the block line honed. You won’t have to buy new bearings to get the clearance where you want it and you will get the crush the bearings are designed for.

RonSSNova

iTrader: (3)

I found that torquing the caps in the proper sequence prior to making measurements made a difference.

My block was line honed.

I was looking to get .0025 and had bought +.001” bearings but ended up with std bearings and got what I wanted. Crank btw was a new Molnar.

Oil pressure is excellent with 10W-30 despite the looser clearances.

Ron

GhostXR

I torqued the caps per service manual (torque 1-20 to 22 Ft-lb to seat caps, loosen, do 1-10 to 15 ft-lb, add 80 degrees, 11-20 to 15 ft-lb, add 53 degrees, side bolts in pairs to 18 ft-lb) I'll have a machinist friend double check me again. I worry that even with the bores corrected I'll still end up on the loose side (since the main bores are. 0009" loose from the "tight" spec and my bearings are about 0.0015 over where I'd like to see them) so I ordered a set of clevite MS2199H1 (0.001" under). We'll see what happens.

RonSSNova

iTrader: (3)

Very good. Keep us posted.

Mine is alum L33 turbo, and when I found a bad thrust, I also noted some slight bearing scuff. Clearance was .0019 at that time.
hence the desire for a bit more bearing clearance. Those bearings were Clevite H series.

Ron

GhostXR

Well, my buddy triple checked me with his tools. Main bores came in at 2.7514. Not sure what I was doing wrong. The clevite bearings came in today and all measured much better, from 0.0018 to 0.0012 so I can proceed with assembling the shortblock, yay! Guess that's a difference between a $25 set of bearings and a $140 set. Lesson learned. Thanks for the help guys!

Fishmasterdan

What wrong with 30's?

tech@WS6store

iTrader: (2)

Clevites arent $140 unless youre buying from the wrong place or switching bearing design.

King are just as good as clevite. We sell both but use the king in all our rebuild kits and have sold hundreds and ive installed at least 20 sets with 0 issue.

GhostXR

@Fishmasterdan Nothing wrong with 30's on an iron block. IMO it's an issue on an aluminum block since it'll grow in the neighborhood of 0.001" at temp.

@ WS6: I originally had King MB5293SI, which measured too loose for my taste. Not a huge loss since they were $25 or so. I replaced them with 0.001 undersize clevite part# MS2199H1 which were $140 through summit (and most suppliers, including your store @ $149.95)

I understand that they may be two different types of bearings, hence the price difference. I have a couple of friends that used kings without issues, that's why I was surprised. No matter, it's solved now, I just finished putting the shortblock together last night.

tech@WS6store

iTrader: (2)

I dont like using the H series on a stock crank. Ive seen issues with oil controls using them plus i want as much bearing surface area contact as possible with the crank.

Whats funny is the h1 is 149 and the h is 139. We have alot of odd price glitches like that. Ill get them fixed though.

01CamaroSSTx

iTrader: (3)

Your not the first person I've heard state this about the H-Series when using the stock crank.

GhostXR

What kind of oil control issues have you seen? Too much windage from oil getting slung around due to narrower contact pattern? This motor will be na in a relatively light car
I wish I could remember what series I used when I built my 2.3t. I *think* those were p-series but that engine sees 7500 rpm and 30 psi boost routinely.

tech@WS6store

iTrader: (2)

Lower than expected oil pressure normally and a drop with rpm vs expected also plus higher oil temp.
Since the same amount is being pumped theoretically it should not make more windage or mist. But the change in area will cause the oil pressure to drop. You can picture that in your mind if you are awake at 1:22 answering tech emails hopped up on mountain dew baja blast.

G Atsma

Whoa... the Mountain Dew mind blast... (yeah it works with original MD too...). Been there.....