Deeohgie69

iTrader: (3)

I was wondering if anyone has used the King XP series bearings before and checked their clearances vs oem?

I talked to King today on the phone and they told me that their standard XP bearings are .0005 for more oil clearance vs oem gm bearings. I wanted to know if anyone could verify this for me?

I measured my clearances with a set of new gm bearings and they all were between .0015-.0017. It is a for a turbo build and I'm shooting for around .0025 for my clearances. They offer the STDX which is .001 extra clearance, but of its true that their XP series are .0005 bigger clearance than OEM, then it would put me around .003 and that's too much for what I am doing.

So if anyone has any data on this and can tell me if it's true about the XP, I would really appreciate it because I don't really want to buy two sets of both bearings.

Thanks

Dave

Edit: Also wanted to ask, if I did go with the extra clearance bearings and the XP did end up running .0005 bigger, what would be the issues I could run into with .003 clearances on rod/main bearings? Could I just throw I high volume melling pump on it and be good to go? Or could it cause other issues? The motor will likely only be between 650-750rwhp at any given time.

pantera_efi

iTrader: (1)

I switched to King Bearings years ago after inspection viewing better quality/size tolerance/cost.

Your question IS not clear, Main or Rod ?

The Main = .0022"-.0025" with smaller = better.
The Rod (Forged not OEM) = .0029"-.0031" as common, span is OK.

The Oil Pump I fit is 2010 Camaro, stock has larger rotors fitted.
This ALSO allows for a LS-7 Timing Chain (IWIS) which is the strongest.

KEEP your Main "small" as the Aluminum block grows MORE than an Iron Block.

Thus what is your block material ?

Lance

Deeohgie69

iTrader: (3)

It's a stock gen 4 iron block. My question is because King bearings told me that their standard XP bearings on main and rod bearings come out to around .002 vs the oem gm bearings of .0015-.0017 that mine read.

He said that if I used their standard XP main and rod bearings that my clearances would be around .002. I wanted to know if anyone knew that to be true? Because I was going to buy the sdxp standard bearings with extra .001 clearance to get me around the .0025 that I'm shooting for. But if their standard main bearings already are around .002 vs the oem gm main bearings that measure .0015-.0017 when I measured, then if I got their standard extra .001 clearance then my main oil clearances will be around .003 according to them because their standard bearings supposedly read about .0005 more than oem.

Does anyone know this to be true?

Edit: both the clearances on the rod and main bearings ended up between .0015-.0017. I'm just trying to see if I can just buy the standard or if I needed their standard extra clearance, but idk if they have more clearance than stock OEM bearings.

pantera_efi

iTrader: (1)

What King Bearings states is TRUE, of course !
NOW, they may have a "hand" on a "mike" different from your hand.
There is the Temperature of crank/rods/block not stated.
The difference IS 1/6 that of the hair on you head.

THE BOTTOM LINE, just buy 1/2 a set of rod bearings, a set of mains.

MY use of "cracked" rods (OEM) in a higher that stock HP engine has never been done.
YOU STATE 750 RWHP, just NOT DONE with Cracked Rods.
Your are ALSO near the limit of the block main caps !
You may also want to notch the rod "big" end (both sides) toward the pin for an oil volume cooling increase.

Lance

Deeohgie69

iTrader: (3)

Ok, thanks for the info. I'm just learning about this side of it so I don't fully understand it yet. So you're saying to just buy a half set of the XP standard rod bearings and mix it with the thicker oem bearings to only loosen the clearances up a little. And then buy a complete set of the mains, so it will open the clearances up to around .002 if that's what the bearings are spec's for?

Also, I was reading about mixing halves of bearings and it says to put the thicker bearings on the top and thinner on bottom. Since the XP are a harder material, should I put those on top vs the oem ones, or did I read what people were doing wrong?

Edit:Also wanted to add, that it will mostly be driven around on low boost which will be around mid 600's and only see full boost probably 15-20% of the time.

pantera_efi

iTrader: (1)

You have the correct understanding, NOT SURE about your OEM bearing choice.

MOST GM OEM bearings ARE steel backed/Aluminum, NOT PERFORMANCE.

You may be better off to use a "tri-metal" design.

READ the back of the chosen bearing, the steel side, and report.

Lance

Deeohgie69

iTrader: (3)

I only used stock oem bearings to check clearances to get an idea in hopes that the extra .001 clearance would put me right in the range I was looking for. The King XP bearings I'm wanting to run are the tri-metal though.

jayyk31

iTrader: (2)

I bought a set of the king XP +.001 extra clearance and I ended up with .0023-.0025. I wanted more clearance so I bought a set of Fed moGul .001 extra clearance and came in .0027-.0030. I was more comfortable with those #'s so I didn't run the king mains. Iron lq4 .030 over w/ forged 4" crank.
Now I am using the king XP rod bearings and I came in at .0023-.0025. Forged 6.125 rods.
Hope this helps