SWRocket

Hi guys,
I have a stock LR4 4.8 engine in my car, with 2 turbos, but I have a failure last week.
Need your help

I want to use the parts that I have in good condition here (I'm in Brazil and shipping and tax is very expensive here)
So I will use my:
4.8/5.3 iron block
4.8 crankshaft (number 482 - 3.267 stroke)
I need 3.800 bore. (max 3.820)

What I need:
Forged rods (callies, eagle, or other than you reccomend) with ARP
Forged pistons kit (JE, Diamond or Wiseco) 3.800-3.820max

My concern is about the rod size and piston height relation, to get the 9,2:1 CR until máx 9,8:1 CR, because I dont find forged rods with the measure of the 4.8 engine (6.275). I'm from Brazil, so I can't buy anything wrong. lol

I find Manley forged rods 6.300 (stock are 3,267)

What you sugest?

thanks

svslow

If you want to use the 4.8 crank you could go with a 5.3 Wiseco piston, 1.300" comp height, and the 6.300" rod. This will put the piston in the hole 0.0065" with the stock 9.240" deck height.

9.240-(3.267/2)-6.300-1.300 = 0.0065" (in the hole)

You could then deck the block to bring compression back up.

SWRocket

What do you think that will be the best assembly using this 4.8/5.3 block?

Thanks for your help!

svslow

As far as I know there are not many good options for a forged 4.8 with off the self parts. It would be a lot easier to get a 3.622" stroke crank and use 5.3 sized rods and pistons.

SWRocket

Deck height is the same?

3.622" stroke crank
3.800" bore pistons
6.098" rods

is this?

If I get 6.125" rods, what will be the CR?

Sorry for the questions... V8 engines is new to me.

svslow

Deck height is the same. CR will mainly depend on the piston design and the cylinder head used. I'm sure there are plenty of people using the 5.3 Wiseco pistons with 6.125" rods.

redtan

iTrader: (5)

Why not bore the block out to LS1/6 specs? Lots more piston choices available at that point.

SWRocket

If I use my:

Stock crank 3.267
Rods 6.300
pistons 3.800:

pistons spec:
• Bore (in) 3.800 in.
• Bore (mm) 96.520mm
• Compression Distance (in) 1.300 in.
• Notes .927 in. pin diameter, designed for use with aftermarket rod.
• Pin Diameter (in) 0.927 in.
• Piston Head Volume (cc) +2.20cc
• Piston Material Forged aluminum
• Piston Ring Thickness 1/16 in. x 1/16 in. x 3.00mm
• Piston Style Flat top, with two valve reliefs
• Quantity Sold as a kit.
• Wrist Pin Style Press-fit or floating

http://www.ebay.com/itm/Wiseco-Pisto...lVL8d8&vxp=mtr

This should fit ok?

SWRocket

I want to avoid buy a new crank, because shipping and tax costs are too hight to Brazil...

So if I have an option that I use my stock block and crank should be better

svslow

Those pistons are what I was referring to in my original post. They would work.

SWRocket

thanks a lot for your help!

About the "Big End Bore", the stock is 2.225"?

redtan

iTrader: (5)

Well bore/piston size has really nothing to do with what crank you can and cannot use.

All I'm saying is that there are a helluva lot more pistons available for the 3.898-3.905 range than at the bore you are currently at. Should make for cheaper and easier to find pistons that will work with your current crank and rods.

SWRocket

I found this Parts:
01 set of 8 Manley Rods ARP2000, 6.300": p/n: 14064R-8
01 set of 8 Wiseco Pistons: p/n: K474M965
8 units Wiseco Piston Rings: p/n: 3805HF
01 set of Main Bearings King XP, p/n: MB5013XP
01 set of Rod Bearings King XP, p/n: C807XPN
01 Melling Oil Pump, p/n: 10296

Problem now to find is the head gasket 3.805 bore

SWRocket

HERE WE GO!

svslow

Nice!

Shaggykjb

Go with the LS9 head gasket. I think it's MLS 7 layers and it's GM built for boost. Will work fine for your bore size. I'm building an iron ls1 from a 4.8 with 3.905" and it fits nice.

SWRocket

What bearings are you using? I buy King Trimetal but I'm a little concern because I see some failure cases of this bearings in Subarus EJ engine...

I already buy a gasket kit...
I'm thinking in do o'rings in the cylinders....

Shaggykjb

Sorry for the late reply. I went with Cevite 77 P series standard size. It's about as good as tri metal can be on a stock bottom end.

SWRocket

what bearings is the best money can buy? lol

Shaggykjb

It depends on if you need tapered bearings for after market rods (h clevite 77 trimetal)
Or stock rods and an untouched crank (p clevite 77 trimetal)