Mike K.

I think I may have a bad ring. If I have to tear the motor down to the point to replace a ring would it be worth having new pistons and rods put in while I'm add it? I would like to spray a 150 shot but I will probably spray only a couple times a week if that,,, keeping this in mind do I have to replace the stock rods or would just replacing the pistons be good enough? If I should replace the rods what is a stock replica? My goal would be to keep the same bore and stroke just want to make the bottom end a little stronger. Also I noticed that alot of the aftermarket 347 piston replacements have a bore of 3.905. I thought the stock bore was
3.898. Is the 3.905 to accomodate a cleanup hone for a rebuild?

Also looking at some piston specs gotten from Thunders website

Diamond Pistons LS1 Forged Flat Top Piston set w/ -2cc Valve Reliefs, 3.905" BORE / 3.622" Stroke / 6.098" Rods / 1.340" Comp Height / .945 x 2.500 Wrist Pins Included

Can somebody run down the list of what each spec means? the first two I get cause they seem to be referring to the stock bore(with cleanup hone?) and stroke.
But this I am not sure of

/ 6.098" Rods / 1.340" Comp Height / .945 x 2.500 Wrist Pins

Any explanations would be nice as I may try to rebuild the motor myself if it turns out that a ring is bad and as you can probably tell this will be my first motor rebuild. Just trying to learn here.

2001CamaroGuy

iTrader: (6)

3.905" is a clean up bore size

3.663" is the stock stroke

6.098" is the stock LS1 rod length. When replaced with an aftermarket forged rod, a 6.100" SBC rod is usually used (much cheaper than having custom rods made) as the large end of the rods (both LS1 and SBC) use a 2.1" bearing (both the same).

1.340" compression height is the distance from the center of the pin to the top of the piston. The thicker the CH, the stronger the piston will be. The CH is reduced (pin is moved higher in the piston) as stroke and/or rod length increase to keep the top of the piston at the same distance from the crank (deck height).

-2cc is a how much "space" the valve reliefs in the pistons will add to the overall cc (how it will effect compression).

.945" wrist pin is the size of the stock LS1's rod wrist pin (if you are reusing the stock rods). If you go with a forged SBC rod, you will use a .927" wrist pin.

2001CamaroGuy

iTrader: (6)

now...with all that said, I am in the same boat as you. I have an 01 that burns oil like CRAZY (rings are shot/were bad from the factory).

In order the swap rings, you (and I) will HAVE to rehone the cylinder (the motor will have to come out of the car) to make the new rings seal. With that in mind, you might as well have the motor bored 0.010" (usually ~$600 for a FULL block work over.....line bore, deck, cylinder bore, and hone) and install forged pistons.

I don't know what to tell you on rods.....some people say the stock rods will do wonders (someone said they got 550+ rwhp through ARP bolted stock rods at 7300RPM) while others say they won't go much past 450 rwhp so......

I personally am going to go with Eagle forged 6.125" rods as they are $400 from Summit/Jegs/etc. and are good for 700 crank hp (must more than I will EVER do).

Mike K.

Thanks it all meakes sense now, while the block is out doesn't the maching shop have to balance the new parts as well and I know I am ignorant but what is an SBC rod?

Chris99WS6PWTMET

Mike, Give CRE Machine (407-649-1789) in Orlando a call. Ask for Dave. They do good machine work and are very familiar with the LS1/6, as they do block work for Norris Motorsports. They just got done doing all my machine work (.005 hone, align bore, clean, new bearings, clearance all bearings, dip/clean block, balance entire assembly). I did not compare prices to other shops as they came highly recommended by Norris and no shops here in Jacksonville had the LS1 torque plate, but it cost me $1100 for everything. All rods/bearings/etc are clearanced and numbered, all I need to do is re-assemble it. They were done in 4 days and have great customer service. Good Luck.

BTW - I spoke to Paul @ Thunder and Chris @ Diamond about what I wanted from the car and took their suggestions on which set up to go with. Great people to deal with.

Mr. B

iTrader: (1)

I thought that the aftermarket rods (ie, Lunati) were 6.125"??

The new Eagle cranks hitting the market also call for 6.100" rods.

I'm a little confused here..

2001CamaroGuy

iTrader: (6)

they come in lots of lengths.....I said a 6.100" because that is the "closest" to stock length rod out there.

A 6.125" rod is used with stroker cranks in order to keep a good rod length to stroke ratio (thus the Lunati rods that are used in their 382 stroker kit are 6.125"). At the same time, adding a longer rod to a stock stroke crank will only make the ratio that much better. The only think to watch out for (going longer) is that you don’t make the rod too long so that the compression height gets so small that:

a) the pin gets into the oil control ring (you burn more oil)
b) the compression height gets so short that lots of nitrous or FI (cylinder pressures) could crack the top ring land

Mike K.

So a 6.125 rod is ok for stock displacement then?
Also has anybody heard more about those eagle rods. Thats a good price.

And help a brother out. What is an SBC rod?

2001CamaroGuy

iTrader: (6)

yep.....I will use a 6.125" rod in whatever I do

a lot of people seem to be using the Eagle rods without any problems. There is a limit to what they will take (Eagle says 700 HP max and I would not run past 7500RPM) but considering the next step up is $800 for Lunati Pro rods.......I think they will do for what I want (especially since there are people pushing ARP bolted stock LS1 rods to 575+ RWHP ).

SBC = Small Block Chevy.....DOHHHHH

SMOKIN01TA

iTrader: (10)

im assuming it means a small block chevy.

99 Black Bird T/A

iTrader: (4)

I'm in the same boat as you guys I have a LS1 with bad leak down and it will need the above too.

IMO if your going to spray - it probably depends on how much you want to spray. If you going to do big shots go forged. I'd have to go forged if I sprayed at all so I wouldn't worry about it.

Mike K.

Damn is all I can say about that.



Do you guys think that the JE pistons are the Diamond pistons are better?

99 Black Bird T/A

iTrader: (4)

I think it might be worth looking into getting which ever you choose coated.

Scott Turvey

The stock rods aren't necessarily the problem, it's the bolts. Chevy has even had service bulletins about not revving them past 5800. If you do use the stock rods, besides replacing the bolts have them checked, ground and shot-peened.

2001CamaroGuy

iTrader: (6)

Everyone I have talked to says they are the same quality product so really its just which ones you can get a good deal on at the time (ie: on sale).

Like T/A said, coating is a good deal. It keeps the heat in the combustion chamber and does not let it saturate the pistons (more power and longer parts life). I plan to having the piston tops and the CC chambers on my heads done when I rebuild (here is one place http://www.swaintech.com/price.html ) as it’s not that expensive and every little bit helps.