I have a 2006 LQ-4 that I would like to overbore and add some good rods and forged pistons to. What is the max over bore that is safe for this motor. Would like to do a stroker kit , but alota $$$$$$ Is this worth doing..... new rods, pistons using the stock crank? I could have the crank nitrided for a litle extra strength. Also would like to end up with around 11:1 compression. This motor would be used for street/strip, not serious racing. Thanks

 

I have seen guys go .060" over but the more common route is .030". Normal shelf pistons can be found with the 4.030" bore and will be cheaper on your wallet. You can easily do just rods and pistons to save some money. I don't know if I would mess with doing anything to the stock crank. They will take a decent amount of power as they are.

Jon

 

Thanks Jon for the information. Do you think this is worth doing? or should I go to a stroker kit. What kind of extra power would that 30 over yield? What would that give in terms of extra cubic inches? I would bump the CR up to maybe 11:1. I also have unported L92 heads and a carb set-up. Thanks

 

I have a "stroked only" 6.0 LQ block that's got forged internals and ARP everything. I'm at 402 ci and love it! I've ordered AFR 230 heads and I've got a FAST 102 coming today for it. It'll put down 500+ to the wheels and be in the high 10's. That'll be enough for me as it's a daily driver.

 

So a stroked 6.0 with no over bore yields a 402? Just a new crank and rods?? How does that work??

 

I believe it's a 4" inch stroke for a 402. And I believe .030 over is a 408.

 

The rods and pistons will be the same price. Just the cost of the crank is added. It just depends if the added HP is worth the $800-900 you spend on a crank. IMO I think it is but if you are on a budget, you can still make good power with a stock stroke application. The HP depends on the heads/cam and supporting mods. Each combo is going to be a little different so it is hard to say. What setup are you planning on running?

Jon

 

Thanks for the info. I didn't know that you could get a 402 with just a crank. If I decide, this is probably the way to go. I doubt that you can make that kind of power of a 402 with just a .030 overbore on a stock motor. I have L92 heads that will support a 402 along with a good cam. I just don't think that doing all that work to a motor (machine work) will be worth it in the long run for a .030 over plus figuring in the cost of new forged rods and pistons. Please correct me if I'm wrong.