Just yesterday - the big brown truck stopped by my house to drop off a new set of Patriot Performance Stage II heads (5.3L milled 10/1000 to clean them up) and a new Futral cam. I ordered a 226/230 .576/.580 113LSA but the cam card with my shipment says its a 228.5/229.3 .578/.596 113LSA (dont know if that kind of variation is typical on custom grinds or if it just means I got myself a bigger cam - lol).

Regardless - someone mentioned to me that due to 230 duration - that I might need new pushrods. Right now, I have the stock length chromolly pushrods that I ran when I was running cam only with the XER 224/224 cam (only 2000 miles on them). Is this thinking right?

I have already spent enough money on what started out as a repair (why replace when you can upgrade right?) so I really dont want to fork out more $$$ unless I need to.

Ultimately, my concern is the safety of the motor so I wont skimp on something if it is recommended or needed but I have only heard "new pushrods" mentioned once - so I am just trying to figure out if that statement carries any validity.

Any input would be appreciated.

 

Anyone?

 

The length of the duration has nothing to do with the length of the pushrods. Its the base circle and how much your heads were milled is what matters. Comp cams all have a base circle that is about .030" smaller than the stock LS1 cam. Since you were already running a Comp XER cam with the .030" smaller base circle, by putting these new heads with a .010" mill, you are actually going to be closer to stock than you were before.

Milling heads, negates a smaller base circle. So, in essence, you are only .020" shorter than stock. Since they dont make a 7.420" pushrod, you can stick with the 7.400" length pushrods. Aaaah, the beauty of hydraulic lifters!

 

***taking hand and passing it quickly overhead***

Ok - so I guess you are saying all is good - lol

Thanks!

 

Yeah, you'll be fine. If you really want to learn about base circles and how cams affect pushrod length, I highly recommend the LS1/LS6 Performance book by Chris Endres. It came out about 3 months ago, and you can get it at almost any book store, including Amazon for about $17. It covers everything from the basics to some moderately advanced concepts, and will make you understand a lot more about your motor.

If you really dont care to learn, then thats okay too!

 

If you have upgraded the pushrods from the stock POS ones and they aren't bent then I would say you should be ok, but if you have spent a lot of cash on your new set-up another $120.00 is a small price to pay for piece of mind(just in case you have a weakened pushrod or two). Sine you already have them out, and they are fairly cheap...why not replace them. If the $120.00 is a major issue then like I said as long as your existing ones are in good shape (not tweaked at all)then you're good to go.

 

Can someone explain the advantage of using hardened pushrods? I have never understood this, seems to me that it is better to have your pushrods as the weak link instead of your valves???

 

From what I understand it is a tradeoff - yes, you would be better off if they were the weak link instead of your valves, However, if they flex, you lose valve motion and hence power. Make sense?

I guess that means if you are an M6 guy with hardened pushrods, Your getting the most from your cam, but you better not miss a shift!!