Right now, I have 127,XXX miles on my stock LS1 with an MS3 cam, PRC stage 2.5 5.3L heads, and a Fast 90mm intake. It has had a good life, and is still running, but is burning a little oil, and I want to rebuild the engine.

What all would be required to rebuild it like new again? I would like to install a MONSTER sized cam, and would love to touch closer to the 500 RWHP mark N/A.

Would I be better off going with a crate motor? If so, what are my options?

I want to stay somewhat cheap, but will do what is required to refresh everything so it is young and healthy again, and really want a larger cam than my already "large-ish" MS3 cam.

Options?

 

Have you done a leak down test? Do you have a catch can? Maybe you only have a problem with your PCV system and your motor is fine. I know this doesn't help you fit a bigger cam but it's just a thought.

 

I basically have your exact combo and put it in a 6.0 after my LS1 blew. It now has more compression plus more hp and tq. If you really want to break the 500 rwhp mark you should just get a 408 or something similar with better heads, cam and intake...that will do it

 

My LS1 with the same heads as you have, a medium cam (228R) and LS6 intake only made 400 RWHP. If you want 500+RWHP I fear a block that you can get over 400 cubes out of, better heads and a slightly bigger cam is in your future.

 

Besides the oil, it has 127,XXX of HARD driven miles. I know the LS1 is a great motor, but its only gonna take the abuse so long. I am wanting to put in an even MORE agressive cam than the MS3 thats in it. So, I want the insurance of the rebuild.

I don't want to drop $4,000+ in a new engine, or slightly less in one that is used.

I am not sure what the CR is currently at. The 5.3L heads did bring it up a bit, so I am guessing my CR is not going to be able to come up much further. I would be happy with whatever a bigger cam would give on the rebuild.

 

If I remember correctly the 5.3L heads bring up the CR by about 0.9

 

Ok you're now saying you'd be happy with whatever power a bigger cam would give you, but before you said you'd like to get around 500 rwhp...you do realize that's not going to happen with just a bigger cam right lol? Also running a bigger cam with those heads on a stock cubes LS1 would not be a wise choice and in reality would not be any faster

 

Have it rebuilt with new pistons and reuse the stock rods with ARP bolts. Use new rings, bearings, and seals. Aftermarket forged pistons are going to have valve reliefs so you can fit a large cam without running into PTV issues, but it will drop the compression a bit if there isn't a small dome or if you don't mill the heads.

 

Thanks for the inputs. Yeah, 500 to the tires would be nice but yes I realize just changing the cam won't do that.

I found a great deal on a new short block, so I'll be going that route.

 

Your going to need a really good head to hit 500whp.

Something like a AFR 210 or TEA Trickflow 215 and a Hellion or Vindicator cam. Compression is going to need to be 11:8-12:1. A Fast 92 should work, also the exhaust will need to be free of any restriction. Some 1 7/8 headers and TSP or Kooks TD's. Valvetrain will also need to be light as possible.

So in a nut shell 500whp out of a 346 will not be cheap. Look up Patrick Gurerra"s "recipe for 500whp" thread.