I will be in the market for an LS1 car in about 3 months, but my budget might only allow me something for around $7,000 which usually means high miles. I will want to do a lot of mods when I have that car, so what I want to know is, is it safe to do heads(probably the Patriot Stage 2 5.3) and a mid-size cam on an LS1 with over 100k miles? I really don't want to destroy the engine, because I would not be able to afford a rebuild. What do you guys think?

 

If you're positive you're going to go heads/cam, I'd rebuild the motor now, then mod the car when you get more money.

Heads/Cam combos make ridiculous power on LS1s. I wouldn't push a high-mileage motor too much.

I know some guys might disagree and say the LS1 is a durable motor, which it certainly is... however, you wouldn't want to risk the chance that the motor would come apart and trash your new parts while you're spinning it to 6700 rpm, would you?

Mike

 

I agree.

 

Id say save up a bit more and just get a low mileage ls1.

 

With high milage cars and upgrading the heads and cam along with compression there is usually an increase in oil comsumption. So like was said above the best advice is rebuilding the motor. Otherwise it will be a crapshoot. Do you feel lucky?

 

That is exactly true.

Oil consumption + aggressive heads/cam tune = Lowers octane/BOOM!

That's what happened to my buddy's car.

Mike

 

hmm, doesn't sound promising at all. So, I guess the increase in compression would cause problems mainly. But what if I just put on a real big cam(like a T-Rex) and leave the heads stock? Would that be ok?

 

That's exponentially worse, considering that the T-rex goes to like 7000+ rpm.

Boom goes the bottom-end.

 

So I guess, just getting a mild cam is really the only option for a high mileage engine.

 

There is still some risk involved with just swapping the cam as well, some people have still spun bearings in their bottom ends. It wouldn't be a bad idea to set aside some money for a new shortblock in the event something does happen in the future.

 

I did a H/C swap at 110K and all is well. When we took the heads off everything looked new. Vertually no discernable wear. Take into account that I ordered this car and have never beaten on severely and have always used a top grade synthetic oil in my SS.

 

This seems like misinformation. On Thunder's website it only says it goes to 6700. You can clearly see RWHP peaks at 6300 on their website. You said 7000+, they quit the dyno pull at 6900.



Ben T.

 

But to maximize a 1/4 mile run with that cam you'd want to shift it at or near 7000 to keep the after shift rpm in a higher hp range.

 

Id rebuild first