well, i figured i should probably make one of these considering i'm gonna try for 250whp out of this little engine.

here's what i'm starting with:



gonna swap out all the main and rod bearings. they're all spun so it's gonna be fun. i'll keep updating this as i make more progress (and more pics too)

 

Hey man, good luck!

 

Please take plenty of photos ive been waiting to see pics of a 3.1 rebuild... Have you considered doing a 3x00 top end swap (aluminum heads larger lower and upper intake plenums) this not only saves 50 lbs in weight but adds about 70 horsepower over the camaro 3.1L. there are threads on the benefits of this swap that are searchable.

the 3.1L comes stock with 140 hp from the GM Documentation i received in the mail,
So getting to 250 is not going to be easy without the right research done.

If you add the 3x00 top end swap, (High flow Aluminum Heads that flowed better than a set of custom ported iron heads ) the larger upper and lower intake plenums that increase airflow and give you much more top end power. You are looking at 210 horsepower with that alone. combine that with the headers you will have to install to take advantage of the d-port exhaust ports on the aluminum heads and you are looking at 225 hp... CAI adds about 8 horsepower so thats 233 hp, add a camshaft 248-250,
get a stage 2 jet chip or better yet PCM4less.com which will add so you are looking at 265 to 267 horsepower add a borla/magnaflow exhaust and yield 7-15% more horsepower I calculated it as 10% (as you would have free flowing headers) and came up with 294 hp add a set of Comp magnum Rocker arms for the 60* V6 and that nets 15-20 horsepower.. and there you have it.... 309-314 horsepower out of a 3.1 V6 Wouldn't Lt1 owners freak knowing your 3.1L with nearly half the displacement can keep up with them without any custom turbo setups or anything.

 

i already knew about the top ends swap. i'm gonna grab some 3500 heads off a G6 and swap them on. the cam i'm gonna go for is going to be a custom grind (around .420" lift for both intake and exhaust). i plan on getting this engine to wrap out to nearly 7.5k rpm. one thing you did forget to mention in you post though, is that you NEED to bump the compression to make any reasonable power gains with the 3.1.

btw, the 3rd gen v6's already have a factory CAI

 

Well I thought that i read that the 3x00 swap bumped compression up to like 11.5:1 or something without changing the 3.1 pistons, the 3x00 pistons give you 9:1 I believe?

 

nope. factory 3.1 pistons are 8.5:1 pistons, swapping to 3500 heads does bump the compression some, but only up to 9:1.

 

Your compression is going to be significantly higher with the 3500 heads, as the combustion chamber is smaller. The good breathing is due to the canted valves and better designed ports. You will need longer pushrods as the rocker arms sit higher, and the reground cam is going to have a smaller base circle.

 

What crank and connecting rods are you going with? Those motors did not like high RPMs in their stock form.

Seems like I can find 3 gen V6s pretty cheap. I was thinking a 3.4 with the 3500 heads might make a nice car for my daughter.

 

pete- you're right. just looked back at thirdgen.org and saw i'm gonna have to run a thicker gasket (to drop compression). i didn't know about the longer pushrods though.

gorn- in their stock form they don't like high rpm because they can't breathe up top, the iron heads flow about as well as an asthmatic breathing through a straw. i'm sticking with my stock bottom end, i won't need anything more that 3.1L for auto-x.

this is also going in today:

 

also, here's a rough idea of what the head swap will look like