3.1 build up ?

[brenth]

ok im thinking of starting a buildup on a 3.1 with only about 82000 miles on it.
its in a 93 gpand hs a auto trans. its already got the basic stuff like performance plugs and wires, ported and polished upper intake, custom coldair intake and simple stuff like that but i want to go a little bit further now. ive got about 1700$ to play with and i realy want to see how far i can go with the 3.1. i do not want to go with a turbo or supercharger or go with a l67 swap. i would like it to be a n/a 3.1. any kind of insight on how to go about building the motor up would be realy good

[FastGT31]

i dont know how mechanically inclined you are but there area few things you can do to gain power. you mentioned you have ported/polished intakes. the best thing you could do is swap them out for a '00+ 3400 lower intake manifold and a 3500 upper intake manifold. you would also want to swap to 3400 heads as well. someone on this board has swapped an entire 3500 topend in their car. might want to consider that. if you have to have the 3.1 manifolds and such, a bigger throttle body will help, FFP makes a underdrive pulley that works well. bens chip is available i believe for your application and that is a nice upgrade. considering i have built a pretty decent 3.1, i know how restrictive the manifolds are and thats why im swapping to a 3400 lim and a 3500 uim. cam and headers make the biggest difference on any motor but really make these come alive.

[brenth]

thanks. i reaaly want to buildup the internals of the engine and would really like some insight on what to use and things of that nature, but yes i am already thinking about doing the intake swaping

[patgizz]

i honestly would dump the 3.1 altogether and go with a 3400. right off the bat you get more displacement, roller cam and rockers, and the superior genIII heads/intakes.

[FastGT31]

as far as internals, i had my crank balanced at a local machine shop, its bored .030 over, has 9.8: CR compared to stock at 8.8:1. moly rings, cast pistons, crane 272 cam, ported/polished heads, 62mm throttle body, crane gold race roller rockers in 1.5 ratio and headers. it all adds up to a nice running 3.1 that makes more power than i thought it would. and to top it all off its running on stock computer programming. actually i need to take the motor out and replace the cam because i think it rounded one intake lobe (not good). before it goes back in, it'll have ported/polished 3400 heads (special thanks to ben), 3400 LIM, 65mm throttle body and a port-matched 3500 UIM (thanks to ben again).

[brenth]

yea i know that would be better to start with but thats takeing the easy way out. as i said i want to see how far i can go with the 3.1. ive had 3 cars with this kinda motor and i really like the 3.1s

[patgizz]

theres a huge difference between taking the easy way out, and doing the smart thing that will provide more power in the long run.

[3100 MPFI]

There is quite a bit of info here that is not quite right. You people are not telling him that if he swap a 3400 SFI HEADS onto his 3.1 MPFI, he will have to do a LOT of work to get it running right.

Also, unless they have come up with somthing I have not heard of, I did not think that the roller rockers on the 3400 would get enough oil, so you would have to use the older 3100 heads and the stamped steel rockers.

Seeing that he has a 1993 GRAND PRIX, then he will NOT have the 3100 SFI.. The Cutlass Supreme was the only car to get the 3100 in 1993.

If you are up to rebuilding the engine, there is a LOT you can do, and the GEN 2 will be a VERY torquey engine.

I have the 3.1 in my 90 STE, and I am going to keep it in there as long as I can. I will be installing the 3100 from my totalled 1996 GP, but that is only AFTER I get it rebuilt, and ready to drop in.

Dropping an SFI engine into the car will require swapping out a LOT of parts.