I originally bought this car about a year and a half ago, and got a lot of guidance from MCF on a motor swap I was forced to do; three days after I bought the ride. My Monte is a 5th gen LS with the 3.1L motor, and I cannot seem to find any aftermarket or performance engine parts. Almost two years of periodically looking, and I have only found sites that specialize in the 3.8, and 3.4's.

Does anyone have any recommendations for getting some more usable HP on the 3.1? I'm not interested in forced induction on this car, that's what my other car is for. I'm not looking to go crazy with this car, but as long as I'm paying for the gas, I'd like to see some satisfying results when I decide to use it.

Are there any websites devoted to 3.1L performance? I can only find 3.8L and 3.4L parts, and 3.1's from Chevy trucks. Do we have a parts catalog or list posted here of parts from the 3.4 and 3.8 that can be used on the 3.1? That could be helpful. I found ZZP's website is great, and they have a ton of stuff for the 3.8 that I wish I could use, but I don't think it will fit.

 

The 3100 and 3400 are a lot a like (basically same engine, minor differences). So it's possible 3400 parts will work.

The BEST/EASIEST thing you could do is a 3400 swap. I've read a lot about this when I was bigger into Grand Ams. To go from a 3100 to a 3400, next to no big work, swap a couple of sensors, no need to change the transmission or the PCM, virtually a direct swap. There is a great write up about putting a 3400 into a '95 Grand Am somewhere on the Internet, outlines some of the "need to know" things.
The other thing I believe you could do is swap the LIM/UIM/Throttle body from a 3400 onto a 3100 (has a larger inlet to flow more air).

My personal opinion, it's not worth going to crazy in spending money on a 3100. But, on the "cheap", you could get a set of L67 coils (the ones on a 3800 Series II SuperCharged) from a salvage yard for $15-$25 and a drop in K&N air filter (I did this on my '94 3100 Grand Am, not a HUGE change in anything, just a little change, slightly improved throttle response and possibly 1 MPG gain). If you could get a PCM tune that may also improve things.

 

Hey, thanks for your response!
Not sure if you missed it, but I mentioned that I just dropped the 3.1 into the car a year and a half ago... I'm not swapping the motor again unless I get an L67. It would only make sense if I had to get rid of the new motor too. It's not the "easiest" option by any means. There are a lot of hurdles to jump when doing a swap. Even if it's a direct motor swap. Big commitment.

Interesting. I wouldn't be opposed to this idea, but I'd have to get a decent increase over stock. On a naturally aspirated 3.1L do you think a bored out throttle body would achieve similar results?

I agree. As stated before I don't want to go crazy on this car. My other car is my go fast turbo project ride. I just want maybe a tad closer to 200hp from the 3.1L for a daily driver. Easily attainable???

 

Simply put, NO. From my little amount of research, the reason a larger throttle body won't work is because the UIM and LIM won't permit the right amount of air flow (those parts are also restrictive).

Now, I have not done a huge wealth of research on this topic (aka, I stumbled up a couple 3100 guys talking about it and thought "hey, that's neat", but I never researched it deeper, so before committing to any parts purchases, do some extra homework, the N-Body crew may be of more use for that info). I'm not sure if there is a gain in swapping for 3400 heads as well.

BTW - I did read the part about you recent swapped a new 3100 into your car. I was just listing the 3400 swap as one option that requires less change then going to an L36 or L67 (since you re-use the same fuel rails, PCM, wiring harnesses and such). From what I've seen the 3100 powered N-body guys would prefer ditch the 3100 for a 3400 (again, as it is almost a direct swap, very little in terms of changes). But I figured like you said, if you were going to do a engine swap, you'd go for the L67.

 

Hmm. Gives me a little to think about I guess. I could consider doing some valvetrain upgrades and using 3.4 heads/components. Maybe I'll have to dig down to engine basics to smooth out air flow and increase gas efficiency. I think I might have a new goal with this car.
Thanks!

 

First I want to say I'm sorry but I am a new user and I cannot create my own thread I have been trying to figure out things I could do to my 3.1 I am considering forced induction but am worried about what that will do to a 3.1 with 189,xxx miles and probably original timing belt it is kinda hard to start about 80% of the time and what I mean by that is I have to give it a little gas to get it to start, the intake gasket leaks out right under the thermostat. In escense I want to have the reliability of a daily driver but I want it to have enough power to blow the doors off most of the rice burners out there it does pretty good already (raced one 3 days after I got it car was fully loaded and I never even took it out of overdrive) I also want to convert it to a manual trans was wondering how difficult it is with this car especially since I think I need to drop the trans (I think I'm missing teeth on the flywheel) also i was wondering if anyone could tell me what the slight tapping sound I can hear at idle is I can here it on alot of gm cars like mine

 

I wouldnt even bother trying to increase the power of an old tired 3100. If you really want to give the car more power I would consider a 3400 or 3800 swap. Also there is no easy way to swap the a manual trans. These cars never came with a manual trans from the factory. Only 2 transmissions would work, the getrag 282 and the 284. The 284 is rare and there arent any parts made anymore to rebuild them with. The 282 is less rare but still pretty uncommon. Not in any way an easy or drop in swap. Dont even think about trying it without a spare vehicle and lots of spare cash. You would need a donor car with everything needed for the swap. Sourcing parts wouldnt be practical at all. The firewall would need modified to accommodate the clutch pedal. Just not a practical swap in any way unless you have the spare cash to throw at it.

 

So swapping to the 3.4 is a good idea? But I basically have to stay with the trans. I will have a spare vehicle as soon as I get my 86 f250 with a 6.9 diesel rebuild finished on here I have read that the 3.4 is a good motor but every car dealer around here wants nothing to do with them claiming they are complete junk

 

F650, it sounds like what you want is a sleeper. Something you can pull up next to a fourty-thousand dollar car and blow the doors off it. The only way you'll be happy doing so with that car is by way of the L67 swap.

The other side of the fence: I'm not trying to make a fool of other people with my car. I'm looking to make myself happier with acceleration and do it without spending a foolish amount of money.

 

@F650 - I posted earlier in this thread one of the BEST thing you can do with a 3100 is scrape it for a 3400 (as it is virtually a direct swap, you change far less with that then going to a 3800). There are limited performance mods for a 3100 (but there are some, so it depends what you want to do in the end). But for BEST performance with these cars, yes a 3800 N/A or S/C is the road to take. When you mentioned the problems starting, if you notice clouds of white smoke in your rear view mirror, you may have failing head gaskets. Honestly, if the car is not running right coupled with miles that high, this does not sound like a good car to try modding at the moment.

@ded548 - Pulling 3400 top end pieces open some doors for you. It's obviously not as good as any available engine swap BUT it will improve what you have. A good community for 3100/3400 information is the N-Body/Grand Am/Skylark/Malibu folks. In the N-bodies, look at '94-'98 (to my knowledge all 3100 powered). Since the 3100 was the biggest engine offered in those days until the 3400, these guys focused on what could be done. Not saying folks here have input on the subject, but a great wealth of info is from the guys that had no bigger drive train choices. Hopefully I've given you some direction to run with.