3.1 power options

[montess408]

what do you have for a car ? what year is it ? i see you aretalking about O.B.D. 1.5 the sad thing here is i dont think that the O.B.D. 1.5 is tunable so for that reason people are going back to O.B.D 1 or updating to O.B.D 2

[pushrod]

pissed

i have a 95 olds cutlass ciera 3100 sfi " M " series. its takin me 2 years from the onset of this project just to find out what cam i have in this beasty, i love the car, it now has some balls, and launches like a missle for what ive invested so far, but everytime i go for the heart, i run into,"i dont know"
because of the year, 95 seems to disappear off everybodys radar, dont know what engine it is, dont know the cam, what valve train etc., had to rent a bore scope, just to figure out it was a roller lifter design, but no roller factory rockers, and they dont fit when tried. its regular stamped rockers, it has the structuarl oil pan, which is way cool for solid launches. i wanted to finf out if they made a 3.1 any later than mine, apparently a 99 big bore intake might fit mine, to open up the breathing, the cam #24505674 was thrown my way, but at $615.00 from the big GM, i said screw that, WOT, has custom grinds at $329.00, and doing a little research into lift and duration the grind #399 looked pretty good, but no, you have to reburn the comp, or go with a stand alone ECM and program it with your lap top, thats all fine and wonderful, but im a man of design your mill, do the work, set the timing and burn baby. this comp stuff is good for management of the hydro carbons, but has hot roddin not been about increasing, volumetric effiency to start with? the industry in years past has finally followed our lead, with roller rockers or lifters from the factory, a little slow, but why mess with the comp, put a damn dial on the dash and adjust for mods done. pushrod

[montess408]

well the 3100 sfi are all the same from 93-99 small port and then 00+ big port the intake manifold will change over but you have to change both UIM and LIM and i am not sure on the heads but you would feel more power if you changed the heads also
and all gen3 motors are roller cam but the roller rockers only came a little later but i think that you could change them over (you may have to change the guides or rocker studs ?)
and if your going to get a cam ben has some good ones you will deffenatly find one that fits your needs
these motors are dis (distributor less ignition ) that the reason you need to tune the ecu
( i am not big on ecu tuning myself thats why i am getting rid of my F.I car )
i am sure sombody here can explaine more on the ecu part than i can but i think that should get you started

[montess408]

i was looking up the obd years and it looks like your car dont have obd1.5 ! your car is a h-body and is not listed in the body styles of 94-95 that got the obd1.5 set ups !! so maybe you should look to see if it's obd or obd2

[pushrod]

obd

how can i tell the difference, is there a tag on the comp or what should i look for to tell if its a obd 1 or 2, thanks

[bszopi]

The Ciera's got the oddball ECM up through 95, as they came with a removable PROM. Do a search on the site, as I know at least 2 people have recently looked into (and discussed) tuning the Ciera PCM.

[geoffinbc]

is there no custom grind cam that will work with the way the obd 1&1/2 is set up, im gettin real pissed with the comp thing, im old school tryin to learn, but to many road blocks, the best ive had xplained is i have to get a stand alone ecm, programable with a lap top, more bucks, what ever happened to stickin cam and related in, time it and burn rubber!!!!!!!!!!! pushrod

I don't know who told you you need a custom tune. That's crap. If you stay with a mild cam like a 252 or 260 cam it will run just fine. Your driving a truck so I would suggest a 252 cam which will build lots of low end torque. The TBI system is very basic and does not freak out when you change stuff. I am still running the stock 2.8L computer but I have a 3.4L engine with 4.3L injectors a larger TB and a different cam and 1.6 ratio rockers. If you throw the scanner on it the fuel trim is bang on 128 all the time. I just tuned it by adjusting fuel pressure. The biggest thing is keeping the manifold vacuum in check and you can do that buy buying a cam meant for driving and not racing.

[bszopi]

I don't know who told you you need a custom tune. That's crap. If you stay with a mild cam like a 252 or 260 cam it will run just fine. Your driving a truck so I would suggest a 252 cam which will build lots of low end torque. The TBI system is very basic and does not freak out when you change stuff. I am still running the stock 2.8L computer but I have a 3.4L engine with 4.3L injectors a larger TB and a different cam and 1.6 ratio rockers. If you throw the scanner on it the fuel trim is bang on 128 all the time. I just tuned it by adjusting fuel pressure. The biggest thing is keeping the manifold vacuum in check and you can do that buy buying a cam meant for driving and not racing.

The original poster is driving a truck and has the 3.1L (or 2.8L?). Pushrod, the guy you are responding to, jumped in on the thread, but his questions are irrelevent to the original question, since he has a 1995 Cutlass Ciera with the 3100 MAF only setup. He could get by with a slightly more aggressive cam and not have to worry about tuning.

[geoffinbc]

Ha Ha makes sense. Stupid hijackers.

[pushrod]

cam

if i can use a slightly more aggressive cam, without worry, that would be great, but where are you guys pullin these numbers, the 252 and 260 grinds, your talkin degrees open, right, but i look at the custom grinds at WOT, i see a 260 but cant find the 252 to compare, steer me in the direction

[geoffinbc]

I was talking non roller cams. Which Crane and COMP both sell.

[pushrod]

cam

ok, so i just have to find those cams, look at thier specs and pick one from the WOT roller grinds thats the closet, right, i allready have a new set of roller lifters here waitin for a cam, cant waste em

[joeisuzu]

Hi.
I'm new here and have a 1992 rodeo. I'm rebuilding the 3.1L right now. According to my engine dyno software its not very hard to get 180 hp and 200 ft lbs of torque. I'm going to find out the accuracy of the software shortly. The only issues I'm having is finding pistons for the "z" vin code engine. Its kind of getting frustrating. I have found 1 set of pistons. They were pretty overpriced ($180.00 for the pistons, $120 for the rings). Witch other vin code pistons will work with the z vin code engine? Anyone have a clue? Also is the 4.3L tb a direct bolt on without changing the computer settings? If so I'm very happy with that! thanks in advance.
Mark.

[geoffinbc]

You need 3.1L Iron head pistons. There is no options. You cannot use aluminum head pistons because they will not give you enough compression. The price you got for a set of new pistons seems reasonable to me.

Your computer will run a 4.3L TBI on top of your 3.1L no problem.

[joeisuzu]

Thanks for the info. So ANY iron head pistons will work? I have found some pistons on a website for 92-94 camaro. They were much cheaper than the above mentioned pistons. Thanks for the info on the 4.3 tbi. I'll send the manifold in now and have it modified.