new to the 3.1 game

[camaro1991]

hi..my name is chris..i just bought my dream car..a 1991 chevrolet camaro rs..it has 94,000 miles on it..i have done a flowmaster muffler,advance timing,msd coil..cold air intake,egr mod,...what cam i do to make it faster???i want a rough idle..but still use stock pcm..i'm plannin on 4.10 gear..this is a daily car..in town so gas milage isn't a problem..please help!!!

[2.8RS]

The biggest cam that you can go is a Comp Cams 260H. You will also need to get the right valve springs and get 1.6:1 rocker rollers. That is the setup that I will be running in my new motor whenever it gets here...

Also get a set of Pacesetter headers to get full benefits of the cam on stock heads.

[geoffinbc]

If your trying to make your car as fast as a V8 then don't bother with the 3.1L it will never come close to even a healthy TPI 350 which is a shitty V8.

The only way your going to do it with a V6 is with money, time and research. Yes it can be done but it should only be done if you really want something different.

So if your goal is never better than a 15 second 1/4 mile then go ahead and wake up the V6. If you want cheep power the V8 is the way to go.

After you let us know your goals then we can dish out a shopping list. Oh don't bother with the 4.10's it makes 1st gear completely useless on a motor only capable of 5000RPM.

[ForcedFirebird]

350TPI wasn't as shitty as the 305TPI .

3.1 MPFI will pull to the 6500 rev limiter.

I've seen a 15.1 1/4 with a nearly stock 3.1 motor, suspension modifications, and 9" slicks.

Betterthanyou is right, though, modding the 3.1 isn't cheap. I have some stuff here if you want they're for the iron heads...

Set of iron heads waiting for a port job,
1.6 Crane Magnum roller rockers,
Crane high energy pushrods,
and lots of MPFI manifold/valve cover gaskets.

PM me if you are interested.

If you are a good fabricator, and don't mind pulling the pistons, a 3x00 top end swap would be beneficial. With a 3.4 and 3500 top end, I should be making more/same power as a stock 350TPI (around 225-250hp).

[camaro1991]

i just want like a rough idle...and like gears,1.6 rockers,and headers..and i'll spray it..just askin..has any 1 ever did a 3.1 that is carbed???I really hate pcm's so that is y i was asking..thanks for the tips..

[ForcedFirebird]

i just want like a rough idle...and like gears,1.6 rockers,and headers..and i'll spray it..just askin..has any 1 ever did a 3.1 that is carbed???I really hate pcm's so that is y i was asking..thanks for the tips..

You'll need a cam to make it idle rough. Yes you can convert to carb, Edlebrock makes a manifold.

[camaro1991]

is the carb setup better over fuel injection????I heard go carb get as crazy with cam you want and get better go as well...

[2.8RS]

You don't have to worry about a cam that is too big for a stock computer tune. The 260H is about as big as a person can go with a stock tune and the 272 is too big for a stock tune. With a carb you don't have to worry about the computer. You will need to dial in the carb but it is much simpler. I am considering a carb swap. I am tired of having to mess with sensors and other electronics going bad.

[Superdave]

if you want the "big cam" sound, i don't think the 260 is going to float your boat. the H272-2 idles pretty mean, your heads don't flow enough to support tht kind of lift to make any power, but it'll sound good if that's all you are after.

Don't expect much of a power gain, If you want some serious power then start looking at swapping an aluminium gen3 top end. Airflow creates horsepower..

[34blazer]

dont go over .450 lift on the ironheads without proper clearancing. the valveguides need to be cut down otherwise the retainers will bottom out on them and wipe the cam.

[Superdave]

dont go over .450 lift on the ironheads without proper clearancing. the valveguides need to be cut down otherwise the retainers will bottom out on them and wipe the cam.

.450 is it???? wow..

how big is the stock cam in those?

[sharkey]

dont go over .450 lift on the ironheads without proper clearancing. the valveguides need to be cut down otherwise the retainers will bottom out on them and wipe the cam.

news to me. im running a comp 260h2 (.440 lift @1.5 rockers) with 1.6 rockers, nets .470 lift. i did have bronze guides put in, but they were never cut down. i had clearance still, no issues at all.

[camaro1991]

so i can go 470. and have a mean idle and use stock pcm??How much of a power gain will i get???

[34blazer]

.450 is it???? wow..

how big is the stock cam in those?

basically .450 net lift is a safe number to start checking clearances. our friend here wants to slide in the biggest cam he can and i dont think he had any plans on checking clearances. and if he ever decided to go with a 1.6 or larger ratio rocker, it will get pretty tight. if i remember correctly, the stock grind is around .380 net with the 1.52's. i ran into problems at .320 lobe lift with the 1.6 rockers (.512 net).

[Superdave]

basically .450 net lift is a safe number to start checking clearances. our friend here wants to slide in the biggest cam he can and i dont think he had any plans on checking clearances. and if he ever decided to go with a 1.6 or larger ratio rocker, it will get pretty tight. if i remember correctly, the stock grind is around .380 net with the 1.52's. i ran into problems at .320 lobe lift with the 1.6 rockers (.512 net).

Yet another reason to go with aluminium heads.. you can go up to .750 lift before checking clearances.. (good luck finding springs)