3.1 build

[2.8RS]

I am swapping a 3.1 into my 89 Camaro that has a 2.8 in it right now. This motor is just going to stay NA and will be my DD so I need it to be reliable. What I need to know is if all of the parts I am going to use will work great with each other. The bottom will be stock. I am also going with stock heads with 1.6 roller rockers with the Comp Cams 260H. Will that work fine with each other and what valve springs do I need to run, I figured stockers wouldn't cut it. Also do I need to run larger injectors with the cam? If I'm not mistaken the stockers are 17 lbs, so do I need 19 lbs injectors. The intake is also stock. Also I hope that all of this will run fine on the stock ECM. I don't want to have to do alot of tuning and I have no problem running a smaller cam if I have to. I already have headers and full exhaust on the car so that isn't a problem.

Thanks.

[DEI37]

I'm not familiar with the cam, so I don't know what the stock PCM will handle. But, I DO know that if you change injector sizes, the PCM won't like you, and you WILL run rich. So, you would need to either find a tuner for yourself, or find a place that can dyno tune your setup, or hope that Ben can do it.

[torq455]

sounds like a great DD street car. great low-mid torque. Comp Cams should be able to give you a matching valve spring set. be sure to tell them you'll have the 1.6 roller tips on. 19 lbs injectors should be just fine. not sure if you'll be rich at WOT, but outside of that the ECM will adjust for the extra air. however, you WILL need Ben to pretune for the WOT. that all sounds like a good reliable upgrade. would be good to bump the CR up a little, but not necessary. don't go bigger on the cam. your intake can barely keep up with the 260. highly recommend mild porting and gasket matching to make the most out of the cam.

[2.8RS]

If it would be better for me to go down to the 250H (I think that is the next size down) then I have no problem doing that. I will gasket match but I don't really plan on doing any porting on the heads or intake. I need as little down time on the swap as possible. This is a budget swap but I want to do everything done right so I am just going to get my heads I have now on my 2.8 rebuilt here locally if I can find a shop who can do it. I just pulled one of my heads and they look like they are in good shape. In fact my whole motor looks better internally than I thought it would.

EDIT:
Also would stock length pushrods be fine with this set-up. And from the above I should be fine with stock injectors correct to reduce the need of custom tuning?

[ForcedFirebird]

If your heads look that good, you can get a cheap valve spring compressor and hand lap the valve seals, clean the valves, and install the springs of choice. I haven't got one yet, but wonder how easy the LSX spring swap is on an iron head?

I believe there are a few 4thgen 3.4's using a stock tune and the 262, but the 272 was too big.

I belive the cam supplier will answer your question about the rods, but I'm pretty sure the stock length will be fine with the iron heads.

[sil]

that cam likes higher CR
na youll need 19's, no bigger
youll end up cutting fuel from everywhere with the 19's
17s would even work although that would be pushing it

[FiredUpZ28]

I said it in a few posts already, all these guys are right too, but dont throw in a cam with stock springs, tune, convertor, intake, or exhaust. All that should be done or a cam simply wont do a lot at all. If you want it just for sound then maybe but otherwise, its just not a wise move. You can use the stock injectors with a small cam, but you need to get a tune no matter which cam you decide on. Good luck with the setup, keep everyone posted!

[2.8RS]

I already have had a cat-back and headers for a while now. For the intake I am getting ported intakes. I have already smoothed out the TB and removed lots of the baffles in the air box and have put in K&N filters. To go with the cam are 1.6 roller rockers and new pushrods/lifters. All I really need for the valve train are valve springs, I still haven't called comp cams for the right springs, I need to do that. I have some 3.1 injectors in the car now. THe ignition is all new also. The only thing really left on the list is getting the motor and having my heads rebuilt. I am still between on going to proted heads later on when I have more money.

[ForcedFirebird]

The only thing really left on the list is getting the motor

Patience, my friend, patience

BTW, may have some ported iron heads once we get you the 3.1 (actually a fully ported top end with a sheet-metal manifold) .

[2.8RS]

Patience, my friend, patience

BTW, may have some ported iron heads once we get you the 3.1 (actually a fully ported top end with a sheet-metal manifold) .

I'm getting excited about getting this build going since the cam should be in in a couple of days . A nice new cam and nothing to put it in. Such a shame.

If I get heads/sheetmetal intake, awesome. If it keeps on going like this I might end up with your 3.4/3500 lol.

[sharkey]

my built up 2.8l ran alright with the stock injectors and the 260h with 1.6:1 rockers. i was able to end up making a lot more power once i was able to tune, but it ran fine with no detonation on stock tune. one thing is however with the low compression you will lose a bunch of low end torque. i beleive that cam is recomended for 9.5-11:1, and trust me, you will lose tons of low end if you dont hit that range.

[2.8RS]

How do I go about bumping up the compression? I read somewhere in another post about pistons that I can use that will get me in the right range.

Also I thought that OBDI couldn't be tuned. There is a local dyno here that I can tune on I believe but that costs $$$. I will be running around on a stock tune for a couple of weeks, I won't be running around on the stock tune for long hopefully.

[ForcedFirebird]

Raising compression....

If you want, 3400 heads will give you about 11:1 (a little higher, actually), but you would need an ignition system...

[2.8RS]

but you would need an ignition system...

More work then I want to do and money I don't want to spend...

[ForcedFirebird]

Next option is to mill the heads/LIM, or custom pistons (as you mentioned).