New 3x00 hybrid questions

[scberetta3800]

Ok, I need to know If It is possible to put a 2.8l crank, rods and pistons in a 3100.
I know that the bores in both engines are the same, and that you can put the 2.8 crank in a 3400.
I'm thinking that it would be a great option for those of us who don't want to reflash our eproms and get better performance from a 2.8l.
If anyone knows anything about this let me know.
thanks.

[3400-95-Modified]

you wont get any better performance because the ECM wont be corrected for any changes you do to it... if you want power you need to correct your ECM for ANY and all engine modifications you do, especially a huge increase in air like a Gen III top end or something.

[scberetta3800]

ok, I guess that if thats the case then I'd still need to redo the ECM. =(
But would it still be possible to use the 2.8 componants in a 3100? I just bought new crank, rings, and pistons for the 2.8, and since there are beter flowing parts in a 3100 I'd be able to optimize the capabilty of the smaller displacement. not only would it not require as much air to pass throught the induction and exhaust, but the shorter stroke would allow higher revs if properly balanced.
I've seen the 2.8 get decent gains with intake and exhaust parts off 3100s, but this setup would be better, I could use the original length pushrods, roller lifters and cam, plus if I got a late enough model I could have the needle bearing rockers.

[Superdave]

yes, the "2800" is possible to build. I'd suggest going with 2.8 Camaro pistons as they will yeild around 11:1 compression.. also a decent cam from the store here would make that engine sing.

[scberetta3800]

cool, aren't the camaro pistons different than the normal "W" pistons other than being flat topped? I like the way your thinking, but I like running 87 octane around town. lol. with 11:1 I'd have to have 100 octane!
what kind of power would I be looking at with this? less than the 3100's 160HP right?

[bszopi]

With tuning, 11:1 can be run just fine on 89 and possibly 87. Its been done many times before.

[torq455]

keep in mind that if you use the 2.8 crank, you're loosing .32 inches of stroke. therefore less total volume is compressed decreasing your compression unless you comp with higher compression pistons.

[Superdave]

In desktop dyno i had a few different 2800's built.. all made over 200 crank HP, highest was at about 220. I can post up the combinations in a few...

[ForcedFirebird]

With tuning, 11:1 can be run just fine on 89 and possibly 87. Its been done many times before.

I need tp post pics of my friends ElCamino. The old 305 was replaced with an iron-head 327 with ~10.5 compression and a TPI swap running on 87.

That's with iron heads [/hijack]

[bszopi]

Here is still my favorite (non-60V6 though)...

http://60degreev6.com/forum/gallery/displayimage.php?imageid=553&original=1

11.2:1, up to 27psi boost, runs on pump gas and gets 30+mpg.

[ForcedFirebird]

Here is still my favorite (non-60V6 though)...

http://60degreev6.com/forum/gallery/displayimage.php?imageid=553&original=1

11.2:1, up to 27psi boost, runs on pump gas and gets 30+mpg.

I'm going to be at 11.5:1 and was thinking about trying low boost with it.

[scberetta3800]

Torq455, I'm going to use the entire rotating assembly from a 2.8 inside a 3100 engine. I'll have less of a stroke, but the piston will come all the way up in the cylinder.

[scberetta3800]

Wow, 11.2:1, Boost, and pump gas, thats crazy!
I think I have everything to write my own Eproms, I'm just lacking experience. I have a ok understanding on blocklearn and integer fuel trim, but how do you adjust Ignition timing? I'm using tunerpro.
oh and What extra mounts do I need to mount a 3100 block in my 88 beretta that has a 2.8? I know there are like two different mounts right?
Am I wrong, or doesn't the 3100 have a larger combustion chamber than the 2.8? that would drop the CR too if thats the case.
thanks for all your help guys!

[torq455]

oh yeah, that's right. forgot about the different pin height.

[torq455]

iirc the 2.8 heads have bigger cc's. you don't program BLM and INT. that's a indication of which block of fuel maping the computer is using. BLM is long term adjustment and INT is short term adjustment and directly related to O2 readings. you change BLM by changing the fuel curve and the computer will adjust BLM accordingly. ideally, you want BLM of 128 and INT of 128, but a range of 125-132 BLM is acceptable. my Z's reading are all over depending on the day. one day it can be 140 and the other will be at 105 between cruise and idle.