3100 heads on a 2.8?

[X11_STE]

Hey guys,
I am looking @ trading for a '88 celeb wagon w/ a 2.8mpfi. The car is in pretty good shape except one of the spark plugs needs heli-coiled. Not a big issue except I have a friend that wants to give me a 3100sfi out of a lumina taxi for free. My friend told me the only thing wrong with the motor is a blown head gasket. My thought is to take the heads off the 3100 and put them on the 2.8. What issues might I run into with this? I mean, a 3100 is basicly a 2.8 stroked, right? Anyways, I look forward to all responds, thanks.

[Guest]

Yeah that's what many refer to as a "hybrid" swap, I prefer Frankenstien.

In your case shouldn't be overly difficult, pretty much similar to what other frankenstien builders have had to do, new throttle cable, intake ducting, new down pipe, some wire harness modifications. Swap the front cover and use the genIII power steering pump, with either new or modified lines, and a few other small issues, but nothing too involved.

Check out www,domesticcrew.com, for the guides there, and there's also a forum with loads of info on it.

[X11_STE]

Thanks raven. Pretty interesting frankenstien. I read the install guide on the website and have to admit, thats a bit more involved than I wanted to get. I was hoping for something a little more plug-n-play. I figured the exhaust would need a little work, which I can do, but wasnt planning on new p/s and alt. problems. I guess I'll take the 3100,rebuild it and maybe go for a little better perforamce & heli-coil the 2.8.

[Superdave]

you can use your original exhaust manifolds and downpipe. I ran the stock 3.1 FWD manifolds on a 2002 3400 for a few months w/o problems. Also, your stock alternator and bracket will work as well... I had a bracket and alternator from a 89 cavalier on my 3400.

you will need the 3100 timing cover and power steering pump, that's simple as pie tho.

[Guest]

you can use your original exhaust manifolds and downpipe. I ran the stock 3.1 FWD manifolds on a 2002 3400 for a few months w/o problems. Also, your stock alternator and bracket will work as well... I had a bracket and alternator from a 89 cavalier on my 3400.

you will need the 3100 timing cover and power steering pump, that's simple as pie tho.

Yep, infact you should use the original alternator, I know there is more space in the A-body that would allow for the newer larger alternator, but I'd just use the original.

I'd recommend the use of the 3100 manifolds, as it will flow better due to the matching of the ports, the genII manifolds dont have enough material to do a complete port match.

[Superdave]

Yep, infact you should use the original alternator, I know there is more space in the A-body that would allow for the newer larger alternator, but I'd just use the original.

I'd recommend the use of the 3100 manifolds, as it will flow better due to the matching of the ports, the genII manifolds dont have enough material to do a complete port match.

Right.. but it's a Celebrity wagon. I doubt he's going for all out performance

besides, the overlap is very minimal. I agree that it's not ideal but it does work...

[Guest]

Right.. but it's a Celebrity wagon. I doubt he's going for all out performance

besides, the overlap is very minimal. I agree that it's not ideal but it does work...

No, but to me using the gen II exhaust manifolds would be like trying to breath through a straw, yeah it can be done, but breathing through a hose is much easier.

[jwvess00]

Hi there!

The 3100 has a blown head gasket? Before spending a ton of cash on this, check the heads to make sure they're not warped.

[X11_STE]

Thanks for the responses guys, they are a great help. I am not looking for "all out performance" but a step up would be nice so I'll look into that. JW, the motor is free so no money there and of course I'll check the heads before re-using them, thanks.
Which is the better intake for this frankenstien? Should I just use the 2.8 bottom end and 3100 total top end? What would my displacement be and what kind of power gains should I expect?

[Guest]

The 3100 heads need to be used with the 3100 intake due to port location shape and size differeing between the two generations. People have used the genII intake manifolds with the genIII heads, but ther port match is no where near something that would be considered usable.

The displacment will stay the same, swapping heads never changes displacment on any engine.

That is determined soley by stroke, x piston diamter.