3.4 3x00 top end swap?

[I-wear-pants]

I picked up a cast iron head 3.4 to swap into my Fiero, and when I was looking for some advice on making more power a guy from rft suggested a 3400 top end swap. I was looking for some info on what is required to do the swap, and what guys that have done it thought of how it performed. Any info is appreciated.

[FieroFanatic]

what you need

I've been looking into this swap myself for my 86 GT. I think you'd be better off getting a complete 3400 engine. For a top-end swap, you would still have to replace the pistons to work with the tiny combustion chambers of the alloy heads. You would also either have to use the roller cam, or figure out a custom length pushrod to work with the hydraulic cam. There also MAY be issues with the ecm, but i'm not sure...

[SappySE107]

The high compression is awesome for NA if you tune it. Seriously, its what id be doing if I had a 3.4 iron head engine in my car and I wanted to get some power out of it. 3500 top end swap is the way to go if you have room. Fiero should be able to make room or just use the 3400 plenum like the fbody guys have to do.

[Kreb]

Sappy - is it realistic to be able to manage detonation on that high a CR? I'd love to do the top end swap on my ride and retain the high compression, but I don't want to have to worry about the engine constantly. I'd think that the key's to making the thing useable on pump gas would be avoiding lean conditions and retarding ignition as necessary, but that means knock sensing, or you could use water injection. What are your thoughts about managing a 12 to 12.5 CR?

[I-wear-pants]

I was thinking I could dish the pistons to lower the compression ratio some. I'd like to have it as high as possible on 93 oct. In general 11:1 is as high as you can go with aluminum heads without pinging. Do you know what the f-body guys are doing about the high compression?