3900 versions and configurations for swap use

[caffeine]

I could snap some pics of the mount bosses. But there is a 3 bolt flange on the left/drivers side of the engine and a 4-bolt/jack shaft flange on the right/passengers side.

The 3500 oil pan may be the same but I don't know for sure. Either way it has very similar dimensions.

I believe the non-AFM lifters are the same as the 3500 lifters. But again not 100% sure. And I know that the 3500 lifters are different from any SBC lifters, although the internal components may be swappable.

[Will'sFiero]

I believe there is only one oil pan that comes on the 3900. The exhaust manifolds you're looking for come from the Uplander/minivans. Supposedly the non-variable intake flows better at most every rpm range except very low; I wouldn't bother with specifically looking for one.

The 3900 is missing one of the bolt holes that the 85-87 Fieros use for the front mount. The 88 mount might work better or worse. You're probably looking at some welding either way.

I've read that the AFM system is problematic. I can't remember exactly why, but GM isn't making the AFM lifters anymore so if something goes wrong with the system you may end up having to delete it anyway.

Are there any pics of the engine mount bosses around?
What's unique about the 3900 oil pan?
Thanks for the info on the manifolds!
I'm not worried about the two stage manifold. 240 ftlbs of torque moves a Fiero quite well; the variable intake ain't no thang. I was just wondering what the relationship between configurations with AFM/DoD and variable intake.

All the new GenV V8's except the supercharged LT4 (including the new 4.3 V6) and some of the Gen IV V8's use AFM... so I @$$ume that the 60 degree uses different lifters and GM isn't making those lifters anymore because they aren't making the 60 degree pushrod engines anymore.

http://gmpowertrain.com/product_guide/2015_Product_Informatin_Guide_US.pdf

[ericjon262]

Might be possible to run it on an OBDI ECM and use a switching output to enable/disable.

A shift light output would almost be perfect since it is based on rpm/load.

I was thinking obd2 and using torque converter clutch output.

big problem I see is that with obd1, you lose VVT, or at least for the time being...

[caffeine]

3900 versions and configurations for swap use

Might be possible to run it on an OBDI ECM and use a switching output to enable/disable.

A shift light output would almost be perfect since it is based on rpm/load.

[ericjon262]

Thanks. My biggest concern with the system is trying to get it to work with a manual trans. if Paul couldn't make it work with a much more decoded V8 PCM, I would bet it will be on the verge of impossible with a V6 PCM all the big tuning companies don't make money on.

[caffeine]

AFM means Active Fuel Management and is what GM is calling DoD these days. I'm not sure if they ever called it DoD on the 3900.

[ericjon262]

by AFM I'm assuming you mean cylinder deactivation or DOD correct? I know Paul(Fieroguru) was working on trying to get DOD to work on his LS4/F40 swap and couldn't get the programming to work. AFAIK, there was no DOD manual trans combo offered by GM.

[caffeine]

I believe there is only one oil pan that comes on the 3900. The exhaust manifolds you're looking for come from the Uplander/minivans. Supposedly the non-variable intake flows better at most every rpm range except very low; I wouldn't bother with specifically looking for one.

The 3900 is missing one of the bolt holes that the 85-87 Fieros use for the front mount. The 88 mount might work better or worse. You're probably looking at some welding either way.

I've read that the AFM system is problematic. I can't remember exactly why, but GM isn't making the AFM lifters anymore so if something goes wrong with the system you may end up having to delete it anyway.

[Will'sFiero]

What were the versions of the 3900 on the market? I hadn't seen this anywhere but Wiki, so I figured I'd repost...

Per: https://en.wikipedia.org/wiki/GM_High_Value_engine#3.9

LZ9: 240/240, VVT, variable plenum
Produced '06 to '11, many apps -- G6, Malibu, Impala, Monte, minivans, Buick Lucerne
Flex fuel version is LGD

LZ8: 233/240, VVT, fixed plenum, AFM/DOD
Produced '07-'08 in Impala (any other apps?)
Flex fuel version is LZG

Which applications had which exhaust manifolds?

I'd like to do a swap on my '88 Fiero with a 282 manual transmission (not any time soon... have other projects and just boning up the brain at this point).

I'd like an AFM engine, and I think that the relatively short gearing of the 282 and light weight of the Fiero can help the engine stay in AFM mode a larger fraction of the time than it would with a taller-geared automatic in a heavier car.

To simplify exhaust fabrication in the Fiero, I'd like to have the crossover-pipe manifolds similar to the older 3100/3400 manifolds and NOT the newer "cast header" style. Which applications got the exhaust I want? Impala again?
[Edit: Uplander and minivan applications]



The wiki article didn't mention the variable plenum on the AFM/DOD engines... Are those two options exclusive? (IE, can the ECM not control both at once?) I remember reading some info about when the variable plenum was used and discontinued.

I'm also interested in photos of the mount bosses on the block so I can be thinking about how to fab mount brackets.

As well, I'd like info on the various oil pans (is there already an oil pan thread?) that fit the 3900. I've seen references to multiple different pans, some of which look like they'd fit the Fiero better than others.
Will 3100/3400/LX9 3500 pans all interchange to the LZ4 and LZ9?

EDIT:
Reference:
http://60degreev6.com/forum/showthre...ping-and-specs
http://www.fiero.nl/forum/Forum2/HTM...72-5.html#p191