3900 versions and configurations for swap use

[Will'sFiero]

The 3900 water crossover could be moved to the other side of the heads. Since the 3900 has different head gaskets left and right, however, you might need to also swap the heads/head gaskets to get proper cooling. For a RWD conversion this is almost essential in order to make room for accessories with a flipped upper intake.

I did notice in the photobucket above that there's a loop of hose from a heater connection on the waterpump casting to a connection on the coolant crossover... What does that do?
Also, with the coolant crossover on the back of the engine, the main coolant outlet points to the trunk in a Fiero, instead of forward to the firewall. This isn't the end of the world, but makes plumbing more complicated. If used on the back of the engine, the coolant crossover might also interfere with the minivan exhaust crossover

What's the difference between the head gaskets? Different size coolant passages?

[caffeine]

It might be a t-stat bypass you're looking at on the crossover. As for the head gaskets, I don't actually know what the difference is just that they are different. I'm thinking they may have differently sized coolant passages to work with the crossover on the front of the engine.

[ericjon262]

here's a list of tunable parameters for the 3900 using tunercat obd2. not sure what HP tuners or EFI live offers, not too interested either, as I have TCobd2 and not the others.

OBD2_56.pdf

[caffeine]

3900 versions and configurations for swap use

Nvm

[ericjon262]

thought on the coolant crossover, why not make one? it's not a complicated part, 2 plates, one bolted to each cylinder head, a little hose, done.

[ericjon262]

http://www.fiero.nl/forum/Forum3/HTM...-26.html#p1011


That's why... I asked on that thread if he meant using the 24x PCM for his next swap in order to try getting AFM/DOD working.

All 3900's are 58x, right?

yes, all are 58x, and AFAIK, they all use the E67 ecm as well...

[Will'sFiero]

thought on the coolant crossover, why not make one? it's not a complicated part, 2 plates, one bolted to each cylinder head, a little hose, done.

Or even weld up some tube in between and save the potential leak points; Yes, it could be built. I'll have to investigate how the original is plumbed internally before I decide how easy or not that might be.

yes, all are 58x, and AFAIK, they all use the E67 ecm as well...

If, as with the LS4 the E67 needs the BCM in order to operate AFM/DOD, then it might not be feasible to implement.

Can't the 58x wheel be swapped for a 24x?
I wonder if the cylinder select in the E40 from the early LS4's could be switched from 8 down to 6 to run the 3900. The 3900 is just 100cc's shy of being 3/4 of a 5.3... That would allow running the AFM/DOD (and cruise control!) with 24x DBW engine management.

[caffeine]

I don't know of any available 24x internal reluctors that will fit a 3900. The equinox 3400 one MAY be useable but IMO it'd be easier to fab an external trigger and then you can run it on whatever you want.

As for the coolant crossover, it would be pretty simple to fab one up. I was gonna start doing that but haven't had time.

[ericjon262]

If, as with the LS4 the E67 needs the BCM in order to operate AFM/DOD, then it might not be feasible to implement.

Can't the 58x wheel be swapped for a 24x?
I wonder if the cylinder select in the E40 from the early LS4's could be switched from 8 down to 6 to run the 3900. The 3900 is just 100cc's shy of being 3/4 of a 5.3... That would allow running the AFM/DOD (and cruise control!) with 24x DBW engine management.

is there a cylinder select option in the LS4 programming? I haven't seen one in the later PCM's that I've looked at (doesn't mean it's not there though...)

I like the idea of the LNJ trigger sounds like the best option to me, I would bet it could be installed as long as the 58x trigger isn't machined into the crank like the earlier triggers. even then a quick trip to the lathe could fix that.

[ericjon262]

FWIW, it looks like tunercat obd2 doesn't support the E40 LS4

[Will'sFiero]

is there a cylinder select option in the LS4 programming? I haven't seen one in the later PCM's that I've looked at (doesn't mean it's not there though...)

I like the idea of the LNJ trigger sounds like the best option to me, I would bet it could be installed as long as the 58x trigger isn't machined into the crank like the earlier triggers. even then a quick trip to the lathe could fix that.

I'm not familiar with the LNJ trigger wheel...
There has to be something in the software that relates firing order to crankshaft position; it may not be a "cylinder select" like the earlier computers had, though.

Edit: Found some LNJ info: http://www.enginebuildermag.com/2011...4l3-5l-engine/
Engine Builder Mag is typically pretty thorough about parts interchangeability... they noticed the same piston part number and other fun configuration management trivia, for example.
It says GM doesn't sell the wheel separately... I thought it WAS available separately for the LS engines... is that not the same wheel as the 60 degree engines?

[ericjon262]

I'm not familiar with the LNJ trigger wheel...
There has to be something in the software that relates firing order to crankshaft position; it may not be a "cylinder select" like the earlier computers had, though.

true. it might be possible to swap the V6 data into the V8 program.

[Will'sFiero]

So to make AFM/DOD work...
Start with LZ8 engine from '07 Impala or LZG engine from '08 Impala

AND (
Swap in LNJ 24x trigger wheel
Swap in 24x crank sensor?
Use LS4 E40 PCM reprogrammed.

OR

Install Impala BCM
)

To verify:
-LNJ trigger wheel fits LZ8 crankshaft
-Compatible crank sensor fits LZ8 block OR LZ8 sensor is compatible
-LS4 E40 (or another app) can be programmed to operate a V6

That's starting to sound like work... and would be mostly for bragging rights
It would be nice to add 90 RWHP, 1.1 liters and pop gas mileage over 30 mpg with a $600 engine (although my 2.8 already gives 28 mpg at 80ish mph).

[ericjon262]

Originally posted by fieroguru:

The E40 (and E67 for that matter) has a field where you enter the # of cylinders and individual cylinder volume. Who knows what happens if you set it to 6 cyl.

with this being said, I would say you need the LS4 trigger wheel.

[NateD4]

Why not order a reluctor laser cut and then hone the bore to fit?