3900 into an f-body

[boostedrs]

forget the part about it going into the rwd car for just now.
what are the main issues in doing the swap when not using the factory ecm


front cover
motor mounts
rember reading something about vvt

[IsaacHayes]

VVT, Varible intake manifold (could probably be activated with window switch, or use the 3500VVT intake), lack of 7x crank sensor

[boostedrs]

ok so the intake manifold would be tossed,
as far as the cam and vvt setup what could be done with this, can the cam be swaped for a reg hyd roller,and can non DOD lifters be installed into the 3900 block.
along with using a standard cam gear to remove the hyd vvt assembly

will the old 2.8/3.1 timming cover bolt onto the 3900 block as well

[IsaacHayes]

The 3500 that has VVT is a destroked 3900, without variable intake. So I assume you could just swap that intake over.

There are 3900's without DoD, so getting one of those is best.
I have no clue about the VVT. Apparently there are a few working on it but I don't know what they found out yet.
No idea about timing cover.

[boostedrs]

can anyone post up pics of the hyd vvt assembly/cam gear for me.maybe its possible i could just weld the whole assembly together in a stright up possition,unless of course i can just swap ove the non vvt cam/assembly

i do understand that getting the vvt to work would be ideal,but i am without a way to control it, so for me just doing away with it would be best

i dont know which the motors are that i found but if they are DOD motors and they were made without it i quess its safe for me to asume i can just swap lifters over if need be

[IsaacHayes]

http://www.bstuff.com/index.php?showtopic=48461&hl=3900&st=0

Read my posts on there that gives you good info. Starts at post 13.

[Guest]

Isn't CNCGuy working on or was working on what it would take to disable the VVT?

[boostedrs]

thnx isaac.

that pretty much narrows it down to 2 things for me then

#1 need to know if i can use the 2.8/3.1/3.4 timming cover on the 3900 block
#2 the biggest thing is what to do with the vvt assembly

does anyone have a 3900 cam and a 31/3400 cam they can post pics of side by side and also measure bearing journals to see if they are the same

would also need a pic of the front of the 3900/31/34xx cam

and pics of the whole vvt assembly would be great

[boostedrs]

i found the pics of the vvt assembly and front of the block


looks like the rwd timming cover will bolt on if the vvt assembly is removed
and

An update on what I'm finding on this engine.

The camshaft has larger journals, 51.5mm vs. 47.5mm. The center tube has been increased in diameter as well as the lobe base diameter (35.5mm) and has .293 lift at the cam. The front journal is wider and has a groove for oil flow to the VVT actuator. The overall length and spacing of cam, journal and lobes are unchanged.

so that renders a cam swap useless to get rid of the vvt,but i wonder if delta would custom grind a 3400 cam with the right size journals to fit into the 3900 block.

always the possibilty of bearing spacers to use standard 2.8/3.1/3100 etc cam bearings and use an earlier roller cam

[Joseph Upson]

Your chances of getting a DOD 3900 are far less than getting a non Active Fuel Management 3900 and from my research they didn't start until 07 with that option which is only available in the chevy Impala, all other 3900s are 6 cylinder mode only.

Me and CNCGuy have done quite a bit of investigative work on it, I found Delta Cam who will resize the journals of the earlier camshafts and CNC has had one modified but has not completed installing it to check for clearances.

I on the other hand intend to use the stock VVT cam with a regrind and a degree wheel to find straight up location for the option to lock the cam into that position, I intend to operate the VVT function in it's full range or I will limit it to a retarded base position and have it retard to max degree from there.

You can remove the variable intake divider which is basically a divider that turns to straight up to separate the plenum into two halfs and horizontal to allow them to mix for top end bias. I wouldn't put a manifold that wasn't designed for it in its place not knowing for sure how it will affect it.

The 04-06 3500 is different than the 07 3500 from the heads up in the major parts and ofcourse the 07 is based on a 3900 block so either the pistons are different or the rods are to make up for the stroke change. Between me and CNCGuy one of us should have this engine installed and working within the next 3 months.

The answers to all of your questions should be here

http://60degreev6.com/showthread.php?t=34223

http://www.fiero.nl/forum/Forum2/HTML/080440.html

[boostedrs]

Your chances of getting a DOD 3900 are far less than getting a non Active Fuel Management 3900 and from my research they didn't start until 07 with that option which is only available in the chevy Impala, all other 3900s are 6 cylinder mode only.

Me and CNCGuy have done quite a bit of investigative work on it, I found Delta Cam who will resize the journals of the earlier camshafts and CNC has had one modified but has not completed installing it to check for clearances.

I on the other hand intend to use the stock VVT cam with a regrind and a degree wheel to find straight up location for the option to lock the cam into that position, I intend to operate the VVT function in it's full range or I will limit it to a retarded base position and have it retard to max degree from there.

You can remove the variable intake divider which is basically a divider that turns to straight up to separate the plenum into two halfs and horizontal to allow them to mix for top end bias. I wouldn't put a manifold that wasn't designed for it in its place not knowing for sure how it will affect it.

The 04-06 3500 is different than the 07 3500 from the heads up in the major parts and ofcourse the 07 is based on a 3900 block so either the pistons are different or the rods are to make up for the stroke change. Between me and CNCGuy one of us should have this engine installed and working within the next 3 months.

The answers to all of your questions should be here

http://60degreev6.com/showthread.php?t=34223

http://www.fiero.nl/forum/Forum2/HTML/080440.html

thnx i had just found that 3900 info thread before,though im only on page 8

ok so delta will resize the journals,with that done bolting on a standard cam gear should work, as long as the gear on the cs is the same as earlier designs (i.e size)

getting the vvt to work is not an option for me even if i could control it, i do not have the room to use that front cover and accesory setup.

as far as the intake i would either gut the valve assembly or just build a sheetmetal manifold.

3 months isnt bad lol im trying not to wait that long though, id like to get some solid info and go pick up a motor in the next 2 weeks and get started need to finish up whatever i end up doing by late august

[Nightingale]

Maybe you should just skip the 3.9L fwd engine altogether and look into swapping over a whole 3.6L vvt dohc engine from the caddies. Granted it'd be alot of work but its got aluminum block and heads and has forged goodies all around.

[IsaacHayes]

I doubt you'll run into a G6 convertible but those have a de-tuned 3900 in them. I really would like to see a pic of that motor though to see if they are using the 3500vvt upper intake.. I believe they probably do...They are 227hp.

The 3.6 being DOHC will be a lot larger. Only 15 more horse too.

[Joseph Upson]

You would want the 3.6 from the Saturn sport utility and one or two other sport utilities with the 275hp rated 3.6 L. The engine in the G6 convertible is probably computer limited or exhaust limited to reduce output but otherwise should be the same as all the others. The 3.6 sounds like a winner except for proof of durability. The Northstar V8 can be a nightmare after the 100K mark with blown head gaskets from normal use and time sert problems on rebuild. I don't want any engine with those kinds of problems or potential for it despite the weight savings of the aluminum block. The iron block engines are long haulers if properly maintained, you can expect 200k out of them.

My mom has the 3.6L in her Saturn Aura and it hauls butt. I wouldn't run against it with my turbo 3100 Fiero. I'm a big fan of the small powerful approach. Can you believe it, GM is making 60 degree V6 engines that have a combined hp & torque average higher than the first TPI V8 engines in the mid 80s. My 85 IROC 215 hp and my 86 IROC 190 hp.

90 IROC Z 210hp 285 tq 5.7L
07 Saturn outlook 275hp 251 tq 3.6L
That's amazing, nearly 2 litres difference nearly! wait that's 2.1L difference.

[boostedrs]

i think its been confirmed that the dohc motor will not fit into an f-body. but i dont recall anyone actually trying to do it.just what ive read on various boards.
so far it seems like all the parts can be had to deal with the vvt in the 3900, so more then likley its gonna be a go