LZ4/Fiero Swap

[neophile_17]

My initial thought was that there is no way this could be done mechanically but after a little more consideration I think something along the lines of the advance mechanism in an old school distributor could work. The oil control system would have to be bypassed in this scheme and it's not something I'd probably take on but it's fascinating nonetheless. Going the electrical route will be tricky unless you have feedback on the angle difference between the cam and the crank. I like that all the hardware is in place for this on the MS3X- I just have interpret the signals and tune the control loop. That's the hope anyway.

I'll take pictures of the cam phaser before I put it all back together. Anything in particular that you want more detail of?

[NateD4]

Use of the stock computer for an LZ is possible. Just have to get EFI live and turn off the vehicle anti theft check.

I'm half way through this swap with both 3.5 and 3.9. The snag I had to figure out is plumbing the coolant system. Wiring isn't too bad as the engines are simpler than the LX in many ways...

[neophile_17]

Nate,

That's interesting. I didn't know that had been done. Do you have a build thread somewhere? I'm sure I'll be running into similar problems soon enough.

I'm assuming that you're talking about the radiator hose and not the heater core lines. I had an initial thought about re-purposing the stock Fiero pipe that crosses to the drivers side but I'm a long way from that point.

[NateD4]

The project is on hold but I've got the 3.5 with F40 in the car. Axles are figured out. Exhaust was in process before I had to move. Wiring isn't terrible. I have all the colors and gauges figured out. And was in the process of drawing the new diagram.

My build is unusual as it is a 3.5 for initial fitment and debug followed by a fully built 3.9L with DOD, VVT and a VGT all run off a C6 ZR1 computer controlled fuel pump.

I'm using stock coolant tubes and cross over pipe welded to fit. It's quite a bit of fab work.

There are several computers capable of running this engine. Though a modified ZR1 computer is probably the best choice given the complexity of my build.

The trouble is getting software figured out

[ericjon262]

The project is on hold but I've got the 3.5 with F40 in the car. Axles are figured out. Exhaust was in process before I had to move. Wiring isn't terrible. I have all the colors and gauges figured out. And was in the process of drawing the new diagram.

My build is unusual as it is a 3.5 for initial fitment and debug followed by a fully built 3.9L with DOD, VVT and a VGT all run off a C6 ZR1 computer controlled fuel pump.

I'm using stock coolant tubes and cross over pipe welded to fit. It's quite a bit of fab work.

There are several computers capable of running this engine. Though a modified ZR1 computer is probably the best choice given the complexity of my build.

The trouble is getting software figured out

I didn't think the ZR1 had VVT?

I feel like the hardest part of running a non stock computer, esp obd1, will be the fact that you basically will need all of the same tables you would use for spark control replicated to control the cam, which then leads to the tuning nightmare of having another big variable to have to dial in. it's the part of swapping to a VVT engine that I dread the most.

[Guest]

I have been in talks with Crane cams and have dropped off a 3900 cam to see what they can do for reproduction and custom specs for the larger cam journals of the lz4/9. they would be based off of the earlier style timing chain so the vvt would be eliminated. This would allow for obd1 and obd 2 setups. I am waiting to hear back for pricing, so not sure if anyone would be interested in this option or not.

[Guest]

I have been in talks with Crane cams and have dropped off a 3900 cam to see what they can do for reproduction and custom specs for the larger cam journals of the lz4/9. they would be based off of the earlier style timing chain so the vvt would be eliminated. This would allow for obd1 and obd 2 setups. I am waiting to hear back for pricing, so not sure if anyone would be interested in this option or not.

Hmmm, that sounds like a great option, and far better than finding or getting bearing spacers made.

If this comes to fruition, I may go to an LZ9 sooner than I would have thought.

Of course, I still want to put a good cam in my LX9 and play with it for a while before any drastic changes are made.

[ericjon262]

I have been in talks with Crane cams and have dropped off a 3900 cam to see what they can do for reproduction and custom specs for the larger cam journals of the lz4/9. they would be based off of the earlier style timing chain so the vvt would be eliminated. This would allow for obd1 and obd 2 setups. I am waiting to hear back for pricing, so not sure if anyone would be interested in this option or not.

OBD2 would still require a custom timing cover with provisions for the 24x CKP, and possibly a special balancer to fit, I'm not sure if the spacing would work between gen 3 and gen 4.

[caffeine]

The gen III timing cover *looks* like it could fit on a gen IV, assuming there wasn't a cam actuator in the way. The water crossover would probably have to be custom to fit with a FWD gen III timing cover.

[Guest]

The gen III timing cover *looks* like it could fit on a gen IV, assuming there wasn't a cam actuator in the way. The water crossover would probably have to be custom to fit with a FWD gen III timing cover.

The plan is to have the obd 1 3 bolt pattern in the front of the cam, that way the cloyes double roller can be used in RWD setups if wanted. I think the double roller will fit behind the fwd timing cover with some grinding on the inside of the cover. if not then obviously a standard single chain can be used.

Also the plan is to have the cam machined with the obd 2 timing ring so to speak on the cam so the obd 2 cam sensor can be used for those in later model cars. The cam sensor is secondary pending cost as I find most people doing 3400 swaps and lx9 swaps are using the 7730 hardware.

with no cam acutator vvt, the rwd timing cover will bolt to the lz4/9.

[neophile_17]

Nate- That's an interesting combination you've got going. Hopefully you get back to it soon. Is the vette computer capable of operating a cable driven TB? Also I noticed that the hole in the block behind the oil filter adapter isn't tapped. Is your setup complete enough that you can tell if the stock filter and adapter will fit the subframe?

Ericjon- With regards to VVT, I'm only planning a 1D table for VVT Angle at RPM. A 2D table may get me better fuel economy but it's not economical compared to the cost of dyno time. I'll make an educated guess, follow it up with street tuning, and dyno tune it for power.

[Guest]

I think the plan for the cam sounds good, and I prefer the 3 bolt pattern over the single bolt. I'm just not a fan of the double roller timing sets that have been available. It seems that the gen3 chains are better for less stretch than the gen1/2 chains, but there's no compatible cam gear to mix and match the two AFAIK.

[ericjon262]

the TCE double rollers required crank and timing cover clearance work to fit. I highly doubt you'll fit the cloyes unit without at least a gen 1 timing cover

[neophile_17]

So I put the phaser back together yesterday. I keep getting errors about a token expiring when trying to post and uploading one photo at a time is tedious. I can email photos if interested.

I know it's speculation at this point but any idea what the earliest timeline would be for the new cam blank?

Sam

[ericjon262]

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