Project: L67 Cavalier swap - it runs!

[MattStrike]

I'm just going to guess that I don't need to give a preface to this one, you all know what it is I do by now. Also, this is just a stock photo of the car.

I had to really piece things together across a few platforms and garner information from several of what remains of the surviving threads to know if it was possible.

The original motor knocks really good, I started it up to hear it for myself. It actually starts really easily for a motor with rod knock, I guess that's a tribute to the 2.4l.

150hp/155tq is about to become 240hp/280tq. Donor is a Riviera (bad idea, really really bad idea, because now I want one of those too now).

Some of the basic roadmap items:
1. Axles (I looked this up first...lol). I found a roadmap using OE axles to mix and match parts on the Grand Am forums to swap from a 4t40 to the 4t65. This is important because the 4t40 axles for the Cavi are the same length as the 4t40 Grand Am axles (I'll post the specifics as I get into this, I'm working from memory right now). So that means that the Grand Am axle solution will work with the Cavi, though there's a possibility that I will have to also use Grand Am wheel bearing hubs or substitute the Cavi outer joint in place of the GA outer.

2. Wiring. The '00+ Cavi's reportedly use the same data bus that is found in the Regals to provide data to the gauge cluster. I expect the drivetrain wiring harness will be on par with what I did for the Montana, if not simpler.

3. Subframe and mounts. The Cavi uses what I will call a half-subframe in the front. I will have to fabricate the 'front half' from new steel and add the appropriate mounts. This is the only real fabrication I expect to need to do.

4. A/C, fuel, Cruise control, and all that... One thing I strive to do with all my projects (mostly) is to not have to delete any emissions codes. This statement obviosly doesn't apply to my truck or the SSEi. I also try my best to avoid all loss of functionality. A/C is the biggest hurdle here - good thing this car is a convertible! All I can say about it at this point is that I will have to be very efficient with all of it, because space is at a premium once a 3800 is shoehorned in. If a Northstar can fit in a Bonneville, I don't see why I can't make everything work.

This project is progressing incrementally at the moment. Don't expect to see major progress before March, for one the local steel supplier is still Covid closed to the public (commercial accounts only, too bad they can't make a deal with the local grocery store to sell stuff), and I'm finishing my Masters right now. This car isn't rusty, it doesn't need a full on overhaul/restoration, anything like that. So I don't think it's going to be as bad as L67 swapping the Camaro, it's going to come down to how mild the weather ends up being and how much free time I have.

And no, it's not my car this time. Helping out a friend.

[CMNTMXR57]

Heck, LS that thing...

[95naSTA]

Don't want to F23 swap it? The gearing and weight would make the car hilarious.

[MattStrike]

If it was my car, I would be manual swapping it regardless of an engine

[Vegafan]

Ok, I'll drop a little personal experience in here before I forget to comment. Check the subframe over carefully.. they are not known for longevity in the rust belt. I have had 2 of the later ecotec cars with holes in the subframes and those were "better" from what I had read.

[MattStrike]

Finally getting started. Side by side, the Goodbye Toby moment:







First up is axles. Looks like I might already have everything I need on hand for the first mockup. The donor was a Riviera, the oil filter adapter from it doesn't fit in the Cavi cradle. I had to remove it to get the whole package in position. Looks like I'll need a pre-2000 oil filter adapter. Overall though the L67 drivetrain package isn't that much larger. The original L67 downpipe looks like it fits fine.

Once I get the axles done I'll start lining it up in the car for motor and trans mounts. For this application I'm thinking of using a mount setup similar to the W-body. The difference is the dogbones might be mounted to the lower front points on the block and trans, due to space constraints. I'll determine that after I get it lined up.

[Sirius]

Sweet! Now I'm jonesing for the next update.

[MattStrike]

Initial fitment check: She's tight!



Actually, it's not that bad. There are some brackets and things on both the motor and the chassis that will have to be modified or removed. The ABS bracket at the very least needs to be trimmed, possibly relocate the ABS module a few inches. And the front engine lift bracket is right on the radiator fan.

At the moment I'm playing with axles. Taking the opportunity to add the components of the Cavi axles to my compendium. Interesting fact: aftermarket replacement list that the axles for this application are the same length on each side. This is false, one side is 1/16" shorter than the other side from the factory - but I guess that's close enough to not matter! Anyhow, completely disassembled the axles today, cleaned them up, just have to find the parts bin that has all my axle parts from the SSEi f40 swap since it's full of goodies.

[retroren]

compendium....hmmm....Matt, you're the only engineer I know that uses 50 cent words not to mention building a budget car rocket ship. This will be one fun ride. An adult go cart:)

Project Montana still running good?

Ren

[MattStrike]

Project Montana is running very well. It's approaching oil change #3 already!

[MattStrike]

Ran into the first snag.

The donor vehicle, a '99 Riv, appeared to have both original C/V axles. Since I'm still taking measurement data for my axle compendium, I need to confirm this, but I can finally answer an old question of mine. The L67 axles, both LH and RH, are different than the rest of the 4t65e fleet. The drivers side axle between the NA and L67 have the same spline in the wheel and transmission shaft, so they interchange physically, but the L67 shafts have a larger diameter. This means that the axle combination that I found for the 4t65e swap is partially incorrect. Because the LH shaft outer joints are the same I just need to source a LH shaft from any non-l67 4t65e car. The RH shaft is going to be interesting, because the 4t65e-HD does have a larger inner spline, so I'm limited to an HD inner tripot that has the smaller spline on the tulip. My recollection from the SSEi was that the '97-'99 center shaft was the smaller 26mm OD on one end and the larger 28mm OD on the other - the Riv has both at 27mm OD. At this point I might have to swap the HD differential out for the standard to be able to use the smaller tripot. But depending on the year it's likely that there does exist a 4t65e-HD axle set that uses a 26mm spline on both ends of the center shaft. I'm going to guess it's on the W-body and H/C body.

[MattStrike]

Today I finally finished the mid-project-clean-up, so started the next step - setting the drivetrain in it's final position (with the help of 4 different bubble levels) with the subframe back it place. Of course, the goal is to set the trans output shafts as close to the original position as possible. At the moment I still need to source a specific set of axles to confirm the fitment, hoping to have that worked out yet this weekend.

Lots of straps and blocks to shim the drivetrain into the ideal position.








The 4t65 is a tighter fit than the 3800. The subframe will have to be trimmed down on the drivers side to clear the side pan.


As a general note, the front of the motor is right up against the cooling fan and radiator. Changing front plugs is going to be a chore. But the back side of the motor has plenty of room to the firewall. At the moment, it looks like spacing the cooling fan closer to the radiator is all I need to do.

[Sirius]

That is a cool apparatus. I don't think I've ever seen anything like that before. Where have I been?

[CMNTMXR57]

Jesus man! IT's almost as bad as an LS4 in a W.

And why haven't you posted this build on TCG?

[MattStrike]

Don't worry about TGC. I like to dump projects on those guys when they are mostly finished, makes it feel more dramatic!

[CMNTMXR57]

I mean, they would love this frankenstein sleeper.

[rustyroger]

That is a cool apparatus. I don't think I've ever seen anything like that before. Where have I been?

You mean the support beam?. Surely every car repair shop has one?.
I've got one in my mancave for changing timing belts etc. for just about any modern fwd car.

Roger.

[MattStrike]

Axle update:


The roadmap for the 4t65 swap was wrong. The axles left to right are about 1/4" different right now, the shorter being the passenger side. I could shimmy the motor a bit to even them out, but the bigger issue is that the supposed 92 grand prix magic axle is too long by about 1", and the same for the axle recipe for the other side. To be fair, this could be a 1" difference in the outer Rpezza joint, since "compressed length" doesn't exactly translate between different joint types.

At the moment I've found 3 different 4t60 LH axles that should be shorter, so going to split those open tomorrow and see what they are.

[MattStrike]

Looks like I figured out a usable axle combination.

Drivers side:
4t65 inner cup (NA cars only), 4t60 tripot (NA cars only), stock 2000 Cavalier center shaft and Rpezza.


Passenger side:
4t65 inner cup (NA cars only), 4t60 tripot (NA cars only), 1991 Olds Cutlass Ciera 3.3L/3-speed auto LH center shaft, Cavalier Rpezza.


How many axles donated themselves to this endeavor?


Too many I'm finding a lot of nuance differences between years that make certain axle combinations a non-working solution. The tripot on 4t60 cars fits a lot of the standard 26mm axles - at least one of the 4t65 axles I have the tripot has a minor difference in the snap ring width, so while it's completely identical and fits the standard 26mm shaft, the snap rings don't fit the grooves. It basically doubled the number of axles needed for the mix-and-match exercise.

At the moment, I don't have a solution for the HD differential, because the 4t65hd uses a larger diameter spline in the transmission as well as a 28mm shaft. All the HD axles I have are 28mm, I don't have an HD inner joint that fits a 26mm shaft. That means the HD differential has to be swapped out of the trans.

[MattStrike]

Now that I have the axles worked out I'm getting the engine mounts and subframe modifications figured out. First up, though, finding out which supercharger belt tensioner assembly will fit:





The W-body tensioner setup is the closest fit, though I will have to modify the W-body bracket significantly. Looks like I will be able to avoid moving the A/C connector, but not fitting the ICM/coils very comfortably in that gap. I'll have to come back to that after the mounts are done though.

Driver side - using the series 3 3800 trans mount and bracket puts it very close to the subframe.


Passenger side - grabbed a series 3 oil pan and mount setup here as well. Looks like I need to cut out the engine mount pocket from a W-body subframe, and hack off the Cavi engine mount bracket.


Still need to source a few minor parts, but the plan is to get some steel cut and tacked into place this weekend.