Caprice Wagon engine swap--worth it?
 

Hi all,

We recently bought a 1994 Chevy Caprice Station Wagon (as a "second car" to our eco-modded 2000 Chevy Metro :)). We plan to use it for carpooling (as it seats up to 8 people) and maybe towing a trailer someday (as it has a 5,000+ lb. towing capacity).

The car has an "LT1" 5.7 liter V8 (260 hp, 330 lb/ft tq). However, the Caprice Sedans from the same era were also available with an "L99" 4.3 liter V8 (200 hp, 245 lb/ft). The two engines are identical except for bore and stroke--all external components are completely interchangeable. I could literally take the LT1 out, put an L99 in, change the PCM, plug everything up, and go. However, I'm afraid that the smaller engine might not have enough "power" for a car this size (especially of we tow with it in the future), and might therefore net little to no change in FE.

Here are some other pertinent specs about the wagon:

-2.56 final drive
-4l60e 4 spd. auto trans (3.059 1st, 0.696 OD)
-4500 lb. curb weight

What do you all think? Would the smaller engine be worth it, and make a significant increase in FE? Or should I stick with the LT1?

Sam

I think I'd look at throwing a GM diesel in there instead of any kind of a gas engine ... I think this thread might give you some ideas: http://ecomodder.com/forum/showthrea...6-a-20367.html

The LT1 is a good, reliable engine that will not have to work itself to death moving that big wagon around. The 4.3s are gutless in a sedan, I can only imagine how bad one would be in a wagon. That, and with a 2:56 axle ratio and the weight of 8 passengers or a trailer, the wagon will need all the help it can get to get rolling or go up hills. You'd have to work the smaller engine so much harder to overcome the gearing and mass of the vehicle that I can't see it having any real benefit over the LT1. If anything, depending on how much towing you plan to do or if you drive in a lot of stop & go traffic, I'd look into a rear axle ratio swap. 2:56s are great - if you are always cruising at highway speeds on flat ground. But they are a lot of gear to overcome from a stop, and with the weight of a trailer behind an already heavy car, they will put a lot of wear on your transmission as it works against them to get all that mass rolling or get it up a hill.

My '96 Fleetwood had a factory trailer package, and that included a limited slip differential with 3:42 gears, there was also another towing package with 2:93 gears. You might be able to find a Caprice/Roadmaster/Fleetwood with a trailer package at a wreckers and score the complete rear axle out of it for cheap. Just grab the PCM out of the trailer package vehicle too! :snail:

i saw a wagon for sale locally here that someone swapped in a t56 6 speed transmission into :)

1996 buick roadmaster wagon 6 SPD. MANUAL

his isnt exactly built for mileage due to the 456 rear but it might do better than the 4l60 with your factory ratio. the 350 should have plenty of low end grunt.

That thing is soooo cool!!

I personally wouldn't mess around with an engine swap without a great reason, IE the old one has a thrown rod and someone gave you a new one for free. It's just so much hassle.

I think going for stealthy aero mods would help you a lot, a belly pan in particular. Grille blocking is probably a no-no if you're doing a lot of towing, I leave that to your discretion.

You should also get a gauge for it, if you don't already have one. That's gonna net you more gains than anything else. I know this from personal experience!

Thanks for the input, everyone. You all confirmed what I was already thinking--an engine swap probably isn't worth it.

A diesel engine would be cool, as would a manual transmission (I think I'd do an NV3500 or NV4500 instead of the T56, though). However, I'd only consider doing those if I had to replace the engine or transmission anyway, which I'm hoping won't be anytime soon (as the car only has 83,000 miles on it right now).

And yes, I fully intend to do some aero mods and some engine/trans tuning as well, and I already have a gauge installed. In fact, I had one soldered in before I even changed the fluids or filters. :D

We've averaged mid 60's MPG with our Metro for several years now. If we can get half of that out of this wagon, I'll be quite happy. :thumbup:

I agree with that opinion. :)

You won't and you never will, no matter how hard you try or how you attempt to mod it. I too own an old Chevy wagon, older than yours. You might get 14 City and 18 Hwy at best - so don't expect much more from it in fuel economy. It's a big, heavy beast. But you can move heavy or large loads with that old wagon, as no modern SUV can, and it would be best if you reserve using it only for that purpose alone. Other than using it for such things, leave it parked. That's what I do. I only drive it a few hundred miles per year. As long as it runs when it's needed, that's all that matters.

Everything has it's purpose. Use your pony as a pony and your workhorse as a workhorse, as needed. ;)

If you are nice with it, you can get 17 in town and 24 on the highway like I do with no mods.

I'd roll that wagon.