Help me swap an engine, car guys!

Factual Questions
1

Right now I have a 1990 Z24, 3.1L auto. I REALLY, REALLY want a stick.

My friend’s boss has a 1989 Z24, 2.8L 5spd. She’s had it for years, with a blown engine. She’s not really trying to get rid of it, but said she’d sell it to me for $400.

From what I know about it, the engine is blown, while the tranny is brand new. The body and paint are in good shape, and the interior is at least as nice as mine.

I’m torn between keeping my car, with various interior upgrades (that couldn’t necessarily be transferred) and my alarm/keyless entry/remote start, and changing out the tranny, or just dumping my working engine in the new car. Either way, I’ll end up with a car that doesn’t run.

My question is: Will the automatic transmission engine need any changes or alterations to fit?

My dad says yes, because it uses a different flywheel (obviously, but that’s a quick swap), but the biggest thing is he claims it uses a different pilot bearing and I’d have to swap the cranks. He also claims that the engine is tuned differently and uses a different computer, along with various and sundry other parts. He says that if I buy the other car, just rebuild the engine and run it, it’d be easier, and probably cheaper.

I say no, because why wouldn’t they just manufacture the transmissions alike enough to accept the same diameter pilot bearing. I also say that it would make no sense, manufacture wise, to have a manufacturing line running for auto engines, and one for manual engines. Then you’d have a static number of each available, whereas if they are the same damn engine, you’d have an infinately dynamic amount available. I also think it’d just be stupid to make two different engines, well, not two different engines, just two that are unalike enough that a direct swap is impossible.

So who’s a doofus, me, or dad?

PS: Allow me to tangent for a while. My car is red/silver. The other one is black/silver. I prefer black to red. I want racing stripes. Should I go Viper/Dodge stripes that run all the way from bottom bumper, over hood, over roof, over deck, down bumper, or LT1/Chevy, with stripes that start at hood, with the same contour as the hood, stop right in front of windshield, start again on roof at contour, stop at back, and start at deck, stop at back? Viper or LT1? Help!

Also, I’m going to have serious engine work done, soon. I’m thinking, leave the 3.1 in the automatic car for NOW, buy the black car with manual, pull and rebuild the engine, but leave it out of the car. Get the stripes put on the car, get the spoiler (off '92 Z24) put on, get new wheels/tires, whatever other cosmetic changes I do. THEN, when I am truly ready for the engine work, pull the 3.1, put the smaller, rebuilt, 2.8 in it, and drive that around. Drop the 3.1 in the black car to take to the race shop, get the heads/block deburred, bored, stroked (the 3.1 also served later life as a 3.4), ported, and tuned, get the turbo work done (yes, I’m getting a twin turbo setup for this car, it’ll cost about $2500), get the headers coated and attached, and the exhaust put in, and then just drop the 3.1 in the Black car and drive off. That way, I have a working car the entire time, I don’t have to worry about when it gets done, and no trying to work (cosmetic or engine wise) on my car while I’m driving it.

Anyways, I’m sorry about the tangent, I just get excited about working on my baby.

Also, if anyones thinking “This guy doesn’t know jack!” I really, really do know what I’m doing. I’ve worked on cars for years, and I’ve rebuilt one pretty much by myself. I know what I’m doing, I just get excited and forget the correct word, or name the wrong thing, sometimes.

–Tim

(Manny: I see three ways for this to go.
1: Then answer my tranny question. GQ
2: They start talking about engine work they’ve had done, and why I shouldn’t do this. MPSIMS
3: They start giving their opinions on what I’d like to do to my car. IMHO

Please move as you see fit.)

2

I’ve decided. LT1. Since it already has silver ground effects (as all z24s do), it would look stupid to have Viper effects. So that part becomes null and void. LT1 it is.

–Tim

3

Your public library has auto repair manuals available, nearly all of which have the complete specifications for engines and transmissions. From the same source, you should be able to determine the inter-changeability of the computer systems. You will also be able to determine the need for factory specialized tools—this is more common than you might think.

From my days as a mechanic, many long years ago, replacing an automatic transmission with a stick shift was usually very involved, tedious, painful and expensive.

It was rare to find a stick shift transmission that would mate with the bell housing on an automatic transmission’s engine. Various companies manufactured adapters for this purpose and this often required repositioning the engine mounts. It was not uncommon to find that changing the length of the drive shaft was neccessary and that is an interesting proposition. Think balance. If you have front wheel drive (I don’t know about the cars you mention) I would guess the drive problem would be compounded. The engine, transmission and drive shaft must be perfectly aligned or catastrophic failure will occur. Achieving this alignment often meant fabricating hangers and braces for the new transmission, plus some very careful measuring and a lot of geometry work.

Installing the clutch linkage often required a lot of ingenuity and access to a machine shop. Plus the interest of an otherwise very busy machinist. Hydraulic clutch systems often proved to be the easiest way to go.

None of which means that it cannot be done—nearly any automotive modification can be accomplished by the intense application of money.

I believe that the best course is to locate a restorable car with the engine/transmission combination you want. If you are a young man, as I presume you are, I know you will not take that advise.

But listen to me now: Buy a complete set of quality hand tools. I mean complete, not some Sears fifty-piece special. Don’t do this kind of job on the dirt in the back yard. Rent a well lighted garage, with room to work and store tools and parts. Buy or build a good workbench or two. Buy an engine stand and a good block and tackle. Buy a couple of floor jacks and plenty of safety stands. Wear safety glasses or goggles. Learn to weld, you will need that skill. Have a systematic plan to do the job and include a check-list. Take a million and two photographs of every part of the original car before you turn the first wrench.
Absolutely identify each and every nut and bolt that comes out of the car as well as that nut and bolts location. Be prepared to spend hundreds of hours and then find you have to start over.

Lots of luck.

4

Let me warn you, I don’t know this car, so there’s a lot of guesses here.

Rebuild the 2.8 engine and run that car.

Here’s why:[ul][li]Swapping in the manual transmission may require your fabbing up clutch linkage.[/li][li]The hole for the clutch pilot bearing may not be finished in the auto engine (just a guess.)[/li][li]The engine management in your car may control the transmission (ie, if it is a lock up tranny) and may expect to see certain speeds at certain RPMs (though this sounds like an OBD-II thing, affecting later cars.)[/li][li]Assuming that the heads and intake flow equally well, the swap would gain you 18 cubic inches, four of which would be restored if you rebored the 2.8 engine.[/li][li]After a swap, you will have a nice car, but it won’t be stock. As a result, you may have problems getting an emissions guy to sign off on it.[/li][li]You could rebuild the 2.8 engine, sell the other car and come out ahead.[/ul][/li]Whichever way you decide to go, I’d plan on spending a few months on the job. You probably won’t need that much time, but it would be better to err on the side of caution.

5

Just a few clarifications, guys.

I will have a 3.1 with an auto, and a 2.8 with a 5 speed.

I am not going to put a non-stock engine or a non-stock transmission in the vehicle. All parts came in the vehicle, stock, unchanged, at one time or another.

They are the exact same engine, block wise, the 3.1 is just rebored and stroked.

I will be putting the automatic engine in the manual car.

I will have both engines and both transmissions. Seeing as how they are the exact same engine, I would figure all the parts would be interchangable.

Louis: I believe you. But I wonder why, if they put the same engine with both transmissions, why it would have a different bellhousing. Money wise, and production wise, that doesn’t seem to make sense. Also, I don’t see why they would use different mounts, or why said mounts wouldn’t already be on the frame, and if they aren’t, why I couldn’t just swap them over from the second car.

Even if I were putting the manual in the automatic chassis, all the trim parts, bolt holes, and or firewall mounts and such for the clutch linkage are already on the vehicle, just either not being used, or covered by trim.

The reason I don’t just get a 3.1 with a manual somewheres is because only about 5% of the run was with a manual.

I live with my dad, who used to be a hot rodder, late sixties, early seventies. He’s got, or has access to through his brothers, nearly every tool you could ever need. We’ve got a garage, we’ve got huge expanses of pavement, we’ve got flood lighting. Believe me, lack of tools or know-how is not a problem. I’ve also already done quite a bit of work myself.

Cornflakes: I’m not swapping in a manual, I’m swapping in an engine from an automatic equipped vehicle into a chassis with a manual transmission.

I will have the original engine from the manual car, which is the same engine as the one I’ll put in, except for the transmission. So I’ll have the correct pilot bearing, if need be.

I do not think it ‘expects’ certain speeds at certain RPMs, since I swapped on smaller tires. This changed 85 mph @ 3500rpm to 95 mph @ 3500rpm, and it didn’t seem to affect the car. I think OBDII came into affect in… uh… 94 or so, right?

Yeah, it only gains 18ci, but it gains 20 hp and 30 lb/ft of torque, if IIRC.

My state does not require any emissions testing, AFAIK. Even so, since the vehicle being worked on is over 10 years old, it’s a moot point.

To all: I plan on keeping this car for at least 5 years, probably more like 10, so time is NOT a problem, I’d just like to get started as soon as possible.

Thanks all for your help so far, and please, if anyone else wants to share, PLEASE do so.

If anyone has any first hand knowledge about the Chevy 3.1, or the Cavalier 5spd, or anything of this nature, PLEASE chime in. I think I’m going to post this on a car guys message board, too, if anyone knows a good one.

–Tim