4ac engine swap

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j0fish
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My tercel:: 1984 toyota tercel 4wd

4ac engine swap

Post by j0fish »

I know the 4ac is one of the more popular and easier engine swaps to do on the tercel and I'm asking since one of my pistons in my 3a broke (it was a matter of time, engine had 360,000 miles on it). Is it easy enough to do with low to mid level mechanical knowledge? I was able to replace the carburetor on mine no problem and my dad knows how a lot of car parts work (as in he used to be a mechanic years and years ago) but I do not want to go in over my head. Should I just have a mechanic do it or is it easy enough for someone like me with the help of my dad to do? As a follow up question, since the 4ac is rwd would I no longer be able to go between 4wd and fwd and just have rwd?

also, I've looked on the forum for a few guides but couldn't find any otherwise I wouldn't be asking this
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Petros
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My tercel:: '84 Tercel4wd w/extensive mods
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Re: 4ac engine swap

Post by Petros »

welcome to the forum,

swapping an engine is a relatively low skill project. You and your dad should be able to do it no problem I would guess. It is a big job with lots of steps, but there is nothing requiring particularly high skill or knowledge. You need to find a good 4ac, otherwise you would have to rebuild it first yourself, making it an even bigger project, and requiring more specialized tools and knowledge.

It is a big and demanding job, there are a lot of steps, and a lot of parts that have to be removed, and replaced. If your dad has ever pulled an engine from any car, than this should be easy. You will want to swap out the intake and exhaust manifolds, the carburator and all of the fuel system, as well as the engine mounts and similar external assemblies like the power steering pump (if you have one), the alternator, starter, etc. it is easiest if you can borrow or rent an engine hoist, or use a "come-along" type hand winch on an overhead beam. I have even stripped all the external parts and lifted the engine out with a loop of chain attached to the engine with a beam through it. Than have one strong person on each end of the beam (on either side of the car), and lift it out of the engine bay.

the 4wd feature is from the transmission and reward, swapping the engine will not turn the car into front wheel drive.

it is a very costly job to pay a shop to do it, it is mostly labor, and shop rate is usually around $80-100 an hour, typically a $1500 or more job, not counting the engine, but including new gaskets, fluids, clutch, etc. (you will want to install a new clutch unless you know yours is not too old). You can do the whole job yourself for about $150-200. in a weekend.

you will not regret going to a 4ac engine, and you will not regret doing it yourself. You will learn a lot about your car, and there will be nothing to be intimidated about doing major repairs on it later. You will not only save lots of money, but you will become an expert on your own Tercel. And likely you will do a better job of it than a shop doing it for money, likely they would cut corners and leave you disappointed. Do the job yourself, you will be glad you did.

Now you just need to find yourself a good 4ac engine.

Good luck.
'87 Tercel 4wd SR5 (current engine swap project)
'84 Tercel 4wd (daily driver, with on going mods)
'92 Mazda MPV 4wd (wife's daily driver)
'85 Tercel 4wd DLX auto(daughter's daily driver)
'01 Honda Civic (other daughter's daily driver)
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Mattel
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My tercel:: 1988 Corolla 4wd Wagon (AKA Corolla All-trac) 5speed, AC, Power Sunroof, Windows, Mirrors, Steering, Locking, Diff Lock, 14" Corolla SX Alloys with Silica Hankook Tyres, 4afe, King Springs, Upgraded Headlights, Full Synth oils, 210,000kms
Location: Melbourne, Australia

Re: 4ac engine swap

Post by Mattel »

Adding to Petros and his always good advice is to change the throwout bearings in the clutch while you are there. and Perhaps brake lines and other items that are easy to get to. check your stearing rack and boots. CV joints, Elec cableing and spray some rustproofing while cleaning around the bay. Always take lots of photos of the dissasembly as a step by step guide. Especially with emmisions tubing and tag and bag everything or place it off one engine and put it on the other as you go. Download the manual and research all the info on here about parts you will need to take off the 3ac like the 4wd's special oil pan etc. Good luck!
Previous: 83 Tercel SR5 4wd, 84 Tercel SR5 4wd
88 Corolla 4wd Wagon 5speed, All power options, Fact Sunroof, Diff Lock, 14" SX Alloys, Hankook Tyres, 4afe, King Springs, Upgraded Headlights, Full Synth oils, Tow Bar, 210,000kms
j0fish
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My tercel:: 1984 toyota tercel 4wd

Re: 4ac engine swap

Post by j0fish »

for clarification by: "the 4wd feature is from the transmission and reward, swapping the engine will not turn the car into front wheel drive."

You mean I will only be able to stay in 4wd if I put the 4ac in? or are you saying that swapping the engine will just keep it as 4wd and fwd?

also, is it bad on the car to stay in 4wd on speeds higher than 30? I was told it'd be bad to the car to do so, so I just keep it in fwd 99% of the time unless I need to go on a gravel road or something.
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Mattel
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Joined: Tue Aug 17, 2004 12:11 am
My tercel:: 1988 Corolla 4wd Wagon (AKA Corolla All-trac) 5speed, AC, Power Sunroof, Windows, Mirrors, Steering, Locking, Diff Lock, 14" Corolla SX Alloys with Silica Hankook Tyres, 4afe, King Springs, Upgraded Headlights, Full Synth oils, 210,000kms
Location: Melbourne, Australia

Re: 4ac engine swap

Post by Mattel »

Your Transmission will work as before if you use your existing transmission and I think flywheel and clutch (clarification needed)

Never use the 4wd on sealed surfaces you need a loose surface like gravel/mud as the wheels need to slip a little bit from front to back as there is no central dif. If you use on dry surfaces you risk binding up and destroying cv joints, transmission etc. Also check your tranmission oil. have you flushed since you bought the car? good luck!
Previous: 83 Tercel SR5 4wd, 84 Tercel SR5 4wd
88 Corolla 4wd Wagon 5speed, All power options, Fact Sunroof, Diff Lock, 14" SX Alloys, Hankook Tyres, 4afe, King Springs, Upgraded Headlights, Full Synth oils, Tow Bar, 210,000kms
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Petros
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My tercel:: '84 Tercel4wd w/extensive mods
Location: Arlington WA USA

Re: 4ac engine swap

Post by Petros »

I do not know where you hear such myths about 4wd: I have driven my T4wd up to 75 mph in 4wd, you will not harm a thing as long as you do not make any turns at those speeds. I use the 4wd to get home everyday because of the steep gravel roads near my home, many times on my way back to work in the morning I drive it to the hwy and forget to put it back into fwd. I reach hwy speeds while in 4wd and I can not tell the difference at all. the only time I notice is when I slow down and turn sharply to pull into a parking space. the steering binds and I usually hear the tires scrub on the parking lot. I have also driven in 4wd on gravel roads up to 70 mph, it actually stablizes the feel and control on a loose surface.

The RWD system is actually the exact same system as used on the RWD corolla, and the FWD system is the same as used on the early Tercel FWD sedan. They cleaverly mated the two through a modified gear box with a simple transfer case on the back of the gear box. It is genious, and they used the parts for the system they already had in inventory for other models of cars. if there was a way to disengage the front drive system, you could drive it in either FWD, RWD or 4WD.

swapping the engine will not affect the selectable 4wd/2wd feature of our cars, that is a function of the transmission, not the engine. your transmission is unaffected by the change. in fact the two engines are almost identical, and are exactly identical on the outside, but you get more hp with the 4ac.
'87 Tercel 4wd SR5 (current engine swap project)
'84 Tercel 4wd (daily driver, with on going mods)
'92 Mazda MPV 4wd (wife's daily driver)
'85 Tercel 4wd DLX auto(daughter's daily driver)
'01 Honda Civic (other daughter's daily driver)
j0fish
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Joined: Tue Jan 31, 2017 6:22 pm
My tercel:: 1984 toyota tercel 4wd

Re: 4ac engine swap

Post by j0fish »

final question: as I said earlier the car has roughly 360,000 miles on it. I love the thing to death and would take it over any car, but the cost for a new engine is going to run me around 1300, not including storage fees and such until summer. I'm 17 (actually 18 as of yesterday now that I think about it) and am heading to college this summer. I'm getting a good deal so I won't need too much of my summer money to go towards college, but I wouldn't want to waste it either. If I fix up the tercel will something else major fail soon at this high a mileage? I would hate to spend enough money to buy a miata and then have the car not last due to how old it is.

If I find a good junkyard engine that is a different story altogether since the engine will only cost 100-200ish and at that point why not fix the car.
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Petros
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Re: 4ac engine swap

Post by Petros »

As the car ages there are a number of things that do wear out and need replacing, most are relatively easy to replace and not too costly (wheel bearings, brakes, seals, and so fourth).

There is one issue that could stop you: the single largest component that is not an easy fix is the transmission. If the gear oil is changed as recommend and it is not abused, it almost lasts indefinably. Though parts do wear out, usually you can get seals and bearings, but if you break any internal parts, likely you would have to replace the whole transmission assembly. they are still available, I have collected a few spares from the local wrecking yard, but they are getting few and far between. You can still find them for $250-500, but you may have to wait to get it. that is why I have a spare trans or two, so when mine give up, I have one I can swap in.

If your transmission is in good shape (shifts smooth and quite, no gear clashing, no whine or grinding), and you have changed the gear oil every 30,000 miles or so as recommended, it should hold up well. There is no reason to think it will not last another 100k miles or more.

when you do your engine swap, I would recommend you replace all the external seals while it it out of the car. You might consider doing an ATF/gear oil flush of the trans and putting some quality gear oil and perhaps synthetic blend, that will reduce future wear.

Where are you getting a price for $1300 for a 4ac engine? Seems rather high. You can rebuild this engine yourself for about $700-800, replacing almost all internal parts, usually you can get good running used engines for about $400 or less. Search craigs list and you might fine one for even less.

good luck.
'87 Tercel 4wd SR5 (current engine swap project)
'84 Tercel 4wd (daily driver, with on going mods)
'92 Mazda MPV 4wd (wife's daily driver)
'85 Tercel 4wd DLX auto(daughter's daily driver)
'01 Honda Civic (other daughter's daily driver)
j0fish
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Posts: 6
Joined: Tue Jan 31, 2017 6:22 pm
My tercel:: 1984 toyota tercel 4wd

Re: 4ac engine swap

Post by j0fish »

I've found a few junkyard 4ac engines but if those do not work I do not think I would have the experience needed to know how to rebuild them. I've checked for engines online but the close-to-new-as-possible ones are around 1300 minus some rebate for the old engine
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Petros
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My tercel:: '84 Tercel4wd w/extensive mods
Location: Arlington WA USA

Re: 4ac engine swap

Post by Petros »

You can do it yourself if you let the local machine shop do most of the internal stuff, there are machine shops here that will do the final assembly for me. there are a lot of machine shops around that will do most of the work for you. get an engine and take it apart, deliver the short block (block, crank, connecting rods, and pistons still in it, all external parts stripped off) and head assembly to the shop and they will renew/refreash them. Installing the head (I have a detailed guild on replacing the head gasket over in the "repair guide" section, and external parts you can likely handle yourself). it is actually easier to pull and replace the engine when the head is off (it weighs a lot less).

so you can actually do a lot of heavy lifting and hard work part yourself, and let the experts at the shop who has proper tools and expericance, to do internal engine rebuild it self. check around your area, get recommendations first, and go ask them for the cost to rebuid your the short block and head on a 4ac.
'87 Tercel 4wd SR5 (current engine swap project)
'84 Tercel 4wd (daily driver, with on going mods)
'92 Mazda MPV 4wd (wife's daily driver)
'85 Tercel 4wd DLX auto(daughter's daily driver)
'01 Honda Civic (other daughter's daily driver)
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