Engine Sawp 3ac to 4ac

Guest_dug320 · Post by **Guest_dug320** » Wed Aug 18, 2004 5:32 pm

I have done my homework. But still have some questions.

I would like to swap my tired worn out 3ac with a newer 4ac in my 85 Tercel 4x4 Wagon. I understand it is a direct swap. BUT, as my education continues, the engine at the recyclers lacks the carb, distributor, alternator and flywheel.

Can I take these parts off of my 3ac and put them on a 4ac with no modifications?

Cheers

arbskynxnex · Post by **arbskynxnex** » Wed Aug 18, 2004 5:41 pm

I'm rebuilding a 4alc for my tercel and I know that the intake and exhaust manifold are the same, therefore you can use the carb you have, and the distributor is the same. The alternator is different, but I think you can mount the bracket from the tercel and use that alternator without trouble. I think the flywheel is different, but I'm not sure since the 3a is still in my car and running, the bolt pattern should be the same though, so you can use your flywheel.

GTSSportCoupe · Post by **GTSSportCoupe** » Wed Aug 18, 2004 5:46 pm

I'm about 99.9% sure that you will have no problems. I believe the top end (head, intake, carb) are the same between the 3AC and 4AC. The blocks are basically identical (besides cylinder bore), so the alternator and it's bracket should transfer. I believe that both flywheels are the six bolt type and probably the same outer diameter (not sure on the outer diameter though). Either way, you are probably best off using the 3AC flywheel.

Guest_dug320 · Post by **Guest_dug320** » Wed Aug 18, 2004 6:33 pm

Great

Is there anything else I should know?

I am not a beginner by any stretch of the imagination with these cars. My first 85 fell apart (rusted) at 420 km. This is my second 85 and it has 260 km. I am just a little tired of this sluggish but relaible 3ac and would like to try something with a little more pickup.

Cheers

This is a great forum! I wish I had found it sooner!

sacwac · Post by **sacwac** » Wed Aug 18, 2004 7:16 pm

420km?!?!?!?!? and the 2nd at 260km?!?!?!?! That's ROUGH driving!!!!

Welcome to the forums.

Guest_dug320 · Post by **Guest_dug320** » Wed Aug 18, 2004 7:52 pm

420,000 and 260,000.

Some a little off road. What a great little machine!

3A-C Power · Post by **3A-C Power** » Wed Aug 18, 2004 8:16 pm

Are you in Canada then, if you are speaking in terms of kilometers? The 3A-C and 4A-C cylinder heads are the same, I checked the part numbers once. The 4A-C has different emissions equipment, but nothing that would make a difference.

GTSSportCoupe · Post by **GTSSportCoupe** » Wed Aug 18, 2004 9:38 pm

Guest_dug320 wrote: This is a great forum! I wish I had found it sooner!

Great to have you! You should register as a member. If you find that every time you visit the board you have to manually re-login when it should be happening automatically, its because your internet privacy settings are not allowing the autologin cookie to load on your computer. All you have to do is set it as low for one login and you won't have any more problems, you can set your privacy setting high again (I'm assuming you're using Microsft IE). If you have any problems, just ask.

Cheers,

Nick

dug320 · Post by **dug320** » Thu Aug 19, 2004 12:10 am

Hi

Yes I am in Vancouver Canada

I have not seen anything on the different emission controls. Based on your experience what are the differences?

Does the 4ac suffer from EGR clogging like the 3ac? I know 3ac's have this problem; if I do not clean the EGR valve before emission testing it will fail on NOx.

Cheers
DUG

arbskynxnex · Post by **arbskynxnex** » Thu Aug 19, 2004 1:03 am

The EGR gets just as clogged on the 4a as the 3a. Mine took about a week soaking in solvent before most of the carbon would come out. The valves are interchangeable, so if you get one with the 4a, save it.

Toodles,
Arb

dug320 · Post by **dug320** » Tue Aug 24, 2004 1:16 am

Hi

I recieved the engine and will take pictures to document the switch.

dug320 · Post by **dug320** » Thu Aug 26, 2004 11:37 pm

Hi

Now that I have had a chance to look at the engine I have some questions.

The engine is from a 85 Corolla FWD. Can I switch with my 3A-C the head and all the emission equipment?

The emission stuff is a little bit different with a few extra hoses. The TVSV on the 4A is at the back and is hooked up to something I do not have in my 3A-C Tercel. If I do switch heads will the water pump on the 3A-C fit the 4A?

The bolt pattern on the flywheel is the same so there are no worries in that department.

Your suggestions are always appreciated.

Cheers
DUG

Fingers · Post by **Fingers** » Fri Aug 27, 2004 12:47 am

Should have no compatibility problems at all. I bought a long block, put all the pieces from the old 3a on it, dropped it in and fired it up. Brackets, pulleys, everything, all went on no problem. There is a writeup of my swap somewhere on this board(2 parts), it may help you with some odds and ends, will let you know exactly what you need, so on and so forth.

The heads, while may be different in their capacities and such, will swap over. All the ports and such match. I did use the 4a head, but it was listed for a rwd 'rolla, don't know if the fwd version is any different. Shouldn't be though. And yes, the water pump is the same/similar-enough to use. I think the part no.s maybe listed different at a parts shop, but mine works fine and keeps my car super cool.

Now I am not saying not to clean the EGR, but mine was completely clogged when I put the car together for emissions, but at normal operating temp I recieved a rapid pass (super low ems). I still haven't replaced it(won't until I finish rebuilding this carb), and I couldn't clean out the old one, but my car still runs fine normally. I have some problems starting it after it has been driven and it sits for more than a short while, but that could be many other things as well.

Anyway, good luck, have fun.

dug320 · Post by **dug320** » Fri Aug 27, 2004 1:17 am

Hi

Your problem could be as simple as one of those black hoses. On mine, one of those hoses was worn enough (lose) to leak a tiny amount of air.

I like your advice and will give it a try.

Cheers
DUG

arbskynxnex · Post by **arbskynxnex** » Sun Aug 29, 2004 11:32 am

One thing you will need to do if you put a 4alc in, is use the oil pan from the 3a. I was under my car last night and discovered this, there is a rather important clearance issue.