Newb looking for a bit of info on 3A scv

[IHblarp]

Hi, I'm a newb to this forum and tercels. I found a tercel for sale that has a blown engine its an 83 with the 3AC engine. the guy selling it has already bought a "crate motor" which he says came from japan because they have to trade out motors every 20-30k? sounded weird to me but i'll go with it for now. The other engine has 3A SCV stamped on it instead of just 3AC. Are these interchangable? parts easy to find? ect? Could anyone point me in the direction of some lit. about these engines. I really want to get this car but also need to know what i'm getting myself into.

Any help would be appreciated, I tried to search but didn't have much luck, so any tips on navigating this site would be nice too.

Thanks

[tercel4wdrules]

Hello and welcome! Yes, the JDM 3A-SCV can be used in place of the 3AC, you'll just have to use the 3AC intake and exhaust manifolds. I see these engines in the junkyard all the time in Tercels and sometimes even in the AE82 Corollas. The SCV stands for Swirl Control Valve, which the 3AC did not have, I believe it has a vacuum doodad at the back of the head that activates it. At least that's what I remembered seeing last time I saw one at the junkyard. The replacement JDM engines for the 3AC have been getting harder to find, at least down here in So Cal, sometimes they don't have them in stock at the importers. I hope this helps.

[IHblarp]

thanks tercel4wd!! So the intake and the exhaust on the scv will not work?? the SCV motor is complete from the air cleaner to the exhaust mainfold. I was hoping that I could just swap the entire assmbly in place of the old motor. What else is different between these is it just the swirl control valve? also whats the JDM?


Sorry for the newb questions, I have been googling all day and have found very limited info, so if anyone has any helpful links i might be able to educate myself a bit before asking you guys more questions

[Highlander]

So THAT'S what my wife's got on her engine! When I posted a question about it last year, no one seemed to know- Great! The SCV seems to have more power than the stock 3AC- i just don't know where to plug the swirl control dashpot in! Can anyone help with that? its currently plugged off.

[tercel4wdrules]

thanks tercel4wd!! So the intake and the exhaust on the scv will not work?? the SCV motor is complete from the air cleaner to the exhaust mainfold. I was hoping that I could just swap the entire assmbly in place of the old motor. What else is different between these is it just the swirl control valve? also whats the JDM?


Sorry for the newb questions, I have been googling all day and have found very limited info, so if anyone has any helpful links i might be able to educate myself a bit before asking you guys more questions

It depends, I haven't seen any complete SCV engines, so I don't know how it looks like, but if you don't have any emissions regulations, you could just drop the complete engine in then. It would be nice if you could post a pic of the crate engine just to see how the exhaust manifold looks like, the intake and exhaust manifolds should likely be similar or the same as the 3AC. Only the 3A-SU had the twin outlet on the exhaust manifold which is better for performance.

JDM stands for Japanese Domestic Market. Don't worry about asking questions, I always like to ask a lot of questions, that's the only way to get informed.

I haven't found much information on the 3A-SCV, but I have seen them around. I yanked the intake manifold off of one at the junkyard, that's when I noticed the vacuum dashpot at the back of the head. Without the appropriate vacuum diagram, I don't know where that dashpot gets its vacuum source.

So THAT'S what my wife's got on her engine! When I posted a question about it last year, no one seemed to know- Great! The SCV seems to have more power than the stock 3AC- i just don't know where to plug the swirl control dashpot in! Can anyone help with that? its currently plugged off.

You posted a question about this a year ago? I guess there aren't too many members with this engine in their car. I would like to get a good look at the intake ports on the head, maybe next time I'm at the junkyard I can pull a head off one of these and have a good look. Perhaps the extra power comes from a slightly higher CR 9.3:1 and the swirl-intake ports. I wish I knew more information on this and there isn't much online either.

[IHblarp]

Cool thanks guys, I guess I might go for it!!! if I do than I'll try to take pics and let you all know anything that I figure out with this motor

[ARCHINSTL]

IHblarp -
Welcome!
And please do a write-up for the Repair Guides section!
Tom M.

[Petros]

These JDM crate motors are usually a good deal, you just do not know until you have it running. I had good luck with them for my Pathfinder and my wife's MPV. They cost less than getting a good gasket set, so if you just want a good running engine, these are a good way to go.

If you have the SU carb set up I would consider keep it and making it work, otherwise it might be better to swap out the intake manifold/carb assembly and exhaust manifold (one gasket needed for it). You might also have to swap out the oil pan and oil pick-up if the engine came out of a different model than the '83-87 Tercel. that is an easy swap too, and you need one gasket for that too (do not over-tighten the pan gasket!).

It sounds like a good deal, how much does he want for the car and crate engine? It is a big job, but as far as pulling and reinstalling an engine, it is easier on this car than most others.

[IHblarp]

thanks petros for the reply! He was asking 1000 for the car, the "crate" motor with unknown (to both him and me) miles, and an engine lift. My girl friend and I went over there the other day and just chilled out and chatted with him for a while and I kinda took a liking to the guy, so after doing a bit of research (which turned up almost nothing) I decided to just go for it. I struck a deal of 650 with everything listed above. I'm on a college budget so i'm a bit apprehensive of how this is going to work out but it will be an adventure none-the less! I don't know what the Au carb is or anything else really about these cars but i'm interested to learn. My buddy had one in high school and we beat the living crap out of it and it just kept on tickin!!! so I've always been convinced that one would be an amazing car especially if someone is willing to show it a bit of respect. Wish me luck!

[danzo]

They cost less than getting a good gasket set

Do you get your gaskets at Nordstrom's? How much do JDM 3AC's cost? I got a whole Fel Pro engine gasket set at Autozone for $45. Did the Japanese motors use Skinner's Union (SU) carbs or was that a misprint? These came on alot of British cars back in the day. They worked OK, but if you don't want to keep it you can prolly sell it to some MG/Triumph guy for a decent amount. I might get what looks to be a rebuilt Aisin (stock US market) carb from a junkyard car, let me know if you have any interest in it.

Welcome Officer blarp - $650 for that car/motor sounds like a good deal, I think you will be happy with it once it's roadworthy. How much rust does it have? Where are you located? As far as the mileage of your "crate" motor - Japan emissions laws require that an engine be removed and replaced with a brand freakin' new one when the car hits 100,000 kms (about 62,000 miles). These removals then of course get shipped out of the country, which is where we benefit. And you thought US emission laws were strict!

Good luck swapping the motor, like Petros said it is much easier to do on this car than most others. Just be careful not to hurt yourself - a borrowed/rented/used motor hoist is almost a must. Do keep us posted.

[IHblarp]

I hope it's decent deal, i'm in new mexico so rust shouldn't be a huge issue. I think the guy lived in North dakota for a while so it might have picked some up there. Are there any areas in particular that I should be esspecially concerned with or look out for? I didn't notice any when I was checking it out but I also wasn't looking for it. As far as the lift goes he is including and engine hoist in the deal so that will definitely be a huge plus.

He was trying to tell me that the SCV motor had around 20k but your 100k kilometers is probably much more accurate.

Iv'e done some mechanical work in the past, mostly building off road type vehicles like Jeeps and Internationals but I've never swapped an engine. Looking at it I think it will go pretty smooth considering that the new motor is complete from air filter to exhaust manifold.

[sdoan]

Hello,

I considered using a swirl head 3A engine, but then found a better non-swirl engine. The swirl mechanism has vanes that stick into the intake tracks in the head just before the intake valves. The vacuum can on the back of the head pulls on a rod that is connected to the 4 vanes causing them to angle into the intake stream setting up the swirl. I don't know if lack of vacuum reduces the angle to minimum, but that would make sense - but you should check. You can see the mechanism to move the vanes by pulling the valve cover. You can see the vanes by pulling the intake/exhaust manifolds. The whole mechanism can be removed (I considered this) from under the valve cover. The fittings that the vanes fit through would have to be removed and replaced by very large bolts with gaskets. As I remember the hole for the vacuum can at the back of the head is easy to block, but I can't remember if it needs a bolt and gasket or a plate and gasket.

The vacuum can at the back of the head may make it difficult to put the engine it the car because there is very little room between the back of the head and the firewall.

I've swapped 2 engines into my 4wd Tercels and it sounds like you have the skills to do it. Label all the vacuum lines and draw diagrams or you will be lost when you try to get it back together. It might help to take photos too. When you pull the engine be careful of the TSTV valve at the front of the head. It is black plastic, has 5 vacuum lines going to it and sticks up like a sore thumb. They are expensive to replace.

My guess is that the SVC engine is not from a Tercel like ours. In that case you will have to remove and replace the oil pan and oil pickup with those on the current engine (the Tercel pan is designed to clear the crossmember and is deeper). The intake and exhaust manifolds will also need to be replaced or the exhaust pipe will not attach when you install the engine. Likewise you will need to remove and replace the flywheel and engine backing plate. The Tercel flywheel is smaller diameter and the backing plate is Tercel specific. I've also had to replace the front pulley on the engines every time I've done it because my alternator uses a 3 groove belt.

Compare the 2 engines and see if you really need to R&R all the stuff. If you need to do it, pull the manifolds off the SVC engine first to get them out of the way and make it easier to move it around. Then pull the pan and oil pickup. Then use a block of wood to block a crank throw to loosen the flywheel and front pulley bolts. I'd then remove the pieces from the original engine in reverse order and install them on the new engine as you go. When you install the oil pan you can use silicon gasket maker without a gasket -that is how Toyota did it from factory and the factory manual (on this site) shows you how to do it. A large tube of gasket maker that you use with a caulking gun costs about $12.

While the engine is out you should replace the timing belt (cheap and easy) and might consider replacing the clutch.

When I did this work I put the engines on blocks of wood or hung them from the hoist as needed, but an engine stand would have been nice to have. If you do put them on blocks you will bend the engine backing plate moving it around but it is easily straightened.

OK, I wrote more than I intended...

Good luck, let us know how it goes.

[Highlander]

IHBlarp- Can you take a pic of the location of the vacuum source line that drives the SCV dashpot and post it please? I'd like to try to figure out what type of vacuum source it needs. That'd be great I've got 3 1/2 T4WDs and they just keep on tickin' when they're maintained.

[IHblarp]

i'll try to get pics once i start. We'll see though cause i don't have a camera so i'll have to try to borrow one. Right now the main goal is getting the thing to my house. It's been sitting for about 5 years, and i didn't even think to check the brakes when i was looking at it the first time. Kinda a bummer when you can finally coerce a friend into helping you tow something and then you find out it has no brakes , guess i should have looked it over a bit more thoroughly. but hopefully i'll conjure a way to get it home tomorrow or sat and this party can really start!!!

[IHblarp]

ok, time for a bit of an update! finally got the car to my house Mon evening. Yesterday i decided to dump some gas down the carb to see if it would even fire. surprisingly it started right up but definitely had a spun bearing or rod knock . So after some discussion with my roommates we decided to drain the tank and see if we could get it to run for an extended period of time to really try to diagnose where the sound was coming from. The gas tank had about 8 gallons of 5 year old gas in it, whew that was fun, it came out looking more like rotten beer than gasoline . So after going through all that trouble my buddy gets in to crank it over and after about ten tries the engine makes a crunch crunch crunch and then turns over with no resistance what so ever!!! sure enough the old rotten timing belt had busted sending the pistons into the head (I'm assuming these are interference motors considering a total loss of compression). So if the old motor wasn't completely toast before now it is!! kinda a bummer, but i was pretty set on swapping in the JDM anyway so its not a huge deal now I just got to make sure the JDM is in better condition when I drop it in.

So on that note what all do you guys recommend I do to the JDM befor dropping it in. It's been sitting out under a tarp for 4-5 years in the weather. Obviously I'm doing the timing belt and oil pan gasket because I'll probably have the swap pans but what else should i plan on doing or at least looking at while the motor is out of the car?