Rebuilding

[Petros]

the 4afe oil pan will not work in the Tercel, but if the 4a oil pain will fit you might be able to adapt the 3a Tercel oil pan and oil pick up to work on the 7af block. The 4a and 7a oil pan never had the cross member going under it. Or you can always fab up your own oil pan like Larry McGraph did on his 4agez conversion.

I opened up the ports, both intake and exhaust, as far as i dared, and cleaned them up to a polished finish, on both the 3a and 4a heads I have used, incluing the 4ac head I am running now on the 4ac engine. BTW, the heads are slightly different, but both 3a an 4ac valves, both intake and exhaust are the same size, same part number. Larger valves would help a lot, but that would be a lot of cost to have a machine shop butcher up a 3a/4a head to install larger seats, guides and valves, plus a lot of port work. It would be easier to use one of the very nice 16 vales heads that are avaialble for the 4afe or 7afe (or 4age).

Why are you so determined to use the 3a/4a head on a 7a engine? It can likely be made to work, after a lot of messing around, but I can tell you it will not be reliable. I have pushed the 3ac head way past its reliability trying to get more power out of it, it is an obsolete design, and a poor design for tweaking more power out of it. I spent 4 years trying to make it reliable with only a little more power output. It does not cool properly, the 8 tiny valves are only good for 60-80 hp, it warps from the extra power out put and compromises the head gasket. I even went to a (costly) custom made all metal copper head gasket. Still leaked because it can not handle the extra power/heat load. More HP means more fuel/air mixture running through it, more stress and more heat load. It cools unevenly and warps the head off the surface because of the large temperature gradiant. Trying to make it more reliable I have fully annealed the head, had it re-alined bored, resurfaced (several times), modified the water jacket and the head gasket, used special head gaskets and head bolts with special assembly lube and calibrated aircraft grade torque wrench on it. all adding up to having a very unreliable head gasket. You will be replacing the head gasket every 3 to six months. Trust me, I have done it. I gave up on it and switched to the 4ac (which is slightly better head and water jacket design than the 3ac). I am preparing a 4age to install as the "final solution" to the crappy 3a/4a head design. Toyota really blew it with the 3a/4a head, all the other import cars have already switch to the 16-valve configuration (honda had it almost a decade ealier) and Toyota was using it on most of their other cars. It was obsolete when it was put in production, it was thrown together for a cheap entry level car, which the great little Tercel4wd inhereted (despite all of its siblings having 16 valve engines or options). It was a bad idea from day one, and not worthy of all the great cars that toyota was making.

I would not waste any time with it, by the time you are done with your Frankenstein 3a/4a/7a monster, the head will give you constant trouble even if you work out the clearance problems you will create. If you want a very reliable high torque and good fuel economy engine use a fully stock 4afe, adapt the ignition and EFI system to the Tercel, (or you can use the carburated 4af engine) and make a custom exhaust, you will have a very reliable and powerful engine, 40 percent more power and nearly twice the torque of the 3ac. Want more power? go 4age, same issues to make it work, but you can use the factory distributor and ignition system, but have to either swap the crank shaft or modify or make a flywheel (4age uses 8 bolt flywheel, 3a, 4a, 7a uses six bolt flywheel, but the 4a crank will swap right into the 4age). Way less trouble, and you have a tested and reliable engine in a production configuration, with a lot of after market parts available to boost the power even further.

What is special about the 3a head, and what do you hope to gain by putting it on a 7a sort block?

[yellowsnow4free]

Thanks for the reply Petros

I wasn't aware that the 3AC and 4AC heads were different, so I usually refer to them as 3AC / 4AC heads; my mistake.

As far as why a "7AC", I guess I know a lot of guys on here do the 3AC to 4AC swap, so I figured why not go 7AC? More displacement seemed like the goal, plus it seemed like it could be done for not much more than a 3AC / 4AC rebuild.

I am preparing a 4age to install as the "final solution" to the crappy 3a/4a head design.

I guess that kinda sums up everything, huh?

I'm all for the 4AGE swap; my main gripe is that in RWD configuration, the swap means gathering costly Corolla GTS parts.

[Petros]

actually snyth found the MR2 intake manifold easier to fit under the hood, and you have to make a new exhaust anyway, might as well included a new header. someone used an MR2 turbo exhaust manifold for his 4age swap for the T4wd, he just used it as a regular exhaust manifold, not turbo. The GTS corrola parts are around, not that costly if you take your time looking for them. Most important RWD part would be the water pump housing so the water inlet/out are in the right place for the Tercel radiator location. You can still buy those new, but I ran across several searching craig's list over several months. You can adapt or fabricate what ever else you need to make it work.

It might even be possible to use the 3ac water pump and housing out of the Tercel on the 4age.

[Petros]

I wasn't aware that the 3AC and 4AC heads were different, so I usually refer to them as 3AC / 4AC heads; my mistake.

There are several versions of the 4ac head, they are almost identical to each other and the 3ac, I think all of the parts are inchangable (guides, valves, rocker assy, etc), but there are changes in the casting. There is one version that has a completely different valve cover, it known as the "wavy" covoer becasue it snakes around some solid bosses over the intake ports, a version never imported but it appears the bosses were designed to take injectors. Also, the intake ports on this version has these big thick ribs or "fins" down the center of the intake ports, some kind of swirl device. I ground it all away so it would not restrict max flow. There are also some changes to the water jacket in how the coolant circulates through the head, likely an improvement over the problems in the 3ac head design. So far I have not had any head gasket problems after a year and half driving around with the built up 4ac engine, and driving it pretty hard.

So, though power limited, it is a vast improvement in power output (and reliability) to swap in the 4ac. I am happy with the power output of mine, but I am still going 4age just to get that little bit more, and to eliminate that darn carb and all the vacuum lines and emissions crap.

[yellowsnow4free]

That's interesting about the MR2 intake manifold; I'll have to dig a little deeper around here into some of the 4AGE swap threads.

The car in question for me is actually a Corolla SR5, not a Tercel, so a 4AGE swap should be quite easy, assuming I can gather all the required Corolla GTS parts. Ideally, I'd like to find a donor Corolla GTS (one that's aesthetically damaged or rusted) and swap it into my car, but the likelihood of finding such a car (especially here in CA) is becoming less and less of a possibility.

Besides, right now my Corolla is my only car, and I don't have the space for a GTS donor, so a swap will be a while down the road (once I get my own place and a 2nd car to daily).

Right now my 4AC has 140k on it with no rebuild. When it comes time to rebuild (assuming I haven't gathered all the GTS parts / a GTS donor car) I'm trying to decide what to do with my 4AC.

My first idea, is a 3AC or 4AC head (whichever is better for cooling and whatnot) plus a 7AFE bottom end with higher compression pistons (~10:1, per your suggestion). Emissions equipment will have to be maintained since I'm in CA, plus stock intake and exhaust manifolds, but I am thinking of adding a Weber and a mild cam. Weber will have to be replaced with a stock carb for smog though.

My other idea is basically the same, but with a 4AC / 4AGE bottom end.

Either way, I know porting work will have to be performed on the head (and your mod to prevent pinging) as well as the intake and exhaust manifolds.

[Petros]

California is a more complicated problem, you are not allowed to swap in any engine or engine parts that was not available for that car in production, or as an option. You have to pass both an emissions test and a visual inspection. So that means 4ac, 4af, 4afe, 4age. However, not likely the inspector will know the difference from the outside if you swap around internal parts, high compression pistons, cams, etc. is there is no way for them to check visually.

I do not know if you can make a 7a engine "look" like a 4ac on the outside, but certainly both the 4af and 4age came in that car so you should be able to swap those over legally, and still pass inspection. Not likely they will inspect the block serial number, but it might be possible if they were suspictious you "tampered" with it. Though as you surmised, it would likely be best to find a whole "donor" car that someone warped around a tree or was badly rear ended, so you will have all the correct bits and pieces to swap over to your chassis. You can find them, they are out there, you might also search the auction sites and see when comes up. There are lots of GTS corollas I have run across that some "drifter" wrecked doing stupid stunts in it showing off. I know people that buy them from the auctions just to part out because there is so much demand for converting an SR5 into a GTS. lots of good condition SR5 corollas out there, but most of the GTS versions have been pretty well trashed.

[yellowsnow4free]

Yeah, CA always makes things more complicated

I think a 7AC could pass. Unless you look at the block serial number it'll look like a stock 4AC.

A carbureted 4AF is also an option, but I'm not 100% sure if that was available in the USA or not. But being a FWD layout engine, it could require a bit of work. Honestly I don't think it would fit in a Corolla due to the distributor location, whereas a Tercel looks like it has more engine bay room.

Of course, the coolest option would be a GTS swap, if I can find a donor car like you said. I have a friend with a Corolla GTS who rolled it drifting, and parted it out for more than he paid for the whole car -_- I'd have to get lucky and find one cheap.

If I wasn't in CA, or smog laws were changed here ( ) I would probably run a 3TC, carb'd 4AGE, or maybe an ITB'd 4AGE (16v or 20v). But that's just wishful thinking now

[lannvouivre]

California is a more complicated problem, you are not allowed to swap in any engine or engine parts that was not available for that cat in production, or as an option. You have to pass both an emissions test and a visual inspection. So that means 4ac, 4af, 4afe, 4age. However, not likely the inspector will know the difference from the outside if you swap around internal parts, high compression pistons, cams, etc. is there is no way for them to check visually.

I do not know if you can make a 7a engine "look" like a 4ac on the outside, but certainly both the 4af and 4age came in that cat so you should be able to swap those over legally, and still pass inspection. Not likely they will inspect the block serial number, but it might be possible if they were suspictious you "tampered" with it. Though as you surmised, it would likely be best to find a whole "donor" cat that someone warped around a tree or was badly rear ended, so you will have all the correct bits and pieces to swap over to your chassis. You can find them, they are out there, you might also search the auction sites and see when comes up. There are lots of GTS corollas I have run across that some "drifter" wrecked doing stupid stunts in it showing off. I know people that buy them from the auctions just to part out because there is so much demand for converting an SR5 into a GTS. lots of good condition SR5 corollas out there, but most of the GTS versions have been pretty well trashed.

If you like to overachieve, swap in the 7a for driving and then put the 3a back in for inspecting! Honestly probably would be easy enough as long as inspections are once a year.

[Petros]

well why not go "whole hog" and get something California "compliant" too: a 7age! with the 4age head and EFI on a 7af short block it will look like the optional 4age installation for the RWD corolla. you just need to round up all of the GTS RWD parts for the engine bay so it will look stock. No need to swap out engines for the annual smog check, and a number of people already pioneered the 4age head on the 7af short block for you so it is more or less all sorted out. You likely can use most of the EFI equipment from the far more common later corolla EFI engines.

[yellowsnow4free]

Petros, a 7AGE would be awesome, however, it'll still require all the same parts as a 4AGE conversion.

That's part of the reason that when I rebuild my 4AC, I'd like to use a 4AGE or 7AFE bottom end (using pistons with the 4AC head in mind though), so that I'll basically have a 4AGE / 7AGE bottom end after I swap pistons, just in case I ever go with a 4AGE / 7AGE conversion.

There is an interesting bill up for discussion here in CA, A.B. 550, which might allow cars to be exempt from smog after they pay a $200 fee? Seems petty, but it does give me a little hope that CA might revise their smog laws soon.

http://www.semasan.com/page.asp?content ... 2&g=SEMAGA

[teranfirbt]

Don't read too much into it, you have to be able to prove that you've "Made every attempt to repair the vehicle" or some such before you can actually get it.

The hardest part will still be the timing belt. The 7A deck is 14.5mm further from the crank than the 3/4A. This means you need a timing belt that is ~29mm longer (depending on how much slack you can pull out with the tensioner... That's a problem that will either need to have something spec'ed from a belt manufacturer (Gates, Goodyear, etc.) or find another car application with the correct length belt that is ~the same width, tooth pitch, and tooth size.
It's totally doable, just needs to have the correct research/parts finding done.

[yellowsnow4free]

Don't read too much into it, you have to be able to prove that you've "Made every attempt to repair the vehicle" or some such before you can actually get it.

Yeah, I'm not holding my breath

The hardest part will still be the timing belt. The 7A deck is 14.5mm further from the crank than the 3/4A. This means you need a timing belt that is ~29mm longer (depending on how much slack you can pull out with the tensioner... That's a problem that will either need to have something spec'ed from a belt manufacturer (Gates, Goodyear, etc.) or find another car application with the correct length belt that is ~the same width, tooth pitch, and tooth size.
It's totally doable, just needs to have the correct research/parts finding done.

For a 7AC, you need a timing belt from a Dodge Colt. The part number is online somewhere, but I don't have access to my links here at work. You can use the 7AFE tensioner, or the 4AC tensioner with the 7AFE tensioner spring or something.

It isn't completely documented, so there will likely be a little experimenting.

[WarWagon]

Who knows anything about bodywork? My wheel well where the mudflaps were, a few dents, and any other rust areas upon further tear down. What are the tools i need. What type of welder would work for this sheet metal?

What is spayed on the under side of terc 4wds? It seems like a type of foam. Would body work be worth it? Even the deer i hit shifted the front end slighty. Worth taking to a body shop?

[teranfirbt]

I've got one of the 100 amp Lincoln 120VAC MIG welders from Home Depot that works extremely well for body work. You'll need to have it set up with gas (not flux core) and .023" wire. I recently modified my hood and was able to weld 16 gauge (1/16" thick) sheet metal to the hood material without burning through. You do have to move fast to not burn through, so practice up on something that isn't your car..

Body work tends to be a rabbit hole that is extremely easy to go very far into. For basic repair work, the critical thing is to cut out the rot, weld in the new, and get it sealed up before it can rust again. Angle grinder with cutting and grinding wheels, small MIG welder, some POR patch to fill voids, and primer/paint will go a lot way. For things that are not visible after repair, I like to use Rustoleum cold galvanizer. It'll protect better than paint and doesn't require nearly the prep work. The most difficult thing to rust protect are the places that are inaccessible after welding. Some people here have sprayed various types of oil in to prevent rust, it's probably your best bet for that sort of work.

[WarWagon]

Teranfirbt, thank you for the great info. I do not know much about body work, but i bet i'll know just a bit more after. Thanks for the specific tool layout; i appreciate it!