CT9A's 3A-C rebuild thread of questions

[CT9A]

OK, I figure I'm going to need some help with this (maybe a lot of help) and it just makes sense to have a thread for it that I (or someone else) can use for a guide.

I finally have the engine pulled and completely stripped down. I cannot afford to buy everything I need at once, so this is going to be a build stretching over a few months. Here's my first barrage of questions.

-Do I need to do anything with the crank shaft? Do I need to get it machined, how would I know if it does?
-How do I tell if the valve guides are needing to be replaced?
-Is there anything I should do with the rest of the car (i.e. tranny, suspension, etc.) while the motor is out? (I'm already planning on doing the fluid changes for the tranny/t-case/diffs)
-Other than the obvious, what needs replaced for maintenance while the motor is out? (I'm already planning on replacing all the seals and gaskets, piston heads, wrist pins, connecting rods, all bearings, all exhaust valves, valve guides if needed)

This is all I can think about for now, I know I'll have more later.

Thanks guys.

[sdoan]

Hello,

I "rebuilt" my 4a by replacing rings and rod & main bearings with stock sizes - no machine work. The only machine work I had done was the cylinder head valve grind for about $100. I lightly honed the bores with a rental hone (a "brush" type hone is easiest to use).

The engine started out with 140,000 miles and all the journal surfaces on the crank looked good (no grooves) and measured OK with micrometer (check every 90 degrees). There was no ridge or bad scratches in the cylinder bores. The pistons had very little wear on them (original machining still evident and almost no polishing).

If your engine is in this good a condition you should be able to rebuild with original pistons and no crank machining.

I got an engine build kit through NAPA with rings, bearings and gaskets for about $160 (I think). The gaskets in the engine kit were a no-name brand. I will not use no-name gaskets again because the head gasket, valve cover gasket and exhaust flange gaskets all failed. Felpro has worked for me. I also bought a new oil pump (NAPA had a good price on Aisin OEM).

Cleaning: don't shot-blast or bead blast parts the glass or mineral fragments embed themselves and are impossible to clean out. A lot of cleaning can be done with laundry detergent and a bucket of HOT water - let it soak. Don't soak aluminum in the detergent solution! The head shop will clean and grind the head and valves.

Flush out all oil passages in the block and the inside of the rocker-shaft.

When you assemble the engine use plastigauge to make sure bearing clearances are within spec (very important). Use a 3/8" beam type torque wrench. I've broken bolts with clicker types. The clicker types seem high-tech, but the beam types are simpler and probably more accurate. You will be using torques at the lower end of the scale for 1/2" drive torque wrenches where they are less accurate and you are more likely to break bolts (ask me how I know!)

Don't use a pan gasket, buy a tube of silicon gasket maker (about $14) and do it like the factory did it.

Retorque the head bolts after warm-up (if I remember the manual says retorque hot - but check this). Re-set valve clearances.

Dumb re-assembly mistakes I made. wrong sparkplug wire order and mis-adjusted valves (set exhausts to intake spec and vice-versa )

Hope this helps!

[sdoan]

-How do I tell if the valve guides are needing to be replaced?

Thanks guys.

The head shop will check the valve guides when they dis-assemble the head.

The same shop can measure your crank if needed. If they machine it they can supply the correct bearings.

If you are replacing pistons they come with wrist pins and rings, but you will have to press them onto the rods.

[Petros]

"CT9A" wrote:

-Do I need to do anything with the crank shaft? Do I need to get it machined, how would I know if it does?

If the engine did not ever break anything (connecting rod, valves, pistons, etc) and the bearing journals are smooth and shiny, the crank is probably good and all it needs is a good cleaning and you can use standard size bearings. When you clean it buy a set of tiny bottle brushes from an auto parts store (they are not expensive), and use it in the oil passage ways in the crank (you will want to use them in the oil galleys in the block too).

Measure the bearing journals with a micrometer per FSM for correct size, rent or borrow the micrometer (or allow your machine shop to measure it). You can test for warp by turning it by hand in the block (with the mains all torqued up properly), with oil in the bearings it should turn smoothly and easily by hand. If not it is warped. I have rebuilt a lot of Toyota and Nissan engines, and I have never found a warped crank, even in one that sucked an exhaust valve and bent the connecting rod. So your crank is likely not warped.

If the journals are scored or blue streaked (from running without oil) this can usually be corrected by hand polishing with strips of 800 grit wet and dry sand paper. With the crank on a bench you tape on strips of sand paper around each journal, use a mild solvent on the paper, and wrap the journal with a thick cord several times. Pull the cord tight and then pull each end of the cord back and fourth (like you are polishing a shoe), about 30 to 60 seconds (sometimes more) of this action on each journal should clean them up nicely. When all the scoring or blue is gone check that the diameter is still within specs (they usually are since this takes off only about 0.0001-2”). It is not necessary to get all of the scores out, though it is desirable, as long as the rest of the journal is smooth and meets min. diameter spec. Leaving a few of the deeper scores could save you from having to regrind the crank. I have done this a number of times with no ill effect (consider the bearings have a large oil groove running half way around the bearing!)

If the journals are badly damaged or out of spec, the crank either has to be reground or replaced. An auto machine shop can verify this by measuring it for you if you are you are not sure. If they regrind the crank journals you will need to buy oversized bearings, so do not buy any bearings until after you clean and inspect your crank. If you have the journals reground you should consider having the crank rebalanced because they take metal off the bearing journals. This is not absolutely necessary, since it is supposed to be done evenly, but it is worth considering.


-How do I tell if the valve guides are needing to be replaced?

If you have a machine shop rebuild your head they can measure all of this for you. If you are doing it yourself you will have to disassemble the valves, springs and keepers, and clean all of the valves (you can usually rent a valve spring compressor free from AutoZone). You do not need the valve spring compressor to disassemble the valves, but it does make it easier. You will need it to assemble them. Use the little bottle brushes to clean the valve guides real good. There will be a lot of tough carbon to remove from the valves, a wire wheel works best, but it can be scraped by hand. BTW, I have found the intakes are usually good and can be reground and used, but unless the exhaust valves are in good shape they should be replaced. They are not too expensive and a failed exhaust valve can trash the whole engine. I have seen it happen lots of times with this engine, it is not worth the risk of reusing the exhaust valves.

Once you have the guides and valves clean you then insert a valve almost all the way in, and wiggle the valve head back and fourth. The spec for how much movement is allowed this is in the FSM. Basically if the sideways slop is more than zero to just detectable movement, you likely need new valves or guides (I have found in this engine the guides are more likely to be worn than the valves, though both usually wear). If the guides are in good shape and not too worn, a machine shop could knurl and ream them to spec. This costs less than replacing them.

All of the seats must be resurfaced, this must be done by an auto machine shop. There is no good way to do this yourself without the proper equipment. The valve faces should also be resurfaced unless you are buying all new valves. Ask the machine shop to do a “four angle” seat recut, and to break the edges. It will improve the airflow and help performance. If you are going to open up the ports and polish them you need to do this before the seats are resurfaced and any guides are replaced. Clean up all of the combustion chambers before you have the head resurfaced too. That way any slips will be cleaned off when it gets machined.

Even if the valves and guides have some wear you can “cheap out” and hand lap all of them instead of paying for a full valve regrind job. I have done this on low budget quickie rebuilds, it makes them better than they were and it cost almost nothing so it can save a lot of money. You buy “valve lapping compound” at a NAPA store (others have it too, but not always). This is like very coarse tooth paste, you put it on the valve faces and than hand rotate the valve into the seat, putting pressure against the seat. This will grind and polish away the worst of the pitting and small amounts of warpage. I have also put a drill on the stem and spun them in place. This will result in a seat wider than spec, but it will seal well and drive just fine. If you do this keep the compound off the stem or it will grind away the stem too. When done, clean all of the compound off of the head and valves or it will grind away at the engine when you get it back together.

-Is there anything I should do with the rest of the car (i.e. tranny, suspension, etc.) while the motor is out? (I'm already planning on doing the fluid changes for the tranny/t-case/diffs)

If you are you going to replace the clutch and T/O bearing, that should be done. I highly recommend having the flywheel lightened and rebalanced (together with the new clutch). Have the machine shop take as much weight off the stock flywheel as possible, you will not regret it (it comes way too heavy). This adds about $80-100 in cost, but it can not be easily done later after the engine is back in the car. This is not an absolute necessity, but it makes a noticeable difference in drivability, throttle response and acceleration.

You might also consider replacing all the sensors and sending units, though I personally would not do this since it adds a lot of cost. Test them first, if out of spec than replace them. It would be nice to clean up the engine compartment when the engine is out. A pressure washer is best, but a stiff brush and hot water with a strong detergent works too. Also clean inside the bell housing in the trans. If there is any indication of a leak, replace the front trans input shaft seal (the seal only cost a few dollars).

Most other assemblies are not affected by having the engine out or not, so other items like brakes or shocks can be done anytime.


-Other than the obvious, what needs replaced for maintenance while the motor is out? (I'm already planning on replacing all the seals and gaskets, piston heads, wrist pins, connecting rods, all bearings, all exhaust valves, valve guides if needed)

It is doubtful the connecting rods need replacing, it would be a waste of money unless they were obviously defective, damaged or badly bent. Take your con rods to the machine shop and they have a simple jig to test them for being true when they install the new pistons. If the journal ends are out of round they have a machine than can fix this too.

Do not replace perfectly serviceable parts, this adds unnecessary expense and that money would be better spent on new or better parts elsewhere. Like invest in a new 2.25” exhaust system, that will gain you way more benefit than replacing perfectly good connecting rods.

Good luck.

Keep the questions coming. These could be all assembled into a complete set of instructions for the "repair guides" section.

[CT9A]

Thanks for the replies guys. I'll take a look at the crank tomorrow, I have a micrometer already, so I can measure myself. However, when I pulled the crank out, I found chunks of metal along the journal in front of cyl. 1. I've looked everything over again, and can't seem to find where the metal came from. I did have cylinders 1 & 2 with extremely loose wrist pins (from what I can gather, this is what was causing the loud knock before I pulled the motor), this is the only thing I can think of that I've found that would explain the metal and is also the reason I was going to replace the connecting rods. If it's not necessary, than all the better, but I'm not sure.

Here's a question that I forgot to ask, and it's probably the most basic. Where can I get a FSM for an '83? I've seen Chilton's and Haynes for 84+, but never one for an '83.

[ARCHINSTL]

Here's a question that I forgot to ask, and it's probably the most basic. Where can I get a FSM for an '83? I've seen Chilton's and Haynes for 84+, but never one for an '83.

You might try the Mothership in CA. I actually got my '86 FSM through Borders, which ordered it directly from Toy; I did not save any money, but was able to use a bunch of gift certificates to Borders I had received. It was $95 - the same as Toy wanted.
I suppose any bookstore could order it, though.
Tom M.

[Petros]

If your crank journals are in good shape, than your crank likely only needs a good cleaning. You can go with standar size bearings and save alot of crank machining.

It will be interesting to learn more about the writs pin problems that caused the knocking. When I got knocking like that it was the piston the was failed, not the wrist pin. Usually the simple press fit wrist pins give good service for a daily driver (simple and inexpensive). But I supose it is possible they could work loose and do damage to the small end of the wrist pin. If that is the case it might indeed be cheaper to replace the rods if the small end is damaged. Though it might be possible to over boar the small end and have the machine shop incert an interfearance fit bushing. Verify cost first though.

Or even better, put in bronze bushings in all the rods to convert them to full floating wrist pins. This is done on high perforcance racing engines, though this is rarely necessary on a daily driver. It does not produce more power but makes the wrist pin installation stronger. Since failed wrist pins are not usually encountered in a street car, it is not necessary to go to floating wrist pins. If I was building an all out racing engine the floating writs pin is the way to go, but somehow I can not come to visuize the Tercel 3ac engine as an "all-out racing engine".

[CT9A]

http://cgi.ebay.com/ebaymotors/1983-Toy ... enameZWD1V

Is this it?

[ARCHINSTL]

My '86 FSM has a different cover, without the car. But it may just be that it has a different cover or is even a later edition - my '86 has the current Toy logo on it, which was not used back then. My '86 OM has an insert picturing the '86 FSM, which cover does look like the one on eBay.
I'd still ask the seller if the 4WD is included, and if it is indeed a genuine Toy manual. He might get pissed, but so what.
If it has the 4WD and is missing no pages - that is a good price; I'd do a BIN on it.
Tom M.

[sdoan]

My 83 manual (copyright 1982 Toyota Motor Corporation) has a different cover. Ask the seller. Mine is 2" thick.

One engine I had was making noise due to a broken piston that made the wrist pin very loose so Petros seems like he's on to something there.

[golden_glory]

Everyone beat me to anything I might have added. All very sound advice, I just rebuilt mine last spring and only had to spend around 180$ for gaskets, pistons, valves and valve guides, and all the bearings on the crank. I will try to find the number for the place I got my parts from, it was a local-ish parts house for engine rebuilders that has no web-site. They were really helpful over the phone and I got my order the next day too. Good luck with the build and remember to check everything at least twice. Oh yeah, if you plan on using a pressurized oil-primer the oil pressure sensor is most likely a British Pipe Thread and not metric or NPT. I forgot what the thread cut is exactly but will also look for that info in my notes.

[takza]

Best bet on the FSM is used. Search online for second hand bookstores. $25 is reasonable if that's the original FSM.

[CT9A]

The manual on Ebay is OEM just to let everyone know.

Question: What is the best way to clean the block and some other parts? These parts have decades and inches worth of crap caked to them from leaks.

[Petros]

Cleaning everything off real good now makes all the work much more enjoyable, and as you take it apart is the best time to do the all the heavy cleaning.

Presuming you do not have a big solvent tank to put it in, best way to "home" clean the engine: Remove all the external stuff like alternators, belts, shrouds, and external covers, take it it outside in the driveway (not on your lawn!) and cover the engine with the foamy "engine degreaser" and use a high pressure blast from a hose hooked to a hot water out let (usually a wash room sink will allow you connect a garden hose). If you have an engine stand this make this job a lot easier. A pressure washer makes this go faster, but it is not necessary.

If the grease is really thick first use a plastic scraper (you can make one from a plastic bucket or quart oil bottle). I would scrape off all I could this way, than brush on odorless paint thinner to soften what is left, then use the degreaser. DO NOT USE GASOLINE, way too dangerous.

Also laundry detergent is really good at cutting grease, use a stiff plastic brush (or old tooth brush) and detergent to cut the grease in the hard to get places. Once the worst of it is off, a can of carb cleaner with rags will get rest of it real nice and clean. A final spray of carb cleaner and a good blast with a compressed air nozzle is the best way to dry them off.

Also, I have used a plastic tub (an used kitty litter pan) to put all the parts in after I remove them and clean them with odorless paint thinner, as you get the parts clean make sure to change out the solvent so you do not deposit grit on the parts. Keep them in a box or shelf covered with clean towels or news paper to keep dust and grit off of them. Do not store the clean parts on the floor, on a shelf or bench away from the dust on the floor. If they are going to sit for a while before you get to them spray some WD40 on the bare metal parts, cyl. bores, journals, etc. to keep moisture and rust away.

When you are ready for reassembly do a final clean with carb cleaner spray or brake parts cleaner, use lots of white paper towels (to verify all the old grease is off) and a final blast with the air nozzle to get any final dust or grit off. Clean and dry all the nuts, bolts and washer in a can with paint thinner, do several wash and rises. Make sure you clean all your tools and sockets the same way before final assembly, getting some sandy grit in the engine during final assembly from your tools (especially the sockets) can do a lot of damage to the oil pump, rings and bearings on your new engine. So being really sanitary on your final assembly, it is important.