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1988 Corolla SR-5
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Discussion Starter · #1 ·
Well happy campers. I have debated this engine build for quite a while, weighing it against a 20V blacktop, 4A-GZE and even a 5S-FE.

My reason for wanting to do a swap is mainly to get more bottom end torque.

The 5S-FE has all the power and torque I want, but that swap is more work, involving custom engine mounts and there is a weight penalty that might upset the cars handling. Not good for autocross.

The 4A-GZE has the torque and power without the weight penalty, drops right in, but I have not been able to find a 2nd generation version.

The 20V has power, but lacks the bottom end torque that I want, and parts availability could be a problem.

The 7A-GE should give me the torque I want with enough horse power for my style of driving, plus parts are readily available.

I have aquired a 7A, and started tearing it down to inspect and recondition the block, before starting the build. I was hoping to take my time and do it right, but due to unforseen circumstances, I need to jump to it.....................My 4A-GE seems to be in the process of up-chucking a rod.

Driving to work this morning, it started rattling like the starter had come loose and was beating between the block and the exhaust manifold. That was not it. The sound is comming from deep inside the block, about the area of #2 rod. I had to have AAA tow the car home this evening, fearing that driving it would do more damage than has already happened.

I was planning to use a small port head and pistons, but I have not yet been able to find a head for a reasonable price.
With the current situation, I need to go ahead with the build using my bigport head.

I already have:
Light weight flywheel (for a SR-5/4A-FE).
OBX adjustable timing gears.
7A-FE gearbox

The stuff I still need to get:
Small port pistons.
High tensile rod end bolts.
Porsche 944 timing belt.

I was hoping to get the 4A-GE dynoed before I did the swap, so I would have a baseline to compare the new engine to. ............ So much for that idea!!!
 

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in your mind what is a "reasonable" price.......

I have 3 smallport heads not in a car... one from a 101 gze, on on my 7ag and one on my newly acquired core motor (needs pistons, rings, bearings, and valve guide seals).


as for the 7age..... if you can, have the crank turned and get undersized bearings.... my 7ag lasted 50 miles due to a 200K mile crank and nobody in town who could turn it.......


also, you will want to use some adjustable cam gears.... when the ae92 had the 7ag in it, it was fast, but could have had more.

Mine is a smallport 7age with brand new (standard) smallport pistons, new rings (had to order for a prelude), and rod bearings. Using a stock HG the CR was IIRC 11.0:1


I can guarantee you, unless your car is a late 89 model, that your whp would have been 90-100whp (100whp if lucky).
 

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these look to be the correct pistons:

http://cgi.ebay.com/ebaymotors/CHEV...ptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessories

the main thing to look for, if you don't know, is to ensure that the 2 top rings are NOT the same size... if they are, the pistons are from a bigport. Only smallport and 20V (but 20V pistons would have a 5th cutout) use different sized rings.

Now for the rings.... if you have any problems, you can look for rings for a 1990 honda prelue 2.0 -- they are the same rings. Carquest/worldpac couldn't order the right ones for a smallport and kept getting bigport rings, but they obviously didn't fit.

my 7ag had NO compression problems at all.
 

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The Return of the Red Coupe
2010 RAV4 V6
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5SFE would involve "a custom mount" as far as I know... however the 5SFE wouldn't be my first choice of motor into a Corolla though.
 

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Discussion Starter · #5 · (Edited)
A reasonable price I think would be a lot less than the one on E-Bay for $650.00, although that one is complete with cams, valves, and intake. It also comes with pistons, rods, MAF sensor, ECU, and wire harness.

I already have the adjustable cam gears.

My crank journals are all in immaculate condition, so I don't think I need to have them turned. The current bearings are standard size, and the oil clearances are all good.
I am replacing the bearings anyway, along with the rod end bolts.
I plan on getting a set of new small port pistons and rings, whichever head I use.

How much do you want for a head?

Thanks for the info on the pistons and rings.



in your mind what is a "reasonable" price.......

I have 3 smallport heads not in a car... one from a 101 gze, on on my 7ag and one on my newly acquired core motor (needs pistons, rings, bearings, and valve guide seals).


as for the 7age..... if you can, have the crank turned and get undersized bearings.... my 7ag lasted 50 miles due to a 200K mile crank and nobody in town who could turn it.......


also, you will want to use some adjustable cam gears.... when the ae92 had the 7ag in it, it was fast, but could have had more.

Mine is a smallport 7age with brand new (standard) smallport pistons, new rings (had to order for a prelude), and rod bearings. Using a stock HG the CR was IIRC 11.0:1


I can guarantee you, unless your car is a late 89 model, that your whp would have been 90-100whp (100whp if lucky).
 

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let me look at the condition of the smallport gze head I have.... the block threw a rod (which that piston had 2 small nicks from the valves, but I'm pretty sure I checked the valves and they weren't bent.... spun fine and no light shining through the seals..... I would double check first, though)....

the cams were out, not 100% sure if the retard to who took it apart kept the tappets in place..... the cams aren't worth much to me but probably not worth shipping for you (added weight).

Part of selling it is the 'cost' of shipping..... and by that I mean finding packaging, packing it well, then going and standing in line for who knows how long.... etc..... If you had the means to come pick it up I would probably say $50 as it is...... but I really hate the post office (or like), lol....

I would have to say $100 plus shipping and I'll go through it checking for straightness, bent valves, and put the cams and cam bearings back in. FYI it was from an ae101 4agze which was very clean internally (no sludge). I'm not going to check the tappets for clearance, though... will include that heads tappets.

The other heads I'm leaning towards keeping.

this is the head in question:


(on the bottom, keep in mind it ran real rich so a lot of that shoud clean off)

you can see 2 small less dark valves -- those are the ones that hit the piston that had a broken rod. Since I would assume the motor just kinda flung the piston up then the valve just pushed it down enough to clear.....
 

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Discussion Starter · #8 · (Edited)
the cams were out, not 100% sure if the retard to who took it apart kept the tappets in place..... the cams aren't worth much to me but probably not worth shipping for you (added weight).

Part of selling it is the 'cost' of shipping..... and by that I mean finding packaging, packing it well, then going and standing in line for who knows how long.... etc..... If you had the means to come pick it up I would probably say $50 as it is...... but I really hate the post office (or like), lol....

I would have to say $100 plus shipping and I'll go through it checking for straightness, bent valves, and put the cams and cam bearings back in. FYI it was from an ae101 4agze which was very clean internally (no sludge). I'm not going to check the tappets for clearance, though... will include that heads tappets.
I like the price, but do you have a regular small port intake to go with it?
Are the big port and small port cams the same?


No that is Piloter. He has an AE101 Corolla, not an AE92.


Just an update:

I pulled the oil pan off my dead 4A-GE to see what exactly is making all the noise. To my surprise it isn't a loose connecting rod end cap as I thought........The crankshaft broke, at the #4 rod journal. :eek:

I have never heard of a crankshaft breaking before.
 

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AE92DX 4AFTE
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wow!!! too mach rev slapping!!!

i'm pretty sure the lift is the same between cams the large-ports have slightly longer duration...

i've seen smallport with bigport cams for turbo app.
 

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Discussion Starter · #10 · (Edited)
The only time I ever got near redline, was at the hyperdrive I participated in at Virginia International Raceway a month ago. I never actually hit redline, so I don't think that was it.
A guy at my nearby Toyota specialist told me he broke one in an MR-2 before, and it was determined to be just fatigue. Just like mine, there was no heat discolouration on the crank or rods.

My cams and head are also screwed!!! So I won't be using those.
Apparently some of the #4 bearing shards, got up into the exhaust cam journals, and the cam and head are scoured.

I'll be pulling the pistons (if they are any good) and putting them in the otherwise stock 7A-FE, until I can get hold of a small port head and pistons. The 4A-GE pistons should boost the compression a fair bit with the 7A-FE head.
 

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Discussion Starter · #11 ·
Here are some photos of my broken crank.
That shiny silver thing at the top of the first photo is the new starter I just put in.
It only started the car about a dozen times before every thing went south.


 

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AE92DX 4AFTE
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wow... how many miles were on it??? i almost think the relatively low 6300 rev limiter saves me everyday!!!

i am in search for a head for the same reason but will the electronics for a big port fit small port?

i have ecu and harness... never seen a single small-port around here..
 

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electronics will fit if you have all of the electronics for it..... keep in mind you'll have a mid 4,000 rpm flat spot where t-vis should be, though.

I rev the piss out of our 4ag's all the time..... wifes 4ag has more miles than the car....

as for an off topic.... picking up something very interesting tomorrow.... (stock map 4age aw11)
 

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AE92DX 4AFTE
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where did they make map 4ag's in us???
 

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Discussion Starter · #16 ·
wow... how many miles were on it???
Mine has 145K. I bought it with 135K, and the guy said it had 7K on a rebuild at that time, but I still had to shim the valves right after I bought it.

I am learning that parts for the 7A engine, are not as readily available as I thought.
I am still waiting on bearings and rod bolts to start reassembly.
Good thing the head bolts for the 4A are the same.
 

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hmm.. parts availability is definitely a must. could you post any pics or walk through shimming valves? i know the basics i just don't know what to use or how to compress the springs etc..

like the actual steps.. thanks
 

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Discussion Starter · #18 · (Edited)
hmm.. parts availability is definitely a must. could you post any pics or walk through shimming valves? i know the basics i just don't know what to use or how to compress the springs etc..

like the actual steps.. thanks
First measure your clearances for each valve, and write them down.

Then remove the shims for the valves that are out of tolerance.

Measure each shim, (you will need a micrometer) then calculate what size shim you need to repl;ace it with to get the correct gap. In the Toyota manuals there is a chart with shim thicknesses and part numbers. You will need this chart to order new shims.

I walked far and wide looking for a Toyota valve spring compression/shim removal tool.
I asked the guys at ToyzUnlimited and they told me that they had one, but it wasn't worth the dirt to bury it. They use a screwdriver and a fine pick.

That is what I ended up using, with the addition of a small magnet.

You need a mediun thickness flat blade screwdriver that will be thin enough to operate in the tight space between the cam, bucket and the head.

Pry against the cam and the edge of the bucket with the screwdriver blade, but (and this is the tricky part) don't block the escape of the shim. This can be frustrating, as the bucket wants to turn, and that causes the screwdriver to slip off. The first few times will cause you to invent some new four letter words, but if you are mechanically inclined, you will be a prow, by time you are done. (JOKE) No, you will probably have it down pat by the tiird shim.

Use the pick to dislodge the shim from the bucket, (the oil holds them in almost like a suction) and use the magnet to pull it out.

Inserting is just about the reverse.

I think the shims cost about $2.50 each from Toyota. I don't know if the auto parts stores sell them. The 4A-FE shims are the same diameter, but the 7A shims are larger.

I hear that some Yamaha motorcycles use the same shims as the 4A engines, but I am not sure. They would probably cost more from Yamaha anyway.

I'll post a How -To thread on this, with photos, when I reassemble my 7A

The easiest way to do this though, is when you need to pull your cams for any reason, check the gaps first, then you won't need any specisl tools (like a screwdriver and magnet) .
Once the cams are out, you just measure the shims and replace as necessary
 

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why didn't you just unbolt the cam bearing caps and pull the shims off with a pic? Makes things go quickly.


To check the shims you need to check the tolerance between the bottom of the cam lobe (lobe facing upwards) and the top of the valve, when sitting completely closed. You do this using a set of blade (darn, can't think of the term.....) to determine the thickness. Write the numbers for each down (in a simple sequential order for you to remember) and compare to your manual (haynes, chiltons, or BGB should all have tolerances). Any that are not within tolerance put in "new" shims that are within the tolerance....

To do this... pull the cams....
Since each cam is different, you could potentially swap shims across the engine to get correct tolerances... again, if one was too high and the other was too low.... if you checked them with a mic (thickness) then add or subract what you need (lets say the shim is 2mm thick and you need a shim that's .5mm higher... find a shim that's 2.5mm thick, again hypothetical)... you should be able to reshim yourself. Someone at some point had a long list of engines that share shims and IIRC Toyota carries 26 different thicknesses....
 

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Discussion Starter · #20 ·
If you are pulling the cams, it is easy.

If you don't want to go through the work of pulling the timing belt and all that stuff, you depress the buckets with the cam in place to get the shims out.

Thanks for filling in the part about the lobe positions for measuring the gaps with a feeler gage.
 
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