I got some comments recently from bot, who suspected that the middle main cap deforming while ARP nuts were tightened could be the reason behind my seized crank.
The possibility of twisted or tweaked middle main cap didnt cross my mind. I had already gotten my block back from machine shop, when bot commented this thing, but I didnt have spare time to actually look my block until now.
I spent two hours carefully taking everything apart and examining the parts (once again). Block still had some cutting oil + metal particle residue from the honing and it probably was also mixed with that ARP moly stuff that was used on the threads. It took some time to get everything clean.
Below: I made a set of cylinder plugs from foam plastic to help with cleaning and installing parts.
Putting everything back together went well. Bearings and ARP studs went in smoothly and so did the crank (after cleaning it millionth time). When I got to the thrust bearings I eyeballed them with suspicion but they didnt reveal anything to me. Lower ones slid in easily and the upper ones went in with the main cap.
Last bits were the MRP girdle and ARP washers and nuts. I tightened the nuts in four steps starting from 20Nm and ending to 80Nm, stopping in between to rotate the crank and see if there were any problems. The crank rotated freely every time.
Below is my torque wrench. I bought this one just for this project to get the critical parts correctly torqued.
It started to seem that the honing did help and the middle cap wasnt causing any trouble. I grabbed the crank from the both ends and tried to shake it, but it felt like there wasnt any play. I went to get Widrics almost unused dial indicator and set it up.
Then I poked the crank with screwdriver like the Toyota manual says.
Result: seems that my crankshaft end play is 0.03mm. Toyota manual says that the minimum acceptable is 0.02mm 😀
I’ve introduced plenty of new parts to my engine block. I have new main bearings and new thrust bearings, both with extra moly coating on them. Also, a set of longer ARP studs (with washers and nuts) for the girdle and the girdle itself.
Every new part creates a huge number of unknowns and it is absolutely important to check that everything is where they should be. Mr. Manon probably disagrees with me, but even the girdle could have been the source for my problems, although it got complemented by the machinist doing the honing 😀
Just by fitting all the parts together I found out that the middle main cap was not the problem. I’m not entirely happy of this method, but it has to do now. I dont have the resources and possibilities of McLaren to build engines 😀
Edit: My preferred method for the problem would have been different. I prefer to measure things until I have numbers, results and hard evidence. Except putting things back together was more practical and efficient method… 😀
I didnt measure the bearings yet, so next time I’ll be messing with plastigage.
Ok, easy start. Jack the car up, remove rear tire.
First look from underside after removing AC compressor. Oil mixed with dirt everywhere. I better check my oil level, feels like my engine has more oil outside than inside.
The AC compressor was also covered in oil. I found it on the bolts too.
And the lower alternator bolt. Completely covered in oil. It seems my engine oil would work wonderfully as penetrating oil.
Broken one on the left
Under all that muck this thing looks surprisingly good. I wonder if this really is a 30-year old alternator. The pulley (and therefore the whole thing inside – the rotor) was rotating very easily. Definetly not a bearing problem.
Toyota part number is 27020-16130 and Denso part number is 121000-2500
A japanese part for Toyota that isnt Denso! Arai electric, never heard of the company but presumably this is a quality spare.
I guess oil, dirt and time got this alternator. Wonder if this is still rebuildable? Burn marks visible on top of the alternator, coming from under the heatshield.
From above. Distributor without cap and rotor. There is still some oil on the heatshield. This is a wild guess, but when the boost builds up, there could be so much pressure inside cylinder head that it is pressurizing the distributor thru the worn shaft seal, then spraying the included oil around engine bay.
I better take the distributor off the engine at some point and examine it.
Old and used distributor cap, still in working order.
Old plug wires. Salvaged the quality Ultra wire that sits between distributor and coil.
After I noticed that something was wrong with the car (the smell, not charging and burn marks) I turned it off and started it couple of times. While turning on the power, the warning lights just briefly blinked and stayed off. I thought that something else was also affected, maybe a relay or a shorted wire.
To my relief, after the alt swap warning lights stayed on when the power was turned on. Seems like no shorted, melted or otherwise damaged electrics.
I’m not sure if the lights were acting before alternator caught fire, but I guess the lights were not supposed to indicate problems this way 😀
The pessimistic AEM voltage gauge is showing surprisingly high voltage.
I dont think Ive ever had this high charge voltage. Goody good 🙂 Runs well.
Shiny alternator, old plug wires, complete wiring loom with relays and a used distributor cap. Carbon canister for some reason came with, no idea why it stuck to my hand.
Tried to peek whats going on with the burned alt. It still smells funny.
Not sure anymore what caused the fire, there doesnt seem to be enough oil to sustain anything else than occassional puff of blue smoke. Probably 30-year old alternator just has had it.
I recently got some comments about the crank binding with the ARP studs and nuts. There might be a different cause for the crank getting stuck what I thought and I want to examine it with care, but right now swapping the alternator and checking the wiring and relays have higher priority. I wanted to have the yearly roadworthiness inspection done, but now the car isnt even remotely safe.
Edit: Well, it is mechanically safe but electric parts seem to catch fire randomly 😀
Oil leaked thru distributor axle seal and started a small fire. Car still runs, but its not charging and there seems to be some kind of relay problem. Most likely my alternator, sprayed with oil from above, is the source of the fire.
I have to go and rummage through my spare parts pile to check if I had a second alternator. I do have a spare distributor, but it needs to be welded.
Below: wiring damage to the distributor wires
Rotor and seal below – very oily. Notice – the damage on the distributor cap is not on the exhaust manifold side. The heat shield has been working perfectly.
Oil inside distributor cap – no fire marks inside.
This will definetly buff out
My Ultra plug wires which I got by accident that really are not for 4A-GZE – also toasted 🙁
Easy fix for this would be a bit wider heat shield that would also work as a oil catcher – directing that leaking oil past the alternator and the hot bits.