millball

Well, I popped the valve cover on my '87 JunkRunner today to check the valve lash and peep the timing chain guides.

The engine has got about 290,000 miles on it and still runs pretty strong, burning a quart of oil in about 800 or 900 miles.

I have put about 10,000 since I got it a couple years ago with a bad tranny.

Found the plastic guides still intact and thought I'd put a torque wrench to the headbolts before checking valve lash.

None moved @ 65fp but the second from rear one on the exhaust side was loose and wouldn't pull down tight.

I took it out and found its lower threads partially stripped, so I cleaned the hole with compressed air and solvent and chased the block threads with a ground spare headbolt:

I can only get a couple threads with another bolt, so I didn't try to tighten it . No joy.

Depthing the hole shows nearly another centimeter of hole in the block below the existing headbolt length.

I'm gonna go to a fastener specialty shop in Tucson and try to get a couple similar bolts a centimeter longer and relieve one of them with the grinder so I can chase whatever lower threads there are in the block and put a slightly longer bolt in there..

The engine was running well with no headgasket issues even with this stripped bolt, so I'm hoping to get a bolt in there that will tighten down, and forestall any future trouble.

I'd really like to see this engine make 300,000, and it does still run strong. Wish me luck.

gsp4life

Ouch, good luck on that. I just had to do a top-end rebuild for a stripped bolt thread. Hope you can find the right bolt and it works out.

Melrose 4r

Sounds like a good plan. I was thinking "heli-coil" at first but the depth would make it difficult. It must have been that way since the last headgasket job, if it ever had one. Good luck!

millball

Yeah, not possible to do any thread repair without head removal.

Just trying to squeeze another 10 or 15 thousand miles out of her if I can.

I've got a fresh engine on the stand for her, but she's still kickin.

This head and block will get thread repair and complete rebuild when it's finally dead. I hope not for awhile yet.

scope103

The extra centimeter of depth is probably not threaded, so just getting a longer bolt wouldn't help. You might be able to make use of that extra length by threading it with a "bottom" tap in the right size. Can't find a bottom tap? Get a taper or plug tap and grind off the tip (where the threads are chamfered). I had a stripped bolt in a cam bearing, and I had to repair it that way.

But to do that with the head on will require a long reach tap (I found a solid carbide tap in the right size for $322.00) or some sort of tap extension.

millball

I don't have a block handy that has no head on it so I can't do a visual. Maybe somebody reading this can examine a block in their possession.

In any case I will know something shortly if I can lay hands on suitable bolts. I'm optimistic that I can get them.

Terrys87

iTrader: (1)

You hit on one thing I have suspected for a while on these 22 motors. Most seem to think the head gaskets blow on these motors. I suspect that it is not the head gaskets actually blowing but that the head bolts loosen and that is what lets the gasket blow on them. It seems to me that number 2 and 4 exhaust seems to be the biggest culprits to me.

If it was me I would chase the threads in the block and go with a new bolt and see if you can get the correct torque with that set up and see how it feels.

millball

Well, I have laid down my money and ordered a couple suitable bolts. Harder to find than I expected, and It's not altogether clear yet that I will actually receive them.

The 22re stock headbolts are M12x1.25x160mm. Not sure of their hardness grade as none I have are marked.. These 160mm bolts are relatively common, and I found plenty of these.

The bolts I ordered are M12x1.25x170mm, grade 10.9 They are 10mm longer than the stock 22re headbolts. This appears to be a very uncommon size bolt.

Fastenal gave me a number for these longer bolts: 11 11 3534, but said that they were not sure of the vendor and waffled when I tried to order some, so who knows???

The bolts I DID order are cylinder/head bolts for some more recent model of British Triumph Scrambler motorcycle. Whoda thought that the Brits would ever go metric??

The M12x1.25x170mm grade 10.9 bolts are Triumph part number: T3332528. Maybe I will have one or two in hand late next week. They're not sure either, but they took my money.

Meanwhile, I just have to run one of my other Toyotas.

Melrose 4r

Don't know about head bolts, but in my experience from flipping many 80's vintage Toyotas back in the early -mid 90's it was the thermostats that would give out in the 100k- 125k miles range, overheat the engine and warp the head. I bought many Tercels and Celicas that needed a head gasket because they had been overheated. Some cars I got free! If I got one that had never been overheated, the first thing I would do is replace the thermostat as a preventative measure.

I never heard of "head gasket failures" until the widely known problems with the v6's.

L5wolvesf

Hope you're triumphant with your project