GDII's 1990 G-Limited

[GDII]

All the valves are now out. The seats need a good clean up and I'll need to reseat them. I'll probably just use a valve grinding paste and do it that way rather than get the machine shop to cut them.

[GDII]

Removing the old crusty hard leaking valve seals. This is probably the main reason for the engine having a little bit of smoke on start up.

[GDII]

Crusty valve seals... Yummy!
The stringy bit you can see on the third one is the remains of the retaining part of the seal that holds it to the head. The spring is to help squeeze the seal against the valve stem making it seal properly.

[85AW20v]

If you're giving the head to a machine shop, get them to do everything. It takes a fair bit of time to cut the seats with grinding paste given the hardness of them. The shop will also get the correct angles machined on both the sealing surface and the valve itself. Doing it yourself, you'll get to a point of "well, that's a lot better than it was, not perfect yet, but it's near enough as damning is to swearing"!! Those last little bits of pitting are the hardest to remove and take a lot of time to get out.

With the time and effort you're putting into this - and everything else you do - I could see you getting it running and then two years later, pulling
the head off to get the valves machined by a shop.

[GDII]

If you're giving the head to a machine shop, get them to do everything. It takes a fair bit of time to cut the seats with grinding paste given the hardness of them. The shop will also get the correct angles machined on both the sealing surface and the valve itself. Doing it yourself, you'll get to a point of "well, that's a lot better than it was, not perfect yet, but it's near enough as damning is to swearing"!! Those last little bits of pitting are the hardest to remove and take a lot of time to get out.

With the time and effort you're putting into this - and everything else you do - I could see you getting it running and then two years later, pulling
the head off to get the valves machined by a shop.

You do make a good point. But then I'll need new shims and it's already gone well out of my budget due to the bore wear.
I guess I opened a can of worms and I'm travelling well down the rabbit hole and haven't quite found the bottom yet. It's not a race engine nor am I chasing power so there's also that to keep in mind.

[Benckj]

Inexpensive
Reliable
Performance

Pick 2.

[GDII]

Inexpensive
Reliable

Performance

Pick 2.

I'll pick those 2. The engine already have performance by default. This build is by no means cheap though.

[Alsw20]

Inexpensive
Reliable
Performance

Pick 2.

How did you end up with just one?

[GDII]

All bagged up. 16 bags tagged so I know which one goes where. Lumping them in one bag would be a bad idea.

[GDII]

Rods off, pistons out! Plans were to reuse these pistons but it seems this engine had other plans.

GEN4 3SGTE rod left, GEN3 3SGTE rod right. Check out the size difference! You are looking at 10mm thick for the GEN4 and 14mm thick for the GEN3. Plus the GEN3 has a bit more material in other places even though the profile for the rods is almost the same with the GEN4 overlaid on the GEN3 effectively hiding it.

Plans were to machine the GEN4 pistons wider to take the stronger GEN3 rods . You can see where the pin goes through the piston the GEN3 is much wider. This idea didn't quite go to plan. A small setback. See next post for why.

[GDII]

The bores of this GEN4 3SGTE are unfortunately oval due to piston skirt wear. You can see here the polished section with vertical lines. The hone marks are still there so it's not terrible but measuring the bores shows they are 0.020-0.060mm out of spec on the skirt sides but in spec for the crank direction.

[GDII]

My brother brought over his precision measuring tools so we could check the engine parts. Here we are measuring the bores and finding that this GEN4 3SGTE isn't 100% happy. The bores have been worn by the piston skirts. I could just hone the bores and go but they are out of spec by 0.020-0.060mm and oval so I can't just put new standard OEM Toyota piston rings in and go. I decided I should do it properly and fix the issue and upgrade at the same time.

[GDII]

Measuring the crank main journals of the 3SGTE. These are to be within the range of 54.988 and 55.003mm. This crank is all in spec so no need to worry here.

[GDII]

Measuring the big end journals. These are to be within 47.985 to 48.000mm. Again, these all measured out fine.

[GDII]

These exhaust manifold studs are a little bit rusty, one is a different type and the other wasn't originally installed due to the manifold design. So I bought 8 new studs to go in place of them. Part number is listed in a previous post.

Now to get them out.