.002" gauge test fails barely between cylinders

How is that different than if the head was warped more but still within its spec (let's say .003) and the block was less (say only .0015), they would both be within their spec but the total would be the same as it is now ? IOW, why is the tolerance bigger on the head side than on the block side ?

 

Trust me. You can machine both the head and the deck of the block.

How else would you build a 1GR which has been over bored?

 

This ^ and it should be checked on a diagonal also to check for twist.

 

You used a .020 feeler gauge which is thicker than 0.0020.

First decimal 3 places is thousands the second is 10 thousands. Perhaps that is causing some confusion.

 

No, nowhere does it say that. I used .002". Where are you getting that from ?

 

There are so many slight variations here that I'd feel confident putting it back together.

*Heads check out well within specs.
*Block is "at" outer limit of what Toyota calls acceptable. Clean the block surface more, make sure the straight edge is clean and remeasure, then remeasure again. Remember, a feeler gauge should easily be able to slide. If it has to be forced, the gauge is to big.

If it were mine, I'd already have the heads back on. I don't think you'll have any issues.

 

Yeah, that's exactly what I did last night, to the tee...

 

I stand corrected. Misread your OP as .020 instead of what you actually posted .002. You are absolutely correct. Thank you for pointing this out.

 

but if you machine the block, a cylinder's TDC may now be sticking above the level of the block's deck

 

Hopefully a machine shop would be qualified enough to not remove 1/4"+. We're talking thousandths here.

And yes, my stock and built blocks have both been machined. It's not magic. Just science and machining.

 

There are also head gaskets that are thicker for this if you have to machine, look into cometic.

 

So are cylinders designed to allow a certain margin of error so that TDC still leaves a little leeway for potential machining, e.g. factory may provide 1/100" (just guessing) of slack on top of TDC ? just curious how machining blocks works. and i am guessing it increases the compression ratio...

 

What Armyoffoo said.

 

Makes sense. Thanks.

 

One more question: can a block be machined without taking it out of the bay ?

 

No, it'll have to be taken to a shop.

 

If you have any questions, get the block and heads down to your local machine shop...they have the tooling to not only measure properly, but do the machining if needed...of course, it needs to be a bare block so it can be cleaned afterwards.

 

First I would like to say that Toyota says to Replace the head or block that is out of specifications. They may have a very good reason for this call as in the water jacket walls are probably already thin and any machining will make them subject to cracking and leaks... I don't think you can bore these engines either for the same reasons. I someone above said they have machined their block and it is working fine. May be, but I don't like playing with fire and going against the design characteristics.

The engine will need to be pulled and taken apart for machining, if you choose to go that way. I would not.

If it was machined it will increase the compression ratio.

I would go with a thicker gasket and use a copper coat sealant.

 

Because the head can be pulled back into shape slightly from the head bolts. The Block, not so much.

Plus as I mentioned earlier a build up of tolerances can sometimes cause issues.

 

The cylinders can definitely not be bored on a Taco as they are just pipes (i think made of stainless steel) surrounded by the water jacket.