TOYOTA engine blueprints

[30psi 4agte]

Im after engine blue prints to make torque plates up that we can clock up blocks from when boring and make bores in the exact spot they are ment to be in.

The blueprints must be the real deal and accurate with measurements.

So if you have any to suite any toyota engine....... or ANY engine for that matter ( ford, holden ,chev, mazda etc)
Or know where to find them

Please let me know
Jordan

[Billzilla]

Just use a head gasket.

[oldcorollas]

at least for japanese motors, you can probably reasonably assume they were designed in mm increments, rather than some half arsed imperial crap

so if you measure the top of a couple of blocks accurately, then you should be pretty close..

for the yank cars (ford, holden) there should be stuff off the shelf?

[abently]

Mill a cylinder Head.. if you can find one cheap enough and use that as your torque plate. Definately as accurate in terms of bore distortion as you will be able to get.

[oldcorollas]

how so? once you remove all the material from the head, it will lose a lot of its stiffness, and then it won't do a good job of pre-distorting the bores..

ie, a cylinder head is not much of a cylinder head if it has 80mm holes bored thru the combustion chambers... all you have left is a shell and some water jackets
it won't load up the same way as a non-holy head....because it will be nowhere near as strong

[abently]

how so? once you remove all the material from the head, it will lose a lot of its stiffness, and then it won't do a good job of pre-distorting the bores..

ie, a cylinder head is not much of a cylinder head if it has 80mm holes bored thru the combustion chambers... all you have left is a shell and some water jackets
it won't load up the same way as a non-holy head....because it will be nowhere near as strong

That is true to some degree.

I have thought about this a while ago, why can't you just bore the cylinders from the other side ? Maybe use two or so headgaskets if you need to clearance any tooling from the cylinder Head ? That would be the optimal method.

[Billzilla]

The bored-head trick has been used quite a few times and it seems to work well enough.

[big_zop]

Mill a cylinder Head.. if you can find one cheap enough and use that as your torque plate. Definately as accurate in terms of bore distortion as you will be able to get.

Well, it would need to be brand new otherwise you would have the same issue that a used block will have and be distorted or even worse, could have a different distortion and you would end up machining that into the block.

And i doubt you would want to use a new head for machining purposes, more specifically the costs involved along with the strenght issues OC has mentioned - which is what a torque plate is required for.

[oldcorollas]

The bored-head trick has been used quite a few times and it seems to work well enough.

so has boring without a torque plate at all
all methods have their shortcomings i suppose...

i guess it comes down to how flexible the block is. some engines will be fine, some won't.

[abently]

Well, it would need to be brand new otherwise you would have the same issue that a used block will have and be distorted or even worse, could have a different distortion and you would end up machining that into the block.

And i doubt you would want to use a new head for machining purposes, more specifically the costs involved along with the strenght issues OC has mentioned - which is what a torque plate is required for.

Lmao... I'm not going to get into the technical details here, just remember that many well reknowned Engine builders still use tubing spacers with the Head bolts on random, non-cost effective engines to replicate the distortion applied to the cylinder walls. It really is just simple physics, of a bolt applying load in a vertical direction which then distorts the cylinder. Obviously the load is applied more uniform then that and that's where bored heads come in, which I'm not sure how a bored torque plate is any better lol... unless designed to replicate all the loads.

Anyhow, I'm not here to start any arguments since I have better things to do with my time, I'm still interested in why people don't bore it from the other side with the Head bolted on ?

[Billzilla]

Anyhow, I'm not here to start any arguments since I have better things to do with my time, I'm still interested in why people don't bore it from the other side with the Head bolted on ?

I suspect because ...

.... the shorter the shaft holding the honing/boring head the stiffer it'll be and if you come up through the bottom the shaft would have to be quite a lot longer than if you come down through the top.
.... the honing/boring head may not fit between a lot of main bearing areas in some blocks.
.... "we never used to do it that way."

[Joshstix]

Plus the torque plate is more about the honing than boring and I can'tt see how yo're going to get a good cross hatch at the top of the bore without the stones moving a fair dstance out of hte bores.

[30psi 4agte]

Just use a head gasket.

No wont work.........it needs to be far more accurate than that. what

the idea behind the torque plates is to beable to set the block up of of the deck plate rather than the bores which may be out slightly due to excessive wear or being machined "out" by someone who was out a few thou when clocking up or even the factory being "out"

having the blue print will allow us to locate the correct position for the bore in the block.
Bolting a torque plate to it that we know has been made to exact specs will allow us to clock up (setup) the block on the jig in exactly the right spot.

[jeffro ra28]

I'm still interested in why people don't bore it from the other side with the Head bolted on ?

If you have actually used a sunnen style hone, you will know how much a PITA it would be to hone from the bottom. If not impossible on most engines. Most likely, you would have to remove the dodgied up head or torque plate every time you wanted to change the stones to a different cylinder. Plus you would not get enough protrusion of the stones at the top of the block to acheive a straight bore. Unless you are actually looking for cylinder bore choke

[fixeruperer]

ill ask my machinist where they got theres from, they probably made it but ill ask if they have spec tommo.