Importance of Using a Torque Plate

[Denio24]

For all engine builders out there, you may know that I was in progress of building my engine. I have finally finished the project and I cannot wait to do it again on future motors. I will have to update my thread with more photos of the build process. When measuring my bores without the torque plate, I noticed that the numbers were way off. With the torque plate, most of my measurements were within .0001-.0002 of each other which is damn near perfect. Here is an example cylinder showing how much a cylinder head can distort a bore, expanding it at the top when all the bolts or studs are torqued down.

CYLINDER #1. It was measured in six places, three of which were executed longitudinally and the other three 90 degrees in the other direction. The numbers were negative because when the head bolts are torqued down the block actually stretches to the final bore size. Going from top to bottom:

[LONGITUDINALLY]
-.0007
-.0003
-.0001

[ACROSS 90*]
-.0015
-.001
-.0004

This can give you an idea of how much the head pulls on the cylinder block, especially a puny 4 cylinder block like ours. Noticing some things: the pull on the block is greater across the block then longitudinally (data across multiple cylinders confirms this). The final bore size was meant to be 3.268 (with the torque plate on almost all of these values were spot on to the final bore size), and in the place of largest distortion without the torque plate it was .0015". Though it may not seem like much, it is definitely something to think about.

[b7_Andy]

Very interesting. So I've heard of a torque plate... what does it look like and how do you use it? Most videos I've seen of people honing a block just put a scrubby on a drill and go for it.


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[enizi]

Good info, did you make your own ?

http://www.superstreetonline.com/how...e-question-it/

[aluthman]

Very interesting. So I've heard of a torque plate... what does it look like and how do you use it? Most videos I've seen of people honing a block just put a scrubby on a drill and go for it.


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Torque plates are more for boring the cylinders. Very little material is removed when honing, and if using the factory bore, you will end up with comparable results to what the factory put out. Some people still use torque plates for honing, but it isn't strictly necessary.

[Denio24]

Torque plates are more for boring the cylinders. Very little material is removed when honing, and if using the factory bore, you will end up with comparable results to what the factory put out. Some people still use torque plates for honing, but it isn't strictly necessary.

Torque plates are used more for honing. The final honing process removes between .005" and .010" of material.

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[aluthman]

Torque plates are used more for honing. The final honing process removes between .005" and .010" of material.

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You mean 0.0005"-0.0010"? Honing removes next to nothing.

[pezgoon]

You mean 0.0005"-0.0010"? Honing removes next to nothing.

I just wanted to point out that in the article posted above the guy does say that you use it during honing, that's the extent of my knowledge though lol

I'll go back to my hole again *creeps out slowly*


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[Denio24]

You mean 0.0005"-0.0010"? Honing removes next to nothing.

I guess my understanding is different than yours. My machinist uses multiple rigid hone passes after the boring, and progressively goes up to a 625 stone (depending on the ring), which can effective remove between .003 and .006 of material.

Torque plates are used more for honing. The final honing process removes between .005" and .010" of material.

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[aluthman]

My machinist told me that 0.001" is the max they remove by honing. Anything more is going to get bored. If you are using a ball hone yourself, they remove next to nothing and don't require a torque plate. You will only remove an appreciable amount of material with a rigid hone. Unless of course you use no lubricant, in which case you screwed everything up already.

[Denio24]

My machinist told me that 0.001" is the max they remove by honing. Anything more is going to get bored. If you are using a ball hone yourself, they remove next to nothing and don't require a torque plate. You will only remove an appreciable amount of material with a rigid hone. Unless of course you use no lubricant, in which case you screwed everything up already.

Just for accuracy, I had a talk with my guy today and he said he takes off .003" during honing. The reason he said it is so much is because he hones multiple times with different grits working up to the final finish, and then I asked why... He said it comes out to be a smoother finish and less metal "tear-out" in the bore, and a quicker break-in - - especially for the rings I'm using.