The making of Torque Plates
 

Well right now I do not have the cash to just order some toque plates.... 2 of them I need quick so I can move on with some engine builds.

If you ever priced out one you know they are between $300-$500 each

So being the redneck that I am, and a cheap wad to boot, I decided I would fab up my own.

I called in a favor with a bud who has acess to a CNC plasma cutter and had him cut the bores in some 1.5 inche thick steel.

Attachment 45512

He has cut out 4 of the 5 plates I wanted to get made.

1 is for a Mazda BP 1.8l

2 is, yes you guessed it a Mitsu 4G63

3 is a SBC

4 is a SBF

The 5th one is a Ford 2.3, told him if I get that in the next month I will be happy.


I have my clean up guy "Fish" grinding off the slag from the plasma cutter

Attachment 45513

After this is done, I will set them up in the drill press and drill the head bolt holes then surface the mating side flat.

I will end up I figure about 3-4 hours of labor into each plate. And save well over $1000.


7 June 2012 I am waiting on my Carbide inserts to show up so I can surface the face of each plate.

Attachment 45514

Bauce

What does a torque plate do exactly? Help prevent distortion while the bores are being machines or something?

I have always wondered why you wouldn't just bore 4 holes in a cylinder head instead of ordering up a piece of steel.

Bikersam... you are close... It causes the distortion as if the head was installed, so when the cylinders are machined, they come closer to being round and straight when the engine is built

Savington.... It is a thought, but with the added height of a 5-6 bolted to the block, it would not fit in some boring stands. Plus it would take alot more machining thu all the cam webbing, water jackets ect...

Update
 

I got in my carbode inserts so now I can surface the plates!!

First remove the insrt holder and remove the PCD insert
Attachment 46089
Next install the carbide insert
Attachment 46090
Tool holder in the cutter head
Attachment 46091

The hold down bolts are too tall, so I have to cut them down first, .015 a pass
Attachment 46092

But not now, they are about level with the plate
Attachment 46093

About to touch off and make the first pass
Attachment 46094

some pretty sparks as it cuts....
Attachment 46097

the surface is starting to come in.
Attachment 46095

Good flat surface, now to flip it over and surface the other side.
Attachment 46096

pics look good. I think some of the blurry ones.... you may be outside of the "macro" range and normal mode would be better, but I can't be sure.

I figured you could just take a bad head, drill out the chambers, then maybee bandsaw it in half lengthwise like a filet... Too redneck?

Hey, bringing this back up. How did you figure out how thick each plate needed to be and what to torque the studs to so that you'd end up with a plate about the same stiffness of the cylinder head?

I'm assuming the math/computer work involved is why they cost $300-$500, for a flat plate of steel with some holes drilled in it.

delete this post please, double post...

Hi,
I am in process of building bottom end for myself and so torque plate. My question is quite simple. Will it be ok to use 2 1" torque plates one over other to get 2" thickness? I do not have 2" AL in stock and also CNC I will be using for this does not have enough stroke to do 50mm thickness. I believe that 2 1" pieces stuck together should give me same result, of course each piece will be distorted differently, but that is not what we care about right ? - important is pressure on the block, which should be distributed better when using 2x1" than 1x1" - maybe worse than using 2" piece. Any thoughts ?
To be benefical for MT users at least a little, in attachment you can found dxf of torque plate. It is made for 86mm bore which is more than biggest bore you will need in miata aplication. There is also holes made for dowel pins, they should be 10mm or so deep. You can also add small chamfers on those holes.

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Thank for you reply. Aluminum because it is much easier to machine, and also because the head itself is made out of aluminum. And also my clever book reccomends to use aluminum lol