Advice on making my own honing plate B/RB and HEMI

just buy a used bhj hemi plate of ebay they pop up now and again cheap, unless your wicked machinist might do more harm than good

The distortion is caused by the bolts being torqued into the deck. The bolt torque is the only force and can be duplicated by just using a spacer. The spacer length is what is critical because you need to have the proper thread engagement into the block.

If you look at a torque plate the material between the bolts isn't doing anything. It can't do much because all of the load is applied with the bolts and there is no other load.

There might be a small amount of clamping load transmitted to the deck from the plate but the primary force is the torque from the bolts.

Engine builders don't use individual spacers because it is a real pain to install them all rather than just drop a plate onto the deck. But for some guy in Peru who doesn't have access to all the parts we have the spacer trick will work just fine.

I don't think the plate does much but if it does then a guy could build a one hole plate and just move it from bore to bore. That would be easier than building a whole plate.

I know that people do all kinds of things but that doesn't mean it matters. Witch doctors flip chicken guts around to cure people, doesn't mean it does anything. A lot of engine builders are witch doctors in their own way. They do certain rituals but it doesn't mean that it makes a difference. Just like ballplayers who wear the same socks for every game or don't shave when they are on a winning streak.

I'm pretty sure that a bolt torqued into a cast iron block 6 inches away doesn't do anything to a cylinder bore. The stress is very local and there isn't enough force involved to move material that is outside the immediate area. The thread torque is only being applied to the threads in the block. Once those threads in the block distort they absorb all of the force and there isn't anything left to move material further away.

Of course, all of this is very dependent on the engine block in question. I think the SB Ford engines are the worst for bore distortion due to thin walls and thin deck. Some engines don't even need torque plates because the head bolts don't go into the deck. The new LS motors are like that with the bolts doing down into the bottom of the block. You can torque on those all day and the cylinder bores don't distort. I think the Mopar NASCAR engine is the same way.

I would think that if you put a head gasket on it
changes the whole thing with the fire ring applying
a completely different force and if I remember correctly
most (if not all) dont use a gasket.... I would also
think that the hot water would also be another major
factor.... JMO

Thanks for all the replies guys.

Im currently making my own honing plate using a parelell decked 2" steel plate.

I am doing it all with a CNC at a friend's shop.

Yes, I would have bought a honing plate instead of messing and making my own....but air freight on a 2" thick steel plate would kinda hurt my wallet a bit!!! I have to figure out things so that they work best for me and achieve good results too!!! Living down here in Peru limits me somehow sometimes...but its all good fun!

The stress is very local

I agree, that's very important. The clamping area isn't much bigger than 1" radial to the bolt itself.
It's not everything, but it's the only certain thing - a full plate cannot duplicate the bending stress of an actual head casting with water passages, let alone a head with rocker stands, accessories and spring tension, and is likely to stress over or under or in the wrong places.
If you can, torquing the mains in place, etc. is also useful, but has far less effect since cylinder distortion is not only much smaller (bolts aren't close to the bore) but much less critical since it's at the lowest point of cylinder pressure.

I had also thought of boring out the chambers of an early hemi head to use as a torque plate. The problem I ran in to was that the headbolts (8 inches long) also hold the rocker stands in place. Are there hones that will reach that far?