Torque Plates

[Roundy]

Hey Guys,

I get the idea behind them, however i am wondering how critical they are?

How much do blocks distort under the load of the head studs?

And if it is a significant amount, then surely the block would also distort a significant amount from the heat variance from the inlet to the outlet of the head, and differences based on the cooling jackets? And there is no real way for joe blow to compensate for that...

Obviously this is dependant on the block in question, but i am just looking for general info at the moment

Cheers
Nathan

[jeffro ra28]

In general applications they are not that important and can still achieve a good cylinder leak rate without using them.

If you are racing in competition and need every ounce of extra power then yea, maybe they are worth it to an extent.

I have pulled down 2 identical engines which one was torque plate honed and one was not. Then inspections carried out side by side for comparison. The wear marks and measurements recorded after being run for a few race meets were very much identical so id say the difference is negligible. Obviously it is also block and engine specific but if i was building a healthy street engine i wouldnt bother to be honest.

To answer your question more specifically, in my experiences they are not critical what so ever.

If you want to actually measure how much they distort you can do a rough simulation by torquing your head studs down without a head using large spacers e.g. gudgeon pins. Then measure with a bore gauge the distortion of the cylinder compared to a non torqued one. Get the drift?

[Billzilla]

It depends on the block - If it's an open block then there's not a lot of difference, but on a closed block there can be with some of them. Something like a 4AGE block don't get a great benefit, but as mentioned above I always would for a race engine.

[Roundy]

What is meant by open block/closed block??

And I am thinking a 3S block, so i would guess very similar architecture to a 4A block.

[jeffro ra28]

Something like the 4a is closed deck, this is open deck,


Notice how the bores are separated by the water gallery compared to say conventional cast iron toyota blocks

[Roundy]

Cheers Jeffro, i thought that was probably what it meant

[oldeskewltoy]

The company who machined my block(4AG)... brings the machining oil up to 180 degrees. Thereby bringing the block upto operating temperature before boring and honing. They also have torque plates