Ok, rebuilding a 350 and going to be stroking it. I got 58cc head combustion chamber and going with a 12cc piston so that puts the compression ratio to 11:1. Now how do I calculate in the head gasket? I want to keep the compression ration at 11:1. Thanks.

Also, could someone explain SAE steel grades to me? I did a search on the web and cannot find a chart and the strength ratings for each.

 

You need to measure the deck clearance and cc the combustion chamber for real results. Then you plug that data into a compression ratio calculator. Or you can go old school and hardcore and do it by hand using geometry. There are hundreds of cr calcs on the internet.

 

The SAE grades shouldn't be that hard to find on the net, surprised ME Leigh didn't tell you .... well, it'd be a long post...

But to start: 1020, 1040 etc.... The 10 refers to carbon steel. So it's only... carbon, and iron. Weak, cheap. the last 2 #'s the the percent carbon, so 1020 = .2% carbon. more carbon = stronger, but brittle. up to ~6% carbon, then it's considered cast iron.

other grades like 4140, the 41 refers to another mix, iron, carbon, moly.... etc... I don't remember any of those, but there are TONS of these to know, 4340, is another example. I have textbooks listing some of these, but not with me here...

Maybe someone knows of a link to tables of properties for these...
(that's a good keyword to throw into google though...)

 

I would have posted but i would have been so long.

What you really want to search for the the ultimate or ulimate tensile strength of steels. You will find that even the lowest grade 10 series can be made really high strength with the right processing and manufactutoring.

One of the mags had a really nice article a couple of years ago. They went really indepth about all the materials used to make engine parts, cost, strength, elements... The hole deal. I will look for it, i should have book marked it because it was really good.

 

So basically there is no universal integer system that is stronger as it gets higher? Its basically a double edged sword, more carbon = stronger but brittle. So its about finding the right balance?

If thats the case, anyone mind explaining me in which order would be strongest?

5140
4340
4130?

 

It goes like this 4340 which is cromoly, then 4130 and 5140 are about equal but have different qualities.

Now this is general strengths, because there are different grades of each, different treatments, and different manufactutoring process that effect strength.

 

http://efunda.com/materials/alloys/a...eels/alloy.cfm

http://efunda.com/materials/alloys/a...h_string=steel

http://www.a-sp.org/database/default.asp?doc=28

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