H/C pistons

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blgitn
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H/C pistons

Post by blgitn » Thu Sep 17, 2020 9:22 pm

What c/r do they come in; Can you get 6:1?

R/Roger.

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DanTreace
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Re: H/C pistons

Post by DanTreace » Thu Sep 17, 2020 9:57 pm

Only one size dome style High Compression piston, they don't come in anything but o.d. sizes for cylinder requirement.

To increase compression ratio, shave the stock iron head. Can't advise how much to shave or what the gain in compression would be.
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Re: H/C pistons

Post by Chad_Marcheese » Thu Sep 17, 2020 10:13 pm

If I recall right, it is approximately 5- 5.5 to 1.

As a person that builds modern performance engines, and have been delving into T engines specs heavily for a couple of my own builds, I can absolutely tell you any number given is just a wild guess until components are measure via liquid and a burette.

Every engine differs, and you can find anywhere from 1/2 to 1 point of compression variance on average when actually measured on all the components (modern day stuff manufactured in the last 25 years is actually very close engine to engine though). All heads, blocks, cranks, and rods are not created equal, they all contribute to the final compression ratio.


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Re: H/C pistons

Post by ModelTWoods » Fri Sep 18, 2020 12:43 am

Jeff Cordes of Houston, told me that a virgin high head can safely be milled .150. If you do that and run any of the commercially available high compression pistons, either Egge or Snyders, you may not get as much compression as from a Z head, but it'll be cheaper and you'll get as much compression as possible from an iron high head.

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Re: H/C pistons

Post by Henry K. Lee » Fri Sep 18, 2020 7:37 am

There is so much meat so to say on the top of those, you can easily machine the tops to make you own custom ratio with even a a low head.

Just saying. You can not run them out of the box with a low head.

Hank


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Re: H/C pistons

Post by Kerry » Fri Sep 18, 2020 5:06 pm

Hank, I've never had a problem fitting out of the box HC domed pistons to a low head. May be some difference in Canadian ones to the USA ones?

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