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posted on February 26th, 2013 at 06:04 PM
Decompression
Hi Guys,
Im putting together a 1955cc engine.
Heads have been heavily fly cut to (from memory) 35cc.
This brings the static compression (with a 1.5mm deck) arround 11.5 (and dynamic around 10).
2 questions.
1) On a VW is there much difference between forged and cast pistons.
2) Is there much difference between running dished pistons and a wider deck height?
2B) Any thoughts on dished pistons. I did see on the net Toyota 1AR-FE pistons are about right (-27cc) (90mm with 22mm pin) which could come in a 0.50
oversize. Any other options.
Just pondering at then moment as I am in Perth for a month (away from my shed).
Newt
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SuperOwen
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posted on February 26th, 2013 at 06:32 PM
If it were me.....I would hemi cut the chambers and blend the left over chamber into the hemi by hand. Be prepared to run a bit more advance.
matberry
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posted on February 26th, 2013 at 06:43 PM
^ me too, Don't go more than 1.5mm deck IMO. Converting pistons can be a pita, and not always successful.
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