compression
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From: conway arkansas
compression
just wodering if i figured correctly, i am very very seriously considering a set of chi 2v heads for my new 400 project, they say that they will cnc the chambers free of charge when i buy the complete head set with valves springs and all, well i figured 9.63:1 with a 74cc head which they say is what it figures up to be after cnc'd, thats with the goddang tmi zero deck piston and a .041 head gasket with a 4.060 bore and a 4.100 head gasket bore which i wasnt sure on, tax money is good this year for once, so i am gonna do it to it this year, thanks for all the help so far been lots of help on alot of things
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From: western montana
make sure you have tims updated info- the pistons are actually .005 in the hole I think...I know he changed some of the info from what he originally had. It was for the pistons that go with the stock 2v head but not sure if it applies to the your heads. Its obviously leads to a little lower compression...not much.
Make sure you post what cam you use and how it runs on pump...i'm trying to get the info together with little luck thus far...I'll be getting the thread up top again soon.
Make sure you post what cam you use and how it runs on pump...i'm trying to get the info together with little luck thus far...I'll be getting the thread up top again soon.
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From: conway arkansas
as always thanks mr. dowty, i do remember tim posting somethin about his pistons being a liittle different than what i had originally read too, have to do a search on this forum i reckon, as for the cam, i havent totally decided on one yet, am kinda leaning towards a cam with a 282 adv, duration with a .550 lift and a 112 llobe center
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From: chicago burbs
lucky, are you figuring using the 14cc dish? Tim also lists a 30cc dish for use with the 60cc chambers. CNC'ing them out to 74cc's will wipe out the chamber as it was designed, you'd be basically back to open chamber heads. the 30cc dish pistons will allow you to leave the chamber as is and make use of the quench. bottom of this TMI page,
http://www.tmeyerinc.com/cart400pistons.htm
http://www.tmeyerinc.com/cart400pistons.htm
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From: western montana
i was thinking the compression chambers were a bit big for chi's.
quench is huge when your pushing the compression factor and want to burn pump...from what i've read it appears folks have gotten well over a point more w/o detonation wigh good quench...i know i'm counting on it.
quench is huge when your pushing the compression factor and want to burn pump...from what i've read it appears folks have gotten well over a point more w/o detonation wigh good quench...i know i'm counting on it.
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From: conway arkansas
well the chamber volume comes right off chi's website where they state they willl cnc any head chamber free of charge when you buy the assembled heads, also above that on the same page it lists it as making the volume a 74cc head, and yea i was figureing it with the 14 cc dish pistons that mr meyer sells, with the aluminum i should be able to run a little higher dynamic compression anyhow shouldnt i? plus the more efficient chamber design,
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From: chicago burbs
yeah, it's one way to go, after looking at the 30cc dish pistons again it looks like 6 of these/1/2 dozen of those in that there isn't a whole lot of piston top left at the deck anyway. you can take away from the piston or the head and the result is about the same.
i have seen a test where they put aluminum against iron at the same CR and the aluminum head went into detonation just like the iron head did. i'm not sure what to believe on that?
i have seen a test where they put aluminum against iron at the same CR and the aluminum head went into detonation just like the iron head did. i'm not sure what to believe on that?
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From: western montana
I'm wondering why chi would have a 74cc closed chamber head? Cut deeper to allow better flow? Maybe that design doesn't neg affect quench as the cuts would be the same limiting the space outside the combustion chamber?
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From: Fairmont
CHI offers the 74cc head & 4V intake ports for kind of the same reason. They can be bolted on existing engines. If they already have a 4bdl intake, the 4V heads bolt right on. If you happen to have a small dome piston for the 74cc heads, then his CNC chambers can bolt right on.