GI.SS Posted December 30, 2013 Report Share Posted December 30, 2013 stock 317's, is it worth the $250 to take the heads off and mill them .030"? what sort of power increase would you typically see from bumping up the CR? I already have head studs and figured if im unbolting them already, is it worth it to mill them? shorter pushrods are in order as well, but I wont know the size I need until I install my cam and measure. Quote Link to comment Share on other sites More sharing options...
Cramer Posted December 30, 2013 Report Share Posted December 30, 2013 I would just get some 243's if you want to bump the compression up. Can be had for the same price as the mill on the heads, and have a little better flow stock. A good valve job would be better. Quote Link to comment Share on other sites More sharing options...
Brentd Posted December 30, 2013 Report Share Posted December 30, 2013 I would just get some 243's if you want to bump the compression up. Can be had for the same price as the mill on the heads, and have a little better flow stock. A good valve job would be better. This is a good idea, and luckily it is one that has been proven multiple times over.....243 heads with a valve job is what I was told to do. Quote Link to comment Share on other sites More sharing options...
AugustBurnsRed19 Posted December 30, 2013 Report Share Posted December 30, 2013 I wouldn't really bother with milling 317s man. If you're looking for a bump in compression the 243s raise the compression almost 1 Rialto Idk If that's spelled right. They go for around 350 used, ported they go for 950 used, brand new 1300, new heads fully ported and bigger valves 2000. Quote Link to comment Share on other sites More sharing options...
GI.SS Posted December 30, 2013 Author Report Share Posted December 30, 2013 guess im just gonna wait it out and get this thing working right cam only and then later on pick up some nice aftermarket castings... Quote Link to comment Share on other sites More sharing options...
shadowsniper3006 Posted December 30, 2013 Report Share Posted December 30, 2013 I'm pretty sure no one has ever gone fast on a set of decked and ported 317s. Waste of money for sure... Quote Link to comment Share on other sites More sharing options...
AugustBurnsRed19 Posted December 31, 2013 Report Share Posted December 31, 2013 (edited) Pick a nice NA cam if you plan on slapping on the 243s once you slap em on you will only be able to spray a little. What do you plan on just a DD right that's what I'm doing here just a heads cam intake dd ported 243s LSr cam tbss intake and possibly move on up to the LSXRT intake sometime! Edited December 31, 2013 by AugustBurnsRed19 (see edit history) Quote Link to comment Share on other sites More sharing options...
GI.SS Posted December 31, 2013 Author Report Share Posted December 31, 2013 I already have a custom cam spec'd by BTR. Specs are floating around the forum somewhere. Rod bolts, and headstuds are sitting on my shelf. Already have a TBSS intake swap on and running. Im waiting on the tail end of the month to order my springs and pushrods then it will be install time. 243's are an option but If I think Ill talk to BTR some more when the time comes for heads. Give me an intelligent reason why I will only be able to spray "a little" if I swapped to 243's? Quote Link to comment Share on other sites More sharing options...
AugustBurnsRed19 Posted January 2, 2014 Report Share Posted January 2, 2014 Well high compression and nitrous don't mix but some ported 243s with a 125 shot will roll nicely! Usually when people spray more than a 150 shot they have 9.5:1 compression. with some 243s your compression will raise to 11.2-5:1 so spraying a big shot especially on a stock bottom end is pushing your luck. But yeah a nice set of heads would be some 243s since you already have the tbss intake! Quote Link to comment Share on other sites More sharing options...
GI.SS Posted January 2, 2014 Author Report Share Posted January 2, 2014 Well high compression and nitrous don't mix but some ported 243s with a 125 shot will roll nicely! Usually when people spray more than a 150 shot they have 9.5:1 compression. with some 243s your compression will raise to 11.2-5:1 so spraying a big shot especially on a stock bottom end is pushing your luck. But yeah a nice set of heads would be some 243s since you already have the tbss intake! That is an entirely incorrect statement. Nitrous loves compression and vice versa. Run a colder plug and yank some timing and watch afr's. Quote Link to comment Share on other sites More sharing options...
GI.SS Posted January 2, 2014 Author Report Share Posted January 2, 2014 With my truck I'm more worried about burning a piston down than anything else. All built nitrous motors are high compression builds. Quote Link to comment Share on other sites More sharing options...
Tyson1972 Posted January 3, 2014 Report Share Posted January 3, 2014 AugustBurnsRed, sorry man but you are way off on your info. If it is boosted(Supercharged, Turbocharged) engine then yes you would need a lower compression ratio. I am speaking from experience with older BBC and SBC engines. It doesn't matter what kind or brand of engine higher compression motors love nitrous. Quote Link to comment Share on other sites More sharing options...
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