383 240z Posted March 16, 2003 Share Posted March 16, 2003 OK my problem was I had a 350 with a 8.21:1 static CR. After following the advice I was given on this site I did a BUNCH of reading. I think that my problem was with the low CR I had to get rid of my 4:11 gears. or get a cam so big that I would need a VERY high stall conveter. So I decided to buy some new pistons. A set of +.030 hyper pistons with an advertised CR of 9.7:1. My 64cc heads with new Z-28 springs (120lbs on the seat) and an Edelbrock RPM intake and a 750 vac 2ndry Holley. The other variables are TH-700R4 with a 2000k converter in a 3000lb car with 4:10 or 3:90 rears on 245/50/15 tires does this sound about right? Keith Quote Link to comment Share on other sites More sharing options...
grumpyvette Posted March 16, 2003 Share Posted March 16, 2003 "I think that my problem was with the low CR I had to get rid of my 4:11 gears. or get a cam so big that I would need a VERY high stall conveter. " that makes no sence! if you needed more dynamic compression you needed EITHER higher static (new higher compression pistons) or a SMALLER CAM, NOT A LARGER CAM! Quote Link to comment Share on other sites More sharing options...
383 240z Posted March 16, 2003 Author Share Posted March 16, 2003 Sorry I miss typed(actually I got the cam cards screwed up) the crane cam tech line explained to me that my goals and my parts were mutually exclusive. they recommended an Energizer 100132 cam with a different intake a 2500 stall converter and a 600 carb and 1:6 rockers my other option is 10.5 pistons a powermax 114561 with a 3k converter and 1;6 rockers. I'm thinking the 9.5:1 will support the gears, let me run a decent stall converter and be able to put the car through the lights at over 100MPH in the lower half otf the 13 sec range. (my overall goal) Keith Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted March 16, 2003 Share Posted March 16, 2003 Keith; Having read elsewhere I think that you should time some runs as you change your cam timing. Your CR changes as you do this but how much average per degree of change I am not aware. Bite a bullet and dyno tune the thing to find where you are really at? Quote Link to comment Share on other sites More sharing options...
grumpyvette Posted March 16, 2003 Share Posted March 16, 2003 your limited to about 4 degrees advance and 6 degrees retard from the standard install marks with any cam before a differant cam will be a MUCH better choice, youll see about a 200rpm shift in the TORQUE PEAK CURVE for every 4 degrees changed, look at this chart http://www.iskycams.com/ART/techinfo/ncrank1.pdf that rarely amounts to a .1 differance in piston location (thats a tenth of an inch ) in relation to valve position and rarely gains or loses you more than 4-6 hp (normally less) Quote Link to comment Share on other sites More sharing options...
383 240z Posted March 16, 2003 Author Share Posted March 16, 2003 does it sound like my goals will be atainable with the parts I have? I can change the 4.11's to a set of 3.90's after a trip to the JY I really hope this will work as I NEED to have this car running by the 1st of May and broken in and tuned by the 17 of May. That is when the tracks start opening up around here. Keith Quote Link to comment Share on other sites More sharing options...
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