rustorbust Posted May 30, 2007 Share Posted May 30, 2007 Other than my z that I am building I also have a 73 chevy vega. I have had this car for about 4 years now and I have been racing it the whole time. I recently pulled the motor looking for a little more. The car runs exceptionally well for the combination. So far to date it has went 6.72@103 with 1.47 60' times with a 150 shot plate system in the 1/8. I have always felt like the car kinda falls over on the top end. Motor is a .030 over 400 flat top forged pistons with 5.7 rods victor junior intake, 850 holley carb heads are edelbrock Performer rpm Part # 6073 70cc chambers The cam is a Lunati .490/.490 lift 290/297 adv duration with a 112 lobe serperation Tranny is a turbo350 3700 hughes converter 12 bolt rearend with 3.73 and 26x8.5 MT's The heads are stock and I dont really want to put all that much money into them cause im looking at putting a whole new motor together within a year, so im just looking at getting a little more out of the motor now and changing the cam to a Comp Cams Extreme Energy 519/523 lift 294/306 adv duration with a 110 seperation To big? To small? Looking for opinions and some input. I recently put some videos on the computer of the car so I thought I would post one on here http://s16.photobucket.com/albums/b33/rustorbust/?action=view¤t=Cap0002-1.flv Quote Link to comment Share on other sites More sharing options...
Pyro Posted May 30, 2007 Share Posted May 30, 2007 Would run better with some 4.11's Cam looks ok. But you really should be comparing the duration at 0.050". My Z with a 292H (244/244) and a 200 shot would run 110 in the 1/8. Using less head (iron eagle), less intake (RPM), and less carb (3310, 750), but more gear (3.90) and a 5 spd. Not sure if that information helps you, but I sure like that old school 292H. Revs to 7200 rpm and is easy on the valve train. I feel those extreme series cams cause a lot of valve train problems (float and wear). In any case, use diesel engine oil with your new cam. Quote Link to comment Share on other sites More sharing options...
grumpyvette Posted May 30, 2007 Share Posted May 30, 2007 since you didn,t give all the info Id need its hard to suggest exactly, but Ive had excellent results in similar combos with this cam (below) http://store.summitracing.com/partdetail.asp?part=CRN%2D110921&autoview=sku keep in mind the solid flat tappet lifter and 106 lca with the 244/252 dur and .518/536 lift makes a great deal of power in the 3500rpm-6700rpm band in similar combos, and it tends to breath and control the valves better than hydrolics of similar durration over 6000rpm btw when you install it, if you have the hood clearance ID certainly try a 2" open carb spacer, those vic jr plenums are on the small side for max power http://store.summitracing.com/partdetail.asp?autofilter=1&part=SUM%2DG1409&N=700+115&autoview=sku Quote Link to comment Share on other sites More sharing options...
rustorbust Posted May 30, 2007 Author Share Posted May 30, 2007 Sorry I didnt give enough info, I do have a phenolic 2" spacer between the carburetor and the intake. I wanted to run a solid lifter cam but I wasnt to sure about the wear that it would put on the valve train. I want as much input as possible on this so If there is any other info that you need please ask and ill get if for you. Thanks Quote Link to comment Share on other sites More sharing options...
grumpyvette Posted May 30, 2007 Share Posted May 30, 2007 what are the heads flowing at .400 and at .500 lift? whats the TRUE compression ratio? whats the header primairy size and length,COLLECTOR dia. /length are you useing roller rockers and what ratio? what rpm are you currently shifting at/, crossing the lights at? whats your average launch rpm? are you manually controlling the shiofts or if not at what rpm does the cars trans shift at in each gear? at what rpm are you dumping the nitrous in?, do you have a rev limiter? does the nitrous have an rpm window? IE does it open at full throttle at less say 4000rpm but cut off if you hit 6800rpm? Quote Link to comment Share on other sites More sharing options...
rustorbust Posted May 30, 2007 Author Share Posted May 30, 2007 -At .400 they flow 238/163 and at .500 the flow 244/175 I/E -10.25 to 1 is the compression ratio -the headers are 1 3/4" primary and 3" collectors, the primary tubes are 31" and im not quite sure what the collector length is? -it has a set of roller rockers (harland sharps 1.5) on it -I have been shifting the car a 5900-6000 and have the rev limiter set at 6200, I am not positive but I beleive that the engine is crossing the 1/8 mile mark at some where around 4200-4500rpm -it has a 3700 stall in it but its hard to get it there, so it stalls to 3000 on the launch -I am shifting the car at 5900-6000 myself -I have the nitous set up on a full throttle swithch so I imagine its probably coming in around 3500 cause I have been leaveing on it. -the nitrous doesnt have any kind of window switch on it or any safety shut off stuff on it, it is something that I have been needing to get setup on the car. Thanks for the help James Quote Link to comment Share on other sites More sharing options...
grumpyvette Posted May 30, 2007 Share Posted May 30, 2007 the crane 110921 looks like a valid sellection, perhaps someone here with far better computer skills than I have can do a dd-2000 software dyno,and compare both your current and the crane cams power curve Quote Link to comment Share on other sites More sharing options...
rustorbust Posted May 31, 2007 Author Share Posted May 31, 2007 Thanks, I went ahead and ordered that cam. Should I go ahead and order the lifters that they recomend or can I run a set up cheaper ones? James Quote Link to comment Share on other sites More sharing options...
grumpyvette Posted May 31, 2007 Share Posted May 31, 2007 http://www.competitionproducts.com/prodinfo.asp?number=651080DL btw use this oil http://www.shell.com/home/Framework?siteId=rotella-en&FC2=/rotella-en/html/iwgen/press_release_2006/zzz_lhn.html&FC3=/rotella-en/html/iwgen/press_release_2006/cj-4_intro_1006.html and these additives on cam lobes http://store.summitracing.com/partdetail.asp?autofilter=1&part=CRN%2D99002%2D1&N=700+115&autoview=sku added to oil http://store.summitracing.com/partdetail.asp?autofilter=1&part=CCA%2D153&N=700+304552+115&autoview=sku Quote Link to comment Share on other sites More sharing options...
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