Guest zfan Posted March 2, 2003 Share Posted March 2, 2003 Well dyno'ed the Z today. Made three pulls and am dissapointed to say the least. The fuel analizer was down so that was a dissapointment in itself..I'm running extremely rich so said the guy running the dyno. He told me to jet the holley down 3-4 jet sizes on both primary and secondaries. My build is as follows: 350 four bolt 30 over 10.3 to 1 compression Pete Jackson gear drive Comp cams extreme energy hyd. roller cam 224/230-502/510 with 110 lobe seperation 1.50 roller rockers Edelbrock rpm 64cc heads ,170 runners Weiand stealth dual plane intake Holley 750 double pumper 70 primaries, 74 secondaries Hooker super comp 1 5/8" long tube headers 2 1/2" dual exhaust with H pipe 2 chamber flowmasters MSD ignition 34 degrees total timing Dyno runs 1. torque-276.4 Hp-269.4 2. torque-274.4 Hp-269.1 3. torque-269.1 Hp-261.3 Max. torque was made at 3500 rpms Max horsepower was made at 5800-6000 Leaning it out will help slightly but not that much! I am seriously thinking of making this my last sbc build. My friends sbc 350 made 350 at the wheels, it's in a 1959 Austin Healy that weighs 2100 to 2200 lbs. Can you say fast car. Should run mid 11's. My other friend made 280 hp at the wheels from his crate ZZ4 and 370ft. lbs of torque at 3k. Mike Quote Link to comment Share on other sites More sharing options...
Guest Drewz Posted March 2, 2003 Share Posted March 2, 2003 Don't give up man!!! There is obviously something not right there. The primary jets are way overboard for sure. Did you get the cam degreed? Are you sure the distributor isn't worn? Plug gaps all right? One didn't get bumped on installation? Start checking the small stuff and you may be pleasantly surprised. Vacum leake are another big one.....Kep your chin up. 8) It is a long path and sometimes very winding but in the end it is worth it. Quote Link to comment Share on other sites More sharing options...
grumpyvette Posted March 2, 2003 Share Posted March 2, 2003 I bet if you kick the timing up to about 38 degrees all in by 3000rpm and jet the carb to about 13:1 youll pull much better #s check the valve lash/ preload adjustment is correct,and make sure the cam is indexed correctly It sounds like either the cam timing,ignition timing and carb fuel/air mix are not correct or mabe even all of them or out of spec. a restricted exhaust will also kill hp really fast so check that also! Quote Link to comment Share on other sites More sharing options...
Guest Drewz Posted March 2, 2003 Share Posted March 2, 2003 Agreed !!! The motor is solid just a couple minor things holdin ya up. I had a 400 in an elcamino with a nice cam carb etc. I was really disappointed with the lack of tire spin off the line and no top end after 5000 so a 2 1/2 dual was thrown on and WOW!!! The thing was awsome !!! 8) 8) Quote Link to comment Share on other sites More sharing options...
z ya Posted March 2, 2003 Share Posted March 2, 2003 zfan, Thats about what I went to dyno mine. I made 275rwhp and 280rwtq. I as well was pig rich with a 10.0 a/f ratio across the board! When I went I was at 33 total timing so that didnt help. Like grumpy said get the the a/f ratio around 13 to 13.5 and total timing in the 36 to 38 range and things will pick up. I plan to go back soon and since the changes I have made. I now have a 650dp and the thing runs MUCH better than the 3310 Holley vac sec. Good luck with the z, you will get it right just be patient! By the way what has been the best pass you have made with these current numbers at the strip???? Quote Link to comment Share on other sites More sharing options...
Guest zfan Posted March 2, 2003 Share Posted March 2, 2003 Actually the a/f was down so no way to get a fuel reading but out of 10 cars in the garage that I was around when they made there pulls mine was the only one that made our eyes burn and breathing difficult Very rich to say the least. I do not like vacuum secondary carbs either that is why I am running a 750 dp with four corner idle and factory deleted choke..cold blooded though. I am taking the carb apart today and am stepping down primary jets from 70's to 66's or 68's not sure and secondaries from 74's to 71 or 72's. I also want to pull my Msd pro billet distributor and have it matched to my motor specs. This distributor came off a sbc 327 that originally came with my Z some 4 years ago. The only changes I ever made to it was to replace the rotor and cap last year. I have made some changes to the car since it last whent to the track so who knows. My tranny was slipping bad and I ran a 3.55 open diff. and ran 12.70 at 114.9 mph with a lousy 2.1 60 ft time. I had a friend who's a mechanic hook me up with a speed freak buddy who built my 700r4 tranny. It now has a shift kit and all stage 9 clutch packs and vette servo. The tranny was out of a vette but had been beat one a little . I also installed a 3.70 LSD rear end and upgraded tires. still no drag radials but yokahama avs intermediates zr rated have helped. I previously had Pep Boy specials on there could smoke the tires for 50 ft. Mike Quote Link to comment Share on other sites More sharing options...
Guest zfan Posted March 2, 2003 Share Posted March 2, 2003 Also cam was installed straight up with no added or retarded degreeing. This cam is actually two or three steps down from the cam I used to run. This cam replaced the 238/246-520/540 hyd. roller cam that was to much for the street and lacked torque wheree I needed it. I believe it was a extreme energy xr288-hr-10, cam I have now is a xr276-hr-10. Mike Quote Link to comment Share on other sites More sharing options...
Guest Your Car is Slow Posted March 3, 2003 Share Posted March 3, 2003 Power Numbers on a dyno are worthless...its a tuning tool...not gods word in how much power you are making (unless you drive a supra). I dont think a dyno run would even be worth the time if the wideband sniffer wasnt working. Take it back and get a measure of the A/F ratio during the run...THEN you have a baseline to work on for improvement. Quote Link to comment Share on other sites More sharing options...
Guest zfan Posted March 4, 2003 Share Posted March 4, 2003 Thanks Guy's. Changed a few things ans it is not rich anymore. Plugs looked really good. Stepped down from a 31 squirter to 28 on primaries and jetted down from 70's to 68's. Car ran so rich that exhaust never got hot and had water spraying out exhaust tips, kinda like a mist. After changes it stopped and exhaust is hotter. I am playing with the secondaries and not sure where I'll stop but ran bigger jets and went to far now I'm going to back it off a few sizes. Also I am running pink cam on 2nd setting may go to 1rst setting and see where it goes from there. I am currently running an MSD pro billet distributor with mechanical advance and do not know for sure where total timing is coming in at. But I am guessing 2500 to 3000 would be a good starting point. Especially in such a light car. Going back to the dyno for A/F reading in the next few day's. Mike Quote Link to comment Share on other sites More sharing options...
z ya Posted March 4, 2003 Share Posted March 4, 2003 Keep us posted!! Quote Link to comment Share on other sites More sharing options...
dune333racing Posted March 9, 2003 Share Posted March 9, 2003 Don't forsake sbc just yet my friend try changeing your heads and intake to something with a little bit more room in the intake runners. Your running a big cam with small heads try getting some brodix heads with like some 200 cc intake runners. just match that cam the best you can i bet you'll have better results. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.