z ya Posted February 6, 2001 Share Posted February 6, 2001 The car is not together yet but am curious about what kind of timeslips I might expect. Here's what is will have(for now) 355 sbc,10.5 comp ratio,rpm air gap manifold, 750 holley vac sec,roller tip rockers 1.5, 1 5/8 coated block hugger headers,2.5 dual flows,performance hei,k&n filter,electric fan.It will also have an 700r4 or 200r4 with 2000 stall.The ratio will be 3.54 open. Quote Link to comment Share on other sites More sharing options...
Guest pauli Posted February 6, 2001 Share Posted February 6, 2001 how much will the car weigh? Quote Link to comment Share on other sites More sharing options...
Kevin Shasteen Posted February 6, 2001 Share Posted February 6, 2001 quote: Originally posted by z ya: The car is not together yet but am curious about what kind of timeslips I might expect. 355 sbc,10.5 comp ratio,rpm air gap manifold, 750 holley vac sec,roller tip rockers 1.5, It will also have an 700r4 or 200r4 with 2000 stall.The ratio will be 3.54 open. Zya, What cylinder heads & how do you know it will make 10.5:1 comp.ratio? Also I'll need to know what tire size you're running & the camshaft's profile. are you going to use; what car & its weight? On the Heads; have they been milled, do you know what CC's their combustion chambers are: on the camshaft-give me lobe lift, duration @ .050 & its lobe separation angle. If I can get that info; if its not too much at this time-we can run some #'s for ya. Before you plunk your money down on an expensive stall cvtr you might post another thread about which converters everyone running auto/trans are using. If the car is a Z; its a light car & may not need a stall cvtr. If I remember some old posts, Myron, got rid of his stall cvtr; Myron...anyone else running auto's wanna jump in here. [This message has been edited by Kevin Shasteen (edited February 05, 2001).] Quote Link to comment Share on other sites More sharing options...
Andrew Bayley Posted February 6, 2001 Share Posted February 6, 2001 Hmmm... I would say anywhere from 13.2 @ 105'ish to maybe as good as 12.7 @ 109'ish. This is assuming you can get it out of the hole. If not, add a good half second to these times. I cannot stress the importance of a good converter. 2000 RPM is O.K. for the street, but it will have it's limitations in even mild drag strip application. I figure since you asked about performance, this is something you are probably going to do more than once in the car's life. The launch is what makes the Z such an incredible drag terror in street trim. For example, my friends supercharged Firebird used to (read... used to ) run away from me on the highway. At the track however, I could run consistant 13.0's to his very traction limited 13.9 - 13.8's It's all in the launch and a converter is where it's going to happen (assuming the tires stay planted). I've made a little web page that has fellow HybidZ members quarter mile performance numbers on it. Feel free to to browse around and ask any questions. Most of us tend to enjoy the occasional "bench race" here and there. http://grannypotts.freeservers.com/Times.html -Andy P.S. I no longer have a problem with those pesky SC Firebirds... Quote Link to comment Share on other sites More sharing options...
z ya Posted February 6, 2001 Author Share Posted February 6, 2001 Sorry I was so vague when I posted this thread, I just woke up!Ok lets try this again.The motor has flat top pistons with 1.94/1.50 291 casting camel hump heads.These are 64 cc chambers.They also have mild port work done on them.The cam is a comp magnum 286 duration with 490 lift on 110 lobe centers. Quote Link to comment Share on other sites More sharing options...
z ya Posted February 6, 2001 Author Share Posted February 6, 2001 Opps I forgot to say that it is an 70 240z. And I am unsure of the weight. Quote Link to comment Share on other sites More sharing options...
Kevin Shasteen Posted February 7, 2001 Share Posted February 7, 2001 Zya: Here's my take on your set up. If I understand correctly this is what you've chosen to go with. 70/240z, 355 10.5:1, 700r4/200r4 trans, 750 Holley, 286Magnum cam w/1.5:1 rockers, 291 Camel Hump Heads 64cc, 3.545 rear gears. For starters, My book "Chevy V8 Interchange Manual" indicates that the 291 came w/larger valves & the smaller 1.94/1.50 valves-so make sure of their size & dont just take someone's word for it. Hotrod magazine did a test of the 286cam & chose the 355sbc w/iron heads(barely above stock) with 1.94/150 heads yielding 8.8:1 & an Edelbrock Performer manifold. This test yielded peak power/torque at: 341 hp @5000 rpm's & 394ft.lbs. @ 3500rpm's. Hotrod, in another magaizine, did a test on the 280Magnum cam; the difference in spec's on your cam are as follows: 280H Duration @ .050/234, lift=480/480, 110LDA 286H Duration @ .050/236, lift=490/490, 110LDA The 280H's performance was on a 355 9.7:1 Comp.Ratio, 750 Holley, Edelbrock Performer RPM (High Rise Dual Plane) Intake w/AFR Alluminum Cyl.Heads running 2.02/1.50 valves. Ignition was a MSD Billet Distributor triggered by a MSD-6AL box. This set up's performance yielded: RPM's..Torque/HP 2500...332..160 2700...343..180 2900...350..195 3100...367..219 3300...382..240 3500...395..260 3700...397..280 3900...399..297 4100...396..308 4300...403..330 (Maximum Torque) 4500...400..340 4700...400..360 4900...400..376 5100...397..380 5300...388..390 5500...380..400 5700...375..404 (Maximum HP) 5900...357..397 6100...348..400 *The figures are Flywheel power/not Rear wheel power: Factor in 15/20% loss to obtain theoretical Rear Wheel power. **This should yield you an ET=11.8 @ 114mph; not including possible wheel spin, tires & gearing your running nor how well you can trip the lights at the track. I figured your car weighed 2900lbs w/you & a full tank of gas. This engine idled @850 w/12.5HG inches of vacuum while the previous engine made only 10.5HG of vacuum at 750rpms & only 13HG inches of vacuum at 1000rpm's. I think the alluminum cyl.heads better indicates what your engine will do since it has a higher comp.ratio & larger valves. The alluminum will dissipate heat quicker than your iron cyl.heads. Having said all that: I hope this isnt your daily driver. If you're running A/C & Power Brakes you may want to consider a Vacuum Assist Canister. Or, you may want to consider another cam w/a wider LDA. Your current LDA of 110 is great for a lopey/choppy idle but low rpm vacuum suffers considerably on a street engine. Comp Cam's has a line of cams for Nitrous engines. You may not be running Nitrous but one of those profiles is close to yours & has a wider LDA of 113-much better idle quality for a daily street driven car. Two profiles are relatively close to your 280H. NX262H-13 Duration @ .050 218/230, Lift=462/480, 113LDA NX268H-13 Duration @ .050 224/236, Lift=477/490, 113LDA Hope this helps. [This message has been edited by Kevin Shasteen (edited February 07, 2001).] Quote Link to comment Share on other sites More sharing options...
MYRON Posted February 7, 2001 Share Posted February 7, 2001 I would suggest not using that converter. I had a B&M 10" 2700 stall that would flash at 4500rpm..."HATED IT"!.. I had traction problems and it was just obnoxious to drive at anything less than 4500 rpm. I put a stock unit back in the car and it is so much nicer to drive.. Quote Link to comment Share on other sites More sharing options...
Kevin Shasteen Posted February 7, 2001 Share Posted February 7, 2001 quote: Originally posted by MYRON: I would suggest not using that converter. I had a B&M 10" 2700 stall that would flash at 4500rpm..."HATED IT"!.. I had traction problems and it was just obnoxious to drive at anything less than 4500 rpm. I put a stock unit back in the car and it is so much nicer to drive.. Myron, I'm glad you chimed in; I thought I remembered somewhere in the past that you had a stall cvtr you were not happy with. Would hate for another V8Z enthusiast to go down that same road when he/she didnt have to. Myron, when you say stock; what do you mean by stock. What was the brand name/diameter in inches(?). Also if I remember your ride has a pretty healthy cam. Why are you selling your old ride & what are your expectations/predictions for your 78Z. Streetable -vs- All out Race/Eng? Quote Link to comment Share on other sites More sharing options...
z ya Posted February 8, 2001 Author Share Posted February 8, 2001 Thanks for input guys!No, this isnt gonna be my daily driver.I want it for weekend cruz nites and bracket racing.I know it will lope pretty hard but thats how I like it!I will go to trick flow 23degree heads when the cash flow is up.Also for sure I will put a vac can on to get the brakes up to snuff.Looks like I will go little tighter on the converter now that I am getting these horror storys on the stall units.I cant wait to get this thing going!!! Quote Link to comment Share on other sites More sharing options...
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