Mikelly Posted June 8, 2001 Share Posted June 8, 2001 Overall, really nice unit. Lack of documentation, but I'm working with a couple of guys to find out exactly where I go from here... Might have to get rid of my cam... We'll see. Found my cam tonight on line in the ISKY online catelog...# is:201282294 Info on it is: High performance use/bracket racing. Lopey idle. 2500 Stall. 9.5-10.5:1 compr. 3.90-4.11 axle ratio. Up to 780 CFM Carb. RPM-Range (3000-7000) Valve Lift (.530 .550) Valve Lash hot (.000 .000) ADV Duration (282 294) .050 Duration (234 246) LC 110 I'm also probably going to go with a cast aluminum exhaust manifold instead of headers... Mike Quote Link to comment Share on other sites More sharing options...
TimZ Posted June 8, 2001 Share Posted June 8, 2001 ...pardon my ignorance, but cast aluminum on the exhaust? Really? Never heard of such a thing... I wouldn't have thought that the aluminum would hold up to the heat. Quote Link to comment Share on other sites More sharing options...
DavyZ Posted June 8, 2001 Share Posted June 8, 2001 Nice specs on the racing cam. Knowing you, you'll put together and engine to stay in one piece at 7000rpm. I'm sure your car will see that if you're going for 200mph...I would love to hear this motor fire up! All the best in the build-up, Mike David Quote Link to comment Share on other sites More sharing options...
Kevin Shasteen Posted June 8, 2001 Share Posted June 8, 2001 Mike, Give me the lo-down on your set up. Is your engine still a 383? I'ld like to see what info I can come up with-merely by you giving me your known spec's? I) What is the maximum RPM you'ld like to maintain? Also-what is your: 1) Bore x Stroke 2) Camshaft Type (Hyd/Mech Flat Tappet/Roller? 2a) I need the Intake Closing ABDC in degrees-get this from your cam's tech line! I need the Seat to Seat closing (maybe the same as "Advertised" but we wont know till you ask your tech line. 3) Which Cylinder Heads have you chose? 3a) What is the width & heighth of the intake port opening on those cyl.heads 3b) What is the advertised cfm they flow? 4) What is the Con.Rod Length & Piston Comp.Height? 5) Still have the 6spd trans? 6) Rear Gears? 7) Tire size? Remember that peak airflow in an engine usually occurs around 78* to 82* ATDC. Depending upon where your cam's Intake Closing will need to compliment your static compression ratio as the moment where your intake valve closes will determine how much cyl.volume remains to be "Compressed" during the "Compression Stroke"; thus I need the Seat-to-Seat" Intake Closing (in Degrees ABDC) which your cam's tech line will have on hand. The connecting rod length & piston compression height will affect the location of the piston in the cylinder/so dont forget that info also! If you can get me the above requested info...I think I could get you a whole slew of results (sounds like fun). Kevin, (Yea,Still an Inliner) [ June 07, 2001: Message edited by: Kevin Shasteen ] Quote Link to comment Share on other sites More sharing options...
Mikelly Posted June 8, 2001 Author Share Posted June 8, 2001 Kevin, This is the same motor I currently have, and Tim, not your ignorance...Mine, Cast Steel manifolds... Slip of the typing...My brain was on overload after talking to Ron on the phone for an hour... Anyway, Kevin, back to your questions... I don't have a lot of the info on the motor as I didn't put it together. I know the total 383 combo is running at 10.1:1 CR, and I am running Dart Conquest aluminum heads with 1.6 E/ 2.05 I valves. Rocker ration is 1.5 and the whole valve train is hydraulic roller. I think (But can't remember for sure) that the rods are 5.7.... other than that info and the specs I provided above on the cam, I know nothing..... Hell I was originally told by the builder that my cam was a one-off (Or maybe I heard him say something else and got confused, but last night I found the print out sheet that came with the cam and was on-line on ISKY's site searching for a cam that matched what was on my sheet and the above listed cam was it... I'll do some more checking in my paper work when I get home, but Ron seems to think that my cam might be to high of a duration for this FI combo... Maximum RPM will be 6500.... Mike [ June 08, 2001: Message edited by: Mikelly ] [ June 08, 2001: Message edited by: Mikelly ] Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted June 8, 2001 Share Posted June 8, 2001 I think the T56 OD numbers (depending on the year of the T56) are more like 5th=.74 and 6th=.5 With a 3.90 rear @ 6000 rpm's I think it will top out at like 235 mph if it'll pull it (wind resistance, parasitic loses, temperatures, grades of the road, all a factor of course). That is with 245/45 profile tires @17" and I know Mikes running wider than that. Run it back through with those OD numbers Kevin and see if I'm close, I just did it quickly on the HybredZ main page using that transmission/rearend java program . Regards, Lone [ June 08, 2001: Message edited by: lonehdrider ] Quote Link to comment Share on other sites More sharing options...
Kevin Shasteen Posted June 8, 2001 Share Posted June 8, 2001 Mike, Which T-56 trans do you have? I forgot you swapped wheels/tires; which size tires are you going with...I went with the tires you had previously forgetting your most recent swap. I also thought you had 3.7 rear gears; did that change or am I just losing it (wouldnt be the first time)? So: 1) Which T-56 do you have? 2) What is your tire size? 3) Which rear gears are you running? Kevin, (Yea,Still an Inliner) Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted June 9, 2001 Share Posted June 9, 2001 I thought he had like a 95' T56 from a firebird as I recall, which should be the lower (numerically) OD gears. The '93 as I recall is the one with a final drive I thought of like .62 for 6th, that one also has reduced torque capabilities (rated at like 400 ft/lbs or something). Your probably right about his rear end ratio, I thought it was 3.90, but now that you mention it, he posted that recently as I recall in one of the forums. I know if thats the case, 200 mph shouldn't be a problem for his set up. Its a long race though not sure what the 'average' speed would be since you have to navigate the 'narrows' (a series of curves in one section which will slow you down) which will be considerably slower and of course trying to not overheat it in the fast section. Should be a challenge for sure. Regards, Lone [ June 08, 2001: Message edited by: lonehdrider ] Quote Link to comment Share on other sites More sharing options...
Kevin Shasteen Posted June 9, 2001 Share Posted June 9, 2001 Mike, Not knowing the exact * (Degrees) ABDC where the Intake Closes nor the Area (Sq.In.) of the Cylinder Head's Intake Port Opening will force us to guess; but not all is lost....going w/current known cam's & cyl.heads we can make a pretty good "Edumacated Guess" & get you in the ball park. Keep in mind-I'm not that Fuel Injected savvy but I have read up on airflow regarding the cyl.head & their required comp.ratio's w/a given choice of camshaft. What I'll do is list three possibilities of a cam's Intake Closing-that being 50*, 60* & 70* ABDC...then give you what compression you will need to run that engine on Pump Gas/Race Gas. The cylinder head issue; well all Dart's Website offered were the Iron Eagle, Pro1 & the 220 heads.....I went w/the Pro1 as it had the 2.05 intake valve & was an alluminum cyl.head; it offered three intake port flow spec's: 200cc, 215cc, 230cc. I went w/the 215 & 230cc heads. These are the knowns: 383 V8 Bore x Stroke = 4.030 x 3.75 265/50/15 Tires = 25.4" Diameter 3.7 Rear gears 6spd trans: 1st = 2.97 2nd = 2.07 3rd = 1.43 4th = 1.00 5th = .80 6th = .62 Cylinder Head's Potential Peak Power 1) 215cc = 462.79 2) 230cc = 495.08 *This figure's is determined by the camshaft you have chosen (Hydraulic Roller) & the port volume it flows. Cylinder Head's Potential Maximum Peak Power/RPM 1) Intake Port Area 1.9 sq.in. = 5744rpms 2) Intake Port Area 1.99 sq.in. = 6017rpms 3) Intake Port Area 2.05 sq.in. = 6197rpms 3) Intake Port Area 2.13 sq.in. = 6439rpms 4) Intake Port Area 2.18 sq.in. = 6591rpms 5) Intake Port Area 2.20 sq.in. = 6651rpms *This figure was determined by the area of the cyl.head's port entrance multiplied by a conversion factor of camshaft choice another cnoversion factor determined by the Displacement of the engine. Compression Ratio Required if Intake Closes at 50*, 60* or 70* ABDC: 50* ABDC Pump Gas = 9.6:1 Race Gas = 10.2:1 60* ABDC Pump Gas = 10.2:1 Race Gas = 10.8:1 70* ABDC Pump Gas = 11.0:1 Race Gas = 11.75:1 I think from these numbers & the fact that you've ran your 1/4 mile in the past w/larger tires & shifting at 6300rpms that a safe cruise speed would be @ 6000rpms; I dont know how long you can continue that cruise speed (but we are just theorizing here). T-56 6spd Trans & 3.7 rear gears 3rd= 1.43 x 3.7= 5.291 @ 6000rpms= 85.72mph 4th= 1.00 x 3.7= 3.7 @ 6000rpms = 122.59mph 5th= .80 x 3.7= 2.96 @ 6000rpms =153.23mph 6th= .62 x 3.7= 2.294 @6000rpms =197.72mph I purposely figured about 300-500rpms on the low side; so you theoretically may hit that 200mph. It all depends on what the Intake Closing ABDC is & what the Area (Sq.In) of your Cylinder Head's Intake Port Entrance equals. Once you've determined what the unknown variable are-you should be able to come up w/some absolute answers....Ala-no more guessing (theoretically speaking-of course)! Hope this helped & not confused. Kevin, (Yea,Still an Inliner) [ June 08, 2001: Message edited by: Kevin Shasteen ] Quote Link to comment Share on other sites More sharing options...
Kevin Shasteen Posted June 9, 2001 Share Posted June 9, 2001 Lone; I think you're correct on his trans; do you know what his tire size is (his most recent swap and are those the tires he gonna be racing with? I'm pretty sure on his rear gears being 3.7. Kevin, (Yea,Still an Inliner) [ June 09, 2001: Message edited by: Kevin Shasteen ] Quote Link to comment Share on other sites More sharing options...
Mikelly Posted June 11, 2001 Author Share Posted June 11, 2001 Sorry guys....Been busy as hell... The tires are 275-40-17 on the rear and are 25.75 tall and I'm running a 3:7 and the 95 Ta T56 trans with the .50 6th gear. Kevin, you are one hell of a number cruncher... Mike Quote Link to comment Share on other sites More sharing options...
Kevin Shasteen Posted June 11, 2001 Share Posted June 11, 2001 Mike, Ready for the new numbers? I confirmed the trans gears from my "Camaro Bolt on Perf.Guide" Copywrite date 1999-should be current (hope Lone lets me get by w/these numbers; haha). 1994+ T-56 1st = 2.66 2nd = 1.78 3rd = 1.30 x 3.7 = 4.81 @ 6k = 95.26mph 4th = 1.00 x 3.7 = 3.70 @ 6k = 124.27mph 5th = .74 x 3.7 = 2.74 @ 6k = 167.94mph 6th = .5 x 3.7 = 1.85 @ 6k = 248.55mph *NOTE: In 6th gear you only need 4850rpm's to reach your 200mph goal w/your 25.77" tires. Good Luck & Hope you reach your objective! Remember to confirm what your cyl'head's intake port opening area (sqare inches) are-this will help you confirm which camshaft is best for your chosen compression. Remember, the area you need to measure is not the immedieat opening-but just inside the port opening exactly adjacent to where the push rods are coming thru the heads-as this is where the cyl.head's biggest restriction is & its that restriction that determines what your cyl.head's peak power (airflow) will be. Mike; have you thought about mounting a Cam Corder in your car somehow, so you can catch all the action during your racing? Kevin, (Yea,Still an Inliner) [ June 10, 2001: Message edited by: Kevin Shasteen ] Quote Link to comment Share on other sites More sharing options...
DavyZ Posted June 11, 2001 Share Posted June 11, 2001 Hrm, a theoretical 248mph? Mike, I'd say even barring wind resistance, you have one heck of a fast car David Quote Link to comment Share on other sites More sharing options...
BLKMGK Posted June 11, 2001 Share Posted June 11, 2001 Heh, now take the info we have on the Z's aero - or lack thereof - and see what sort of HP it takes to push 200+mph. Drag goes up exponentially and pushing a .5 OD at speed it tough to say the least. The torque load on the trans is incredible and most cars end up seeing faster numbers in a non-overdriven gear. 124mph seems awful low for 4th though - is a 3.7 really that steep? Must be these short tires we run Quote Link to comment Share on other sites More sharing options...
Mikelly Posted June 11, 2001 Author Share Posted June 11, 2001 Well I'm working on that as well... A G-nose like front end (Maybe not Exactly a G-nose, but a varient of it), headlight covers, and chin splitter/ bellypans will aid in that fight to cheat the wind. Also account for lowering the car sufficiantly to allow it to get as close to the gorund as reaonably possible... Mike Quote Link to comment Share on other sites More sharing options...
Kevin Shasteen Posted June 12, 2001 Share Posted June 12, 2001 I remember reading some report on the Viper when they first came out; the driver was attempting to hit the 200mph max...some mild perf.mod's had been done. I dont actually remember the outcome (its been too long ago) but what I do remember is that the Viper actually lost "MPH" speed when they shifted to 6th gear due to the drag at high speed; had to downshift back to 5th to get his speed up! What does all this mean...Ownt Know(?)! Just thought I'ld throw it out at ya just to be aware of drag & the importance of overcoming it. Got my fingers crossed as I'm sure everyone on this board does; hoping Mike hits his objective! Good Luck Dudeman! Kevin, (Yea,Still an Inliner) Quote Link to comment Share on other sites More sharing options...
Scottie-GNZ Posted June 12, 2001 Share Posted June 12, 2001 There is certainly a lot of drag at those speeds, but I think what happened to the Viper, even with its huge displacement, is that the overall ratio of 6th was so high, it caused the engine to fall below the torque curve. Quote Link to comment Share on other sites More sharing options...
BLKMGK Posted June 12, 2001 Share Posted June 12, 2001 Yes, Scottie that is exactly what occured. I can't help but wonder too what the torque rating of the T56 is in 5th and 6th gears. I know some of the transmissions out there have very weak OD ratings - the stress could kill it. Never NOS a T5 in 5th BTW Quote Link to comment Share on other sites More sharing options...
randy 77zt Posted June 12, 2001 Share Posted June 12, 2001 most of the big v8 cars in open road races like silver state classic run 4 spds and 2.3 rear gears.most transmissions the od gears cant take the abuse.4th gear is 1 to1 on most trans-no load is sent through counter shaft gear cluster-so there is no load on trans.plus depending on length there is a maximum shaft speed for drive shaft but on a z the drive shaft is so short it probably doesnt matter.with a t56 in a v8 z top speed will probably be hit in 5th because of wind drag.most od gears are in tail shaft housing with reverse but i havent rebuilt a t56 so i dont know how they are layed out. Quote Link to comment Share on other sites More sharing options...
Mikelly Posted June 12, 2001 Author Share Posted June 12, 2001 This is all good info... If I can't get the responses I'm looking for from the Henesssey Camp on T56 durability and open road racing, I'll contact Lingenfelter. If need be, I'll sell the T56 and buy a Richmond... Bottom line is this: I'm getting to 200MPH or taking flight trying. I appreciate the info you guys are generating on this. With the control arms, day to day life, and trying to keep some semblance of fitness, it is hard thinking everything through. I consider you guys my technical "Advance Team"! Keep the discussions and questions coming. Mike Quote Link to comment Share on other sites More sharing options...
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