Guest Anonymous Posted December 21, 2001 Share Posted December 21, 2001 Well needless to say I am impressed but also highly skeptical of my #'s. They were run through a Desktop Dyno 2000. Now I know that there are a ton of things that can skew the #'s like barometer, elevation, etc... Pete is already going to go home and run some #'s also. For those interested here is the most accurate guess work on my combo: Vic. Jr. manifold, Ported L98 corvette heads, 175cc runners, 230 cfm @26.HG(EDUCATED GUESS), 56 cc combustion chambers, 1.94 intake valve, 1.50 ex. valve. The port work included lots of velocity enhancing tricks like short side radiusing, floor dropping, smoothing, and bowl blending. The pistons are forged Lunati with a comp. ratio of 10:3.1 with my chamber size. The rods are Lunati Pro Mod 6.125" long connecting rods (640 grams) with a 3.25" stroke steel crank. The bore size will be 4.030". The cam #'s are as fallows: 242@.050" duration intake, 250@.050 duration exhaust. The lift is .510 in, .530 ex. The lobe seperation angle is on a 110. The cam is a solid lifter Comp Cams custom grind. Those #'s are with a 1.5" rocker whereas I will be using a Comp Cams Stainless 1.6" rockers. I will be using S&S full length 1 and 3/4" headers and a Demon 750+ cfm double pumper carb. Using these #'s my buddy came up with some really high #s. They are as fallows: 2000rpm: 123hp, 323 tq. 2500rpm: 163hp, 342tq. 3000rpm: 205hp. 358 tq. 3500rpm: 260hp. 390tq. 4000rpm: 319hp. 419tq. 4500rpm: 379hp. 442tq. 5000rpm: 429hp. 450tq. 5500rpm: 469hp.* 448tq.* 6000rpm: 495hp.* 433tq.* 6500rpm: 513hp. 415tq. 7000rpm: 506hp. 380tq. 7500rpm: 495hp. 347tq. 8000rpm: 464hp. 305tq. 8500rpm: 435hp. 269tq. *= volumetric efficiency is 97.3% at this rpm Like I said these #'s seem high for such a small motor. The rpm band is really where I like it in the 2500 to 7500 range with a viable street curve. The motor won't actually see anything higher than 7500 rpm in the real world. Give me some feed back on what you guys think(Grumpyvette). If I could squeeze a real 425hp@7200 and make 300lbs. at 2000rpm with a peak of 385 in the 4500-5800 range I would be very satisfied. Let me know what you guys think! Quote Link to comment Share on other sites More sharing options...
z ya Posted December 21, 2001 Share Posted December 21, 2001 Sounds sweet Jason! My motor on Grumpys computer dyno only put out 386 hp/396 torque. Go for man sounds like it should rip! My z is just about done . All thats left is getting the exhuast installed and putting in the shifter. I will let ya know how it goes when it done. Good luck, Ron Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted December 21, 2001 Share Posted December 21, 2001 Well let's get that rowing stick in there and go for a ride with the headers uncapped! One of your first cruise destinations will have to be a Sunday drive to Discovery Bay to take me for a spin! My brother still hasn't been for a ride in a V8 Z! Maybe you could change that! Fill me in as soon as you are up and rolling and I'll even come out and see you!! Have a great holiday!!! Quote Link to comment Share on other sites More sharing options...
MYRON Posted December 21, 2001 Share Posted December 21, 2001 Hey, I havnt run my DD2000 in a while but my 355CI with 2.05/1.60 dart heads with 215cc runners and 64cc chambers(10.21CR)gasket matched to a Brodix HV1 pro bracket intake that was also plenum ported with an 830cfm(750base/850body)HP4150 carb and a solid roller setup .554 int/.567ex and 1.65 roller rockers which adds something like .030 to total lift on both making around .585 and .596 max lift... DD2000 claimed 464HP and 434TQ.. then I ran the car with a Gtech pro and it claimed 386 RWHP and 0-60 in 4.5 sec and 1/4 mile 12.24 at 117... it also cut a 1.79 60 foot but the diff blew when I hit 2nd so i never really got to dial it in... Hope this helps... Myron Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted December 22, 2001 Share Posted December 22, 2001 Thanks Myron! I really believe that my numbers are anywhere between 50 to 100 hp too high. Boy would it be cool if they weren't! Too bad my t-5 won't last long behind it! Looks like Pete is gonna have to get me a T3550 to handle the torque! Your motor sounds like a differential eating beast also! Thanks for the reply and good luck with the rear end! Quote Link to comment Share on other sites More sharing options...
Mike C Posted December 22, 2001 Share Posted December 22, 2001 Your "real world" guess of around 425hp seems reasonable, but, I don't believe even a heavily worked set of L98 heads would be anywhere near 500hp. Especially with the 1.94 valves still. Seems like a pretty good combo all and all. The short stroke and 7000+ rpm capability should bode well for reaching the 400hp mark. For my $, the super broad rpm range makes the car MUCH more fun to drive. Can't wait to see what the chassis dyno says! Quote Link to comment Share on other sites More sharing options...
grumpyvette Posted December 22, 2001 Share Posted December 22, 2001 440hp/ 410ftlbs is what my computer says with that new data, let us know what you get on a dyno, (remember that is flywheel #s so the dyno should read about 369hp at the rear wheels)BTW that should be good for a 11.7et at 116mph Quote Link to comment Share on other sites More sharing options...
pparaska Posted December 22, 2001 Share Posted December 22, 2001 Jason, I used the cam lobe specs from Comp Cams for the 280-1 and 285-1 lobes: http://www.compcams.com/catalog/232.html and flow numbers for ported L98s from here: http://personal.mia.bellsouth.net/clt/m/g/mgervin/chp/flowchrt.htm I ran this with your setup and large tube headers through mufflers in DD2000 and got: 441 hp @ 6500 421 lbft @ 4500 Very close to Grumpy's numbers. I agree with Mike C. Those heads even with the best porting probably will be very hard to get past 450hp. Not to be concerned, I'd think - that's still going to be fun in a light little 240Z! Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted December 22, 2001 Share Posted December 22, 2001 So Pete, Grumpy, how much more power would his engine put out if it had a set of pocket ported 23 degree TFS heads or Canfields? Quote Link to comment Share on other sites More sharing options...
pparaska Posted December 22, 2001 Share Posted December 22, 2001 Using CHP's numbers: http://www.chevyhiperformance.com/editorial/article_popup.jsp?id=42119 469 hp @ 6500 433 ft lb @ 5000 I think it's cam limited (lift mostly) at this point. The heads flow better at large lifts (lower lifts also) and you need more duration and lift to get the power up. But then how streetable will it be? I ran the 12-679-4 290/296adv 252/260@.050 .540/.558" solid extreme flat tapet cam on this engine (with Canfields) and it put out 480 hp @6500 426 ft lb @5000 It still had 304 ft lbs at 3000, 281 ft lbs at 2500. I'd be concerned about streetability. I'd imagine with a cam with that duration and LSA, the idle vacuum would be below 10 psi. Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted December 22, 2001 Share Posted December 22, 2001 Wow, that's pretty disappointing. So for a cam with between 220-230 degrees of duration, ~0.520" of lift, and 112* LSA (what I'm thinking of running) the difference between ported L98s and TFS/Canfield/AFR heads shouldn't be more than 20bhp then. Is this a valid conclusion? Does DD2000 take into account the increased port volume of these heads when calculating the power curve? The Edelbrock RPMs look like decent heads, they don't flow as well but they are 170cc vs 195-200cc. Would that be a better choice for a 6500-7000rpm 327, or should I stick with the bigger ports? Quote Link to comment Share on other sites More sharing options...
grumpyvette Posted December 22, 2001 Share Posted December 22, 2001 Hydra I have run both those heads on my vette (L98 aluminum and TRICKFLOW ) and I think the L98 heads are OVER RATED and the TRICKFLOW heads are UNDER RATED as far as the power that DD-2000 shows they make) and don,t get so impressed with hp numbers what you should be doing is trying to get that car to run low 11 second ET 1/4 mile times, any faster than that and you won,t be able to reliably drive it on the street and any slower than about 12.8 ET 1/4 mile times and you won,t be able to kick A$$ on the street! so someware in that area is what you should be trying for and hp is some what meaningless as anything over 350 at the rear wheels will get you low 11s Quote Link to comment Share on other sites More sharing options...
Mike C Posted December 23, 2001 Share Posted December 23, 2001 I don't see any reason you can't do all of those things. I drive my Camaro to the track (65 miles each way) and run 12.7's at 110. And it is at LEAST 1000# heavier than a sb z. As far as aftermarket vs. stock cylinder heads, If you look at David Vizards book "How to build and modify small block chevy cylinder heads",his worked set of 186 castings flow 260+ cfm at .500 lift. This is as good as most of the aftermarket aluminum heads, and the low lift flow is better in a large number of the cases. A well worked set of GM castings can be as good as most aftermarket heads, at least with standard port locations and valve angles. Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted December 23, 2001 Share Posted December 23, 2001 Thank ou gentlemen for your insight. All I have to say is that you guys reconfirmed my original goals will be met and a little more with my little "baby motor" project. If it comes up with 370hp at the wheels and has the capability to go 11.70's at 116 I would be very pleased. I would really like to drive to the track and put up 12.30's at 116 on daily driver Z rated rubber. I do agree that the heads are the weak point but they make great torque over a wide range and I already own them.(key point) They used to make 430hp@6100 AND 440tq.@4100 on a Stock shortblock and cam ZZ4 and at peak hp it was at 101+ efficiency. When the little bugger is in and running it will have to make it to the chassis dyno to squeeze the max out of the combo... Thank you guys again and merry Xmas! Quote Link to comment Share on other sites More sharing options...
DavyZ Posted December 24, 2001 Share Posted December 24, 2001 Jason, if your combo is really good for an 11 second Z, well that's just sick I tell you. Feel free to send me those pathetic heads...anytime I get the FIRST RIDE!!! Shoudl be fun too! Call me when you get the motor in; I'd love to come take a look at it. Merry Christmas to you too! Davy Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted December 24, 2001 Share Posted December 24, 2001 Well Davy you know that I have a seat saved for ya! I really enjoy throwing my cars around for ya, and I promise this time to belt you in!! Merry Xmas to ya all!! Quote Link to comment Share on other sites More sharing options...
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