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#81
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That’s great, yes it does!
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Wernher Von Braun warned before his retirement from NASA back in 1972, that the next world war would be against the ETs! And he was not talking about 1/8 or 1/4 mile ETs! 1) 1940s 100% silver 4 cup tea server set. Two dry rotted 14 x 10 Micky Thompson slicks. 1) un-mailed in gift coupon from a 1972 box of corn flakes. Two pairs of brown leather flip flops, never seen more then 2 mph. Education is what your left with once you forget things! |
The Following User Says Thank You to steve25 For This Useful Post: | ||
#82
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Cliff, please explain if you don't mind... I've researched the camshaft for this combination for days and nights for the last two weeks. In the end I learned that the Comp XE camshafts are hated by most, liked by a few, and I would likely never choose one of those. I have also learned that for a hydraulic flat tappet application, the Lunati VooDoo and the Crower camshafts are the two front runners, atleast for shelf camshafts, in builds like this. I have also learned that even though the VooDoo appears on paper to be a short seat duration camshaft, it really is not as short as one would believe, do to the lift at which it is rated. I read over on the Chevelle forum where Harold was talking about his VooDoo designs, and said that those Seat Durations were measured at .007- .0078", so that it would appear smaller on paper. I would think this would make the VooDoo 704 up towards the mid 280's for seat duration if it were measured at .006" like most are. I have read the opposite is true for the Crower camshafts, some say they are measured at .0045", so that makes them appear to have more seat duration on paper when compared to most camshafts that are rates at .006", having said that, I know the Crower would still probably have more seat duration than the 704 Lunati, if measure at the same lift, but then you start thinking about Jim Hands engine, and how well it ran with that Wolverine camshaft. I believe it only had around 285 seat duration. I have used the Crower camshafts in the past as well with great results, but I just wanted to try something different this time around, and I thought the 704 would work great for this application, according to the results that other people have had with similar combinations using the 704. The Lobe Seperation is indeed narrower, 110° vs 112+, but most agree that with the way Harold designed these camshafts, with the Lobe Offset from the centerline of the camshaft core, and the opening ramp vs closing ramp differences, they still produce the powerband of a wider lobe seperation camshaft. Now, with all of this being said, I have never had experiance with a VooDoo camshaft, I'm just going off of all of the research that I have done. Now you have me second guessing myself on my camshaft pick Cliff. LOL
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1978 Trans Am Pump Gas 461 Stroker |
#83
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Not a lot to explain, but CYLINDER PRESSURE is controlled by the camshaft. How much and when it occurs. The cam compliments the CID and static compression ratio and should be chosen accordingly.
Cams with tighter LSA narrow up power and higher peak torque. I think it was mentioned at least once on this thread that they will make "more power". I agree, peak numbers anyhow, and that fact RAISES cylinder pressure and makes peak number occur at lower RPM's. Just something to keep in mind choosing camshafts. Short seat timing, tighter LSA, earlier ICL (closing the intake sooner), lobes with improved cylinder filling qualities, etc basically improve VE and make the engine more efficient a bit earlier in the RPM range. Folks look at ALL that stuff with a "static" mind, not "dynamic". You can take a lower compression engine and very quickly make it act like a much higher compression engine. Case in point. I've had half dozen 455's here to date with relatively "low" compression ratios that ping HARD on pump gas with "normal" timing/fuel curves. Common denominator in all of them were short seat timing cams on tight LSA's. The worst of the bunch were the two that used the Comp XR276HR cam followed very closely by one using an XE268 flat cam in it. One was 9.5 to 1 the other about 9.3. I could NOT figure it out at first, but kept pulling out timing and adding fuel. Never really cured either one of them, but learned from it. Then jump ahead about 15 years and I get a call from a custom who bought a custom carb kit with tuning parts. He's on the dyno and his "fresh" 455 topped with professionally ported #96 heads (250cfm), 9.3 compression, etc is pinging hard and they haven't put a lot of timing to it yet. They ended up spinning the rod bearings on the dyno. I suggested a cam swap instead of continuing to blame the carburetor (happens a lot from folks unfamiliar with them when Q-jets are asked to support big power levels). The dyno charts are below. Combo #1 didn't make chit for power anyhow, and had a "quirky" idle quality the engine builder didn't much like. He noted that the second camshaft idled better with not much more than a "deep/heavy" sound and nearly smooth. Of course this happened because he was able to run more timing, at idle and total as well, plus the engine was just overall a LOT happier with it anyhow, which is pretty obvious by the dyno results........
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If you can read this, thank a teacher. If you can read this in English, thank a Veteran! https://cliffshighperformance.com/ 73 Ventura, SOLD 455, 3740lbs, 11.30's at 120mph, 1977 Pontiac Q-jet, HO intake, HEI, 10" converter, 3.42 gears, DOT's, 7.20's at 96mph and still WAY under the roll bar rule. Best ET to date 7.18 at 97MPH (1/8th mile), |
#84
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Quote:
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1978 Trans Am Pump Gas 461 Stroker |
#85
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Quote:
Stan
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Stan Weiss/World Wide Enterprises Offering Performance Software Since 1987 http://www.magneticlynx.com/carfor/carfor.htm David Vizard & Stan Weiss' IOP / Flow / Induction Optimization - Cam Selection Software http://www.magneticlynx.com/DV Download FREE 14 Trial IOP / Flow Software http://www.magneticlynx.com/DV/Flow_..._Day_Trial.php Pontiac Pump Gas List http://www.magneticlynx.com/carfor/pont_gas.htm Using PMD Block and Heads List http://www.magneticlynx.com/carfor/pont_pmd.htm |
The Following User Says Thank You to Stan Weiss For This Useful Post: | ||
#86
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I have no direct experience with that Lunati cam in a 455 Pontiac build but suspect you'll be OK with it, at least as far as managing pump fuel at that compression. It will also "feel" strong, as tight LSA cams tend to really punch a lot of power into the mid-range, further exploiting what Pontiac 455's do very well right to start with.
I've ran all sorts of cams in 455's, went tighter LSA a few times and not overly impressed with them so tend to go the other direction these days with longer seat timing. Even with that said the most impressive cams I've used in them were really tight LSA IF you were only evaluating them "by the seat of your pants". The best word I can use is "explosive" power when you go to full throttle. To date the best of the tight LSA cams I've tried was the Crower 60913. It specs at 308/314, 248/256@.050", 108LSA. Talk about BRUTAL mid-range power. Whack a decent 455 build hard with that cam in it and you'll have to go back and look for your hat, glasses, drivers and passengers side doors and EVERYTHING that was on the dash will be up in the back window!!! As good as it sounds at the track it never produced the numbers we were looking for. Typically low 12's around 112mph for most runs. We replaced that cam with one of Dave's "Road Pavers" and a set of his #62 iron heads. The new combo is strong for sure, but power is "flat", somewhat boring as it just pulls really hard everyplace, no "rush of power anyplace. The car with no other changes has went bottom 11's over 118mph.........so once again NEVER evaluate the performance of the vehicle with a "butt meter"!.....LOL.....
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If you can read this, thank a teacher. If you can read this in English, thank a Veteran! https://cliffshighperformance.com/ 73 Ventura, SOLD 455, 3740lbs, 11.30's at 120mph, 1977 Pontiac Q-jet, HO intake, HEI, 10" converter, 3.42 gears, DOT's, 7.20's at 96mph and still WAY under the roll bar rule. Best ET to date 7.18 at 97MPH (1/8th mile), |
The Following User Says Thank You to Cliff R For This Useful Post: | ||
#87
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Quote:
IRC, the Wolverine cam Jim Hand initially ran had more seat timing than the Lunati 704. Closer to 290intake and 300 on the exhaust. I do not remember the numbers exactly. But Stan Weiss probably has the file becuase the exhaust profile from the SUMMIT 2802 cam is the profile used on INTAKE profile of that Wolverine cam. Basically summit has the 2800, 2801, 2802, well if Summit had one cam bigger in that cam family called Summit 2803, it would be the same as the Wolverine cam Hand used. Hand initially used that Wolverine cam, then I think he tried a custom Bullet 285* version in his car with the same .050” durations. As far as I know the Bullet cam was the quickest of all the cams he tried, I think that Wolverine was 2nd. The Bullet cam should have had similar characteristics to the Lunati Voodoo, very similar to the 112 LSA Bullet versions I mentioned earlier in the thread. 4 speed cars often run narrower LSA’s to match up the gear changes better and make them faster. Although with the big crank it may end being more than the st10 is up for. Lol Last edited by Jay S; 03-21-2021 at 08:05 PM. Reason: Err |
The Following User Says Thank You to Jay S For This Useful Post: | ||
#88
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This what I have for the 2802 exhaust lobe. The duration and area are what they are. The opening and closing numbers will change based on what CL is.
Stan CAM______Lift______Opens___Closes__Duration _________________Deg_BBDC__Deg_ATDC_____________Ar ea _________0.00600____79.00_|__35.00_|_294.00_|__26. 59 _________0.01000____74.31_|__29.34_|_283.65_|__26. 55 _________0.02000____66.29_|__19.77_|_266.06_|__26. 42 _________0.04000____55.93_|___7.59_|_243.51_|__26. 08 _________0.05000____52.00_|___3.00_|_235.00_|__25. 92 _________0.10000____36.00_|_-14.00_|_202.00_|__24.73 _________0.15000____19.50_|_-27.50_|_172.00_|__22.81 _________0.20000_____4.50_|_-42.50_|_142.00_|__20.18 _________0.25000___-12.00_|_-59.50_|_108.50_|__16.46 _________0.30000___-33.93_|_-81.68_|__64.39_|__10.39
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Stan Weiss/World Wide Enterprises Offering Performance Software Since 1987 http://www.magneticlynx.com/carfor/carfor.htm David Vizard & Stan Weiss' IOP / Flow / Induction Optimization - Cam Selection Software http://www.magneticlynx.com/DV Download FREE 14 Trial IOP / Flow Software http://www.magneticlynx.com/DV/Flow_..._Day_Trial.php Pontiac Pump Gas List http://www.magneticlynx.com/carfor/pont_gas.htm Using PMD Block and Heads List http://www.magneticlynx.com/carfor/pont_pmd.htm |
The Following User Says Thank You to Stan Weiss For This Useful Post: | ||
#89
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Do you have a link for your previous build ?
PM sent |
#90
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1978 Trans Am Pump Gas 461 Stroker |
#91
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Previous build? Which one John?
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1978 Trans Am Pump Gas 461 Stroker |
#92
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Just an update.... We have now recieved the 704 Camshaft, the Rotating Assmebly from Butler shipped yesterday, so we should have it Tuesday, and then off to the machine shop to get the Block bored and decked. I had Butler polish the rear journal where the seal rides on the new crank as well, so that we don't have any problems with the Viton seal and Serrations, I figured its better to be on the safe side in that area. We also picked up a new Ram 1557 Flywheel that should be here next week as well.
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1978 Trans Am Pump Gas 461 Stroker Last edited by TransAm 474; 03-27-2021 at 12:32 PM. |
#93
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Another Update here guys.... we got it together, installed, and broken in now! Everything seems to be going great so far, atleast in the shop, we haven't driven it yet. We had SMI do the 800cfm qjet for it, and Cliff recurve the distributor.
Just a little refresh of the build, 1979 Trans Am Numbers matching W72 PWH 400 Butler 467 stroker kit 4.181" Bore Eagle 4.250" Crank Eagle 6.800" H-Beam rods Ross Flat Top 8cc 2VR Total Seal Classic rings Melling M54DS pump with .062" shim added in cap Zero Decked .039" quench using 1016 Felpro head gaskets Stock(unported) 6X4 heads with 96cc chamber Ferrea valves, Crower 68404 spring set up at 1.550" I.H. 9.37-1 compression Stock iron Intake SMI 800cfm Quadrajet 76 Jet/46K Pri Rods, DA Sec Rods Lunati VooDoo 704 Camshaft 281/289@.006" Advertised Duration 233/241 Dur@.050" .504"/.527" Lift 110° Lobe Separation Installed at 103° Intake Centerline Crower Cam Saver Lifters Factory stamped rockers with 7/16" studs and poly locks Butler 9.200" .116" Wall Pushrods Hooker 1 3/4" Super Comp headers Factory distributor recurved by Cliff Ruggles Powermaster XS 9510 Starter Super T-10 4-Speed manual transmission 3.23 gears Timing is set at 14° Initial and has 30° at 3200 RPM, Cliff said it will probably gain another couple degrees beyond 3200, so he recommended leaving it there for now. We are at about 1100 ft. Elevation, and the engine makes right at 14" of vacuum at 840 Idle RPM. It has a little racy rumble, but it's really fairly mild, in fact, more mild than I expected, but should work great for a street car. The car seems to fire off immediately. It has an electric choke, so give it a couple good pumps and it fires at the hit of the key, and gets right up to fast idle until it warms. Hot starts are immediate as well. Throttle response seems to be fantastic so far, I have the mixture screws at 2.5 turns out, which is where Sean Murphy at SMI already had them set by default, and it seems to like that best. I'll report back with a performance update after it is driven to see how it runs.
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1978 Trans Am Pump Gas 461 Stroker Last edited by TransAm 474; 10-16-2021 at 01:33 AM. |
The Following User Says Thank You to TransAm 474 For This Useful Post: | ||
#94
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Sounds great!
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Skip Fix 1978 Trans Am original owner 10.99 @ 124 pump gas 455 E heads, NO Bird ever! 1981 Black SE Trans Am stockish 6X 400ci, turbo 301 on a stand 1965 GTO 4 barrel 3 speed project 2004 GTO Pulse Red stock motor computer tune 13.43@103.4 1964 Impala SS 409/470ci 600 HP stroker project 1979 Camaro IAII Edelbrock head 500" 695 HP 10.33@132 3595lbs |
The Following User Says Thank You to Skip Fix For This Useful Post: | ||
#95
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Hey, what did the power from this W72 come out as? I am now building almost the same PWH engine, keeping a lot of the same stock components as yours, but planning on porting those heads, and I've got a Doug Nash 4+1 instead of the Borg Warner Super T-10 going to the 3.23 in the back.
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