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Old 03-21-2021, 09:39 AM
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That’s great, yes it does!

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  #82  
Old 03-21-2021, 09:43 AM
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Quote:
Originally Posted by Cliff R View Post
Steve, the real "oversight" is not factoring the camshaft into the equation, not missing 1.5 CC's during their calculations during the planning stages.....FWIW......
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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  #83  
Old 03-21-2021, 10:55 AM
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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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  #84  
Old 03-21-2021, 11:58 AM
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Quote:
Originally Posted by Cliff R View Post
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........
Thanks Cliff, I appreciate it, and I understand completley. Wouldn't you agree that both the XR276HR and XE268 both are quite a bit smaller camshafts than the 704 Lunati? Especially when you consider that the Comp cams are measured at .006" vs the Lunati .007-.0078", which would make the Lunati quite a bit bigger in reality, if it was compared at .006". Also the 10° difference at .050" 224/230 of the XR276HR vs 233/241 of the 704 Lunati? I know the 704 does have the narrower lobe seperation, and has been said to supposedly act much more like the wider lobe seperation camshafts in reality, due to the lobe offset and design. I believe the Voodoo closes the Intake valve at around 64°, atleast according to the 276/281 on the Cam Card, but that number would be skewed, if the Voodoo Seat Duration is indeed actually measured up at .007-.0078" instead of .006". That would actually make it close a little later than is published. The card shows it closes the Intake Valve at 42.5°@ 050" I believe. Again, I'm trying to learn here LOL

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  #85  
Old 03-21-2021, 01:12 PM
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Quote:
Originally Posted by TransAm 474 View Post
Thanks Cliff, I appreciate it, and I understand completley. Wouldn't you agree that both the XR276HR and XE268 both are quite a bit smaller camshafts than the 704 Lunati? Especially when you consider that the Comp cams are measured at .006" vs the Lunati .007-.0078", which would make the Lunati quite a bit bigger in reality, if it was compared at .006". Also the 10° difference at .050" 224/230 of the XR276HR vs 233/241 of the 704 Lunati? I know the 704 does have the narrower lobe seperation, and has been said to supposedly act much more like the wider lobe seperation camshafts in reality, due to the lobe offset and design. I believe the Voodoo closes the Intake valve at around 64°, atleast according to the 276/281 on the Cam Card, but that number would be skewed, if the Voodoo Seat Duration is indeed actually measured up at .007-.0078" instead of .006". That would actually make it close a little later than is published. The card shows it closes the Intake Valve at 42.5°@ 050" I believe. Again, I'm trying to learn here LOL
A 233 0.050" degree duration @ 106 ICL is 10.5 / 42.5

Stan

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  #86  
Old 03-21-2021, 01:39 PM
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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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  #87  
Old 03-21-2021, 07:43 PM
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Quote:
Originally Posted by TransAm 474 View Post
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.
For clarification: On the CAM CARD that comes with the 704 Lunati should say it has “Advertised duration” and list 281 intake 289 exhaust. That is the .006” tappet ratings. Unless they make a change to the card, that 281,289 is what it was last year and in pasts years.

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
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Old 03-21-2021, 08:03 PM
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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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Old 03-21-2021, 09:33 PM
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Do you have a link for your previous build ?

PM sent

  #90  
Old 03-21-2021, 09:51 PM
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Quote:
Originally Posted by Jay S View Post
For clarification: On the CAM CARD that comes with the 704 Lunati should say it has “Advertised duration” and list 281 intake 289 exhaust. That is the .006” tappet ratings. Unless they make a change to the card, that 281,289 is what it was last year and in pasts years.
Thanks for the clarification Jay. I haven't recieved the camshaft yet as I just ordered it a few days ago, so I haven't got a card to look at yet Lol. I sure hope it works out great for this build, it seems others have been very pleased with it in similar builds.

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  #91  
Old 03-21-2021, 09:54 PM
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Do you have a link for your previous build ?

PM sent
Previous build? Which one John?

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Pump Gas 461 Stroker
  #92  
Old 03-27-2021, 12:19 PM
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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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Last edited by TransAm 474; 03-27-2021 at 12:32 PM.
  #93  
Old 10-16-2021, 01:24 AM
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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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Last edited by TransAm 474; 10-16-2021 at 01:33 AM.
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Old 10-16-2021, 10:04 AM
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Sounds great!

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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
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1979 Camaro IAII Edelbrock head 500" 695 HP 10.33@132 3595lbs
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Old 10-25-2022, 05:20 AM
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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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